1
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Marder M, Geremia Parise A. Extending cognition: a vegetal rejoinder to extensionless thought and to extended cognition. PLANT SIGNALING & BEHAVIOR 2024; 19:2345984. [PMID: 38654490 PMCID: PMC11057674 DOI: 10.1080/15592324.2024.2345984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/17/2024] [Indexed: 04/26/2024]
Abstract
In this paper, we propose a crucial supplement to the framework of plant cognition, namely extending cognition. We argue that plants and other organisms with an open-ended body plan actively extend their cognition when growing tissues or organs. Their cognition expands with their body expansion. After considering the defining features of extending cognition, we present a model where growth, along with aspects of plant physiology (e.g. biochemical exudates), as well as the "negative extension" of growing away from obstacles or stressful environments, are the building blocks for a more refined understanding of plant cognition. We conclude by outlining the general implications of the theory of extending cognition and indicating directions for future research.
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Affiliation(s)
- Michael Marder
- Department of Philosophy, University of the Basque Country, UPV-EHU, Vitoria-Gasteiz, Spain
- Philosophy, Ikerbasque: Basque Foundation for Science, Vitoria, Spain
| | - André Geremia Parise
- School of Biological Sciences, University of Reading, Reading, UK
- School of Agriculture, Policy and Development, University of Reading, Reading, UK
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2
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Yang C, Zhang Z, Yuan Y, Zhang D, Jin H, Li Y, Du S, Li X, Fang B, Wei F, Yan G. Natural variation in photosynthetic electron transport of wheat flag leaves in response to dark-induced senescence. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 259:113018. [PMID: 39182402 DOI: 10.1016/j.jphotobiol.2024.113018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 08/11/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024]
Abstract
Early leaf senescence affects photosynthetic efficiency and limits growth during the late production stage of winter wheat (Triticum aestivum). Natural variation in photosystem response to senescence represents a valuable resource for improving the aging traits of flag leaves. To explore the natural variation of different phases of photosynthetic electron transport in modern wheat cultivars during senescence, we exposed the flag leaves of 32 wheat cultivars to dark conditions to induce senescence process, and simultaneously measured prompt fluorescence and modulated 820 nm reflection. The results showed that the chlorophyll content, activity of PSII donor side, PSI and electron transfer between PSII and PSI were all decreased during dark-induced senescence, but they showed different sensitivity to dark-induced senescence. Furthermore, natural variation in photosynthetic parameters among the 32 wheat cultivars were also observed and showed by variation coefficient of the different parameters. We observed that PSII and PSI activity showed less sensitivity to dark-induced senescence than electron transfer between them, while PSII and PSI activity exhibit greater natural variation than electron transport between PSII and PSI. It suggests that Cytb6f might degrade faster and have less variation than PSII and PSI during dark-induced senescence.
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Affiliation(s)
- Cheng Yang
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Zishan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yuan Yuan
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Deqi Zhang
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Haiyang Jin
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Ying Li
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Simeng Du
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Xiangdong Li
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China.
| | - Baoting Fang
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
| | - Fang Wei
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Ge Yan
- Wheat Research Institute, Henan Academy of Agricultural Sciences, Postgraduate T&R Base of Zhengzhou University, Zhengzhou 450002, China; School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
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3
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Eckardt NA, Avin-Wittenberg T, Bassham DC, Chen P, Chen Q, Fang J, Genschik P, Ghifari AS, Guercio AM, Gibbs DJ, Heese M, Jarvis RP, Michaeli S, Murcha MW, Mursalimov S, Noir S, Palayam M, Peixoto B, Rodriguez PL, Schaller A, Schnittger A, Serino G, Shabek N, Stintzi A, Theodoulou FL, Üstün S, van Wijk KJ, Wei N, Xie Q, Yu F, Zhang H. The lowdown on breakdown: Open questions in plant proteolysis. THE PLANT CELL 2024; 36:2931-2975. [PMID: 38980154 PMCID: PMC11371169 DOI: 10.1093/plcell/koae193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/16/2024] [Accepted: 06/19/2024] [Indexed: 07/10/2024]
Abstract
Proteolysis, including post-translational proteolytic processing as well as protein degradation and amino acid recycling, is an essential component of the growth and development of living organisms. In this article, experts in plant proteolysis pose and discuss compelling open questions in their areas of research. Topics covered include the role of proteolysis in the cell cycle, DNA damage response, mitochondrial function, the generation of N-terminal signals (degrons) that mark many proteins for degradation (N-terminal acetylation, the Arg/N-degron pathway, and the chloroplast N-degron pathway), developmental and metabolic signaling (photomorphogenesis, abscisic acid and strigolactone signaling, sugar metabolism, and postharvest regulation), plant responses to environmental signals (endoplasmic-reticulum-associated degradation, chloroplast-associated degradation, drought tolerance, and the growth-defense trade-off), and the functional diversification of peptidases. We hope these thought-provoking discussions help to stimulate further research.
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Affiliation(s)
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Poyu Chen
- School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Qian Chen
- Ministry of Agriculture and Rural Affairs Key Laboratory for Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Jun Fang
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, Strasbourg 67084, France
| | - Abi S Ghifari
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Angelica M Guercio
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston B1 2RU, UK
| | - Maren Heese
- Department of Developmental Biology, University of Hamburg, Ohnhorststr. 18, Hamburg 22609, Germany
| | - R Paul Jarvis
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Simon Michaeli
- Department of Postharvest Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel
| | - Monika W Murcha
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Sergey Mursalimov
- Department of Postharvest Sciences, Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion 7505101, Israel
| | - Sandra Noir
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12, rue du Général Zimmer, Strasbourg 67084, France
| | - Malathy Palayam
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Bruno Peixoto
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford OX1 3RB, UK
| | - Pedro L Rodriguez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia, Valencia ES-46022, Spain
| | - Andreas Schaller
- Department of Plant Physiology and Biochemistry, Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, Ohnhorststr. 18, Hamburg 22609, Germany
| | - Giovanna Serino
- Department of Biology and Biotechnology, Sapienza Universita’ di Roma, p.le A. Moro 5, Rome 00185, Italy
| | - Nitzan Shabek
- Department of Plant Biology, College of Biological Sciences, University of California-Davis, Davis, CA 95616, USA
| | - Annick Stintzi
- Department of Plant Physiology and Biochemistry, Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | | | - Suayib Üstün
- Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Bochum 44780, Germany
| | - Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY 14853, USA
| | - Ning Wei
- School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feifei Yu
- College of Grassland Science and Technology, China Agricultural University, Beijing 100083, China
| | - Hongtao Zhang
- Plant Sciences and the Bioeconomy, Rothamsted Research, Harpenden AL5 2JQ, UK
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Xue H, Zhou W, Yang L, Li S, Lei P, An X, Jia M, Zhang H, Yu F, Meng J, Liu X. Endoplasmic reticulum protein ALTERED MERISTEM PROGRAM 1 negatively regulates senescence in Arabidopsis. PLANT PHYSIOLOGY 2024; 196:273-290. [PMID: 38781292 DOI: 10.1093/plphys/kiae299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/02/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Plant senescence is a highly regulated developmental program crucial for nutrient reallocation and stress adaptation in response to developmental and environmental cues. Stress-induced and age-dependent natural senescence share both overlapping and distinct molecular responses and regulatory schemes. Previously, we have utilized a carbon-deprivation (C-deprivation) senescence assay using Arabidopsis (Arabidopsis thaliana) seedlings to investigate senescence regulation. Here we conducted a comprehensive time-resolved transcriptomic analysis of Arabidopsis wild type seedlings subjected to C-deprivation treatment at multiple time points, unveiling substantial temporal changes and distinct gene expression patterns. Moreover, we identified ALTERED MERISTEM PROGRAM 1 (AMP1), encoding an endoplasmic reticulum protein, as a potential regulator of senescence based on its expression profile. By characterizing loss-of-function alleles and overexpression lines of AMP1, we confirmed its role as a negative regulator of plant senescence. Genetic analyses further revealed a synergistic interaction between AMP1 and the autophagy pathway in regulating senescence. Additionally, we discovered a functional association between AMP1 and the endosome-localized ABNORMAL SHOOT3 (ABS3)-mediated senescence pathway and positioned key senescence-promoting transcription factors downstream of AMP1. Overall, our findings shed light on the molecular intricacies of transcriptome reprogramming during C-deprivation-induced senescence and the functional interplay among endomembrane compartments in controlling plant senescence.
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Affiliation(s)
- Hui Xue
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
- Institute of Future Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wenhui Zhou
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Lan Yang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shuting Li
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Pei Lei
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xue An
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Min Jia
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hongchang Zhang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Fei Yu
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
- Institute of Future Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jingjing Meng
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiayan Liu
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
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Lacrampe N, Lugan R, Dumont D, Nicot PC, Lecompte F, Colombié S. Modelling metabolic fluxes of tomato stems reveals that nitrogen shapes central metabolism for defence against Botrytis cinerea. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4093-4110. [PMID: 38551810 PMCID: PMC11233421 DOI: 10.1093/jxb/erae140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 03/28/2024] [Indexed: 07/11/2024]
Abstract
Among plant pathogens, the necrotrophic fungus Botrytis cinerea is one of the most prevalent, leading to severe crop damage. Studies related to its colonization of different plant species have reported variable host metabolic responses to infection. In tomato, high N availability leads to decreased susceptibility. Metabolic flux analysis can be used as an integrated method to better understand which metabolic adaptations lead to effective host defence and resistance. Here, we investigated the metabolic response of tomato infected by B. cinerea in symptomless stem tissues proximal to the lesions for 7 d post-inoculation, using a reconstructed metabolic model constrained by a large and consistent metabolic dataset acquired under four different N supplies. An overall comparison of 48 flux solution vectors of Botrytis- and mock-inoculated plants showed that fluxes were higher in Botrytis-inoculated plants, and the difference increased with a reduction in available N, accompanying an unexpected increase in radial growth. Despite higher fluxes, such as those involved in cell wall synthesis and other pathways, fluxes related to glycolysis, the tricarboxylic acid cycle, and amino acid and protein synthesis were limited under very low N, which might explain the enhanced susceptibility. Limiting starch synthesis and enhancing fluxes towards redox and specialized metabolism also contributed to defence independent of N supply.
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Affiliation(s)
- Nathalie Lacrampe
- PSH unit, INRAE, F-84914 Avignon, France
- UMR Qualisud, Avignon Université, F-84916 Avignon, France
| | | | | | | | | | - Sophie Colombié
- UMR 1332 BFP, INRAE, Univ Bordeaux, F-33883 Villenave d’Ornon, France
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6
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Yumoto G, Nishio H, Muranaka T, Sugisaka J, Honjo MN, Kudoh H. Seasonal switching of integrated leaf senescence controls in an evergreen perennial Arabidopsis. Nat Commun 2024; 15:4719. [PMID: 38849351 PMCID: PMC11161623 DOI: 10.1038/s41467-024-48814-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 05/10/2024] [Indexed: 06/09/2024] Open
Abstract
Evergreeness is a substantial strategy for temperate and boreal plants and is as common as deciduousness. However, whether evergreen plants switch foliage functions between seasons remains unknown. We conduct an in natura study of leaf senescence control in the evergreen perennial, Arabidopsis halleri. A four-year census of leaf longevity of 102 biweekly cohorts allows us to identify growth season (GS) and overwintering (OW) cohorts characterised by short and extended longevity, respectively, and to recognise three distinct periods in foliage functions, i.e., the growth, overwintering, and reproductive seasons. Photoperiods during leaf expansion separate the GS and OW cohorts, providing primal control of leaf senescence depending on the season, with leaf senescence being shut down during winter. Phenotypic and transcriptomic responses in field experiments indicate that shade-induced and reproductive-sink-triggered senescence are active during the growth and reproductive seasons, respectively. These secondary controls of leaf senescence cause desynchronised and synchronised leaf senescence during growth and reproduction, respectively. Conclusively, seasonal switching of leaf senescence optimises resource production, storage, and translocation for the season, making the evergreen strategy adaptively relevant.
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Affiliation(s)
- Genki Yumoto
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan.
| | - Haruki Nishio
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan
- Data Science and AI Innovation Research Promotion Center, Shiga University, Banba 1-1-1, Hikone, 522-8522, Japan
| | - Tomoaki Muranaka
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-0814, Japan
| | - Jiro Sugisaka
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan
| | - Mie N Honjo
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan
| | - Hiroshi Kudoh
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, 520-2113, Japan.
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7
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Asad MAU, Yan Z, Zhou L, Guan X, Cheng F. How abiotic stresses trigger sugar signaling to modulate leaf senescence? PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 210:108650. [PMID: 38653095 DOI: 10.1016/j.plaphy.2024.108650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 04/05/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
Plants have evolved the adaptive capacity to mitigate the negative effect of external adversities at chemical, molecular, cellular, and physiological levels. This capacity is conferred by triggering the coordinated action of internal regulatory factors, in which sugars play an essential role in the regulating chloroplast degradation and leaf senescence under various stresses. In this review, we summarize the recent findings on the senescent-associated changes in carbohydrate metabolism and its relation to chlorophyl degradation, oxidative damage, photosynthesis inhibition, programmed cell death (PCD), and sink-source relation as affected by abiotic stresses. The action of sugar signaling in regulating the initiation and progression of leaf senescence under abiotic stresses involves interactions with various plant hormones, reactive oxygen species (ROS) burst, and protein kinases. This discussion aims to elucidate the complex regulatory network and molecular mechanisms that underline sugar-induced leaf senescence in response to various abiotic stresses. The imperative role of sugar signaling in regulating plant stress responses potentially enables the production of crop plants with modified sugar metabolism. This, in turn, may facilitate the engineering of plants with improved stress responses, optimal life span and higher yield achievement.
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Affiliation(s)
- Muhmmad Asad Ullah Asad
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Zhang Yan
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Lujian Zhou
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Xianyue Guan
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Fangmin Cheng
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China; Collaborative Innovation Centre for Modern Crop Production Co-sponsored by Province and Ministry, Nanjing, China.
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Xue Q, Shen C, Liu Q, Liu P, Guo D, Zheng L, Liu J, Liu C, Ye Q, Wang T, Dong J. The PtdIns3P phosphatase MtMP promotes symbiotic nitrogen fixation via mitophagy in Medicago truncatula. iScience 2023; 26:107752. [PMID: 37954141 PMCID: PMC10638472 DOI: 10.1016/j.isci.2023.107752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/07/2023] [Accepted: 08/24/2023] [Indexed: 11/14/2023] Open
Abstract
Symbiotic nitrogen fixation is a complex process in which legumes interact with rhizobia under nitrogen starvation. In this study, we found that myotubularin phosphatase (MtMP) is mainly expressed in roots and nodules in Medicago truncatula. MtMP promotes autophagy by dephosphorylating PtdIns3P on autophagosomes. The mp mutants inoculated with rhizobia showed a significant reduction in nitrogenase activity and significantly higher number of mitochondria than those of wild-type plants under nitrogen starvation, indicating that MtMP is involved in mitophagy of the infection zone. Mitophagy may provide carbon skeletons and nitrogen for the development of bacteroids and the reprogramming of infected cells. In conclusion, we found, for the first time, that myotubularin phosphatase is involved in autophagy in plants. MtMP-involved autophagy plays an active role in symbiotic nitrogen fixation. These results deepen our understanding of symbiotic nitrogen fixation.
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Affiliation(s)
- Qixia Xue
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Chen Shen
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qianwen Liu
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Peng Liu
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Da Guo
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Lihua Zheng
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jinling Liu
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Chang Liu
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qinyi Ye
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Tao Wang
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jiangli Dong
- College of Biological Sciences, China Agricultural University, Beijing, China
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Tan S, Sha Y, Sun L, Li Z. Abiotic Stress-Induced Leaf Senescence: Regulatory Mechanisms and Application. Int J Mol Sci 2023; 24:11996. [PMID: 37569371 PMCID: PMC10418887 DOI: 10.3390/ijms241511996] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
Leaf senescence is a natural phenomenon that occurs during the aging process of plants and is influenced by various internal and external factors. These factors encompass plant hormones, as well as environmental pressures such as inadequate nutrients, drought, darkness, high salinity, and extreme temperatures. Abiotic stresses accelerate leaf senescence, resulting in reduced photosynthetic efficiency, yield, and quality. Gaining a comprehensive understanding of the molecular mechanisms underlying leaf senescence in response to abiotic stresses is imperative to enhance the resilience and productivity of crops in unfavorable environments. In recent years, substantial advancements have been made in the study of leaf senescence, particularly regarding the identification of pivotal genes and transcription factors involved in this process. Nevertheless, challenges remain, including the necessity for further exploration of the intricate regulatory network governing leaf senescence and the development of effective strategies for manipulating genes in crops. This manuscript provides an overview of the molecular mechanisms that trigger leaf senescence under abiotic stresses, along with strategies to enhance stress tolerance and improve crop yield and quality by delaying leaf senescence. Furthermore, this review also highlighted the challenges associated with leaf senescence research and proposes potential solutions.
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Affiliation(s)
| | | | - Liwei Sun
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Zhonghai Li
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
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Gil MF, Azzara N, Fassolari M, Berón CM, Battaglia ME. Hormone released by the microalgae Neochlorisaquatica and alkalinization influence growth of terrestrial and floating aquatic plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 197:107635. [PMID: 36933508 DOI: 10.1016/j.plaphy.2023.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/09/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
The microalgae Neochloris aquatica were previously evaluated as a potential biological control agent and source of bioactive compounds against immature stages of Culex quinquefasciatus. Larvae reared on microalgae suspension showed mortality or drastic effects with morphological alterations and damage in the midgut. N. aquatica have nutritional and toxic effects, resulting in delayed life cycle and incomplete adult development. Given the possibility of its use as a biological control agent, in this work we evaluate the effect of microalgae on other organisms of the environment, such as plants. Arabidopsis thaliana, a terrestrial plant, and Lemna sp., a floating aquatic plant, were selected as examples. Interaction assays and compound evaluations showed that the microalgae release auxins causing root inhibition, smaller epidermal cells and hairy root development. In Lemna sp., a slight decrease in growth rate was observed, with no deleterious effects on the fronds. On the other hand, we detected a detrimental effect on plants when interactions were performed in a closed environment, in a medium containing soluble carbonate, in which microalgae culture rapidly modifies the pH. The experiments showed that alkalinization of the medium inhibits plant growth, causing bleaching of leaves or fronds. This negative effect in plants was not observed when plants and microalgae were cultured in carbonate-free media. In conclusion, the results showed that N. aquatica can modify plant growth without being harmful, but the rapid alkalinization produced by carbon metabolism of microalgae under CO2-limiting conditions, could regulate the number of plants.
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Affiliation(s)
- M Florencia Gil
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes, 3103, (7600) Mar del Plata, Argentina
| | - Nayla Azzara
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes, 3103, (7600) Mar del Plata, Argentina
| | - Marisol Fassolari
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes, 3103, (7600) Mar del Plata, Argentina
| | - Corina M Berón
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes, 3103, (7600) Mar del Plata, Argentina.
| | - Marina E Battaglia
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes, 3103, (7600) Mar del Plata, Argentina.
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11
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Zheng Y, Cabassa-Hourton C, Planchais S, Crilat E, Clément G, Dacher M, Durand N, Bordenave-Jacquemin M, Guivarc'h A, Dourmap C, Carol P, Lebreton S, Savouré A. Pyrroline-5-carboxylate dehydrogenase is an essential enzyme for proline dehydrogenase function during dark-induced senescence in Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2023; 46:901-917. [PMID: 36583533 DOI: 10.1111/pce.14529] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 12/17/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
During leaf senescence, nitrogen is remobilized and carbon backbones are replenished by amino acid catabolism, with many of the key reactions occurring in mitochondria. The intermediate Δ1 -pyrroline-5-carboxylate (P5C) is common to some catabolic pathways, thus linking the metabolism of several amino acids, including proline and arginine. Specifically, mitochondrial proline catabolism involves sequential action of proline dehydrogenase (ProDH) and P5C dehydrogenase (P5CDH) to produce P5C and then glutamate. Arginine catabolism produces urea and ornithine, the latter in the presence of α-ketoglutarate being converted by ornithine δ-aminotransferase (OAT) into P5C and glutamate. Metabolic changes during dark-induced leaf senescence (DIS) were studied in Arabidopsis thaliana leaves of Col-0 and in prodh1prodh2, p5cdh and oat mutants. Progression of DIS was followed by measuring chlorophyll and proline contents for 5 days. Metabolomic profiling of 116 compounds revealed similar profiles of Col-0 and oat metabolism, distinct from prodh1prodh2 and p5cdh metabolism. Metabolic dynamics were accelerated in p5cdh by 1 day. Notably, more P5C and proline accumulated in p5cdh than in prodh1prodh2. ProDH1 enzymatic activity and protein amount were significantly down-regulated in p5cdh mutant at Day 4 of DIS. Mitochondrial P5C levels appeared critical in determining the flow through interconnected amino acid remobilization pathways to sustain senescence.
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Affiliation(s)
- Yao Zheng
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Cécile Cabassa-Hourton
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Séverine Planchais
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Emilie Crilat
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Gilles Clément
- Institut Jean-Pierre Bourgin, UMR 1318, INRAE-AgroParisTech, Centre INRAE, Versailles, France
| | - Matthieu Dacher
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Nina Durand
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Marianne Bordenave-Jacquemin
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Anne Guivarc'h
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Corentin Dourmap
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Pierre Carol
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Sandrine Lebreton
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
| | - Arnould Savouré
- Sorbonne Université, UPEC, CNRS, IRD, INRAE, Institute of Ecology and Environmental Sciences of Paris (iEES), Paris, France
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12
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Li S, Xie H, Zhou L, Dong D, Liu Y, Jia C, Han L, Chao Y, Chen Y. Overexpression of MsSAG113 gene promotes leaf senescence in alfalfa via participating in the hormone regulatory network. FRONTIERS IN PLANT SCIENCE 2022; 13:1085497. [PMID: 36570962 PMCID: PMC9774027 DOI: 10.3389/fpls.2022.1085497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Introduction Alfalfa (Medicago sativa) is a kind of high quality leguminous forage species, which was widely cultivated in the world. Leaf senescence is an essential process in plant development and life cycle. Here, we reported the isolation and functional analysis of an alfalfa SENESCENCE-ASSOCIATED GENE113 (MsSAG113), which belongs to the PP2C family and mainly plays a role in promoting plant senescence. Methods In the study, Agrobacterium-mediated, gene expression analysis, next generation sequencing, DNA pull-down, yeast single hybridization and transient expression were used to identify the function of MsSAG113 gene. Results The MsSAG113 gene was isolated from alfalfa, and the transgenic plants were obtained by Agrobacterium-mediated method. Compared with the wildtype, transgenic plants showed premature senescence in leaves, especially when cultivated under dark conditions. Meanwhile, application of exogenous hormones ABA, SA, MeJA, obviously acclerated leaf senescence of transgenic plants. Furthermore, the detached leaves from transgenic plants turned yellow earlier with lower chlorophyll content. Transcriptome analysis identified a total of 1,392 differentially expressed genes (DEGs), involving 13 transcription factor families. Of which, 234 genes were related to phytohormone synthesis, metabolism and transduction. Pull-down assay and yeast one-hybrid assay confirmed that alfalfa zinc finger CCCH domain-containing protein 39 (MsC3H-39) could directly bind the upstream of MsSAG113 gene. In conclusion, the MsSAG113 gene plays a crucial role in promoting leaf senescence in alfalfa via participating in the hormone regulatory network. Discussion This provides an essential basis for further analysis on the regulatory network involving senescence-associated genes in alfalfa.
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Affiliation(s)
- Shuwen Li
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Hong Xie
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Lingfang Zhou
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Di Dong
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Yaling Liu
- Inner Mongolia M-Grass Ecology And Environment (Group) Co., Ltd, Hohhot, China
| | - Chenyan Jia
- Inner Mongolia M-Grass Ecology And Environment (Group) Co., Ltd, Hohhot, China
| | - Liebao Han
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Yuehui Chao
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Yinglong Chen
- The University of Western Australia (UWA) Institute of Agriculture, and University of Western Australia School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
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13
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Danziger N, Bernstein N. Too Dense or Not Too Dense: Higher Planting Density Reduces Cannabinoid Uniformity but Increases Yield/Area in Drug-Type Medical Cannabis. FRONTIERS IN PLANT SCIENCE 2022; 13:713481. [PMID: 36247643 PMCID: PMC9559401 DOI: 10.3389/fpls.2022.713481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 06/15/2022] [Indexed: 06/16/2023]
Abstract
A major challenge for utilizing cannabis for modern medicine is the spatial variability of cannabinoids in the plant, which entail differences in medical potency. Since secondary metabolism is affected by environmental conditions, a key trigger for the variability in secondary metabolites throughout the plant is variation in local micro-climates. We have, therefore, hypothesized that plant density, which is well-known to alter micro-climate in the canopy, affects spatial standardization, and concentrations of cannabinoids in cannabis plants. Canopy density is affected by shoot architecture and by plant spacing, and we have therefore evaluated the interplay between plant architecture and plant density on the standardization of the cannabinoid profile in the plant. Four plant architecture modulation treatments were employed on a drug-type medicinal cannabis cultivar, under a density of 1 or 2 plants/m2. The plants were cultivated in a naturally lit greenhouse with photoperiodic light supplementation. Analysis of cannabinoid concentrations at five locations throughout the plant was used to evaluate treatment effects on chemical uniformity. The results revealed an effect of plant density on cannabinoid standardization, as well as an interaction between plant density and plant architecture on the standardization of cannabinoids, thus supporting the hypothesis. Increasing planting density from 1 to 2 plants/m2 reduced inflorescence yield/plant, but increased yield quantity per area by 28-44% in most plant architecture treatments. The chemical response to plant density and architecture modulation was cannabinoid-specific. Concentrations of cannabinoids in axillary inflorescences from the bottom of the plants were up to 90% lower than in the apical inflorescence at the top of the plant, considerably reducing plant uniformity. Concentrations of all detected cannabinoids in these inflorescences were lower at the higher density plants; however, cannabinoid yield per cultivation area was not affected by neither architecture nor density treatments. Cannabigerolic acid (CBGA) was the cannabinoid least affected by spatial location in the plant. The morpho-physiological response of the plants to high density involved enhanced leaf drying at the bottom of the plants, increased plant elongation, and reduced cannabinoid concentrations, suggesting an involvement of chronic light deprivation at the bottom of the plants. Therefore, most importantly, under high density growth, architectural modulating treatments that facilitate increased light penetration to the bottom of the plant such as "Defoliation", or that eliminated inflorescences development at the bottom of the plant such as removal of branches from the lower parts of the plant, increased chemical standardization. This study revealed the importance of plant density and architecture for chemical quality and standardization in drug-type medical cannabis.
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14
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Liebsch D, Juvany M, Li Z, Wang HL, Ziolkowska A, Chrobok D, Boussardon C, Wen X, Law SR, Janečková H, Brouwer B, Lindén P, Delhomme N, Stenlund H, Moritz T, Gardeström P, Guo H, Keech O. Metabolic control of arginine and ornithine levels paces the progression of leaf senescence. PLANT PHYSIOLOGY 2022; 189:1943-1960. [PMID: 35604104 PMCID: PMC9342962 DOI: 10.1093/plphys/kiac244] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/11/2022] [Indexed: 06/12/2023]
Abstract
Leaf senescence can be induced by stress or aging, sometimes in a synergistic manner. It is generally acknowledged that the ability to withstand senescence-inducing conditions can provide plants with stress resilience. Although the signaling and transcriptional networks responsible for a delayed senescence phenotype, often referred to as a functional stay-green trait, have been actively investigated, very little is known about the subsequent metabolic adjustments conferring this aptitude to survival. First, using the individually darkened leaf (IDL) experimental setup, we compared IDLs of wild-type (WT) Arabidopsis (Arabidopsis thaliana) to several stay-green contexts, that is IDLs of two functional stay-green mutant lines, oresara1-2 (ore1-2) and an allele of phytochrome-interacting factor 5 (pif5), as well as to leaves from a WT plant entirely darkened (DP). We provide compelling evidence that arginine and ornithine, which accumulate in all stay-green contexts-likely due to the lack of induction of amino acids (AAs) transport-can delay the progression of senescence by fueling the Krebs cycle or the production of polyamines (PAs). Secondly, we show that the conversion of putrescine to spermidine (SPD) is controlled in an age-dependent manner. Thirdly, we demonstrate that SPD represses senescence via interference with ethylene signaling by stabilizing the ETHYLENE BINDING FACTOR1 and 2 (EBF1/2) complex. Taken together, our results identify arginine and ornithine as central metabolites influencing the stress- and age-dependent progression of leaf senescence. We propose that the regulatory loop between the pace of the AA export and the progression of leaf senescence provides the plant with a mechanism to fine-tune the induction of cell death in leaves, which, if triggered unnecessarily, can impede nutrient remobilization and thus plant growth and survival.
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Affiliation(s)
- Daniela Liebsch
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Marta Juvany
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Zhonghai Li
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Hou-Ling Wang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Agnieszka Ziolkowska
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Daria Chrobok
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Clément Boussardon
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Xing Wen
- Department of Biology, Institute of Plant and Food Science, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Simon R Law
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Helena Janečková
- Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Biophysics, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
| | - Bastiaan Brouwer
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Pernilla Lindén
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Nicolas Delhomme
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden
| | - Hans Stenlund
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden
| | - Thomas Moritz
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden
- Novo Nordisk Centre for Basic Metabolic Research, University of Copenhagen, D-2200 Copenhagen N, Denmark
| | - Per Gardeström
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
| | - Hongwei Guo
- Department of Biology, Institute of Plant and Food Science, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China
| | - Olivier Keech
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
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15
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Sasi JM, Gupta S, Singh A, Kujur A, Agarwal M, Katiyar-Agarwal S. Know when and how to die: gaining insights into the molecular regulation of leaf senescence. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:1515-1534. [PMID: 36389097 PMCID: PMC9530073 DOI: 10.1007/s12298-022-01224-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/17/2022] [Accepted: 08/21/2022] [Indexed: 06/16/2023]
Abstract
Senescence is the ultimate phase in the life cycle of leaves which is crucial for recycling of nutrients to maintain plant fitness and reproductive success. The earliest visible manifestation of leaf senescence is their yellowing, which usually commences with the breakdown of chlorophyll. The degradation process involves a gradual and highly coordinated disassembly of macromolecules resulting in the accumulation of nutrients, which are subsequently mobilized from the senescing leaves to the developing organs. Leaf senescence progresses under overly tight genetic and molecular control involving a well-orchestrated and intricate network of regulators that coordinate spatio-temporally with the influence of both internal and external cues. Owing to the advancements in omics technologies, the availability of mutant resources, scalability of molecular analyses methodologies and the advanced capacity to integrate multidimensional data, our understanding of the genetic and molecular basis of leaf ageing has greatly expanded. The review provides a compilation of the multitier regulation of senescence process and the interrelation between the environment and the terminal phase of leaf development. The knowledge gained would benefit in devising the strategies for manipulation of leaf senescence process to improve crop quality and productivity.
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Affiliation(s)
- Jyothish Madambikattil Sasi
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Shitij Gupta
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Apurva Singh
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
| | - Alice Kujur
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
- USDA-ARS Plant Genetics Research Unit, The Donald Danforth Plant Science Center, St. Louis, MO 63132 USA
- Centre of Excellence in Genomics and Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad, Telangana 502324 India
| | - Manu Agarwal
- Department of Botany, University of Delhi North Campus, Delhi, 110007 India
| | - Surekha Katiyar-Agarwal
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 India
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16
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Pham G, Shin DM, Kim Y, Kim SH. Ran-GTP/-GDP-dependent nuclear accumulation of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and TGACG-BINDING FACTOR2 controls salicylic acid-induced leaf senescence. PLANT PHYSIOLOGY 2022; 189:1774-1793. [PMID: 35417014 PMCID: PMC9237681 DOI: 10.1093/plphys/kiac164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/08/2022] [Indexed: 05/11/2023]
Abstract
Leaf senescence is the final stage of leaf development and can be triggered by various external factors, such as hormones and light deprivation. In this study, we demonstrate that the overexpression of the GTP-bound form of Arabidopsis (Arabidopsis thaliana) Ran1 (a Ras-related nuclear small G-protein, AtRan1) efficiently promotes age-dependent and dark-triggered leaf senescence, while Ran-GDP has the opposite effect. Transcriptome analysis comparing AtRan1-GDP- and AtRan1-GTP-overexpressing transgenic plants (Ran1T27Nox and Ran1G22Vox, respectively) revealed that differentially expressed genes (DEGs) related to the senescence-promoting hormones salicylic acid (SA), jasmonic acid, abscisic acid, and ethylene (ET) were significantly upregulated in dark-triggered senescing leaves of Ran1G22Vox, indicating that these hormones are actively involved in Ran-GTP/-GDP-dependent, dark-triggered leaf senescence. Bioinformatic analysis of the promoter regions of DEGs identified diverse consensus motifs, including the bZIP motif, a common binding site for TGACG-BINDING FACTOR (TGA) transcription factors. Interestingly, TGA2 and its interactor, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1), which are two positive transcriptional regulators of SA signaling, differed in their extent of accumulation in the nucleus versus cytoplasm of Ran1T27Nox and Ran1G22Vox plants. Moreover, SA-induced, Ran-GTP-/-GDP-dependent functions of NPR1 included genome-wide global transcriptional reprogramming of genes involved in cell death, aging, and chloroplast organization. Furthermore, the expression of AtRan1-GTP in SA signaling-defective npr1 and SA biosynthesis-deficient SA-induction deficient2 genetic backgrounds abolished the effects of AtRan1-GTP, thus retarding age-promoted leaf senescence. However, ET-induced leaf senescence was not mediated by Ran machinery-dependent nuclear shuttling of ETHYLENE-INSENSITIVE3 and ETHYLENE-INSENSITIVE3-LIKE1 proteins. We conclude that Ran-GTP/-GDP-dependent nuclear accumulation of NPR1 and TGA2 represents another regulatory node for SA-induced leaf senescence.
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Affiliation(s)
| | | | - Yoon Kim
- Division of Biological Science and Technology, Yonsei University, Yonseidae 1 Gil, Wonju-Si 220-710, South Korea
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17
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Liu S, Liu Y, Wang T, Zhang J. The effects of different light storage conditions on volatile flavor compounds and sensory properties of melon fruit. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.101826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Li J, Gong J, Zhang L, Shen H, Chen G, Xie Q, Hu Z. Overexpression of SlPRE5, an atypical bHLH transcription factor, affects plant morphology and chlorophyll accumulation in tomato. JOURNAL OF PLANT PHYSIOLOGY 2022; 273:153698. [PMID: 35461174 DOI: 10.1016/j.jplph.2022.153698] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/11/2022] [Accepted: 04/11/2022] [Indexed: 05/22/2023]
Abstract
The basic helix-loop-helix (bHLH) transcription factors play vital regulatory roles in a series of metabolic, physiological, and developmental processes of plants. Here, SlPRE5, an atypical bHLH gene, was isolated from tomato. SlPRE5 was noticeably expressed in young leaves, sepals, and flowers. SlPRE5-overexpressing plants exhibited rolling leaves with reduced chlorophyll content, increased stem internode length, leaf angle, and compound leaf length. The water loss rate of mature leaves and the content of starch were significantly reduced, while the content of gibberellin was significantly increased in transgenic plants. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) showed that SlPRE5 could interact with SlAIF1, SlAIF2, and SlPAR1. qRT-PCR and RNA-seq results revealed that the expression levels of genes related to chloroplast development, chlorophyll metabolism, gibberellin metabolism and signal transduction, starch, photosynthesis, and cell expansion were significantly altered in SlPRE5-overexpression plants. Collectively, our results suggest that SlPRE5 is a crucial transcription factor involved in plant morphology and chlorophyll accumulation in tomato leaves.
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Affiliation(s)
- Jing Li
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Jun Gong
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Lincheng Zhang
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Hui Shen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Guoping Chen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Qiaoli Xie
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Zongli Hu
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
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19
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Magen S, Seybold H, Laloum D, Avin-Wittenberg T. Metabolism and autophagy in plants - A perfect match. FEBS Lett 2022; 596:2133-2151. [PMID: 35470431 DOI: 10.1002/1873-3468.14359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 01/18/2023]
Abstract
Autophagy is a eukaryotic cellular transport mechanism that delivers intracellular macromolecules, proteins, and even organelles to a lytic organelle (vacuole in yeast and plants/lysosome in animals) for degradation and nutrient recycling. The process is mediated by highly conserved Autophagy-Related (ATG) proteins. In plants, autophagy maintains cellular homeostasis under favorable conditions, guaranteeing normal plant growth and fitness. Severe stress such as nutrient starvation and plant senescence further induce it, thus ensuring plant survival under unfavorable conditions by providing nutrients through the removal of damaged or aged proteins, or organelles. In this article, we examine the interplay between metabolism and autophagy, focusing on the different aspects of this reciprocal relationship. We show that autophagy has a strong influence on a range of metabolic processes, whereas, at the same time, even single metabolites can activate autophagy. We highlight the involvement of ATG genes in metabolism, examine the role of the macronutrients carbon and nitrogen, as well as various micronutrients, and take a closer look at how the interaction between autophagy and metabolism impacts on plant phenotypes and yield.
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Affiliation(s)
- Sahar Magen
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Heike Seybold
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Daniel Laloum
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
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20
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Zareen S, Ali A, Lim CJ, Khan HA, Park J, Xu ZY, Yun DJ. The Transcriptional Corepressor HOS15 Mediates Dark-Induced Leaf Senescence in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:828264. [PMID: 35283908 PMCID: PMC8914473 DOI: 10.3389/fpls.2022.828264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/14/2022] [Indexed: 05/23/2023]
Abstract
Multiple endogenous and environmental signals regulate the intricate and highly complex processes driving leaf senescence in plants. A number of genes have been identified in a variety of plant species, including Arabidopsis, which influence leaf senescence. Previously, we have shown that HOS15 is a multifunctional protein that regulates several physiological processes, including plant growth and development under adverse environmental conditions. HOS15 has also been reported to form a chromatin remodeling complex with PWR and HDA9 and to regulate the chromatin structure of numerous genes. However, unlike PWR and HDA9, the involvement of HOS15 in leaf senescence is yet to be identified. Here, we report that HOS15, together with PWR and HDA9, promotes leaf senescence via transcriptional regulation of SAG12/29, senescence marker genes, and CAB1/RCBS1A, photosynthesis-related genes. The expression of ORE1, SAG12, and SAG29 was downregulated in hos15-2 plants, whereas the expression of photosynthesis-related genes, CAB1 and RCBS1A, was upregulated. HOS15 also promoted senescence through dark stress, as its mutation led to a much greener phenotype than that of the WT. Phenotypes of double and triple mutants of HOS15 with PWR and HDA9 produced phenotypes similar to those of a single hos15-2. In line with this observation, the expression levels of NPX1, APG9, and WRKY57 were significantly elevated in hos15-2 and hos15/pwr, hos15/hda9, and hos15/pwr/hda9 mutants compared to those in the WT. Surprisingly, the total H3 acetylation level decreased in age-dependent manner and under dark stress in WT; however, it remained the same in hos15-2 plants regardless of dark stress, suggesting that dark-induced deacetylation requires functional HOS15. More interestingly, the promoters of APG9, NPX1, and WRKY57 were hyperacetylated in hos15-2 plants compared to those in WT plants. Our data reveal that HOS15 acts as a positive regulator and works in the same repressor complex with PWR and HDA9 to promote leaf senescence through aging and dark stress by repressing NPX1, APG9, and WRKY57 acetylation.
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Affiliation(s)
- Shah Zareen
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Akhtar Ali
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
- Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
| | - Chae Jin Lim
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Haris Ali Khan
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Junghoon Park
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
| | - Zheng-Yi Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, China
| | - Dae-Jin Yun
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, China
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21
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Jedynak P, Trzebuniak KF, Chowaniec M, Zgłobicki P, Banaś AK, Mysliwa-Kurdziel B. Dynamics of Etiolation Monitored by Seedling Morphology, Carotenoid Composition, Antioxidant Level, and Photoactivity of Protochlorophyllide in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2022; 12:772727. [PMID: 35265091 PMCID: PMC8900029 DOI: 10.3389/fpls.2021.772727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Although etiolated Arabidopsis thaliana seedlings are widely used as a model to study the de-etiolation process, the etiolation itself at the molecular level still needs elucidation. Here, we monitored the etiolation dynamics for wild type A. thaliana seedlings and lutein-deficient (lut2) mutant between 2 and 12 days of their growth in the absence of light. We analyzed the shape of the apex, the growth rate, the carotenoids and protochlorophyllide (Pchlide) accumulation, and the light-dependent protochlorophyllide oxidoreductase (LPOR) transcripts. Differences concerning the apical hook curvature and cotyledon opening among seedlings of the same age were observed, mostly after day 6 of the culture. We categorized the observed apex shapes and presented quantitatively how distribution among the categories changed during 12 days of seedling growth. The Pchlide654/Pchlide633 ratio, corresponding to the amount of the photoactive Pchlide, was the highest in the youngest seedlings, and decreased with their age. LPORA, LPORB, and LPORC transcripts were detected in etiolated seedlings, and their content decreased during seedling growth. Expression of SAG12 or SAG13 senescence markers, depletion in antioxidants, and excess ion leakage were not observed during the etiolation. Lack of lutein in the lut2 mutant resulted in slow Pchlide accumulation and affected other xanthophyll composition.
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Affiliation(s)
- Pawel Jedynak
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Kamil Filip Trzebuniak
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Magdalena Chowaniec
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Piotr Zgłobicki
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Agnieszka Katarzyna Banaś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Beata Mysliwa-Kurdziel
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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22
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Fisher KE, Krishnamoorthy P, Joens MS, Chory J, Fitzpatrick JAJ, Woodson JD. Singlet Oxygen Leads to Structural Changes to Chloroplasts during their Degradation in the Arabidopsis thaliana plastid ferrochelatase two Mutant. PLANT & CELL PHYSIOLOGY 2022; 63:248-264. [PMID: 34850209 DOI: 10.1093/pcp/pcab167] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/01/2021] [Accepted: 11/22/2021] [Indexed: 06/13/2023]
Abstract
During stress, chloroplasts produce large amounts of reactive oxygen species (ROS). Chloroplasts also contain many nutrients, including 80% of a leaf's nitrogen supply. Therefore, to protect cells from photo-oxidative damage and to redistribute nutrients to sink tissues, chloroplasts are prime targets for degradation. Multiple chloroplast degradation pathways are induced by photo-oxidative stress or nutrient starvation, but the mechanisms by which damaged or senescing chloroplasts are identified, transported to the central vacuole and degraded are poorly defined. Here, we investigated the structures involved with degrading chloroplasts induced by the ROS singlet oxygen (1O2) in the Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant. Under mild 1O2 stress, most fc2 chloroplasts appeared normal, but had reduced starch content. A subset of chloroplasts was degrading, and some protruded into the central vacuole via 'blebbing' structures. A 3D electron microscopy analysis demonstrated that up to 35% of degrading chloroplasts contained such structures. While the location of a chloroplast within a cell did not affect the likelihood of its degradation, chloroplasts in spongy mesophyll cells were degraded at a higher rate than those in palisade mesophyll cells. To determine if degrading chloroplasts have unique structural characteristics, allowing them to be distinguished from healthy chloroplasts, we analyzed fc2 seedlings grown under different levels of photo-oxidative stress. A correlation was observed among chloroplast swelling, 1O2 signaling and the state of degradation. Finally, plastoglobule (PG) enzymes involved in chloroplast disassembly were upregulated while PGs increased their association with the thylakoid grana, implicating an interaction between 1O2-induced chloroplast degradation and senescence pathways.
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Affiliation(s)
- Karen E Fisher
- The School of Plant Sciences, University of Arizona, 1140 E South Campus Dr., Tucson, AZ 85721, USA
| | - Praveen Krishnamoorthy
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
| | | | - Joanne Chory
- Plant Biology Laboratory and the Howard Hughes Medical Institute, The Salk Institute, 10010 N Torrey Pines Rd., La Jolla, CA 92037, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
- Departments of Cell Biology & Physiology and Neuroscience, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Jesse D Woodson
- The School of Plant Sciences, University of Arizona, 1140 E South Campus Dr., Tucson, AZ 85721, USA
- Washington University Center for Cellular Imaging, Washington University School of Medicine, 660 W. Euclid Avenue, St. Louis, MO 63110, USA
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23
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Chloroplast Protein Tic55 Involved in Dark-Induced Senescence through AtbHLH/AtWRKY-ANAC003 Controlling Pathway of Arabidopsis thaliana. Genes (Basel) 2022; 13:genes13020308. [PMID: 35205352 PMCID: PMC8872272 DOI: 10.3390/genes13020308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 12/04/2022] Open
Abstract
The chloroplast comprises the outer and inner membranes that are composed of the translocon protein complexes Toc and Tic (translocon at the outer/inner envelope membrane of chloroplasts), respectively. Tic55, a chloroplast Tic protein member, was shown to be not vital for functional protein import in Arabidopsis from previous studies. Instead, Tic55 was revealed to be a dark-induced senescence-related protein in our earlier study. To explore whether Tic55 elicits other biological functions, a tic55-II knockout mutant (SALK_086048) was characterized under different stress treatments. Abiotic stress conditions, such as cold, heat, and high osmotic pressure, did not cause visible effects on tic55-II mutant plant, when compared to the wild type (WT). In contrast, senescence was induced in the individually darkened leaves (IDLs), resulting in the differential expression of the senescence-related genes PEROXISOME DEFECTIVE 1 (PED1), BLUE COPPER-BINDING PROTEIN (BCB), SENESCENCE 1 (SEN1), and RUBISCO SMALL SUBUNIT GENE 2B (RBCS2B). The absence of Tic55 in tic55-II knockout mutant inhibited expression of the senescence-related genes PED1, BCB, and SEN1 at different stages of dark adaptation, while causing stimulation of RBCS2B gene expression at an early stage of dark response. Finally, yeast one-hybrid assays located the ANAC003 promoter region with cis-acting elements are responsible for binding to the different AtbHLH proteins, thereby causing the transactivation of an HIS3 reporter gene. ANAC003 was shown previously as a senescence-related protein and its activation would lead to expression of senescence-associated genes (SAGs), resulting in plant senescence. Thus, we propose a hypothetical model in which three signaling pathways may be involved in controlling the expression of ANAC003, followed by expression of SAGs that in turn leads to leaf senescence in Arabidopsis by this study and previous data.
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Wang C, Ding Y, Wang W, Zhao X, Liu Y, Timko MP, Zhang Z, Zhang H. Insights into Gene Regulation of Jasmonate-Induced Whole-Plant Senescence of Tobacco under Non-Starvation Conditions. PLANT & CELL PHYSIOLOGY 2022; 63:45-56. [PMID: 34523687 DOI: 10.1093/pcp/pcab140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Jasmonate (JA)-induced plant senescence has been mainly studied with a dark/starvation-promoted system using detached leaves; yet, the induction of whole-plant senescence by JA remains largely unclear. This work reports the finding of a JA-induced whole-plant senescence of tobacco under light/non-starvation conditions and the investigation of underlying regulations. Methyl jasmonate (MeJA) treatment induces the whole-plant senescence of tobacco in a light-intensity-dependent manner, which is suppressed by silencing of NtCOI1 that encodes the receptor protein of JA-Ile (the bioactive derivative of JA). MeJA treatment could induce the senescence-specific cysteine protease gene SAG12 and another cysteine protease gene SAG-L1 to high expression levels in the detached leaf patches under dark conditions but failed to induce their expression in tobacco whole plants under light conditions. Furthermore, MeJA attenuates the RuBisCo activase (RCA) level in the detached leaves but has no effect on this protein in the whole plant under light conditions. A genome-wide transcriptional assay also supports the presence of a differential regulatory pattern of senescence-related genes during MeJA-induced whole-plant senescence under non-starvation conditions and results in the finding of a chlorophylase activity increase in this process. We also observed that the MeJA-induced senescence of tobacco whole plants is reversible, which is accompanied by a structural change of chloroplasts. This work provides novel insights into JA-induced plant senescence under non-starvation conditions and is helpful to dissect the JA-synchronized process of whole-plant senescence.
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Affiliation(s)
- Chunkai Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Yongqiang Ding
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Wenjing Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Xue Zhao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Yanhua Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Michael P Timko
- Department of Biology, University of Virginia, Gilmer Hall, 485 McCormick Road, Charlottesville, VA 22904, USA
| | - Zhongfeng Zhang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
| | - Hongbo Zhang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, No. 11 Fourth Keyuan Road, Laoshan District, Qingdao 266101, China
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25
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Zheng S, Lu J, Yu D, Li J, Zhou H, Jiang D, Liu Z, Zhuang C. Hexokinase gene OsHXK1 positively regulates leaf senescence in rice. BMC PLANT BIOLOGY 2021; 21:580. [PMID: 34879830 PMCID: PMC8653616 DOI: 10.1186/s12870-021-03343-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 11/13/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND Leaf senescence is a highly complex and meticulous regulatory process, and the disruption of any factor involved in leaf senescence might lead to premature or delayed leaf senescence and thus result in reduced or increased crop yields. Despite sincere efforts by scientists, there remain many unsolved problems related to the regulatory factors and molecular mechanisms of leaf senescence. RESULTS This study successfully revealed that OsHXK1 was highly expressed in senescent leaves of rice. The upregulation of OsHXK1 led to premature senescence of rice leaves, a decreased level of chlorophyll, and damage to the chloroplast structure. The overexpression of OsHXK1 resulted in increases in glucose and ROS levels and produced programmed cell death (PCD) signals earlier at the booting stage. Further analysis showed that expression level of the respiratory burst oxidase homolog (RBOH) genes and OsGLO1 were increased in OsHXK1-overexpressing plants at the booting stage. CONCLUSIONS Overall, the outcomes of this study suggested that OsHXK1 could act as a positive regulator of rice leaf senescence by mediating glucose accumulation and inducing an increase in ROS.
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Affiliation(s)
- Shaoyan Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Jingqin Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Di Yu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Jing Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Hai Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Dagang Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Zhenlan Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Chuxiong Zhuang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
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26
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Wu HY, Liu LA, Shi L, Zhang WF, Jiang CD. Photosynthetic acclimation during low-light-induced leaf senescence in post-anthesis maize plants. PHOTOSYNTHESIS RESEARCH 2021; 150:313-326. [PMID: 34086146 DOI: 10.1007/s11120-021-00851-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
Low light conditions not only induce leaf senescence, but also photosynthetic acclimation. This study aimed to determine whether plants exhibit photosynthetic acclimation during low-light-induced leaf senescence. The influences of shading on leaf senescence and photosynthetic acclimation were explored in post-anthesis maize plants. The results showed that whole shading (WS) of maize plants accelerated leaf senescence, whereas partial shading (PS) slowed leaf senescence. WS led to larger decreases in the photosynthetic rate (Pn) and stomatal conductance (Gs) compared to those of the PS treatment. Interestingly, chlorophyll a fluorescence (ChlF) demonstrated that the absorption flux (ABS/CSo) and trapped energy flux (TRo/CSo) per cross section in leaves remained relatively stable under WS, whereas significant decreases in the active PSII reaction centers (RC/CSo) resulted in considerable increases in absorption (ABS/RC) and trapped energy flux (TRo/RC) per reaction center. ABS/CSo, TRo/CSo, ABS/RC, and TRo/RC increased markedly under PS, whereas there were slight decreases in RC/CSo and electron transport activity. These results suggest that the PS treatment resulted in obvious improvements in the absorption and capture of light energy in shaded leaves. Further analysis demonstrated that both the WS and PS treatments resulted in a greater decrease in the activity of Rubisco compared to that of phosphoenolpyruvate carboxylase (PEPC). Moreover, PEPC activity in PS was maintained at a high level. Consequently, the current study proposed that the improvement of the absorption and capture of light energy and the maintenance of PEPC activity of mesophyll cells were due to photosynthetic acclimation of low-light-induced leaf senescence in maize plants. In addition, the rate of senescence of vascular bundle cells in maize leaves exceeded that of mesophyll cells under low light, showing obvious tissue specificity.
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Affiliation(s)
- Han-Yu Wu
- Key Laboratory of Oasis Eco-Agriculture, Xinjiang Production and Construction Corps/College of Agronomy, Shihezi University, Shihezi, 832003, China
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Li-An Liu
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lei Shi
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Wang-Feng Zhang
- Key Laboratory of Oasis Eco-Agriculture, Xinjiang Production and Construction Corps/College of Agronomy, Shihezi University, Shihezi, 832003, China.
| | - Chuang-Dao Jiang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
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27
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Ma L, Li R, Ma L, Song N, Xu Z, Wu J. Involvement of NAC transcription factor NaNAC29 in Alternaria alternata resistance and leaf senescence in Nicotiana attenuata. PLANT DIVERSITY 2021; 43:502-509. [PMID: 35024519 PMCID: PMC8720690 DOI: 10.1016/j.pld.2020.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/16/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
NAC-LIKE, ACTIVATED BY AP3/PI (NAP) is a NAC transcription factor regulating leaf senescence in Arabidopsis thaliana. In wild tobacco Nicotiana attenuata, a nuclear localized NAC transcription factor NaNAC29 was identified to be highly elicited after inoculation of Alternaria alternata, a notorious necrotic fungus on tobacco species. The NaNAC29 possesses similar tertiary structure to NAP with 60% amino acid identity. However, it remains unknown the role of NaNAC29 in plant defense responses to A. alternata and leaf senescence in N. attenuata. In this paper, Defensin-like protein 1 (NaDLP1) was highly induced in N. attenuata after A. alternata inoculation and bigger lesions were developed in NaDLP1-silenced plants. Interestingly, A. alternata-induced NaDLP1 was reduced by 76% in VIGS NaNAC29 plants and by 61% in JA deficient irAOC plants at 3 days post inoculation. The regulation of NaDLP1 expression by NaNAC29 was clearly independent on JA pathway, since exogenous methyl jasmonate treatment could not complement the induction levels of NaDLP1 in NaNAC29-silenced plants to the levels in WT plants. Otherwise, the expression of NaNAC29 was low expressed in young leaves but highly in senescent leaves and dark-treated leaves. NaNAC29-silenced plants, which were generated by virus-induced gene silencing (VIGS NaNAC29), showed delayed senescence phenotype. In addition, constitutive over-expression of NaNAC29 in A. thaliana could rescue the delayed-senescence phenotype of nap and caused precocious leaf senescence of wild-type Col-0 plants. All the data above demonstrate that NaNAC29 is a NAP homolog in N. attenuata participating in the defense responses to A. alternata by regulation of a defensin protein NaDLP1 and promoting leaf senescence.
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Affiliation(s)
- Lan Ma
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
| | - Rongping Li
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
- University of Chinese Academy of Science, Beijing 100049, China
| | - Luoyan Ma
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
| | - Na Song
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
- University of Chinese Academy of Science, Beijing 100049, China
| | - Zhen Xu
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
- University of Chinese Academy of Science, Beijing 100049, China
| | - Jinsong Wu
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Lanhei Road 132, 650201, Kunming, China
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Overexpressing 7-Hydroxymethyl Chlorophyll a Reductase Alleviates Non-Programmed Cell Death during Dark-Induced Senescence in Intact Arabidopsis Plants. Biomolecules 2021; 11:biom11081143. [PMID: 34439809 PMCID: PMC8394709 DOI: 10.3390/biom11081143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 11/17/2022] Open
Abstract
Leaf senescence, the last stage of leaf development, is a well-regulated and complex process for investigation. For simplification, dark-induced leaf senescence has frequently been used to mimic the natural senescence of leaves because many typical senescence symptoms, such as chlorophyll (Chl) and protein degradation, also occur under darkness. In this study, we compared the phenotypes of leaf senescence that occurred when detached leaves or intact plants were incubated in darkness to induce senescence. We found that the symptoms of non-programmed cell death (non-PCD) with remaining green coloration occurred more heavily in the senescent leaves of whole plants than in the detached leaves. The pheophorbide a (Pheide a) content was also shown to be much higher in senescent leaves when whole plants were incubated in darkness by analyses of leaf Chl and its metabolic intermediates. In addition, more serious non-PCD occurred and more Pheide a accumulated in senescent leaves during dark incubation if the soil used for plant growth contained more water. Under similar conditions, the non-PCD phenotype was alleviated and the accumulation of Pheide a was reduced by overexpressing 7-hydroxymethyl Chl a (HMChl a) reductase (HCAR). Taken together, we conclude that a high soil water content induced non-PCD by decreasing HCAR activity when whole plants were incubated in darkness to induce senescence; thus, the investigation of the fundamental aspects of biochemistry and the regulation of leaf senescence are affected by using dark-induced leaf senescence.
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29
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Xu X, Jibran R, Wang Y, Dong L, Flokova K, Esfandiari A, McLachlan ARG, Heiser A, Sutherland-Smith AJ, Brummell DA, Bouwmeester HJ, Dijkwel PP, Hunter DA. Strigolactones regulate sepal senescence in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5462-5477. [PMID: 33970249 DOI: 10.1093/jxb/erab199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/08/2021] [Indexed: 05/07/2023]
Abstract
Flower sepals are critical for flower development and vary greatly in life span depending on their function post-pollination. Very little is known about what controls sepal longevity. Using a sepal senescence mutant screen, we identified two Arabidopsis mutants with delayed senescence directly connecting strigolactones with senescence regulation in a novel floral context that hitherto has not been explored. The mutations were in the strigolactone biosynthetic gene MORE AXILLARY GROWTH1 (MAX1) and in the strigolactone receptor gene DWARF14 (AtD14). The mutation in AtD14 changed the catalytic Ser97 to Phe in the enzyme active site, which is the first mutation of its kind in planta. The lesion in MAX1 was in the haem-iron ligand signature of the cytochrome P450 protein, converting the highly conserved Gly469 to Arg, which was shown in a transient expression assay to substantially inhibit the activity of MAX1. The two mutations highlighted the importance of strigolactone activity for driving to completion senescence initiated both developmentally and in response to carbon-limiting stress, as has been found for the more well-known senescence-associated regulators ethylene and abscisic acid. Analysis of transcript abundance in excised inflorescences during an extended night suggested an intricate relationship among sugar starvation, senescence, and strigolactone biosynthesis and signalling.
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Affiliation(s)
- Xi Xu
- Massey University, School of Fundamental Sciences, Palmerston North, New Zealand
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Rubina Jibran
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Yanting Wang
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Lemeng Dong
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Kristyna Flokova
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Azadeh Esfandiari
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Andrew R G McLachlan
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Axel Heiser
- Hopkirk Research Institute, AgResearch Limited, Palmerston North, New Zealand
| | | | - David A Brummell
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - Harro J Bouwmeester
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Paul P Dijkwel
- Massey University, School of Fundamental Sciences, Palmerston North, New Zealand
| | - Donald A Hunter
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
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30
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Yi SY, Rameneni JJ, Lee M, Song SG, Choi Y, Lu L, Lee H, Lim YP. Comparative Transcriptome-Based Mining of Senescence-Related MADS, NAC, and WRKY Transcription Factors in the Rapid-Senescence Line DLS-91 of Brassica rapa. Int J Mol Sci 2021; 22:ijms22116017. [PMID: 34199515 PMCID: PMC8199657 DOI: 10.3390/ijms22116017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 11/16/2022] Open
Abstract
Leaf senescence is a developmental process induced by various molecular and environmental stimuli that may affect crop yield. The dark-induced leaf senescence-91 (DLS-91) plants displayed rapid leaf senescence, dramatically decreased chlorophyll contents, low photochemical efficiencies, and upregulation of the senescence-associated marker gene BrSAG12-1. To understand DLS molecular mechanism, we examined transcriptomic changes in DLS-91 and control line DLS-42 following 0, 1, and 4 days of dark treatment (DDT) stages. We identified 501, 446, and 456 DEGs, of which 16.7%, 17.2%, and 14.4% encoded TFs, in samples from the three stages. qRT-PCR validation of 16 genes, namely, 7 MADS, 6 NAC, and 3 WRKY, suggested that BrAGL8-1, BrAGL15-1, and BrWRKY70-1 contribute to the rapid leaf senescence of DLS-91 before (0 DDT) and after (1 and 4 DDT) dark treatment, whereas BrNAC046-2, BrNAC029-2/BrNAP, and BrNAC092-1/ORE1 TFs may regulate this process at a later stage (4 DDT). In-silico analysis of cis-acting regulatory elements of BrAGL8-1, BrAGL42-1, BrNAC029-2, BrNAC092-1, and BrWRKY70-3 of B. rapa provides insight into the regulation of these genes. Our study has uncovered several AGL-MADS, WRKY, and NAC TFs potentially worthy of further study to understand the underlying mechanism of rapid DLS in DLS-91.
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Affiliation(s)
- So Young Yi
- Institute of Agricultural Science, Chungnam National University, Daejeon 34134, Korea; (S.Y.Y.); (J.J.R.); (M.L.)
| | - Jana Jeevan Rameneni
- Institute of Agricultural Science, Chungnam National University, Daejeon 34134, Korea; (S.Y.Y.); (J.J.R.); (M.L.)
| | - Myungjin Lee
- Institute of Agricultural Science, Chungnam National University, Daejeon 34134, Korea; (S.Y.Y.); (J.J.R.); (M.L.)
| | - Seul Gi Song
- Molecular Genetics and Genomics Laboratory, Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon 34134, Korea; (S.G.S.); (Y.C.); (L.L.); (H.L.)
| | - Yuri Choi
- Molecular Genetics and Genomics Laboratory, Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon 34134, Korea; (S.G.S.); (Y.C.); (L.L.); (H.L.)
| | - Lu Lu
- Molecular Genetics and Genomics Laboratory, Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon 34134, Korea; (S.G.S.); (Y.C.); (L.L.); (H.L.)
| | - Hyeokgeun Lee
- Molecular Genetics and Genomics Laboratory, Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon 34134, Korea; (S.G.S.); (Y.C.); (L.L.); (H.L.)
| | - Yong Pyo Lim
- Molecular Genetics and Genomics Laboratory, Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon 34134, Korea; (S.G.S.); (Y.C.); (L.L.); (H.L.)
- Correspondence: ; Tel.: +82-42-821-5739; Fax: +82-42-821-8847
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Nakamura S, Hagihara S, Otomo K, Ishida H, Hidema J, Nemoto T, Izumi M. Autophagy Contributes to the Quality Control of Leaf Mitochondria. PLANT & CELL PHYSIOLOGY 2021; 62:229-247. [PMID: 33355344 PMCID: PMC8112837 DOI: 10.1093/pcp/pcaa162] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/05/2020] [Indexed: 05/11/2023]
Abstract
In autophagy, cytoplasmic components of eukaryotic cells are transported to lysosomes or the vacuole for degradation. Autophagy is involved in plant tolerance to the photooxidative stress caused by ultraviolet B (UVB) radiation, but its roles in plant adaptation to UVB damage have not been fully elucidated. Here, we characterized organellar behavior in UVB-damaged Arabidopsis (Arabidopsis thaliana) leaves and observed the occurrence of autophagic elimination of dysfunctional mitochondria, a process termed mitophagy. Notably, Arabidopsis plants blocked in autophagy displayed increased leaf chlorosis after a 1-h UVB exposure compared to wild-type plants. We visualized autophagosomes by labeling with a fluorescent protein-tagged autophagosome marker, AUTOPHAGY8 (ATG8), and found that a 1-h UVB treatment led to increased formation of autophagosomes and the active transport of mitochondria into the central vacuole. In atg mutant plants, the mitochondrial population increased in UVB-damaged leaves due to the cytoplasmic accumulation of fragmented, depolarized mitochondria. Furthermore, we observed that autophagy was involved in the removal of depolarized mitochondria when mitochondrial function was disrupted by mutation of the FRIENDLY gene, which is required for proper mitochondrial distribution. Therefore, autophagy of mitochondria functions in response to mitochondrion-specific dysfunction as well as UVB damage. Together, these results indicate that autophagy is centrally involved in mitochondrial quality control in Arabidopsis leaves.
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Affiliation(s)
- Sakuya Nakamura
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
| | - Shinya Hagihara
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
| | - Kohei Otomo
- Exploratory Research Center on Life and Living Systems (ExCELLs), National Institute of Natural Sciences, Okazaki, 444-8787 Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Study (SOKENDAI), Hayama, 240-0193 Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020 Japan
| | - Hiroyuki Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Sciences, Tohoku University, Sendai, 980-0845, Japan
| | - Jun Hidema
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan
| | - Tomomi Nemoto
- Exploratory Research Center on Life and Living Systems (ExCELLs), National Institute of Natural Sciences, Okazaki, 444-8787 Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Study (SOKENDAI), Hayama, 240-0193 Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020 Japan
| | - Masanori Izumi
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, 322-0012 Japan
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AtWAKL10, a Cell Wall Associated Receptor-Like Kinase, Negatively Regulates Leaf Senescence in Arabidopsis thaliana. Int J Mol Sci 2021; 22:ijms22094885. [PMID: 34063046 PMCID: PMC8124439 DOI: 10.3390/ijms22094885] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 01/22/2023] Open
Abstract
Receptor-like kinases (RLKs) constitute a large group of cell surface receptors that play crucial roles in multiple biological processes. However, the function of most RLKs in plants has not been extensively explored, and much less for the class of cell wall associated kinases (WAKs) and WAK-like kinases (WAKLs). In this study, analyses of developmental expression patterns uncovered a putative role of AtWAKL10 in modulating leaf senescence, which was further investigated at physiological and molecular levels. The expression level of AtWAKL10 increased with the developmental progression and was rapidly upregulated in senescing leaf tissues. The promoter of AtWAKL10 contains various defense and hormone responsive elements, and its expression could be significantly induced by exogenous ABA, JA and SA. Moreover, the loss-of-function atwakl10 mutant showed earlier senescence along the course of natural development and accelerated leaf senescence under darkness and hormonal stresses, while plants overexpressing AtWAKL10 showed an opposite trend. Additionally, some defense and senescence related WRKY transcription factors could bind to the promoter of AtWAKL10. In addition, deletion and overexpression of AtWAKL10 caused several specific transcriptional alterations, including genes involved in cell extension, cell wall modification, defense response and senescence related WRKYs, which may be implicated in regulatory mechanisms adopted by AtWAKL10 in controlling leaf senescence. Taken together, these results revealed that AtWAKL10 negatively regulated leaf senescence.
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Nakamura S, Hagihara S, Izumi M. Mitophagy in plants. Biochim Biophys Acta Gen Subj 2021; 1865:129916. [PMID: 33932484 DOI: 10.1016/j.bbagen.2021.129916] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/06/2021] [Accepted: 04/26/2021] [Indexed: 12/11/2022]
Abstract
Mitochondria play a central role in primary metabolism in plants as well as in heterotrophic eukaryotes. Plants must control the quality and number of mitochondria in response to a changing environment, across cell types and developmental stages. Mitophagy is defined as the degradation of mitochondria by autophagy, an evolutionarily conserved system for the removal and recycling of intracellular components. Recent studies have highlighted the importance of mitophagy in plant stress responses. This review article summarizes our current knowledge of plant mitophagy and discusses the underlying mechanisms. In plants, chloroplasts cooperate with mitochondria for energy production, and autophagy also targets chloroplasts through a process known as chlorophagy. Advances in plant autophagy studies now allow a comparative analysis of the autophagic turnover of mitochondria and chloroplasts, via the selective degradation of their soluble proteins, fragments, or entire organelles.
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Affiliation(s)
- Sakuya Nakamura
- Center for Sustainable Resource Science (CSRS), RIKEN, 351-0198 Wako, Japan
| | - Shinya Hagihara
- Center for Sustainable Resource Science (CSRS), RIKEN, 351-0198 Wako, Japan
| | - Masanori Izumi
- Center for Sustainable Resource Science (CSRS), RIKEN, 351-0198 Wako, Japan.
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Gutbrod P, Yang W, Grujicic GV, Peisker H, Gutbrod K, Du LF, Dörmann P. Phytol derived from chlorophyll hydrolysis in plants is metabolized via phytenal. J Biol Chem 2021; 296:100530. [PMID: 33713704 PMCID: PMC8054155 DOI: 10.1016/j.jbc.2021.100530] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/01/2021] [Accepted: 03/09/2021] [Indexed: 12/30/2022] Open
Abstract
Phytol is the isoprenoid alcohol bound in ester linkage to chlorophyll, the most abundant photosynthetic pigment in plants. During leaf senescence, large amounts of phytol are released by chlorophyll degradation. However, the pathway of phytol catabolism in plants is unknown. We hypothesized that phytol degradation in plants might involve its oxidation into the long-chain aldehyde phytenal. Using GC-MS for aldehyde quantification after derivatization with methylhydroxylamine, phytenal was identified in leaves, whereas other long-chain aldehydes (phytanal and pristanal) were barely detectable. We found that phytenal accumulates during chlorotic stresses, for example, salt stress, dark-induced senescence, and nitrogen deprivation. The increase in the phytenal content is mediated at least in part independently of enzyme activities, and it is independent of light. Characterization of phytenal accumulation in the pao1 mutant affected in chlorophyll degradation revealed that phytenal is an authentic phytol metabolite derived from chlorophyll breakdown. The increase in phytenal was even stronger in mutants affected in the production of other phytol metabolites including vte5-2 (tocopherol deficient) and pes1 pes2 (fatty acid phytyl ester deficient). Therefore, phytenal accumulation is controlled by competing, alternative pathways of phosphorylation (leading to tocopherol production) or esterification (fatty acid phytyl ester production). As a consequence, the content of phytenal is maintained at low levels, presumably to minimize its toxic effects caused by its highly reactive aldehyde group that can form covalent bonds with and inactivate the amino groups of proteins.
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Affiliation(s)
- Philipp Gutbrod
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany
| | - Wentao Yang
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany; Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Goran Vuk Grujicic
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany
| | - Helga Peisker
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany
| | - Katharina Gutbrod
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany
| | - Lin Fang Du
- Key Laboratory of Bio-Resources and Eco-Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Bonn, Germany.
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New insights into the response of maize to fluctuations in the light environment. Mol Genet Genomics 2021; 296:615-629. [PMID: 33630129 DOI: 10.1007/s00438-021-01761-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/11/2021] [Indexed: 10/22/2022]
Abstract
Light is the most important environmental cue signaling the transition from skotomorphogenesis to photomorphogenesis, thus affecting plant development and metabolic activity. How the light response mechanisms of maize seedlings respond to fluctuations in the light environment has not been well characterized to date. In this study, we built a gene coexpression network from a dynamic transcriptomic map of maize seedlings exposed to different light environments. Coexpression analysis identified ten modules and multiple genes that closely correlate with photosynthesis and characterized hub genes associated with regulatory networks, duplication events, domestication and improvement. In addition, we identified that 38% of hub genes underwent duplication events, 74% of which are related to photosynthesis. Moreover, we captured the dynamic expression atlas of gene sets involved in the chloroplast photosynthetic apparatus and photosynthetic carbon assimilation in different light environments, which should help to elucidate the key mechanisms and regulatory networks that underlie photosynthesis in maize. Insights from this study provide a valuable resource to better understand the genetic mechanisms of the response to fluctuations in the light environment in maize.
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Eckstein A, Grzyb J, Hermanowicz P, Zgłobicki P, Łabuz J, Strzałka W, Dziga D, Banaś AK. Arabidopsis Phototropins Participate in the Regulation of Dark-Induced Leaf Senescence. Int J Mol Sci 2021; 22:ijms22041836. [PMID: 33673252 PMCID: PMC7918785 DOI: 10.3390/ijms22041836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Senescence is the final stage of plant development, affecting individual organs or the whole organism, and it can be induced by several environmental factors, including shading or darkness. Although inevitable, senescence is a complex and tightly regulated process, ensuring optimal remobilization of nutrients and cellular components from senescing organs. Photoreceptors such as phytochromes and cryptochromes are known to participate in the process of senescence, but the involvement of phototropins has not been studied to date. We investigated the role of these blue light photoreceptors in the senescence of individually darkened Arabidopsis thaliana leaves. We compared several physiological and molecular senescence markers in darkened leaves of wild-type plants and phototropin mutants (phot1, phot2, and phot1phot2). In general, all the symptoms of senescence (lower photochemical activity of photosystem II, photosynthetic pigment degradation, down-regulation of photosynthetic genes, and up-regulation of senescence-associated genes) were less pronounced in phot1phot2, as compared to the wild type, and some also in one of the single mutants, indicating delayed senescence. This points to different mechanisms of phototropin operation in the regulation of senescence-associated processes, either with both photoreceptors acting redundantly, or only one of them, phot1, playing a dominant role.
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Affiliation(s)
- Aleksandra Eckstein
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
- Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdansk, Poland
| | - Joanna Grzyb
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland;
| | - Paweł Hermanowicz
- Laboratory of Photobiology, The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; (P.H.); (J.Ł.)
| | - Piotr Zgłobicki
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
| | - Justyna Łabuz
- Laboratory of Photobiology, The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; (P.H.); (J.Ł.)
| | - Wojciech Strzałka
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
| | - Dariusz Dziga
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland;
| | - Agnieszka Katarzyna Banaś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland; (A.E.); (P.Z.); (W.S.)
- Correspondence:
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37
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Fernández Nevyl S, Battaglia ME. Developmental plasticity in Arabidopsis thaliana under combined cold and water deficit stresses during flowering stage. PLANTA 2021; 253:50. [PMID: 33506329 DOI: 10.1007/s00425-021-03575-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 01/19/2021] [Indexed: 05/02/2023]
Abstract
Morpho-physiological changes were observed in Arabidopsis plants acclimated to long-term combined cold and water deficit stresses. Limiting growth and differences in bolting, flowering, and silique development were evidenced. In nature, plants are exposed to multiple and simultaneous abiotic stresses that influence their growth, development, and reproduction. In the last years, the study of combined stresses has aroused the interest to know the physiological and molecular responses, because these new stress conditions are probed to be different from the sum of the individual stress. We are interested in the study of the acclimation of plants growing under the combination of cold and water deficit stresses prevalent in cold-arid or semi-arid climates worldwide. We hypothesized that the reproduction of the acclimated plants will be compromised and affected. Arabidopsis plants were submitted to long-term combined stress from the beginning to the reproductive stage, when floral bud was visible, until the silique development. Our results demonstrate severe morpho-anatomical changes after acclimation to combined stress. Inflorescence stem morphology was altered having a delayed bolting and a limited growth. Flowering and silique formation were delayed, and a higher size in the corolla and the petals was observed. Flower and silique number were severely diminished as a result of combined stress, unlike acclimated plants to individual cold stress. These traits were recovered after deacclimation to optimal conditions and plants achieved similar silique production as control plants. The long-term stress results suggest that there is not a single dominant stress, but there is an alternating dominance depending on the structure or the plant stage development evaluated.
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Affiliation(s)
- Solange Fernández Nevyl
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación Para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, 7600, Mar del Plata, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (FCEyN, UNMdP), Funes 3250, 7600, Mar del Plata, Argentina
| | - Marina E Battaglia
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación Para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, 7600, Mar del Plata, Argentina.
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38
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Xie Y, Ma M, Liu Y, Wang B, Wei H, Kong D, Wang H. Arabidopsis FHY3 and FAR1 Function in Age Gating of Leaf Senescence. FRONTIERS IN PLANT SCIENCE 2021; 12:770060. [PMID: 34777451 PMCID: PMC8584998 DOI: 10.3389/fpls.2021.770060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/07/2021] [Indexed: 05/11/2023]
Abstract
Leaf senescence is the terminal stage of leaf development. Both light and the plant hormone ethylene play important roles in regulating leaf senescence. However, how they coordinately regulate leaf senescence during leaf development remains largely unclear. In this study, we show that FHY3 and FAR1, two homologous proteins essential for phytochrome A-mediated light signaling, physically interact with and repress the DNA binding activity of EIN3 (a key transcription factor essential for ethylene signaling) and PIF5 (a bHLH transcription factor negatively regulating light signaling), and interfere with their DNA binding to the promoter of ORE1, which encodes a key NAC transcription factor promoting leaf senescence. In addition, we show that FHY3, PIF5, and EIN3 form a tri-protein complex(es) and that they coordinately regulate the progression of leaf senescence. We show that during aging or under dark conditions, accumulation of FHY3 protein decreases, thus lifting its repression on DNA binding of EIN3 and PIF5, leading to the increase of ORE1 expression and onset of leaf senescence. Our combined results suggest that FHY3 and FAR1 act in an age gating mechanism to prevent precocious leaf senescence by integrating light and ethylene signaling with developmental aging.
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Affiliation(s)
- Yurong Xie
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mengdi Ma
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yang Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baobao Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hongbin Wei
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Dexin Kong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Haiyang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
- *Correspondence: Haiyang Wang,
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Deng K, Wang W, Feng L, Yin H, Xiong F, Ren M. Target of rapamycin regulates potassium uptake in Arabidopsis and potato. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 155:357-366. [PMID: 32798904 DOI: 10.1016/j.plaphy.2020.07.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/24/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Potassium (K) is an essential inorganic nutrient needed by plants for their growth and development. The conserved target of rapamycin (TOR) kinase, a well-known nutrition signaling integrator, has crucial roles in regulating growth and development in all eukaryotes. Emerging evidence suggests that TOR is a core regulator of nutrient absorption and utilization in plants. However, it is still unclear whether there is a causative link between the TOR pathway and potassium absorption. Here, we show that the expression of some potassium transporters and channels was regulated by TOR, and the suppression of TOR activity significantly affected potassium uptake in Arabidopsis and potato. Furthermore, we discovered that a Type 2A phosphatase-associated protein of 46 kDa (TAP46), a direct TOR downstream effector, could interact with CBL-interacting protein kinase 23 (CIPK23) in Arabidopsis and potato. In Arabidopsis, the K+ channel AKT1 conducting K+ uptake was significantly regulated by Calcineurin B-like Calcium Sensor Protein 1/9 (CBL1/9)-CIPK23 modules. We found that the cbl1cbl9, cipk23 (lks1-2 and lks1-3), and akt1 mutants were more hyposensitive to the TOR inhibitor than the wild-type, and the TOR inhibitor induced the downregulation of K+ uptake rate in the wild-type more than in these mutants. In addition, the overexpression of CIPK23 could effectively restore the defects in growth and potassium uptake induced by the TOR inhibitors. Thus, our work reveals a link between TOR signaling and CIPK23 and provides new insight into the regulation of potassium uptake in plants.
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Affiliation(s)
- Kexuan Deng
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Wanjing Wang
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Li Feng
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 45000, China
| | - Huan Yin
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Fangjie Xiong
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Maozhi Ren
- School of Life Sciences, Chongqing University, Chongqing, 401331, China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 45000, China.
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40
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Chemical Genetics Approach Identifies Abnormal Inflorescence Meristem 1 as a Putative Target of a Novel Sulfonamide That Protects Catalase2-Deficient Arabidopsis against Photorespiratory Stress. Cells 2020; 9:cells9092026. [PMID: 32887516 PMCID: PMC7563276 DOI: 10.3390/cells9092026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 11/24/2022] Open
Abstract
Alterations of hydrogen peroxide (H2O2) levels have a profound impact on numerous signaling cascades orchestrating plant growth, development, and stress signaling, including programmed cell death. To expand the repertoire of known molecular mechanisms implicated in H2O2 signaling, we performed a forward chemical screen to identify small molecules that could alleviate the photorespiratory-induced cell death phenotype of Arabidopsisthaliana mutants lacking H2O2-scavenging capacity by peroxisomal catalase2. Here, we report the characterization of pakerine, an m-sulfamoyl benzamide from the sulfonamide family. Pakerine alleviates the cell death phenotype of cat2 mutants exposed to photorespiration-promoting conditions and delays dark-induced senescence in wild-type Arabidopsis leaves. By using a combination of transcriptomics, metabolomics, and affinity purification, we identified abnormal inflorescence meristem 1 (AIM1) as a putative protein target of pakerine. AIM1 is a 3-hydroxyacyl-CoA dehydrogenase involved in fatty acid β-oxidation that contributes to jasmonic acid (JA) and salicylic acid (SA) biosynthesis. Whereas intact JA biosynthesis was not required for pakerine bioactivity, our results point toward a role for β-oxidation-dependent SA production in the execution of H2O2-mediated cell death.
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Li J, Chen G, Zhang J, Shen H, Kang J, Feng P, Xie Q, Hu Z. Suppression of a hexokinase gene, SlHXK1, leads to accelerated leaf senescence and stunted plant growth in tomato. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110544. [PMID: 32771157 DOI: 10.1016/j.plantsci.2020.110544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 05/18/2023]
Abstract
Sugars are the key regulatory molecules that impact diverse biological processes in plants. Hexokinase, the key rate-limiting enzyme in hexose metabolism, takes part in the first step of glycolytic pathway. Acting as a sensor that mediates sugar regulation, hexokinase has been proved to play significant roles in regulating plant growth and development. Here, we isolated a hexokinase gene SlHXK1 from tomato. Its transcript levels were higher in flowers and leaves than in other organs and decreased during leaf and petiole development. SlHXK1-RNAi lines displayed advanced leaf senescence and stunted plant growth. Physiological features including plant height, leaf length, thickness and size, the contents of chlorophyll, starch and MDA, and hexokinase activity were dramatically altered in SlHXK1-RNAi plants. Dark-induced leaf senescence were advanced and the transcripts of senescence-related genes after darkness treatment were markedly increased in SlHXK1-RNAi plants. RNA-seq and qRT-PCR analyses showed that the transcripts of genes related to plant hormones, photosynthesis, chloroplast development, chlorophyll synthesis and metabolism, cellular process, starch and sucrose metabolism, and senescence were significantly altered in SlHXK1-RNAi plants. Taken together, our data demonstrate that SlHXK1 is a significant gene involved in leaf senescence and plant growth and development in tomato through affecting starch turnover.
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Affiliation(s)
- Jing Li
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Guoping Chen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Jianling Zhang
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Hui Shen
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Jing Kang
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Panpan Feng
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Qiaoli Xie
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
| | - Zongli Hu
- Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, People's Republic of China.
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Veliz CG, Criado MV, Galotta MF, Roberts IN, Caputo C. Regulation of senescence-associated protease genes by sulphur availability according to barley (Hordeum vulgare L.) phenological stage. ANNALS OF BOTANY 2020; 126:435-444. [PMID: 32300777 PMCID: PMC7424724 DOI: 10.1093/aob/mcaa071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Proteases are responsible for protein degradation during leaf senescence, allowing nutrients to be redirected to sink tissues. In a previous work, we reported that sulphur deficiency produced a delay in the leaf senescence of barley (Hordeum vulgare L.) plants, at both vegetative and reproductive stages. In this work, we analyse the effect of sulphur deficiency on the expression of several genes coding for proteases of different catalytic groups, which have been strongly associated with leaf senescence. METHODS Four independent experiments were performed in order to impose low sulphur availability conditions: one of steady-state sulphur deficiency during the vegetative stage and three of sulphur starvation during vegetative and reproductive stages. KEY RESULTS Sulphur deficiency inhibited or reduced the senescence-associated induction of seven of the eight proteases analysed. Their induction, as well as senescence and phloem amino acid remobilization, could be achieved with senescence inducers such as methyl-jasmonate (a hormonal stimulus) and darkness, but with different rates of induction dependent on each gene. Sulphur deficiency also exerted an opposite effect on the expression of two cysteine-protease genes (HvSAG12 and HvLEGU) as well as on one serine-protease gene (HvSUBT) according to leaf age and plant phenological stages. All three genes were induced in green leaves but were repressed in senescent leaves of sulphur-deficient plants at the vegetative stage. At the reproductive stage, both cysteine-proteases were only repressed in senescent leaves, while the serine-protease was induced in green and senescent leaves by sulphur deficiency. CONCLUSIONS Our results highlight the relevance of adequate sulphur nutrition in order to ensure leaf senescence onset and induction of protease genes, which will consequently impact on grain protein composition and quality. In addition, our results provide evidence that leaf age, plant developmental stage and the nature of the stress modulate the sulphur responses.
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Affiliation(s)
- Cintia G Veliz
- CONICET—Universidad de Buenos Aires, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA), Buenos Aires, Argentina
| | - Maria Victoria Criado
- Cátedra de Microbiología, Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Biología Aplicada y Alimentos, Buenos Aires, Argentina
- CONICET—Universidad de Buenos Aires, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA), Buenos Aires, Argentina
| | - María Florencia Galotta
- CONICET—Universidad de Buenos Aires, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA), Buenos Aires, Argentina
| | - Irma N Roberts
- Cátedra de Microbiología, Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Biología Aplicada y Alimentos, Buenos Aires, Argentina
- CONICET—Universidad de Buenos Aires, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA), Buenos Aires, Argentina
| | - Carla Caputo
- CONICET—Universidad de Buenos Aires, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA), Buenos Aires, Argentina
- Cátedra de Bioquímica, Universidad de Buenos Aires, Facultad de Agronomía, Departamento de Biología Aplicada y Alimentos, Buenos Aires, Argentina
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Liu J, Chafi R, Legarrea S, Alba JM, Meijer T, Menken SBJ, Kant MR. Spider Mites Cause More Damage to Tomato in the Dark When Induced Defenses Are Lower. J Chem Ecol 2020; 46:631-641. [PMID: 32588284 PMCID: PMC7371662 DOI: 10.1007/s10886-020-01195-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 06/12/2020] [Accepted: 06/17/2020] [Indexed: 11/18/2022]
Abstract
Plants have evolved robust mechanisms to cope with incidental variation (e.g. herbivory) and periodical variation (e.g. light/darkness during the day-night cycle) in their environment. It has been shown that a plant's susceptibility to pathogens can vary during its day-night cycle. We demonstrated earlier that the spider mite Tetranychus urticae induces jasmonate- and salicylate-mediated defenses in tomato plants while the spider mite T. evansi suppresses these defenses probably by secreting salivary effector proteins. Here we compared induction/suppression of plant defenses; the expression of mite-effector genes and the amount of damage due to mite feeding during the day and during the night. T. urticae feeding upregulated the expression of jasmonate and salicylate marker-genes albeit significantly higher under light than under darkness. Some of these marker-genes were also upregulated by T. evansi-feeding albeit to much lower levels than by T. urticae-feeding. The expression of effector 28 was not affected by light or darkness in either mite species. However, the expression of effector 84 was considerably higher under light, especially for T. evansi. Finally, while T. evansi produced overall more feeding damage than T. urticae both mites produced consistently more damage during the dark phase than under light. Our results suggest that induced defenses are subject to diurnal variation possibly causing tomatoes to incur more damage due to mite-feeding during the dark phase. We speculate that mites, but especially T. evansi, may relax effector production during the dark phase because under these conditions the plant's ability to upregulate defenses is reduced.
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Affiliation(s)
- Jie Liu
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Rachid Chafi
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Saioa Legarrea
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Juan M Alba
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Tomas Meijer
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Steph B J Menken
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Merijn R Kant
- Section Molecular and Chemical Ecology, Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands.
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Dhar N, Caruana J, Erdem I, Subbarao KV, Klosterman SJ, Raina R. The Arabidopsis SENESCENCE-ASSOCIATED GENE 13 Regulates Dark-Induced Senescence and Plays Contrasting Roles in Defense Against Bacterial and Fungal Pathogens. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:754-766. [PMID: 32065029 DOI: 10.1094/mpmi-11-19-0329-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
SENESCENCE-ASSOCIATED GENE 13 (SAG13) of Arabidopsis is a widely conserved gene of unknown function that has been extensively used as a marker of plant senescence. SAG13 induction occurs during plant cell death processes, including senescence and hypersensitive response, a type of programmed cell death that occurs in response to pathogens. This implies that SAG13 expression is regulated through at least two different signaling pathways affecting these two different processes. Our work highlights a contrasting role for SAG13 in regulating resistance against disease-causing biotrophic bacterial and necrotrophic fungal pathogens with contrasting infection strategies. We provide further evidence that SAG13 is not only induced during oxidative stress but also plays a role in protecting the plant against other stresses. SAG13 is also required for normal seed germination, seedling growth, and anthocyanin accumulation. The work presented here provides evidence for the role of SAG13 in regulating multiple plant processes including senescence, defense, seed germination, and abiotic stress responses. SAG13 is a valuable molecular marker for these processes and is conserved in multiple plant species, and this knowledge has important implications for crop improvement.
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Affiliation(s)
- Nikhilesh Dhar
- Department of Biology, Syracuse University, Syracuse, NY 13210, U.S.A
- Department of Plant Pathology, University of California, Davis, Salinas, CA 93905, U.S.A
| | - Julie Caruana
- Department of Biology, Syracuse University, Syracuse, NY 13210, U.S.A
- ASEE Postdoctoral Fellow, Naval Research Lab, Washington DC 20375, U.S.A
| | - Irmak Erdem
- Department of Biology, Syracuse University, Syracuse, NY 13210, U.S.A
| | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, Salinas, CA 93905, U.S.A
| | | | - Ramesh Raina
- Department of Biology, Syracuse University, Syracuse, NY 13210, U.S.A
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Zhang Z, Li W, Gao X, Xu M, Guo Y. DEAR4, a Member of DREB/CBF Family, Positively Regulates Leaf Senescence and Response to Multiple Stressors in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2020; 11:367. [PMID: 32296455 PMCID: PMC7136848 DOI: 10.3389/fpls.2020.00367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 03/13/2020] [Indexed: 05/25/2023]
Abstract
Leaf senescence is a programmed developmental process regulated by various endogenous and exogenous factors. Here we report the characterization of the senescence-regulating role of DEAR4 (AT4G36900) from the DREB1/CBF (dehydration-responsive element binding protein 1/C-repeat binding factor) family in Arabidopsis. The expression of DEAR4 is associated with leaf senescence and can be induced by ABA, JA, darkness, drought and salt stress. Transgenic plants over-expressing DEAR4 showed a dramatically enhanced leaf senescence phenotype under normal and dark conditions while the dear4 knock-down mutant displayed delayed senescence. DEAR4 over-expressing plants showed decreased seed germination rate under ABA and salt stress conditions as well as decreased drought tolerance, indicating that DEAR4 was involved in both senescence and stress response processes. Furthermore, we found that DEAR4 protein displayed transcriptional repressor activities in yeast cells. DEAR4 could directly repress the expression of a subset of COLD-REGULATED (COR) and RESPONSIVE TO DEHYDRATION (RD) genes which have been shown to be involved in leaf longevity and stress response. Also we found that DERA4 could induce the production of Reactive oxygen species (ROS), the common signal of senescence and stress responses, which gives us the clue that DEAR4 may play an integrative role in senescence and stress response via regulating ROS production.
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Kim Y, Park SU, Shin DM, Pham G, Jeong YS, Kim SH. ATBS1-INTERACTING FACTOR 2 negatively regulates dark- and brassinosteroid-induced leaf senescence through interactions with INDUCER OF CBF EXPRESSION 1. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1475-1490. [PMID: 31783407 PMCID: PMC7031079 DOI: 10.1093/jxb/erz533] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/28/2019] [Indexed: 05/25/2023]
Abstract
ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic helix-loop-helix (bHLH) transcription factor. We demonstrated that AIF2 retards dark-triggered and brassinosteroid (BR)-induced leaf senescence in Arabidopsis thaliana. Dark-triggered BR synthesis and the subsequent activation of BRASSINAZOLE RESISTANT 1 (BZR1), a BR signaling positive regulator, result in BZR1 binding to the AIF2 promoter in a dark-dependent manner, reducing AIF2 transcript levels and accelerating senescence. BR-induced down-regulation of AIF2 protein stability partly contributes to the progression of dark-induced leaf senescence. Furthermore, AIF2 interacts with INDUCER OF CBF EXPRESSION 1 (ICE1) via their C-termini. Formation of the AIF2-ICE1 complex and subsequent up-regulation of C-REPEAT BINDING FACTORs (CBFs) negatively regulates dark-triggered, BR-induced leaf senescence. This involves antagonistic down-regulation of PHYTOCHROME INTERACTING FACTOR 4 (PIF4), modulated through AIF2-dependent inhibition of ICE1's binding to the promoter. PIF4-dependent activities respond to dark-induced early senescence and may promote BR synthesis and BZR1 activation to suppress AIF2 and accelerate dark-induced senescence. Taken together, these findings suggest a coordination of AIF2 and ICE1 functions in maintaining stay-green traits.
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Affiliation(s)
- Yoon Kim
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
| | - Seon-U Park
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
| | - Dong-Min Shin
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
| | - Giang Pham
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
| | - You Seung Jeong
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
| | - Soo-Hwan Kim
- Division of Biological Science and Technology, Yonsei University, Wonju-Si, Republic of Korea
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StABI5 Involved in the Regulation of Chloroplast Development and Photosynthesis in Potato. Int J Mol Sci 2020; 21:ijms21031068. [PMID: 32041112 PMCID: PMC7036812 DOI: 10.3390/ijms21031068] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/30/2020] [Accepted: 02/04/2020] [Indexed: 01/04/2023] Open
Abstract
Abscisic acid (ABA) insensitive 5 (ABI5)—a core transcription factor of the ABA signaling pathway—is a basic leucine zipper transcription factor that plays a key role in the regulation of seed germination and early seedling growth. ABI5 interacts with other phytohormone signals to regulate plant growth and development, and stress responses in Arabidopsis, but little is known about the functions of ABI5 in potatoes. Here, we find that StABI5 is involved in the regulation of chloroplast development and photosynthesis. Genetic analysis indicates that StABI5 overexpression transgenic potato lines accelerate dark-induced leaf yellowing and senescence. The chlorophyll contents of overexpressed StABI5 transgenic potato lines were significantly decreased in comparison to those of wild-type Desiree potatoes under dark conditions. Additionally, the RNA-sequencing (RNA-seq) analysis shows that many metabolic processes are changed in overexpressed StABI5 transgenic potatoes. Most of the genes involved in photosynthesis and carbon fixation are significantly down-regulated, especially the chlorophyll a-b binding protein, photosystem I, and photosystem II. These observations indicate that StABI5 negatively regulates chloroplast development and photosynthesis, and provides some insights into the functions of StABI5 in regard to potato growth.
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Guo J, Li H, Zhou C, Yang Y. Effects of Flag Leaf and Number of Vegetative Ramets on Sexual Reproductive Performance in the Clonal Grass Leymus chinensis. FRONTIERS IN PLANT SCIENCE 2020; 11:534278. [PMID: 33193474 PMCID: PMC7661390 DOI: 10.3389/fpls.2020.534278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 10/12/2020] [Indexed: 05/16/2023]
Abstract
Sexual reproduction is vital for population adaptation in clonal plants. The flag leaf is considered to be the primary contributor to sexual reproduction in cereal crops, and there is no unified conclusion on the effect of the number of vegetative ramets on grain yield. However, what effects of the flag leaf and the number of vegetative ramets on sexual reproductive performance of clonal grasses are largely unknown. To test this, under field natural conditions, we grew the rhizomatous grass Leymus chinensis in a homogeneous environment and conducted studies concerning the growth, reproduction and physiology of reproductive ramets in clonal populations. We measured the growth characteristics of different aged leaves, dynamically measured the net photosynthetic rate of different aged leaves and organ biomass, measured the sexual reproductive characteristics of reproductive ramets that had different numbers of connecting vegetative ramets, and performed isotope (15N) labeling of ramet pairs at the seed-filling stage. In L. chinensis clonal populations, from the heading stage, the photosynthetic contribution of the functional leaves to seed production was much greater than that of the flag leaf; the photosynthetic capacity of both the functional leaves and the flag leaf all gradually declined. Vegetative ramets translocated their own resources to the connected reproductive ramets, and a large proportion of translocated resources were allocated to the leaf and stem to sustain life activities; increase in the number of connecting vegetative ramets increased floret number, seed number, seed-setting rate, inflorescence biomass, seed biomass, and reproductive allocation of reproductive ramets, and these parameters significantly and positively correlated with the biomass of connecting vegetative ramets. We conclude that the functional leaf rather than the flag leaf of L. chinensis is the primary contributor to seed production. Reproductive ramets adopt a strategy of growth first and reproduction later to allocate the translocated resources between the organs, but vegetative ramets are very advantageous for sexual reproduction under the tillering node connection form in L. chinensis. Overall, our study implies that vegetative ramets not only play an important role in the spatial expansion but also in the sexual reproduction of clonal plant populations.
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Affiliation(s)
- Jian Guo
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
| | - Haiyan Li
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
- *Correspondence: Haiyan Li,
| | - Chan Zhou
- School of Life Sciences, Liaoning University, Shenyang, China
| | - Yunfei Yang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China
- Yunfei Yang,
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49
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Woodson JD. Chloroplast stress signals: regulation of cellular degradation and chloroplast turnover. CURRENT OPINION IN PLANT BIOLOGY 2019; 52:30-37. [PMID: 31442733 DOI: 10.1016/j.pbi.2019.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 06/02/2019] [Accepted: 06/05/2019] [Indexed: 05/11/2023]
Abstract
For 40 years, it has been known that chloroplasts signal to the nucleus and the cell to coordinate gene expression, maximize photosynthesis, and avoid stress. However, the signaling mechanisms have been challenging to uncover due to the complexity of these signals and the stresses that induce them. New research has shown that many signals are induced by singlet oxygen, a natural by-product of inefficient photosynthesis. Chloroplast singlet oxygen not only regulates nuclear gene expression, but also cellular degradation and cell death. Stressed chloroplasts also induce post-translational mechanisms, including autophagy, that allows individual chloroplasts to regulate their own degradation and turnover. Such chloroplast quality control pathways may allow cells to maintain healthy populations of chloroplasts and to avoid cumulative photo-oxidative stress in stressful environments.
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Affiliation(s)
- Jesse D Woodson
- University of Arizona, School of Plant Sciences, 303 Forbes Hall, 1140 E. South Campus Drive, Tucson, AZ 85721-0036, United States.
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50
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Bovet L, Cheval C, Hilfiker A, Battey J, Langlet D, Broye H, Schwaar J, Ozelley P, Lang G, Bakaher N, Laparra H, Goepfert S. Asparagine Synthesis During Tobacco Leaf Curing. PLANTS 2019; 8:plants8110492. [PMID: 31718005 PMCID: PMC6918383 DOI: 10.3390/plants8110492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/01/2019] [Accepted: 11/05/2019] [Indexed: 12/22/2022]
Abstract
Senescence is a genetically controlled mechanism that modifies leaf chemistry. This involves significant changes in the accumulation of carbon- and nitrogen-containing compounds, including asparagine through the activity of asparagine synthetases. These enzymes are required for nitrogen re-assimilation and remobilization in plants; however, their mechanisms are not fully understood. Here, we report how leaf curing—a senescence-induced process that allows tobacco leaves to dry out—modifies the asparagine metabolism. We show that leaf curing strongly alters the concentration of the four main amino acids, asparagine, glutamine, aspartate, and glutamate. We demonstrate that detached tobacco leaf or stalk curing has a different impact on the expression of asparagine synthetase genes and accumulation of asparagine. Additionally, we characterize the main asparagine synthetases involved in the production of asparagine during curing. The expression of ASN1 and ASN5 genes is upregulated during curing. The ASN1-RNAi and ASN5-RNAi tobacco plant lines display significant alterations in the accumulation of asparagine, glutamine, and aspartate relative to wild-type plants. These results support the idea that ASN1 and ASN5 are key regulators of asparagine metabolism during leaf curing.
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