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Hao Q, Li T, Lu G, Wang S, Li Z, Gu C, Kong F, Shu Q, Li Y. Chlorophyllase (PsCLH1) and light-harvesting chlorophyll a/b binding protein 1 (PsLhcb1) and PsLhcb5 maintain petal greenness in Paeonia suffruticosa 'Lv Mu Yin Yu'. J Adv Res 2024:S2090-1232(24)00388-6. [PMID: 39236974 DOI: 10.1016/j.jare.2024.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 08/01/2024] [Accepted: 09/01/2024] [Indexed: 09/07/2024] Open
Abstract
INTRODUCTION Green flowers are not an adaptive trait in natural plants due to the challenge for pollinators to discriminate from leaves, but they are valuable in horticulture. The molecular mechanisms of green petals remain unclear. Tree peony (Paeonia suffruticosa) is a globally cultivated ornamental plant and considered the 'King of Flowers' in China. The P. suffruticosa 'Lv Mu Yin Yu (LMYY)' cultivar with green petals could be utilized as a representative model for understanding petal-specific chlorophyll (Chl) accumulation and color formation. OBJECTIVES Identify the key genes related to Chl metabolism and understand the molecular mechanism of petal color changes. METHODS The petal color parameter was analyzed at five developmental stages using a Chroma Spectrophotometer, and Chl and anthocyanin accumulation patterns were examined. Based on comparative transcriptomes, differentially expressed genes (DEGs) were identified, among which three were functionally characterized through overexpression in tobacco plants or silencing in 'LMYY' petals. RESULTS During flower development and blooming, flower color changed from green to pale pink, consistent with the Chl and anthocyanin levels. The level of Chl demonstrated a similar pattern with petal epidermal cell striation density. The DEGs responsible for Chl and anthocyanin metabolism were characterized through a comparative transcriptome analysis of flower petals over three critical developmental stages. The key chlorophyllase (PsCLH1) and light-harvesting chlorophyll a/b binding protein 1 (PsLhcb1) and PsLhcb5 influenced the Chl accumulation and the greenness of 'LMYY' petals. CONCLUSION PsCLH1, PsLhcb1, and PsLhcb5 were critical in accumulating the Chl and maintaining the petal greenness. Flower color changes from green to pale pink were regulated by the homeostasis of Chl degradation and anthocyanin biosynthesis. This study offers insights into underlying molecular mechanisms in the green petal and a strategy for germplasm innovation.
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Affiliation(s)
- Qing Hao
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.
| | - Tongtong Li
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.
| | - Gaojie Lu
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.
| | - Shuo Wang
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.
| | - Zhen Li
- College of Agricultural Science and Engineering, Liaocheng University, Liaocheng 252000, China.
| | - Cancan Gu
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao 266109, China.
| | - Fan Kong
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qingyan Shu
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yang Li
- State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China.
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Kim M, Hyeon DY, Kim K, Hwang D, Lee Y. Phytohormonal regulation determines the organization pattern of shoot aerenchyma in greater duckweed (Spirodela polyrhiza). PLANT PHYSIOLOGY 2024; 195:2694-2711. [PMID: 38527800 PMCID: PMC11288743 DOI: 10.1093/plphys/kiae173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/27/2024]
Abstract
Airspace or aerenchyma is crucial for plant development and acclimation to stresses such as hypoxia, drought, and nutritional deficiency. Although ethylene-mediated signaling cascades are known to regulate aerenchyma formation in stems and roots under hypoxic conditions, the precise mechanisms remain unclear. Moreover, the cellular dynamics underlying airspace formation in shoots are poorly understood. We investigated the stage-dependent structural dynamics of shoot aerenchyma in greater duckweed (Spirodela polyrhiza), a fast-growing aquatic herb with well-developed aerenchyma in its floating fronds. Using X-ray micro-computed tomography and histological analysis, we showed that the spatial framework of aerenchyma is established before frond volume increases, driven by cell division and expansion. The substomatal cavity connecting aerenchyma to stomata formed via programmed cell death (PCD) and was closely associated with guard cell development. Additionally, transcriptome analysis and pharmacological studies revealed that the organization of aerenchyma in greater duckweed is determined by the interplay between PCD and proliferation. This balance is governed by spatiotemporal regulation of phytohormone signaling involving ethylene, abscisic acid, and salicylic acid. Overall, our study reveals the structural dynamics and phytohormonal regulation underlying aerenchyma development in duckweed, improving our understanding of how plants establish distinct architectural arrangements. These insights hold the potential for wide-ranging application, not only in comprehending aerenchyma formation across various plant species but also in understanding how airspaces are formed within the leaves of terrestrial plants.
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Affiliation(s)
- Min Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Do Young Hyeon
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyungyoon Kim
- Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Daehee Hwang
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Bioinformatics Institute, Bio-MAX, Seoul National University, Seoul 08826, Republic of Korea
| | - Yuree Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Republic of Korea
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Ma Y, Sun J, Zhang X, Sadaqat M, Tahir Ul Qamar M, Liu T. Comparative genomics analysis of pheophorbide a oxygenase ( PAO) genes in eight pyrus genomes and their regulatory role in multiple stress responses in Chinese pear ( Pyrus bretschneideri). Front Genet 2024; 15:1396744. [PMID: 38689648 PMCID: PMC11058654 DOI: 10.3389/fgene.2024.1396744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 04/02/2024] [Indexed: 05/02/2024] Open
Abstract
Pyrus (pear) is among the most nutritious fruits and contains fibers that have great health benefits to humans. It is mostly cultivated in temperate regions globally and is highly subjected to biotic and abiotic stresses which affect its yield. Pheophorbide a oxygenase (PAO) is an essential component of the chlorophyll degradation system and contributes to the senescence of leaves. It is responsible for opening the pheophorbide a porphyrin macrocycle and forming the main fluorescent chlorophyll catabolite However, this gene family and its members have not been explored in Pyrus genomes. Here we report a pangenome-wide investigation has been conducted on eight Pyrus genomes: Cuiguan, Shanxi Duli, Zhongai 1, Nijisseiki, Yunhong No.1, d'Anjou, Bartlett v2.0, and Dangshansuli v.1.1. The phylogenetic history, their gene structure, conservation patterns of motifs, their distribution on chromosomes, and gene duplication are studied in detail which shows the intraspecific structural conservation as well as evolutionary patterns of Pyrus PAOs. Cis-elements, protein-protein interactions (PPI), and the Gene Ontology (GO) enrichment analyses show their potential biological functions. Furthermore, their expression in various tissues, fruit hardening conditions, and drought stress conditions is also studied. Based on phylogenetics, the identified PAOs were divided into four groups. The expansion of this gene family in Pyrus is caused by both tandem and segmental duplication. Moreover, positive and negative selection pressure equally directed the gene's duplication process. The Pyrus PAO genes were enriched in hormones-related, light, development, and stress-related elements. RNA-seq data analysis showed that PAOs have varied levels of expression under diseased and abiotic stress conditions. The 3D structures of PAOs are also predicted to get more insights into functional conservation. Our research can be used further to get a deeper knowledge of the PAO gene family in Pyrus and to guide future research on improving the genetic composition of Pyrus to enhance stress tolerance.
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Affiliation(s)
- Yuchen Ma
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
| | - Jiao Sun
- Engineering Research Center of Coal-Based Ecological Carbon Sequestration Technology of the Ministry of Education, Shanxi Datong University, Datong, China
- Key Laboratory of Graphene Forestry Application of National Forest and Grass Administration, Shanxi Datong University, Datong, China
| | - Xiao Zhang
- Engineering Research Center of Coal-Based Ecological Carbon Sequestration Technology of the Ministry of Education, Shanxi Datong University, Datong, China
- Key Laboratory of Graphene Forestry Application of National Forest and Grass Administration, Shanxi Datong University, Datong, China
| | - Muhammad Sadaqat
- Integrative Omics and Molecular Modeling Laboratory, Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad, Pakistan
| | - Muhammad Tahir Ul Qamar
- Integrative Omics and Molecular Modeling Laboratory, Department of Bioinformatics and Biotechnology, Government College University Faisalabad (GCUF), Faisalabad, Pakistan
| | - Tingting Liu
- College of Horticulture, Shanxi Agricultural University, Jinzhong, China
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Xiong B, Li L, Li Q, Mao H, Wang L, Bie Y, Zeng X, Liao L, Wang X, Deng H, Zhang M, Sun G, Wang Z. Identification of Photosynthesis Characteristics and Chlorophyll Metabolism in Leaves of Citrus Cultivar ( Harumi) with Varying Degrees of Chlorosis. Int J Mol Sci 2023; 24:ijms24098394. [PMID: 37176103 PMCID: PMC10179384 DOI: 10.3390/ijms24098394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/22/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
In autumn and spring, citrus leaves with a Ponkan (Citrus reticulata Blanco cv. Ponkan) genetic background (Harumi, Daya, etc.) are prone to abnormal physiological chlorosis. The effects of different degrees of chlorosis (normal, mild, moderate and severe) on photosynthesis and the chlorophyll metabolism of leaves of Citrus cultivar (Harumi) were studied via field experiment. Compared with severe chlorotic leaves, the results showed that chlorosis could break leaf metabolism balance, including reduced chlorophyll content, photosynthetic parameters, antioxidant enzyme activity and enzyme activity related to chlorophyll synthesis, increased catalase and decreased enzyme activity. In addition, the content of chlorophyll synthesis precursors showed an overall downward trend expected for uroporphyrinogen III. Furthermore, the relative expression of genes for chlorophyll synthesis (HEMA1, HEME2, HEMG1 and CHLH) was down-regulated to some extent and chlorophyll degradation (CAO, CLH, PPH, PAO and SGR) showed the opposite trend with increased chlorosis. Changes in degradation were more significant. In general, the chlorosis of Harumi leaves might be related to the blocked transformation of uroporphyrinogen III (Urogen III) to coproporphyrinogen III (Coprogen III), the weakening of antioxidant enzyme system activity, the weakening of chlorophyll synthesis and the enhancement in degradation.
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Affiliation(s)
- Bo Xiong
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Li
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Qin Li
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Huiqiong Mao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixinyi Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuhui Bie
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Xin Zeng
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Liao
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Xun Wang
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Honghong Deng
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingfei Zhang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Guochao Sun
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhihui Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
- Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China
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Singh DP, Bisen MS, Prabha R, Maurya S, Yerasu SR, Shukla R, Tiwari JK, Chaturvedi KK, Farooqi MS, Srivastava S, Rai A, Sarma BK, Rai N, Singh PM, Behera TK, Farag MA. Untargeted Metabolomics of Alternaria solani-Challenged Wild Tomato Species Solanum cheesmaniae Revealed Key Metabolite Biomarkers and Insight into Altered Metabolic Pathways. Metabolites 2023; 13:585. [PMID: 37233626 PMCID: PMC10220610 DOI: 10.3390/metabo13050585] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 05/27/2023] Open
Abstract
Untargeted metabolomics of moderately resistant wild tomato species Solanum cheesmaniae revealed an altered metabolite profile in plant leaves in response to Alternaria solani pathogen. Leaf metabolites were significantly differentiated in non-stressed versus stressed plants. The samples were discriminated not only by the presence/absence of specific metabolites as distinguished markers of infection, but also on the basis of their relative abundance as important concluding factors. Annotation of metabolite features using the Arabidopsis thaliana (KEGG) database revealed 3371 compounds with KEGG identifiers belonging to biosynthetic pathways including secondary metabolites, cofactors, steroids, brassinosteroids, terpernoids, and fatty acids. Annotation using the Solanum lycopersicum database in PLANTCYC PMN revealed significantly upregulated (541) and downregulated (485) features distributed in metabolite classes that appeared to play a crucial role in defense, infection prevention, signaling, plant growth, and plant homeostasis to survive under stress conditions. The orthogonal partial least squares discriminant analysis (OPLS-DA), comprising a significant fold change (≥2.0) with VIP score (≥1.0), showed 34 upregulated biomarker metabolites including 5-phosphoribosylamine, kaur-16-en-18-oic acid, pantothenate, and O-acetyl-L-homoserine, along with 41 downregulated biomarkers. Downregulated metabolite biomarkers were mapped with pathways specifically known for plant defense, suggesting their prominent role in pathogen resistance. These results hold promise for identifying key biomarker metabolites that contribute to disease resistive metabolic traits/biosynthetic routes. This approach can assist in mQTL development for the stress breeding program in tomato against pathogen interactions.
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Affiliation(s)
| | | | - Ratna Prabha
- ICAR-Indian Agricultural Statistics Research Institute, Library Avenue, New Delhi 110012, India
| | - Sudarshan Maurya
- ICAR-Indian Institute of Vegetable Research, Varanasi 221305, India
| | | | - Renu Shukla
- Indian Council of Agricultural Research, New Delhi 110012, India
| | | | | | - Md. Samir Farooqi
- ICAR-Indian Agricultural Statistics Research Institute, Library Avenue, New Delhi 110012, India
| | - Sudhir Srivastava
- ICAR-Indian Agricultural Statistics Research Institute, Library Avenue, New Delhi 110012, India
| | - Anil Rai
- ICAR-Indian Agricultural Statistics Research Institute, Library Avenue, New Delhi 110012, India
| | - Birinchi Kumar Sarma
- Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Nagendra Rai
- ICAR-Indian Institute of Vegetable Research, Varanasi 221305, India
| | | | | | - Mohamed A. Farag
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo 11562, Egypt
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Assessment of the Molecular Responses of an Ancient Angiosperm against Atypical Insect Oviposition: The Case of Hass Avocados and the Tephritid Fly Anastrepha ludens. Int J Mol Sci 2023; 24:ijms24032060. [PMID: 36768387 PMCID: PMC9916504 DOI: 10.3390/ijms24032060] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Anastrepha spp. (Diptera: Tephritidae) infestations cause significant economic losses in commercial fruit production worldwide. However, some plants quickly counteract the insertion of eggs by females by generating neoplasia and hindering eclosion, as is the case for Persea americana Mill., cv. Hass (Hass avocados). We followed a combined transcriptomics/metabolomics approach to identify the molecular mechanisms triggered by Hass avocados to detect and react to the oviposition of the pestiferous Anastrepha ludens (Loew). We evaluated two conditions: fruit damaged using a sterile pin (pin) and fruit oviposited by A. ludens females (ovi). We evaluated both of the conditions in a time course experiment covering five sampling points: without treatment (day 0), 20 min after the treatment (day 1), and days 3, 6, and 9 after the treatment. We identified 288 differentially expressed genes related to the treatments. Oviposition (and possibly bacteria on the eggs' surface) induces a plant hypersensitive response (HR), triggering a chitin receptor, producing an oxidative burst, and synthesizing phytoalexins. We also observed a process of cell wall modification and polyphenols biosynthesis, which could lead to polymerization in the neoplastic tissue surrounding the eggs.
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7
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Dey D, Nishijima M, Tanaka R, Kurisu G, Tanaka H, Ito H. Crystal structure and reaction mechanism of a bacterial Mg-dechelatase homolog from the Chloroflexi Anaerolineae. Protein Sci 2022; 31:e4430. [PMID: 36173179 PMCID: PMC9514216 DOI: 10.1002/pro.4430] [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: 07/04/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/05/2022]
Abstract
Chlorophyll degradation plays a myriad of physiological roles in photosynthetic organisms, including acclimation to light environment and nutrient remobilization during senescence. Mg extraction from chlorophyll a is the first and committed step of the chlorophyll degradation pathway. This reaction is catalyzed by the Mg-dechelatase enzyme encoded by Stay-Green (SGR). The reaction mechanism of SGR protein remains elusive since metal ion extraction from organic molecules is not a common enzymatic reaction. Additionally, experimentally derived structural information about SGR or its homologs has not yet been reported. In this study, the crystal structure of the SGR homolog from Anaerolineae bacterium was determined using the molecular replacement method at 1.85 Å resolution. Our previous study showed that three residues-H32, D34, and D62 are essential for the catalytic activity of the enzyme. Biochemical analysis involving mutants of D34 residue further strengthened its importance in the functioning of the dechelatase. Docking simulation also revealed the interaction between the D34 side chain and central Mg ion of chlorophyll a. Structural analysis showed the arrangement of D34/H32/D62 in the form of a catalytic triad that is generally found in hydrolases. The probable reaction mechanism suggests that deprotonated D34 side chain coordinates and destabilizes Mg, resulting in Mg extraction. Besides, H32 possibly acts as a general base catalyst and D62 facilitates H32 to be a better proton acceptor. Taken together, the reaction mechanism of SGR partially mirrors the one observed in hydrolases.
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Affiliation(s)
- Debayan Dey
- Graduate School of Life ScienceHokkaido UniversitySapporoJapan
- Institute of Low Temperature ScienceHokkaido UniversitySapporoJapan
| | | | - Ryouichi Tanaka
- Institute of Low Temperature ScienceHokkaido UniversitySapporoJapan
| | - Genji Kurisu
- Institute for Protein ResearchOsaka UniversitySuitaJapan
| | - Hideaki Tanaka
- Institute for Protein ResearchOsaka UniversitySuitaJapan
| | - Hisashi Ito
- Institute of Low Temperature ScienceHokkaido UniversitySapporoJapan
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Hauenstein M, Hörtensteiner S, Aubry S. Side-chain modifications of phyllobilins may not be essential for chlorophyll degradation in Arabidopsis. PLANT DIRECT 2022; 6:e441. [PMID: 36035897 PMCID: PMC9399834 DOI: 10.1002/pld3.441] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 05/27/2023]
Abstract
Disposing efficiently and safely chlorophyll derivatives during senescence requires a coordinated pathway that is well conserved throughout green plants. The PAO/phyllobilin pathway catalyzes the degradation of the chlorophyll during senescence and allows detoxification of the pigment and its subsequent export from the chloroplast. Although most of the chloroplastic reactions involved in chlorophyll degradation are well understood, the diversity of enzymes responsible for downstream modifications of non-phototoxic phyllobilins remains to be explored. More than 40 phyllobilins have been described to date, but only three enzymes catalyzing side-chain reactions have been identified in Arabidopsis thaliana, namely, TIC55, CYP89A9, and MES16. Here, by generating a triple mutant, we evaluate the extent to which these enzymes are influencing the rate and amplitude of chlorophyll degradation at the metabolite as well as its regulation at the transcriptome level. Our data show that major side-chain modifications of phyllobilins do not influence significantly chlorophyll degradation or leaf senescence, letting the physiological relevance of their striking diversity an open question.
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Affiliation(s)
- Mareike Hauenstein
- Department of Plant and Microbial BiologyUniversity of ZürichZürichSwitzerland
| | | | - Sylvain Aubry
- Department of Plant and Microbial BiologyUniversity of ZürichZürichSwitzerland
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Li J, Chen M, Fan T, Mu X, Gao J, Wang Y, Jing T, Shi C, Niu H, Zhen S, Fu J, Zheng J, Wang G, Tang J, Gou M. Underlying mechanism of accelerated cell death and multiple disease resistance in a maize lethal leaf spot 1 allele. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3991-4007. [PMID: 35303096 DOI: 10.1093/jxb/erac116] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Multiple disease resistance (MDR) in maize has attracted increasing attention. However, the interplay between cell death and metabolite changes and their contributions to MDR remains elusive in maize. In this study, we identified a mutant named as lesion mimic 30 (les30) that showed 'suicidal' lesion formation in the absence of disease and had enhanced resistance to the fungal pathogen Curvularia lunata. Using map-based cloning, we identified the causal gene encoding pheophorbide a oxidase (PAO), which is known to be involved in chlorophyll degradation and MDR, and is encoded by LETHAL LEAF SPOT1 (LLS1). LLS1 was found to be induced by both biotic and abiotic stresses. Transcriptomics analysis showed that genes involved in defense responses and secondary metabolite biosynthesis were mildly activated in leaves of the les30 mutant without lesions, whilst they were strongly activated in leaves with lesions. In addition, in les30 leaves with lesions, there was overaccumulation of defense-associated phytohormones including jasmonic acid and salicylic acid, and of phytoalexins including phenylpropanoids, lignin, and flavonoids, suggesting that their biosynthesis was activated in a lesion-dependent manner. Taken together, our study implies the existence of an interactive amplification loop of interrupted chlorophyll degradation, cell death, expression of defense-related genes, and metabolite changes that results in suicidal lesion formation and MDR, and this has the potential to be exploited by genetic manipulation to improve maize disease resistance.
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Affiliation(s)
- Jiankun Li
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Mengyao Chen
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Tianyuan Fan
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xiaohuan Mu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Jie Gao
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Ying Wang
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Teng Jing
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Cuilan Shi
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Hongbin Niu
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Sihan Zhen
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Junjie Fu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jun Zheng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Guoying Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jihua Tang
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
- The Shennong Laboratory, Zhengzhou, Henan 450002, China
| | - Mingyue Gou
- State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
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Zhang J, Li H, Huang X, Xing J, Yao J, Yin T, Jiang J, Wang P, Xu B. STAYGREEN-mediated chlorophyll a catabolism is critical for photosystem stability during heat-induced leaf senescence in perennial ryegrass. PLANT, CELL & ENVIRONMENT 2022; 45:1412-1427. [PMID: 35192197 DOI: 10.1111/pce.14296] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/23/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
Suppression of the chlorophyll a (Chl a) Mg-dechelatase gene, SGR/NYE1, blocks the degradation of Chl a, resulting in a 'stay-green' trait. In this study, we investigated the effect of Chl a catabolism on plant heat-induced leaf senescence in perennial ryegrass (Lolium perenne L.). Under heat stress, the LpSGR-RNAi lines not only lost the stay-green phenotype but also showed accelerated leaf senescence with increased chloroplast disruption, more loss of photosystem (PS) proteins, lower PSⅡ quantum yields, higher levels of energy dissipation, increased accumulation of reactive oxygen species (ROS) and lower ROS-scavenging enzyme activities. Transcriptome analysis revealed that the suppression of LpSGR downregulated genes encoding PS proteins and ROS-scavenging enzymes and upregulated those encoding ROS-generation enzymes under heat stress. To account for the possible side-effects resulting from constitutive suppression of LpSGR on plant growth and heat tolerance, we constructed an ethanol-inducible RNAi vector to suppress LpSGR functions. In the absence of ethanol induction, these lines exhibited the same growth and heat tolerance as the wildtype (WT). Upon ethanol induction, the transgenic lines showed compromised heat tolerance and a postharvest stay-green phenotype. Taken together, SGR-mediated Chl a catabolism is required for plant heat tolerance.
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Affiliation(s)
- Jing Zhang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Hui Li
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Xinru Huang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jing Xing
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jiaming Yao
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Tingchao Yin
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jiafu Jiang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture and Rural Affairs, Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Puchang Wang
- Guizhou Institute of Prataculture, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou, China
| | - Bin Xu
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
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11
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Yu Y, Zhang Q, Sun S, Yang J. Upregulated expression of RESPIRATORY BURST OXIDASE HOMOLOG D underlies lesion-mimic phenotype in dark-treated Arabidopsis pheide a oxygenase mutant leaves. PLANTA 2022; 255:110. [PMID: 35471712 DOI: 10.1007/s00425-022-03895-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Upregulated expression of RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD) encoding a plasma membrane NADPH oxidase is responsible for the lesion-mimic phenotype in detached Arabidopsis leaves with mutation of PHEIDE a OXYGENASE during extended darkness. Chlorophyll degradation is an indispensable process in leaf senescence, either age-dependent or dark-induced. Besides higher chlorophyll retention, a lesion-mimic phenotype (abbreviated as LMP afterwards) was exhibited in Arabidopsis leaves with mutation of PHEIDE a OXYGENASE (PaO) involved in chlorophyll degradation during dark incubation, but the associated mechanism remains elusive. We found that dark-treated pao leaves showed higher membrane damage and H2O2 accumulation, while scavenging H2O2 by its chemical scavenger diminished LMP. RBOHD which encodes NADPH oxidase was strikingly up-regulated in pao leaves during dark treatment. Chemical inhibition of NADPH oxidase or mutation of RBOHD in pao leaves suppressed LMP. Thus, our study suggests that up-regulated RBOHD transcription is responsible for the formation of LMP in dark-treated pao leaves and there may be a retrograde signaling pathway mediating upregulation of RBOHD which remains to be elucidated.
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Affiliation(s)
- Yongfan Yu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Qiang Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Sujing Sun
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Jiading Yang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China.
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12
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Schumacher I, Menghini D, Ovinnikov S, Hauenstein M, Fankhauser N, Zipfel C, Hörtensteiner S, Aubry S. Evolution of chlorophyll degradation is associated with plant transition to land. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:1473-1488. [PMID: 34931727 PMCID: PMC9306834 DOI: 10.1111/tpj.15645] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/09/2021] [Accepted: 12/15/2021] [Indexed: 05/27/2023]
Abstract
Chlorophyll, the central pigment of photosynthesis, is highly photo‐active and degraded enzymatically during leaf senescence. Merging comparative genomics and metabolomics, we evaluate the extent to which the chlorophyll detoxification pathway has evolved in Viridiplantae. We argue that cytosolic detoxification of phyllobilins in particular was a critical process to the green lineage’s transition to land.
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Affiliation(s)
- Isabel Schumacher
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Damian Menghini
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Serguei Ovinnikov
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Mareike Hauenstein
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Niklaus Fankhauser
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Cyril Zipfel
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Stefan Hörtensteiner
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
| | - Sylvain Aubry
- Department of Plant and Microbial BiologyUniversity of ZürichZürich8008Switzerland
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13
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Zhao Y, Xu W, Wang L, Han S, Zhang Y, Liu Q, Liu B, Zhao X. A Maize Necrotic Leaf Mutant Caused by Defect of Coproporphyrinogen III Oxidase in the Porphyrin Pathway. Genes (Basel) 2022; 13:genes13020272. [PMID: 35205317 PMCID: PMC8872553 DOI: 10.3390/genes13020272] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
Lesion mimic mutants provide ideal genetic materials for elucidating the molecular mechanism of cell death and disease resistance. The maize necrotic leaf mutant (nec-t) is a recessive mutant with necrotic spots and yellow-green leaves. In this study, we found that nec-t was a light and temperature-dependent mutant. Map-based cloning and the allelic test revealed that nec-t was a novel allelic mutant of the Necrotic4 gene. Necrotic4 encodes the coproporphyrinogen III oxidase (CPX1), a key enzyme in the tetrapyrrole pathway, catalyzing coproporphyrinogen III oxidate to protoporphyrinogen IX. Subcellular localization showed that the necrotic4 protein was localized in the chloroplast. Furthermore, RNA-seq analysis showed that the Necrotic4 mutation caused the enhanced chlorophyll degradation and reactive oxygen species (ROS) response. The mechanism of plant lesion formation induced by light and temperature is not clear. Our research provides a basis for understanding the molecular mechanism of necrosis initiation in maize.
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Affiliation(s)
- Yan Zhao
- College of Life Sciences/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China;
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
| | - Wei Xu
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
| | - Lijing Wang
- College of Life Sciences, De Zhou University, Dezhou 253023, China;
| | - Shuai Han
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
| | - Yongzhong Zhang
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
| | - Qingzhi Liu
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
| | - Baoshen Liu
- College of Agronomy/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China; (W.X.); (S.H.); (Y.Z.); (Q.L.)
- Correspondence: (B.L.); (X.Z.); Tel.: +86-0538-8242226 (B.L. & X.Z.)
| | - Xiangyu Zhao
- College of Life Sciences/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China;
- Correspondence: (B.L.); (X.Z.); Tel.: +86-0538-8242226 (B.L. & X.Z.)
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14
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Research Progress in the Interconversion, Turnover and Degradation of Chlorophyll. Cells 2021; 10:cells10113134. [PMID: 34831365 PMCID: PMC8621299 DOI: 10.3390/cells10113134] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/06/2021] [Accepted: 11/08/2021] [Indexed: 01/01/2023] Open
Abstract
Chlorophylls (Chls, Chl a and Chl b) are tetrapyrrole molecules essential for photosynthetic light harvesting and energy transduction in plants. Once formed, Chls are noncovalently bound to photosynthetic proteins on the thylakoid membrane. In contrast, they are dismantled from photosystems in response to environmental changes or developmental processes; thus, they undergo interconversion, turnover, and degradation. In the last twenty years, fruitful research progress has been achieved on these Chl metabolic processes. The discovery of new metabolic pathways has been accompanied by the identification of enzymes associated with biochemical steps. This article reviews recent progress in the analysis of the Chl cycle, turnover and degradation pathways and the involved enzymes. In addition, open questions regarding these pathways that require further investigation are also suggested.
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15
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Dey D, Dhar D, Fortunato H, Obata D, Tanaka A, Tanaka R, Basu S, Ito H. Insights into the structure and function of the rate-limiting enzyme of chlorophyll degradation through analysis of a bacterial Mg-dechelatase homolog. Comput Struct Biotechnol J 2021; 19:5333-5347. [PMID: 34745453 PMCID: PMC8531759 DOI: 10.1016/j.csbj.2021.09.023] [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: 08/15/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 12/13/2022] Open
Abstract
The Mg-dechelatase enzyme encoded by the Stay-Green (SGR) gene catalyzes Mg2+ dechelation from chlorophyll a. This reaction is the first committed step of chlorophyll degradation pathway in plants and is thus indispensable for the process of leaf senescence. There is no structural information available for this or its related enzymes. This study aims to provide insights into the structure and reaction mechanism of the enzyme through biochemical and computational analysis of an SGR homolog from the Chloroflexi Anaerolineae (AbSGR-h). Recombinant AbSGR-h with its intact sequence and those with mutations were overexpressed in Escherichia coli and their Mg-dechelatase activity were compared. Two aspartates - D34 and D62 were found to be essential for catalysis, while R26, Y28, T29 and D114 were responsible for structural maintenance. Gel filtration analysis of the recombinant AbSGR-h indicates that it forms a homo-oligomer. The three-dimensional structure of AbSGR-h was predicted by a deep learning-based method, which was evaluated by protein structure quality evaluation programs while structural stability of wild-type and mutant forms were investigated through molecular dynamics simulations. Furthermore, in concordance with the results of enzyme assay, molecular docking concluded the significance of D34 in ligand interaction. By combining biochemical analysis and computational prediction, this study unveils the detailed structural characteristics of the enzyme, including the probable pocket of interaction and the residues of structural and functional importance. It also serves as a basis for further studies on Mg-dechelatase such as elucidation of its reaction mechanism or inhibitor screening.
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Affiliation(s)
- Debayan Dey
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.,Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Dipanjana Dhar
- Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.,Department of Natural History Sciences, Hokkaido University, Sapporo 060-0810, Japan
| | - Helena Fortunato
- Department of Natural History Sciences, Hokkaido University, Sapporo 060-0810, Japan
| | - Daichi Obata
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Soumalee Basu
- Department of Microbiology, University of Calcutta, Kolkata 700019, India
| | - Hisashi Ito
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
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16
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Bhatt M, Pandey SS, Tiwari AK, Tiwari BS. Plastid-mediated singlet oxygen in regulated cell death. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:686-694. [PMID: 33768665 DOI: 10.1111/plb.13260] [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: 10/28/2020] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Reactive oxygen species (ROS) generation within a cell is a natural process of specific subcellular components involved in redox reactions. Within a plant cell, chloroplasts are one of the major sources of ROS generation. Plastid-generated ROS molecules include singlet oxygen (1 O2 ), superoxide radical (O2 - ), hydroxyl radical (OH• ) and hydrogen peroxide (H2 O2 ), which are produced mainly during photochemical reactions of photosynthesis and chlorophyll biosynthetic process. Under normal growth and developmental, generated ROS molecules act as a secondary messenger controlling several metabolic reactions; however, perturbed environmental conditions lead to multi-fold amplification of cellular ROS that eventually kill the target cell. To maintain homeostasis between production and scavenging of ROS, the cell has instituted several enzymatic and non-enzymatic antioxidant machineries to maintain ROS at a physiological level. Among chloroplastic ROS molecules, excess generation of singlet oxygen (1 O2 ) is highly deleterious to the cell metabolic functions and survival. Interestingly, within cellular antioxidant machinery, enzymes involved in detoxification of 1 O2 are lacking. Recent studies suggest that under optimal concentrations, 1 O2 acts as a signalling molecule and drives the cell to either the acclimation pathway or regulated cell death (RCD). Stress-induced RCD is a survival mechanism for the whole plant, while the involvement of chloroplasts and chloroplast-localized molecules that execute RCD are not well understood. In this review, we advocate for participation of chloroplasts-generated 1 O2 in signalling and RCD in plants.
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Affiliation(s)
- M Bhatt
- Institute of Advanced Research, Gandhinagar, Gujrat, India
| | - S S Pandey
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, H.P., India
| | - A K Tiwari
- Institute of Advanced Research, Gandhinagar, Gujrat, India
| | - B S Tiwari
- Institute of Advanced Research, Gandhinagar, Gujrat, India
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17
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Rice Lesion Mimic Mutants (LMM): The Current Understanding of Genetic Mutations in the Failure of ROS Scavenging during Lesion Formation. PLANTS 2021; 10:plants10081598. [PMID: 34451643 PMCID: PMC8400881 DOI: 10.3390/plants10081598] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 01/02/2023]
Abstract
Rice lesion mimic mutants (LMMs) form spontaneous lesions on the leaves during vegetative growth without pathogenic infections. The rice LMM group includes various mutants, including spotted leaf mutants, brown leaf mutants, white-stripe leaf mutants, and other lesion-phenotypic mutants. These LMM mutants exhibit a common phenotype of lesions on the leaves linked to chloroplast destruction caused by the eruption of reactive oxygen species (ROS) in the photosynthesis process. This process instigates the hypersensitive response (HR) and programmed cell death (PCD), resulting in lesion formation. The reasons for lesion formation have been studied extensively in terms of genetics and molecular biology to understand the pathogen and stress responses. In rice, the lesion phenotypes of most rice LMMs are inherited according to the Mendelian principles of inheritance, which remain in the subsequent generations. These rice LMM genetic traits have highly developed innate self-defense mechanisms. Thus, although rice LMM plants have undesirable agronomic traits, the genetic principles of LMM phenotypes can be used to obtain high grain yields by deciphering the efficiency of photosynthesis, disease resistance, and environmental stress responses. From these ailing rice LMM plants, rice geneticists have discovered novel proteins and physiological causes of ROS in photosynthesis and defense mechanisms. This review discusses recent studies on rice LMMs for the Mendelian inheritances, molecular genetic mapping, and the genetic definition of each mutant gene.
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18
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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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19
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Ma L, Li G. Arabidopsis FAR-RED ELONGATED HYPOCOTYL3 negatively regulates carbon starvation responses. PLANT, CELL & ENVIRONMENT 2021; 44:1816-1829. [PMID: 33715163 DOI: 10.1111/pce.14044] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 03/01/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
Light is one of the most important environmental factors that affects various cellular processes in plant growth and development; it is also crucial for the metabolism of carbohydrates as it provides the energy source for photosynthesis. Under extended darkness conditions, carbon starvation responses are triggered by depletion of stored energy. Although light rapidly inhibits starvation responses, the molecular mechanisms by which light signalling affects this process remain largely unknown. In this study, we showed that the Arabidopsis thaliana light signalling protein FAR-RED ELONGATED HYPOCOTYL3 (FHY3) and its homolog FAR-RED IMPAIRED RESPONSE1 (FAR1) are essential for plant survival after extended darkness treatment at both seedling and adult stages. Transmission electron microscopy analyses revealed that disruption of both FHY3 and FAR1 resulted in destruction of chloroplast envelopes and thylakoid membranes under extended darkness conditions. Furthermore, treatment with sucrose, but not glucose, completely rescued carbon starvation-induced cell death in the rosette leaves and arrested early seedling establishment in the fhy3 far1 plants. We thus concluded that the light signalling proteins FHY3 and FAR1 negatively regulate carbon starvation responses in Arabidopsis.
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Affiliation(s)
- Lin Ma
- School of Biological Science and Technology, University of Jinan, Jinan, China
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Gang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
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20
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Zhao X, Jia T, Hu X. HCAR Is a Limitation Factor for Chlorophyll Cycle and Chlorophyll b Degradation in Chlorophyll- b-Overproducing Plants. Biomolecules 2020; 10:E1639. [PMID: 33291365 PMCID: PMC7762049 DOI: 10.3390/biom10121639] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 11/17/2022] Open
Abstract
The chlorophyll (Chl) cycle is the metabolic pathway for Chl a and Chl b inter-conversion. In this pathway, Chl b is synthesized from Chl a by the catalyzing action of chlorophyllide a oxygenase (CAO). In contrast, Chl b is firstly reduced to produce 7-hydroxymethyl Chl (HMChl) a, which is catalyzed by two isozymes of Chl b reductase (CBR), non-yellow coloring 1 (NYC1) and NYC1-like (NOL). Subsequently, HMChl a is reduced to Chl a by HMChl a reductase (HCAR). CAO plays a pivotal role in Chl a/b ratio regulation and plants over-accumulate Chl b in CAO-overexpressing plants. NYC1 is more accumulated in Chl-b-overproducing plants, while HCAR is not changed. To investigate the role of HCAR in Chl cycle regulation, the Chl metabolites of Chl-b-overproducing plants were analyzed. The results showed that HMChl a accumulated in these plants, and it decreased and the Chl a/b ratio increased by overexpressing HCAR, implying HCAR is insufficient for Chl cycle in Chl-b-overproducing plants. Furthermore, during dark-induced senescence, the non-programmed cell death symptoms (leaves dehydrated with green color retained) of Chl-b-overproducing plants were obviously alleviated, and the content of HM pheophorbide (HMPheide) a and Pheide b were sharply decreased by overexpressing HCAR. These results imply that HCAR is also insufficient for Chl degradation in Chl-b-overproducing plants during senescence, thus causing the accumulation of Chl metabolites and non-programmed cell death of leaves. With these results taken together, we conclude that HCAR is not well regulated and it is a limiting factor for Chl cycle and Chl b degradation in Chl-b-overproducing plants.
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Affiliation(s)
- Xuan Zhao
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, China; (X.Z.); (T.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Ting Jia
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, China; (X.Z.); (T.J.)
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Xueyun Hu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, China; (X.Z.); (T.J.)
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
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21
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Nyawade S, Gitari HI, Karanja NN, Gachene CKK, Schulte-Geldermann E, Sharma K, Parker ML. Enhancing Climate Resilience of Rain-Fed Potato Through Legume Intercropping and Silicon Application. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.566345] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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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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Ekhtari S, Razeghi J, Hasanpur K, Kianianmomeni A. Different regulations of cell-type transcription by UV-B in multicellular green alga Volvox carteri. PLANT SIGNALING & BEHAVIOR 2019; 14:1657339. [PMID: 31446835 PMCID: PMC6804692 DOI: 10.1080/15592324.2019.1657339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 06/03/2023]
Abstract
There is a scarcity of research reports on the effect of ultraviolet (UV)-B radiation on genome-wide transcriptional regulation in the multicellular green microalga including Volvox carteri (V. carteri). This microalga possesses only two cell types including mortal and motile somatic cells, as well as immortal and immotile reproductive cells. Therefore, the present study evaluated the effect of low-dose UV-B radiation on the cell-type-specific gene expression pattern of reproductive and somatic cells in an asexual life cycle of V. carteri using RNA sequence method. To this end, the separated reproductive and somatic cells were treated for 1 hour at an intensity of 0.056 mW/cm-2 UV-B radiation. Then, a transcriptome analysis was conducted between the UV-B and white light treated groups in either of the cell types. Based on differential gene expression analyses, no differentially expressed genes were found in reproductive cells under the treatment as compared to the control group. This type of cell maintained its steady state. However, treating the somatic cells with UV-B radiation led to at least 126 differentially expressed genes compared to the untreated control group. In addition, the results of a direct comparison demonstrated a restricted and wide response to UV-B radiation in somatic cells as compared to reproductive cells. Based on the results, UV-B radiation could be involved in cell-type-specific regulation of biological pathways.
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Affiliation(s)
- S. Ekhtari
- Department of Plant Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - J. Razeghi
- Department of Plant Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - K. Hasanpur
- Department of Animal Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - A. Kianianmomeni
- Department of Cellular and Developmental Biology of Plants, Faculty of Natural Sciences, University of Bielefeld, Bielefeld, Germany
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Wang Y, Tan J, Wu Z, VandenLangenberg K, Wehner TC, Wen C, Zheng X, Owens K, Thornton A, Bang HH, Hoeft E, Kraan PAG, Suelmann J, Pan J, Weng Y. STAYGREEN, STAY HEALTHY: a loss-of-susceptibility mutation in the STAYGREEN gene provides durable, broad-spectrum disease resistances for over 50 years of US cucumber production. THE NEW PHYTOLOGIST 2019; 221:415-430. [PMID: 30022503 DOI: 10.1111/nph.15353] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/13/2018] [Indexed: 05/22/2023]
Abstract
The Gy14 cucumber (Cucumis sativus) is resistant to oomyceteous downy mildew (DM), bacterial angular leaf spot (ALS) and fungal anthracnose (AR) pathogens, but the underlying molecular mechanisms are unknown. Quantitative trait locus (QTL) mapping for the disease resistances in Gy14 and further map-based cloning identified a candidate gene for the resistant loci, which was validated and functionally characterized by spatial-temporal gene expression profiling, allelic diversity and phylogenetic analysis, as well as local association studies. We showed that the triple-disease resistances in Gy14 were controlled by the cucumber STAYGREEN (CsSGR) gene. A single nucleotide polymorphism (SNP) in the coding region resulted in a nonsynonymous amino acid substitution in the CsSGR protein, and thus disease resistance. Genes in the chlorophyll degradation pathway showed differential expression between resistant and susceptible lines in response to pathogen inoculation. The causal SNP was significantly associated with disease resistances in natural and breeding populations. The resistance allele has undergone selection in cucumber breeding. The durable, broad-spectrum disease resistance is caused by a loss-of-susceptibility mutation of CsSGR. Probably, this is achieved through the inhibition of reactive oxygen species over-accumulation and phytotoxic catabolite over-buildup in the chlorophyll degradation pathway. The CsSGR-mediated host resistance represents a novel function of this highly conserved gene in plants.
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Affiliation(s)
- Yuhui Wang
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Junyi Tan
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Zhiming Wu
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
- Institute of Cash Crops, Hebei Academy of Agriculture & Forestry Sciences, Shijiazhuang, Hebei, 050051, China
| | - Kyle VandenLangenberg
- Horticultural Science Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Todd C Wehner
- Horticultural Science Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Changlong Wen
- Beijing Vegetable Research Center, Beijing Academy of Agricultural and Forestry Sciences, Beijing, 100097, China
| | | | - Ken Owens
- Magnum Seeds Inc., Dixon, CA, 95620, USA
| | | | | | - Eric Hoeft
- HM Clause Seed Company, Davis, CA, 95618, USA
| | | | - Jos Suelmann
- Bayer Vegetable Seeds, 6083 AB, Nunhem, the Netherlands
| | - Junsong Pan
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
- Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200241, China
| | - Yiqun Weng
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
- USDA-ARS Vegetable Crops Research Unit, Madison, WI, 53705, USA
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25
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Schelkunov MI, Penin AA, Logacheva MD. RNA-seq highlights parallel and contrasting patterns in the evolution of the nuclear genome of fully mycoheterotrophic plants. BMC Genomics 2018; 19:602. [PMID: 30092758 PMCID: PMC6085651 DOI: 10.1186/s12864-018-4968-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 07/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While photosynthesis is the most notable trait of plants, several lineages of plants (so-called full heterotrophs) have adapted to obtain organic compounds from other sources. The switch to heterotrophy leads to profound changes at the morphological, physiological and genomic levels. RESULTS Here, we characterize the transcriptomes of three species representing two lineages of mycoheterotrophic plants: orchids (Epipogium aphyllum and Epipogium roseum) and Ericaceae (Hypopitys monotropa). Comparative analysis is used to highlight the parallelism between distantly related fully heterotrophic plants. In both lineages, we observed genome-wide elimination of nuclear genes that encode proteins related to photosynthesis, while systems associated with protein import to plastids as well as plastid transcription and translation remain active. Genes encoding components of plastid ribosomes that have been lost from the plastid genomes have not been transferred to the nuclear genomes; instead, some of the encoded proteins have been substituted by homologs. The nuclear genes of both Epipogium species accumulated nucleotide substitutions twice as rapidly as their photosynthetic relatives; in contrast, no increase in the substitution rate was observed in H. monotropa. CONCLUSIONS Full heterotrophy leads to profound changes in nuclear gene content. The observed increase in the rate of nucleotide substitutions is lineage specific, rather than a universal phenomenon among non-photosynthetic plants.
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Affiliation(s)
- Mikhail I Schelkunov
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.
| | - Aleksey A Penin
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia.,A.N Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Maria D Logacheva
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia. .,Skolkovo Institute of Science and Technology, Moscow, Russia. .,Extreme Biology Laboratory, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.
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26
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Kuai B, Chen J, Hörtensteiner S. The biochemistry and molecular biology of chlorophyll breakdown. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:751-767. [PMID: 28992212 DOI: 10.1093/jxb/erx322] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Chlorophyll breakdown is one of the most obvious signs of leaf senescence and fruit ripening. The resulting yellowing of leaves can be observed every autumn, and the color change of fruits indicates their ripening state. During these processes, chlorophyll is broken down in a multistep pathway, now termed the 'PAO/phyllobilin' pathway, acknowledging the core enzymatic breakdown step catalysed by pheophorbide a oxygenase, which determines the basic linear tetrapyrrole structure of the products of breakdown that are now called 'phyllobilins'. This review provides an update on the PAO/phyllobilin pathway, and focuses on recent biochemical and molecular progress in understanding phyllobilin-modifying reactions as the basis for phyllobilin diversity, on the evolutionary diversity of the pathway, and on the transcriptional regulation of the pathway genes.
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Affiliation(s)
- Benke Kuai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Junyi Chen
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
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Midega CA, Wasonga CJ, Hooper AM, Pickett JA, Khan ZR. Drought-tolerant Desmodium species effectively suppress parasitic striga weed and improve cereal grain yields in western Kenya. CROP PROTECTION (GUILDFORD, SURREY) 2017; 98:94-101. [PMID: 28775391 PMCID: PMC5465939 DOI: 10.1016/j.cropro.2017.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/14/2017] [Accepted: 03/17/2017] [Indexed: 05/04/2023]
Abstract
The parasitic weed Striga hermonthica Benth. (Orobanchaceae), commonly known as striga, is an increasingly important constraint to cereal production in sub-Saharan Africa (SSA), often resulting in total yield losses in maize (Zea mays L.) and substantial losses in sorghum (Sorghum bicolor (L.) Moench). This is further aggravated by soil degradation and drought conditions that are gradually becoming widespread in SSA. Forage legumes in the genus Desmodium (Fabaceae), mainly D. uncinatum and D. intortum, effectively control striga and improve crop productivity in SSA. However, negative effects of climate change such as drought stress is affecting the functioning of these systems. There is thus a need to identify and characterize new plants possessing the required ecological chemistry to protect crops against the biotic stress of striga under such environmental conditions. 17 accessions comprising 10 species of Desmodium were screened for their drought stress tolerance and ability to suppress striga. Desmodium incanum and D. ramosissimum were selected as the most promising species as they retained their leaves and maintained leaf function for longer periods during their exposure to drought stress conditions. They also had desirable phenotypes with more above ground biomass. The two species suppressed striga infestation, both under controlled and field conditions, and resulted in significant grain yield increases, demonstrating the incremental capability of Desmodium species in striga suppression. These results demonstrate beneficial effects of Desmodium species in enhancing cereal productivity in dry areas.
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Affiliation(s)
- Charles A.O. Midega
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya
| | - Charles J. Wasonga
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya
| | - Antony M. Hooper
- Biological Chemistry and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - John A. Pickett
- Biological Chemistry and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Zeyaur R. Khan
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya
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Hu X, Kato Y, Sumida A, Tanaka A, Tanaka R. The SUFBC 2 D complex is required for the biogenesis of all major classes of plastid Fe-S proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:235-248. [PMID: 28103400 DOI: 10.1111/tpj.13483] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 05/15/2023]
Abstract
Iron-sulfur (Fe-S) proteins play crucial roles in plastids, participating in photosynthesis and other metabolic pathways. Fe-S clusters are thought to be assembled on a scaffold complex composed of SUFB, SUFC and SUFD proteins. However, several additional proteins provide putative scaffold functions in plastids, and, therefore, the contribution of SUFB, C and D proteins to overall Fe-S assembly still remains unclear. In order to gain insights regarding Fe-S cluster biosynthesis in plastids, we analyzed the complex composed of SUFB, C and D in Arabidopsis by blue native-polyacrylamide gel electrophoresis. Using this approach, a major complex of 170 kDa containing all subunits was detected, indicating that these proteins constitute a SUFBC2 D complex similar to their well characterized bacterial counterparts. The functional effects of SUFB, SUFC or SUFD depletion were analyzed using an inducible RNAi silencing system to specifically target the aforementioned components; resulting in a decrease of various plastidic Fe-S proteins including the PsaA/B and PsaC subunits of photosystem I, ferredoxin and glutamine oxoglutarate aminotransferase. In contrast, the knockout of potential Fe-S scaffold proteins, NFU2 and HCF101, resulted in a specific decrease in the PsaA/B and PsaC levels. These results indicate that the functions of SUFB, SUFC and SUFD for Fe-S cluster biosynthesis cannot be replaced by other scaffold proteins and that SUFBC2 D, NFU2 and HCF101 are involved in the same pathway for the biogenesis of PSI. Taken together, our results provide in vivo evidence supporting the hypothesis that SUFBC2 D is the major, and possibly sole scaffold in plastids.
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Affiliation(s)
- Xueyun Hu
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang City, Sichuan, 621010, China
| | - Yukako Kato
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Akihiro Sumida
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
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León J, Costa Á, Castillo MC. Nitric oxide triggers a transient metabolic reprogramming in Arabidopsis. Sci Rep 2016; 6:37945. [PMID: 27885260 PMCID: PMC5122866 DOI: 10.1038/srep37945] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/02/2016] [Indexed: 01/15/2023] Open
Abstract
Nitric oxide (NO) regulates plant growth and development as well as responses to stress that enhanced its endogenous production. Arabidopsis plants exposed to a pulse of exogenous NO gas were used for untargeted global metabolomic analyses thus allowing the identification of metabolic processes affected by NO. At early time points after treatment, NO scavenged superoxide anion and induced the nitration and the S-nitrosylation of proteins. These events preceded an extensive though transient metabolic reprogramming at 6 h after NO treatment, which included enhanced levels of polyamines, lipid catabolism and accumulation of phospholipids, chlorophyll breakdown, protein and nucleic acid turnover and increased content of sugars. Accordingly, lipid-related structures such as root cell membranes and leaf cuticle altered their permeability upon NO treatment. Besides, NO-treated plants displayed degradation of starch granules, which is consistent with the increased sugar content observed in the metabolomic survey. The metabolic profile was restored to baseline levels at 24 h post-treatment, thus pointing up the plasticity of plant metabolism in response to nitroxidative stress conditions.
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Affiliation(s)
- José León
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
| | - Álvaro Costa
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
| | - Mari-Cruz Castillo
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
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30
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Shimoda Y, Ito H, Tanaka A. Arabidopsis STAY-GREEN, Mendel's Green Cotyledon Gene, Encodes Magnesium-Dechelatase. THE PLANT CELL 2016; 28:2147-2160. [PMID: 27604697 PMCID: PMC5059807 DOI: 10.1105/tpc.16.00428] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/22/2016] [Accepted: 09/06/2016] [Indexed: 05/18/2023]
Abstract
Pheophytin a is an essential component of oxygenic photosynthetic organisms because the primary charge separation between chlorophyll a and pheophytin a is the first step in the conversion of light energy. In addition, conversion of chlorophyll a to pheophytin a is the first step of chlorophyll degradation. Pheophytin is synthesized by extracting magnesium (Mg) from chlorophyll; the enzyme Mg-dechelatase catalyzes this reaction. In this study, we report that Mendel's green cotyledon gene, STAY-GREEN (SGR), encodes Mg-dechelatase. The Arabidopsis thaliana genome has three SGR genes, SGR1, SGR2, and STAY-GREEN LIKE (SGRL). Recombinant SGR1/2 extracted Mg from chlorophyll a but had very low or no activity against chlorophyllide a; by contrast, SGRL had higher dechelating activity against chlorophyllide a compared with chlorophyll a All SGRs could not extract Mg from chlorophyll b Enzymatic experiments using the photosystem and light-harvesting complexes showed that SGR extracts Mg not only from free chlorophyll but also from chlorophyll in the chlorophyll-protein complexes. Furthermore, most of the chlorophyll and chlorophyll binding proteins disappeared when SGR was transiently expressed by a chemical induction system. Thus, SGR is not only involved in chlorophyll degradation but also contributes to photosystem degradation.
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Affiliation(s)
- Yousuke Shimoda
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo 060-0819, Japan
| | - Hisashi Ito
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo 060-0819, Japan
- CREST, Japan Science and Technology Agency, Kita-ku, Sapporo 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo 060-0819, Japan
- CREST, Japan Science and Technology Agency, Kita-ku, Sapporo 060-0819, Japan
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31
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Yin XR, Xie XL, Xia XJ, Yu JQ, Ferguson IB, Giovannoni JJ, Chen KS. Involvement of an ethylene response factor in chlorophyll degradation during citrus fruit degreening. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 86:403-12. [PMID: 27037684 DOI: 10.1111/tpj.13178] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/19/2016] [Accepted: 03/23/2016] [Indexed: 05/07/2023]
Abstract
Chlorophyll degradation naturally occurs during plant senescence. However, in fruit such as citrus, it is a positive characteristic, as degreening is an important colour development contributing to fruit quality. In the present work, Citrus sinensis Osbeck, cv. Newhall fruit was used as a model for chlorophyll degradation. An ethylene response factor, CitERF13, was isolated and its transcriptional changes were closely correlated with fruit peel degreening during development or in response to ethylene. Dual-luciferase and yeast one-hybrid assays, as well as motif mutation, indicated that CitERF13 directly binds to the CitPPH promoter and enhances its activity. Transient and stable over-expression of CitERF13 resulted in rapid chlorophyll degradation in Nicotiana tabacum leaves and led to accumulation of pheophorbide (Pheide) a, a metabolite of pheophorbide hydrolase (PPH). Similar results were observed from transient transformation of CitERF13 in citrus fruit peel. Moreover, this function of CitERF13 was conserved within Arabidopsis and tomato, as the homologs AtERF17 and SlERF16 similarly acted as activators of PPH genes and accelerators of chlorophyll degradation.
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Affiliation(s)
- Xue-Ren Yin
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Xiu-Lan Xie
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Xiao-Jian Xia
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Jing-Quan Yu
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
| | - Ian B Ferguson
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- New Zealand Institute for Plant & Food Research Limited, Private Bag, 92169, Auckland, New Zealand
| | - James J Giovannoni
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853, USA
- US Department of Agriculture/Agriculture Research Service, Robert W. Holley Centre for Agriculture and Health, Ithaca, NY, 14853, USA
| | - Kun-Song Chen
- College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
- The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China
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Xie Q, Liang Y, Zhang J, Zheng H, Dong G, Qian Q, Zuo J. Involvement of a Putative Bipartite Transit Peptide in Targeting Rice Pheophorbide a Oxygenase into Chloroplasts for Chlorophyll Degradation during Leaf Senescence. J Genet Genomics 2016; 43:145-54. [DOI: 10.1016/j.jgg.2015.09.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/27/2015] [Accepted: 09/15/2015] [Indexed: 11/15/2022]
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Sapeta H, Lourenço T, Lorenz S, Grumaz C, Kirstahler P, Barros PM, Costa JM, Sohn K, Oliveira MM. Transcriptomics and physiological analyses reveal co-ordinated alteration of metabolic pathways in Jatropha curcas drought tolerance. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:845-60. [PMID: 26602946 DOI: 10.1093/jxb/erv499] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Jatropha curcas, a multipurpose plant attracting a great deal of attention due to its high oil content and quality for biofuel, is recognized as a drought-tolerant species. However, this drought tolerance is still poorly characterized. This study aims to contribute to uncover the molecular background of this tolerance, using a combined approach of transcriptional profiling and morphophysiological characterization during a period of water-withholding (49 d) followed by rewatering (7 d). Morphophysiological measurements showed that J. curcas plants present different adaptation strategies to withstand moderate and severe drought. Therefore, RNA sequencing was performed for samples collected under moderate and severe stress followed by rewatering, for both roots and leaves. Jatropha curcas transcriptomic analysis revealed shoot- and root-specific adaptations across all investigated conditions, except under severe stress, when the dramatic transcriptomic reorganization at the root and shoot level surpassed organ specificity. These changes in gene expression were clearly shown by the down-regulation of genes involved in growth and water uptake, and up-regulation of genes related to osmotic adjustments and cellular homeostasis. However, organ-specific gene variations were also detected, such as strong up-regulation of abscisic acid synthesis in roots under moderate stress and of chlorophyll metabolism in leaves under severe stress. Functional validation further corroborated the differential expression of genes coding for enzymes involved in chlorophyll metabolism, which correlates with the metabolite content of this pathway.
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Affiliation(s)
- Helena Sapeta
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Tiago Lourenço
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Stefan Lorenz
- Fraunhofer IGB, Functional Genomics Lab, Nobelstr. 12, D-70569, Stuttgart, Germany
| | - Christian Grumaz
- Fraunhofer IGB, Functional Genomics Lab, Nobelstr. 12, D-70569, Stuttgart, Germany
| | - Philipp Kirstahler
- Fraunhofer IGB, Functional Genomics Lab, Nobelstr. 12, D-70569, Stuttgart, Germany
| | - Pedro M Barros
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Joaquim Miguel Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Plant Molecular Ecophysiology Lab, Av. da República, 2780-157 Oeiras, Portugal
| | - Kai Sohn
- Fraunhofer IGB, Functional Genomics Lab, Nobelstr. 12, D-70569, Stuttgart, Germany
| | - M Margarida Oliveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal iBET, Apartado 12, 2781-901 Oeiras, Portugal
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Atanasov KE, Barboza-Barquero L, Tiburcio AF, Alcázar R. Genome Wide Association Mapping for the Tolerance to the Polyamine Oxidase Inhibitor Guazatine in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2016; 7:401. [PMID: 27092150 PMCID: PMC4820465 DOI: 10.3389/fpls.2016.00401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/14/2016] [Indexed: 05/09/2023]
Abstract
Guazatine is a potent inhibitor of polyamine oxidase (PAO) activity. In agriculture, guazatine is used as non-systemic contact fungicide efficient in the protection of cereals and citrus fruits against disease. The composition of guazatine is complex, mainly constituted by a mixture of synthetic guanidated polyamines (polyaminoguanidines). Here, we have studied the effects from exposure to guazatine in the weed Arabidopsis thaliana. We report that micromolar concentrations of guazatine are sufficient to inhibit growth of Arabidopsis seedlings and induce chlorosis, whereas germination is barely affected. We observed the occurrence of quantitative variation in the response to guazatine between 107 randomly chosen Arabidopsis accessions. This enabled us to undertake genome-wide association (GWA) mapping that identified a locus on chromosome one associated with guazatine tolerance. CHLOROPHYLLASE 1 (CLH1) within this locus was studied as candidate gene, together with its paralog (CLH2). The analysis of independent clh1-2, clh1-3, clh2-3, clh2-2, and double clh1-2 clh2-3 mutant alleles indicated that CLH1 and/or CLH2 loss-of-function or expression down-regulation promote guazatine tolerance in Arabidopsis. We report a natural mechanism by which Arabidopsis populations can overcome toxicity by the fungicide guazatine.
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Affiliation(s)
- Kostadin E. Atanasov
- Laboratory of Plant Physiology, Department of Natural Products, Plant Biology and Soil Science, Faculty of Pharmacy, University of BarcelonaBarcelona, Spain
| | - Luis Barboza-Barquero
- Centro para Investigaciones en Granos y Semillas, Universidad de Costa RicaSan José, Costa Rica
| | - Antonio F. Tiburcio
- Laboratory of Plant Physiology, Department of Natural Products, Plant Biology and Soil Science, Faculty of Pharmacy, University of BarcelonaBarcelona, Spain
| | - Rubén Alcázar
- Laboratory of Plant Physiology, Department of Natural Products, Plant Biology and Soil Science, Faculty of Pharmacy, University of BarcelonaBarcelona, Spain
- *Correspondence: Rubén Alcázar
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Wang J, Ye B, Yin J, Yuan C, Zhou X, Li W, He M, Wang J, Chen W, Qin P, Ma B, Wang Y, Li S, Chen X. Characterization and fine mapping of a light-dependent leaf lesion mimic mutant 1 in rice. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 97:44-51. [PMID: 26410574 DOI: 10.1016/j.plaphy.2015.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 05/10/2023]
Abstract
Plants that spontaneously produce lesion mimics or spots, without any signs of obvious adversity, such as pesticide and mechanical damage, or pathogen infection, are so-called lesion mimic mutants (lmms). In rice, many lmms exhibit enhanced resistance to pathogens, which provides a unique opportunity to uncover the molecular mechanism underlying lmms. We isolated a rice light-dependent leaf lesion mimic mutant 1 (llm1). Lesion spots appeared in the leaves of the llm1 mutant at the tillering stage. Furthermore, the mutant llm1 had similar agronomic traits to wild type rice. Trypan blue and diamiobenzidine staining analyses revealed that the lesion spot formation on the llm1 mutant was due to programmed cell death and reactive oxygen species. The chloroplasts were severely damaged in the llm1 mutant, suggesting that chloroplast damage was associated with the formation of lesion spots in llm1. More importantly, llm1 exhibited enhanced resistance to bacterial blight pathogens within increased expression of pathogenesis related genes (PRs). Using a map-based cloning approach, we delimited the LLM1 locus to a 121-kb interval between two simple sequence repeat markers, RM17470 and RM17473, on chromosome 4. We sequenced the candidate genes on the interval and found that a base mutation had substituted adenine phosphate for thymine in the last exon of LOC_Os04g52130, which led to an amino acid change (Asp(388) to Val) in the llm1 mutant. Our investigation showed that the putative coproporphyrinogen III oxidase (CPOX) encoded by LOC_Os04g52130 was produced by LLM1 and that amino acid Asp(388) was essential for CPOX function. Our study provides the basis for further investigations into the mechanism underlying lesion mimic initiation associated with LLM1.
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Affiliation(s)
- Jing Wang
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Bangquan Ye
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Junjie Yin
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Can Yuan
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Xiaogang Zhou
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Weitao Li
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Min He
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Jichun Wang
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Weilan Chen
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Peng Qin
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Bintian Ma
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China
| | - Yuping Wang
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China
| | - Shigui Li
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; State Key Laboratory of Hybrid Rice, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China
| | - Xuewei Chen
- Rice Research Institute, Sichuan Agricultural University at Wenjiang, Chengdu, Sichuan 611130, China; Key Laboratory of Major Crop Diseases, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; State Key Laboratory of Hybrid Rice, Sichuan Agricultural University at Wenjiang, Chengdu 611130, China; Collaborative Innovation Center for Hybrid Rice in Yangtze River Basin at Sichuan, Chengdu 611130, China.
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Xiao HJ, Liu KK, Li DW, Arisha MH, Chai WG, Gong ZH. Cloning and characterization of the pepper CaPAO gene for defense responses to salt-induced leaf senescence. BMC Biotechnol 2015; 15:100. [PMID: 26498743 PMCID: PMC4619409 DOI: 10.1186/s12896-015-0213-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/06/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pheophorbide a oxygenase (PAO) is an important enzyme in the chlorophyll catabolism pathway and is involved in leaf senescence. It opens the porphyrin macrocycle of pheophorbide a and finally forms the primary fluorescent chlorophyll catabolite. Previous studies have demonstrated the function of PAO during cell death. However, the characterizaton of PAO during leaf senescence induced by environmental factors is not well understood. METHODS Homology-based cloning and RACE techniques were used to obtain the full-length cDNA of the CaPAO gene. CaPAO expression was determined by quantitative real-time PCR. Function of CaPAO gene were studied using virus-induced gene silencing and transgenic techniques with tobacco plants (Nicotiana tabacum). RESULTS A novel PAO gene CaPAO was isolated from pepper (Capsicum annuum L.). The full-length CaPAO cDNA is comprised of 1838 bp, containing an open reading frame of 1614 bp, and encodes a 537 amino acid protein. This deduced protein belongs to the Rieske-type iron-sulfur superfamily, containing a conserved Rieske cluster. CaPAO expression, as determined by quantitative real-time PCR, was higher in leaves than roots, stems and flowers. It was upregulated by abscisic acid, methyl jasmonate and salicylic acid. Moreover, CaPAO was significantly induced by high salinity and osmotic stress treatments and also was regulated by Phytophthora capsici. The virus-induced gene silencing technique was used to silence the CaPAO gene in pepper plants. After 3 days of high salt treatment, the chlorophyll breakdown of CaPAO-silenced pepper plants was retarded. RD29A promoter-inducible expression vector was constructed and transferred into tobacco plant. After 7 days of salt treatment, the leaves of transgenic plants were severely turned into yellow, the lower leaves showed necrotic symptom and chlorophyll content was significantly lower than that in the control plants. CONCLUSIONS The expression of CaPAO gene was induced in natural senescence and various stresses. The CaPAO gene may be related to defense responses to various stresses and play an important role in salt-induced leaf senescence.
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Affiliation(s)
- Huai-Juan Xiao
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
- College of Horticulture, Henan Agricultural University, Zhengzhou, Henan, P. R. China.
| | - Ke-Ke Liu
- College of Horticulture, Henan Agricultural University, Zhengzhou, Henan, P. R. China.
| | - Da-Wei Li
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
| | - Mohamed Hamed Arisha
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
- Faculty of Agriculture, Zagazig University, Zagazig, Sharkia P. R. Egypt.
| | - Wei-Guo Chai
- Institute of Vegetables, Hangzhou Academy of Agricultural Sciences, Hangzhou, Zhejiang, P. R. China.
| | - Zhen-Hui Gong
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
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Ishiga Y, Rao Uppalapati S, Gill US, Huhman D, Tang Y, Mysore KS. Transcriptomic and metabolomic analyses identify a role for chlorophyll catabolism and phytoalexin during Medicago nonhost resistance against Asian soybean rust. Sci Rep 2015; 5:13061. [PMID: 26267598 PMCID: PMC4533520 DOI: 10.1038/srep13061] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/13/2015] [Indexed: 01/05/2023] Open
Abstract
Asian soybean rust (ASR) caused by Phakopsora pachyrhizi is a devastating foliar disease affecting soybean production worldwide. Understanding nonhost resistance against ASR may provide an avenue to engineer soybean to confer durable resistance against ASR. We characterized a Medicago truncatula-ASR pathosystem to study molecular mechanisms of nonhost resistance. Although urediniospores formed appressoria and penetrated into epidermal cells of M. truncatula, P. pachyrhizi failed to sporulate. Transcriptomic analysis revealed the induction of phenylpropanoid, flavonoid and isoflavonoid metabolic pathway genes involved in the production of phytoalexin medicarpin in M. truncatula upon infection with P. pachyrhizi. Furthermore, genes involved in chlorophyll catabolism were induced during nonhost resistance. We further characterized one of the chlorophyll catabolism genes, Stay-green (SGR), and demonstrated that the M. truncatula sgr mutant and alfalfa SGR-RNAi lines showed hypersensitive-response-like enhanced cell death upon inoculation with P. pachyrhizi. Consistent with transcriptomic analysis, metabolomic analysis also revealed the accumulation of medicarpin and its intermediate metabolites. In vitro assay showed that medicarpin inhibited urediniospore germination and differentiation. In addition, several triterpenoid saponin glycosides accumulated in M. truncatula upon inoculation with P. pachyrhizi. In summary, using multi-omic approaches, we identified a correlation between phytoalexin production and M. truncatula defense responses against ASR.
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Affiliation(s)
- Yasuhiro Ishiga
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | | | - Upinder S. Gill
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA
| | - David Huhman
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA
| | - Yuhong Tang
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA
| | - Kirankumar S. Mysore
- Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA
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Sakuraba Y, Park SY, Paek NC. The Divergent Roles of STAYGREEN (SGR) Homologs in Chlorophyll Degradation. Mol Cells 2015; 38:390-5. [PMID: 25913011 PMCID: PMC4443279 DOI: 10.14348/molcells.2015.0039] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 03/06/2015] [Indexed: 12/25/2022] Open
Abstract
Degradation of chlorophyll (Chl) by Chl catabolic enzymes (CCEs) causes the loss of green color that typically occurs during senescence of leaves. In addition to CCEs, staygreen1 (SGR1) functions as a key regulator of Chl degradation. Although sgr1 mutants in many plant species exhibit a stay-green phenotype, the biochemical function of the SGR1 protein remains elusive. Many recent studies have examined the physiological and molecular roles of SGR1 and its homologs (SGR2 and SGR-LIKE) in Chl metabolism, finding that these proteins have different roles in different species. In this review, we summarize the recent studies on SGR and discuss the most likely functions of SGR homologs.
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Affiliation(s)
- Yasuhito Sakuraba
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921,
Korea
| | - So-Yon Park
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061-0331,
USA
| | - Nam-Chon Paek
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921,
Korea
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 232-916,
Korea
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Heinrich S, Valentin K, Frickenhaus S, Wiencke C. Temperature and light interactively modulate gene expression in Saccharina latissima (Phaeophyceae). JOURNAL OF PHYCOLOGY 2015; 51:93-108. [PMID: 26986261 DOI: 10.1111/jpy.12255] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 09/16/2014] [Indexed: 06/05/2023]
Abstract
Macroalgae of the order Laminariales (kelp) are important components of cold-temperate coastal ecosystems. Major factors influencing their distribution are light (including UV radiation) and temperature. Therefore, future global environmental changes potentially will impact their zonation, distribution patterns, and primary productivity. Many physiological studies were performed on UV radiation and temperature stress in kelp but combinatory effects have not been analyzed and so far no study is available on the molecular processes involved in acclimation to these stresses. Therefore, sporophytes of Saccharina latissima were exposed for 2 weeks to 12 combinations of photosynthetically active radiation (PAR), UV radiation and temperature. Subsequently, microarray hybridizations were performed to determine changes in gene expression patterns. Several effects on the transcriptome were observed after exposure experiments. The strongest effect of temperature on gene expression was observed at 2°C. Furthermore, UV radiation had stronger effects on gene expression than high PAR, and caused stronger induction genes correlated with categories such as photosynthetic components and vitamin B6 biosynthesis. Higher temperatures ameliorated the negative effects of UV radiation in S. latissima. Regulation of reactive oxygen species (ROS) scavenging seems to work in a compartment specific way. Gene expression profiles of ROS scavengers indicated a high amount of oxidative stress in response to the 2°C condition as well as to excessive light at 12°C. Interestingly, stress levels that did not lead to physiological alterations already caused by a transcriptomic response.
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Affiliation(s)
- Sandra Heinrich
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Klaus Valentin
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Stephan Frickenhaus
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
| | - Christian Wiencke
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570, Bremerhaven, Germany
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Jia T, Ito H, Hu X, Tanaka A. Accumulation of the NON-YELLOW COLORING 1 protein of the chlorophyll cycle requires chlorophyll b in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:586-596. [PMID: 25557327 DOI: 10.1111/tpj.12753] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 12/14/2014] [Accepted: 12/18/2014] [Indexed: 06/04/2023]
Abstract
Chlorophyll a and chlorophyll b are interconverted in the chlorophyll cycle. The initial step in the conversion of chlorophyll b to chlorophyll a is catalyzed by the chlorophyll b reductases NON-YELLOW COLORING 1 (NYC1) and NYC1-like (NOL), which convert chlorophyll b to 7-hydroxymethyl chlorophyll a. This step is also the first stage in the degradation of the light-harvesting chlorophyll a/b protein complex (LHC). In this study, we examined the effect of chlorophyll b on the level of NYC1. NYC1 mRNA and NYC1 protein were in low abundance in green leaves, but their levels increased in response to dark-induced senescence. When the level of chlorophyll b was enhanced by the introduction of a truncated chlorophyllide a oxygenase gene and the leaves were incubated in the dark, the amount of NYC1 was greatly increased compared with that of the wild type; however, the amount of NYC1 mRNA was the same as in the wild type. In contrast, NYC1 did not accumulate in the mutant without chlorophyll b, even though the NYC1 mRNA level was high after incubation in the dark. Quantification of the LHC protein showed no strong correlation between the levels of NYC1 and LHC proteins. However, the level of chlorophyll fluorescence of the dark adapted plant (Fo ) was closely related to the accumulation of NYC1, suggesting that the NYC1 level is related to the energetically uncoupled LHC. These results and previous reports on the degradation of chlorophyllide a oxygenase suggest that the a feedforward and feedback network is included in chlorophyll cycle.
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Affiliation(s)
- Ting Jia
- Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo, 060-0819, Japan
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Bruggeman Q, Raynaud C, Benhamed M, Delarue M. To die or not to die? Lessons from lesion mimic mutants. FRONTIERS IN PLANT SCIENCE 2015; 6:24. [PMID: 25688254 PMCID: PMC4311611 DOI: 10.3389/fpls.2015.00024] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/12/2015] [Indexed: 05/19/2023]
Abstract
Programmed cell death (PCD) is a ubiquitous genetically regulated process consisting in an activation of finely controlled signaling pathways that lead to cellular suicide. Although some aspects of PCD control appear evolutionary conserved between plants, animals and fungi, the extent of conservation remains controversial. Over the last decades, identification and characterization of several lesion mimic mutants (LMM) has been a powerful tool in the quest to unravel PCD pathways in plants. Thanks to progress in molecular genetics, mutations causing the phenotype of a large number of LMM and their related suppressors were mapped, and the identification of the mutated genes shed light on major pathways in the onset of plant PCD such as (i) the involvements of chloroplasts and light energy, (ii) the roles of sphingolipids and fatty acids, (iii) a signal perception at the plasma membrane that requires efficient membrane trafficking, (iv) secondary messengers such as ion fluxes and ROS and (v) the control of gene expression as the last integrator of the signaling pathways.
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Affiliation(s)
- Quentin Bruggeman
- Institut de Biologie des Plantes, UMR CNRS 8618, Université Paris-Sud, Saclay Plant SciencesOrsay, France
| | - Cécile Raynaud
- Institut de Biologie des Plantes, UMR CNRS 8618, Université Paris-Sud, Saclay Plant SciencesOrsay, France
| | - Moussa Benhamed
- Institut de Biologie des Plantes, UMR CNRS 8618, Université Paris-Sud, Saclay Plant SciencesOrsay, France
- Division of Biological and Environmental Sciences and Engineering, Center for Desert Agriculture, King Abdullah University of Science and TechnologyThuwal, Saudi Arabia
| | - Marianne Delarue
- Institut de Biologie des Plantes, UMR CNRS 8618, Université Paris-Sud, Saclay Plant SciencesOrsay, France
- *Correspondence: Marianne Delarue, Institut de Biologie des Plantes, UMR CNRS 8618, Université Paris-Sud, Saclay Plant Sciences, Bâtiment 630, Route de Noetzlin, 91405 Orsay Cedex, France e-mail:
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Ohmiya A, Hirashima M, Yagi M, Tanase K, Yamamizo C. Identification of genes associated with chlorophyll accumulation in flower petals. PLoS One 2014; 9:e113738. [PMID: 25470367 PMCID: PMC4254739 DOI: 10.1371/journal.pone.0113738] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/29/2014] [Indexed: 11/18/2022] Open
Abstract
Plants have an ability to prevent chlorophyll accumulation, which would mask the bright flower color, in their petals. In contrast, leaves contain substantial amounts of chlorophyll, as it is essential for photosynthesis. The mechanisms of organ-specific chlorophyll accumulation are unknown. To identify factors that determine the chlorophyll content in petals, we compared the expression of genes related to chlorophyll metabolism in different stages of non-green (red and white) petals (very low chlorophyll content), pale-green petals (low chlorophyll content), and leaves (high chlorophyll content) of carnation (Dianthus caryophyllus L.). The expression of many genes encoding chlorophyll biosynthesis enzymes, in particular Mg-chelatase, was lower in non-green petals than in leaves. Non-green petals also showed higher expression of genes involved in chlorophyll degradation, including STAY-GREEN gene and pheophytinase. These data suggest that the absence of chlorophylls in carnation petals may be caused by the low rate of chlorophyll biosynthesis and high rate of degradation. Similar results were obtained by the analysis of Arabidopsis microarray data. In carnation, most genes related to chlorophyll biosynthesis were expressed at similar levels in pale-green petals and leaves, whereas the expression of chlorophyll catabolic genes was higher in pale-green petals than in leaves. Therefore, we hypothesize that the difference in chlorophyll content between non-green and pale-green petals is due to different levels of chlorophyll biosynthesis. Our study provides a basis for future molecular and genetic studies on organ-specific chlorophyll accumulation.
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Affiliation(s)
- Akemi Ohmiya
- National Institute of Floricultural Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8519, Japan
- * E-mail:
| | - Masumi Hirashima
- National Institute of Floricultural Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8519, Japan
| | - Masafumi Yagi
- National Institute of Floricultural Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8519, Japan
| | - Koji Tanase
- National Institute of Floricultural Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8519, Japan
| | - Chihiro Yamamizo
- National Institute of Floricultural Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8519, Japan
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Sakuraba Y, Park SY, Kim YS, Wang SH, Yoo SC, Hörtensteiner S, Paek NC. Arabidopsis STAY-GREEN2 is a negative regulator of chlorophyll degradation during leaf senescence. MOLECULAR PLANT 2014; 7:1288-1302. [PMID: 24719469 DOI: 10.1093/mp/ssu045] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Chlorophyll (Chl) degradation causes leaf yellowing during senescence or under stress conditions. For Chl breakdown, STAY-GREEN1 (SGR1) interacts with Chl catabolic enzymes (CCEs) and light-harvesting complex II (LHCII) at the thylakoid membrane, possibly to allow metabolic channeling of potentially phototoxic Chl breakdown intermediates. Among these Chl catabolic components, SGR1 acts as a key regulator of leaf yellowing. In addition to SGR1 (At4g22920), the Arabidopsis thaliana genome contains an additional homolog, SGR2 (At4g11910), whose biological function remains elusive. Under senescence-inducing conditions, SGR2 expression is highly up-regulated, similarly to SGR1 expression. Here we show that SGR2 function counteracts SGR1 activity in leaf Chl degradation; SGR2-overexpressing plants stayed green and the sgr2-1 knockout mutant exhibited early leaf yellowing under age-, dark-, and stress-induced senescence conditions. Like SGR1, SGR2 interacted with LHCII but, in contrast to SGR1, SGR2 interactions with CCEs were very limited. Furthermore, SGR1 and SGR2 formed homo- or heterodimers, strongly suggesting a role for SGR2 in negatively regulating Chl degradation by possibly interfering with the proposed CCE-recruiting function of SGR1. Our data indicate an antagonistic evolution of the functions of SGR1 and SGR2 in Arabidopsis to balance Chl catabolism in chloroplasts with the dismantling and remobilizing of other cellular components in senescing leaf cells.
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Affiliation(s)
- Yasuhito Sakuraba
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - So-Yon Park
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea; Present address: Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ye-Sol Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea; Present address: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185, Korea
| | - Seung-Hyun Wang
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Soo-Cheul Yoo
- Department of Plant & Environmental Science, Hankyong National University, Ansung 456-749, Korea
| | | | - Nam-Chon Paek
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
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Jarvis P, López-Juez E. Biogenesis and homeostasis of chloroplasts and other plastids. Nat Rev Mol Cell Biol 2014; 14:787-802. [PMID: 24263360 DOI: 10.1038/nrm3702] [Citation(s) in RCA: 403] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chloroplasts are the organelles that define plants, and they are responsible for photosynthesis as well as numerous other functions. They are the ancestral members of a family of organelles known as plastids. Plastids are remarkably dynamic, existing in strikingly different forms that interconvert in response to developmental or environmental cues. The genetic system of this organelle and its coordination with the nucleocytosolic system, the import and routing of nucleus-encoded proteins, as well as organellar division all contribute to the biogenesis and homeostasis of plastids. They are controlled by the ubiquitin-proteasome system, which is part of a network of regulatory mechanisms that integrate plastid development into broader programmes of cellular and organismal development.
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Affiliation(s)
- Paul Jarvis
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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Kusaba M, Tanaka A, Tanaka R. Stay-green plants: what do they tell us about the molecular mechanism of leaf senescence. PHOTOSYNTHESIS RESEARCH 2013; 117:221-34. [PMID: 23771643 DOI: 10.1007/s11120-013-9862-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/25/2013] [Indexed: 05/08/2023]
Abstract
A practical approach to increasing crop yields is to extend the duration of active photosynthesis. Stay-green is a term that is used to describe mutant and transgenic plants or cultivars with the trait of maintaining their leaves for a longer period of time than the wild-type or crosses from which they are derived. Analyzing stay-green genotypes contributes to our understanding of the molecular mechanism regulating leaf senescence which may allow us to extend the duration of active photosynthesis in crop plants. This article summarizes recent studies on stay-green plants and the insights they provide on the mechanism of leaf senescence. Briefly, mutations suppressing ethylene, abscisic acid, brassinosteroid, and strigolactone signal transduction or those activating cytokinin signaling often lead to stay-green phenotypes indicating a complex signaling network regulating leaf senescence. Developmentally regulated transcription factors, including NAC or WRKY family members, play key roles in the induction of leaf senescence and thus alteration in the activity of these transcription factors also result in stay-green phenotypes. Impairment in the enzymatic steps responsible for chlorophyll breakdown also leads to stay-green phenotypes. Some of these genotypes die in the middle of the process of chlorophyll breakdown due to the accumulation of toxic intermediates, while others appear to stay-green but their photosynthetic activity declines in a manner similar to wild-type plants. Alterations in certain metabolic pathways in chloroplasts (e.g., photosynthesis) can lead to a delayed onset of leaf senescence with maintenance of photosynthetic activity longer than wild-type plants, indicating that chloroplast metabolism can also affect the regulatory mechanism of leaf senescence.
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Affiliation(s)
- Makoto Kusaba
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
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46
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Hörtensteiner S. Update on the biochemistry of chlorophyll breakdown. PLANT MOLECULAR BIOLOGY 2013; 82:505-17. [PMID: 22790503 DOI: 10.1007/s11103-012-9940-z] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 06/28/2012] [Indexed: 05/18/2023]
Abstract
In land plants, chlorophyll is broken down to colorless linear tetrapyrroles in a highly conserved multi-step pathway. The pathway is termed the 'PAO pathway', because the opening of the chlorine macrocycle present in chlorophyll catalyzed by pheophorbide a oxygenase (PAO), the key enzyme of the pathway, provides the characteristic structural basis found in all further downstream chlorophyll breakdown products. To date, most of the biochemical steps of the PAO pathway have been elucidated and genes encoding many of the chlorophyll catabolic enzymes been identified. This review summarizes the current knowledge on the biochemistry of the PAO pathway and provides insight into recent progress made in the field that indicates that the pathway is more complex than thought in the past.
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Affiliation(s)
- Stefan Hörtensteiner
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
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Tang C, Wang X, Duan X, Wang X, Huang L, Kang Z. Functions of the lethal leaf-spot 1 gene in wheat cell death and disease tolerance to Puccinia striiformis. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:2955-69. [PMID: 23811695 PMCID: PMC3697956 DOI: 10.1093/jxb/ert135] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Pheophorbide a oxygenase (PaO) is a key enzyme in chlorophyll catabolism that is known to suppress cell death in maize and Arabidopsis. The catalytic activity of PaO in chlorophyll degradation has been clearly demonstrated, but the function of PaO in the regulation of cell death and plant-microbe interactions is largely unknown. In this study, we characterized a PaO homologue in wheat of the lethal leaf-spot 1 gene, TaLls1, that was induced in leaves infected by Puccinia striiformis f.sp. tritici (Pst) and wounding treatment. The TaLls1 protein contains a conserved Rieske [2Fe-2S] motif and a mononuclear iron-binding site typical of PaOs. Silencing of TaLls1 by virus-induced gene silencing in wheat led to leaf cell death without pathogen attacks, possibly due to the accumulation of pheophorbide a (upstream substrate of PaO), indicating a suppressor role of TaLls1, while overexpression of TaLls1 also triggered cell death in both tobacco and wheat leaves, probably owing to the accumulation of the red chlorophyll catabolite (downstream product of PaO). Further deletion mutant analysis showed that the conserved Rieske domain, but not the iron-binding site, was essential for cell death induction. These results thus suggest a threshold for TaLls1 in maintaining cell homeostasis to adapt in various stresses, and shed new light on the role of TaLls1 in cell death regulation. Furthermore, silencing of TaLls1 in wheat did not change the disease symptoms but enhanced tolerance to Pst via an significant increase in H2O2 generation, elevated cell death occurrence, and upregulation of pathogenesis-related genes.
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Affiliation(s)
- Chunlei Tang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, PR China
| | - Xiaojie Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Xiaoyuan Duan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, PR China
| | - Xiaodong Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, PR China
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48
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Guo CY, Wu GH, Xing J, Li WQ, Tang DZ, Cui BM. A mutation in a coproporphyrinogen III oxidase gene confers growth inhibition, enhanced powdery mildew resistance and powdery mildew-induced cell death in Arabidopsis. PLANT CELL REPORTS 2013; 32:687-702. [PMID: 23462936 DOI: 10.1007/s00299-013-1403-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 02/07/2013] [Accepted: 02/20/2013] [Indexed: 05/27/2023]
Abstract
A gene encoding a coproporphyrinogen III oxidase mediates disease resistance in plants by the salicylic acid pathway. A number of genes that regulate powdery mildew resistance have been identified in Arabidopsis, such as ENHANCED DISEASE RESISTANCE 1 to 3 (EDR1 to 3). To further study the molecular interactions between the powdery mildew pathogen and Arabidopsis, we isolated and characterized a mutant that exhibited enhanced resistance to powdery mildew. The mutant also showed dramatic powdery mildew-induced cell death as well as growth defects and early senescence in the absence of pathogens. We identified the affected gene by map-based cloning and found that the gene encodes a coproporphyrinogen III oxidase, a key enzyme in the tetrapyrrole biosynthesis pathway, previously known as LESION INITIATION 2 (LIN2). Therefore, we designated the mutant lin2-2. Further studies revealed that the lin2-2 mutant also displayed enhanced resistance to Hyaloperonospora arabidopsidis (H.a.) Noco2. Genetic analysis showed that the lin2-2-mediated disease resistance and spontaneous cell death were dependent on PHYTOALEXIN DEFICIENT 4 (PAD4), SALICYLIC ACID INDUCTION-DEFICIENT 2 (SID2), and NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), which are all involved in salicylic acid signaling. Furthermore, the relative expression levels of defense-related genes were induced after powdery mildew infection in the lin2-2 mutant. These data indicated that LIN2 plays an important role in cell death control and defense responses in plants.
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Affiliation(s)
- Chuan-yu Guo
- College of Life Science, Shihezi University, Shihezi, 832003, Xinjiang, PR China.
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49
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Ramel F, Ksas B, Akkari E, Mialoundama AS, Monnet F, Krieger-Liszkay A, Ravanat JL, Mueller MJ, Bouvier F, Havaux M. Light-induced acclimation of the Arabidopsis chlorina1 mutant to singlet oxygen. THE PLANT CELL 2013; 25:1445-62. [PMID: 23590883 PMCID: PMC3663279 DOI: 10.1105/tpc.113.109827] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/11/2013] [Accepted: 03/24/2013] [Indexed: 05/18/2023]
Abstract
Singlet oxygen (¹O₂) is a reactive oxygen species that can function as a stress signal in plant leaves leading to programmed cell death. In microalgae, ¹O₂-induced transcriptomic changes result in acclimation to ¹O₂. Here, using a chlorophyll b-less Arabidopsis thaliana mutant (chlorina1 [ch1]), we show that this phenomenon can also occur in vascular plants. The ch1 mutant is highly photosensitive due to a selective increase in the release of ¹O₂ by photosystem II. Under photooxidative stress conditions, the gene expression profile of ch1 mutant leaves very much resembled the gene responses to ¹O₂ reported in the Arabidopsis mutant flu. Preexposure of ch1 plants to moderately elevated light intensities eliminated photooxidative damage without suppressing ¹O₂ formation, indicating acclimation to ¹O₂. Substantial differences in gene expression were observed between acclimation and high-light stress: A number of transcription factors were selectively induced by acclimation, and contrasting effects were observed for the jasmonate pathway. Jasmonate biosynthesis was strongly induced in ch1 mutant plants under high-light stress and was noticeably repressed under acclimation conditions, suggesting the involvement of this hormone in ¹O₂-induced cell death. This was confirmed by the decreased tolerance to photooxidative damage of jasmonate-treated ch1 plants and by the increased tolerance of the jasmonate-deficient mutant delayed-dehiscence2.
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Affiliation(s)
- Fanny Ramel
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Brigitte Ksas
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Elsy Akkari
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Alexis S. Mialoundama
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg cedex, France
| | - Fabien Monnet
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
- Université d’Avignon et des Pays de Vaucluse, 84000 Avignon, France
| | - Anja Krieger-Liszkay
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Institut de Biologie et de Technologies de Saclay, Centre National de la Recherche Scientifique, Unité de Recherche Associée 2096, Service de Bioénergétique, Biologie Structurale et Mécanisme, F-91191 Gif-sur-Yvette cedex, France
| | - Jean-Luc Ravanat
- Laboratoire Lésions des Acides Nucléiques, Institut Nanosciences et Cryogénie, Service de Chimie Inorganique et Biologique, Unité Mixte de Recherche E3 Commissariat à l’Energie Atomique et aux Energies Alternatives–Université Joseph Fourier, F-38054 Grenoble cedex 9, France
| | - Martin J. Mueller
- Julius-von-Sachs-Institute for Biosciences, Pharmaceutical Biology, Biocenter, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Florence Bouvier
- Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg cedex, France
| | - Michel Havaux
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologies, Laboratoire d’Ecophysiologie Moléculaire des Plantes, F-13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, F-13108 Saint-Paul-lez-Durance, France
- Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
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50
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Hörtensteiner S. The Pathway of Chlorophyll Degradation: Catabolites, Enzymes and Pathway Regulation. PLASTID DEVELOPMENT IN LEAVES DURING GROWTH AND SENESCENCE 2013. [DOI: 10.1007/978-94-007-5724-0_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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