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Yang B, Tan Z, Yan J, Zhang K, Ouyang Z, Fan R, Lu Y, Zhang Y, Yao X, Zhao H, Wang X, Lu S, Guo L. Phospholipase-mediated phosphate recycling during plant leaf senescence. Genome Biol 2024; 25:199. [PMID: 39075580 PMCID: PMC11285201 DOI: 10.1186/s13059-024-03348-x] [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: 02/27/2024] [Accepted: 07/23/2024] [Indexed: 07/31/2024] Open
Abstract
BACKGROUND Phosphorus is a macronutrient necessary for plant growth and development and its availability and efficient use affect crop yields. Leaves are the largest tissue that uses phosphorus in plants, and membrane phospholipids are the main source of cellular phosphorus usage. RESULTS Here we identify a key process for plant cellular phosphorus recycling mediated by membrane phospholipid hydrolysis during leaf senescence. Our results indicate that over 90% of lipid phosphorus, accounting for more than one-third of total cellular phosphorus, is recycled from senescent leaves before falling off the plants. Nonspecific phospholipase C4 (NPC4) and phospholipase Dζ2 (PLDζ2) are highly induced during leaf senescence, and knockouts of PLDζ2 and NPC4 decrease the loss of membrane phospholipids and delay leaf senescence. Conversely, overexpression of PLDζ2 and NPC4 accelerates the loss of phospholipids and leaf senescence, promoting phosphorus remobilization from senescent leaves to young tissues and plant growth. We also show that this phosphorus recycling process in senescent leaves mediated by membrane phospholipid hydrolysis is conserved in plants. CONCLUSIONS These results indicate that PLDζ2- and NPC4-mediated membrane phospholipid hydrolysis promotes phosphorus remobilization from senescent leaves to growing tissues and that the phospholipid hydrolysis-mediated phosphorus recycling improves phosphorus use efficiency in plants.
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Affiliation(s)
- Bao Yang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Department of Biology, University of Missouri, St. Louis, MO, 63121, USA
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Zengdong Tan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Yazhouwan National Laboratory, Sanya, 572025, Hainan, China
| | - Jiayu Yan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Ke Zhang
- Department of Biology, University of Missouri, St. Louis, MO, 63121, USA
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Zhewen Ouyang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Ruyi Fan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Yefei Lu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Yuting Zhang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Yazhouwan National Laboratory, Sanya, 572025, Hainan, China
| | - Xuan Yao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Yazhouwan National Laboratory, Sanya, 572025, Hainan, China
| | - Hu Zhao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Xuemin Wang
- Department of Biology, University of Missouri, St. Louis, MO, 63121, USA
- Donald Danforth Plant Science Center, St. Louis, MO, 63132, USA
| | - Shaoping Lu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
| | - Liang Guo
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
- Yazhouwan National Laboratory, Sanya, 572025, Hainan, China.
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2
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Barros JAS, Cavalcanti JHF, Pimentel KG, Magen S, Soroka Y, Weiss S, Medeiros DB, Nunes-Nesi A, Fernie AR, Avin-Wittenberg T, Araújo WL. The interplay between autophagy and chloroplast vesiculation pathways under dark-induced senescence. PLANT, CELL & ENVIRONMENT 2023; 46:3721-3736. [PMID: 37615309 DOI: 10.1111/pce.14701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/14/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023]
Abstract
In cellular circumstances where carbohydrates are scarce, plants can use alternative substrates for cellular energetic maintenance. In plants, the main protein reserve is present in the chloroplast, which contains most of the total leaf proteins and represents a rich source of nitrogen and amino acids. Autophagy plays a key role in chloroplast breakdown, a well-recognised symptom of both natural and stress-induced plant senescence. Remarkably, an autophagic-independent route of chloroplast degradation associated with chloroplast vesiculation (CV) gene was previously demonstrated. During extended darkness, CV is highly induced in the absence of autophagy, contributing to the early senescence phenotype of atg mutants. To further investigate the role of CV under dark-induced senescence conditions, mutants with low expression of CV (amircv) and double mutants amircv1xatg5 were characterised. Following darkness treatment, no aberrant phenotypes were observed in amircv single mutants; however, amircv1xatg5 double mutants displayed early senescence and altered dismantling of chloroplast and membrane structures under these conditions. Metabolic characterisation revealed that the functional lack of both CV and autophagy leads to higher impairment of amino acid release and differential organic acid accumulation during starvation conditions. The data obtained are discussed in the context of the role of CV and autophagy, both in terms of cellular metabolism and the regulation of chloroplast degradation.
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Affiliation(s)
- Jessica A S Barros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - João Henrique F Cavalcanti
- Instituto de Educação, Agricultura e Ambiente, Universidade Federal do Amazonas, Humaitá, Amazonas, Brazil
| | - Karla G Pimentel
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Sahar Magen
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Yoram Soroka
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Shahar Weiss
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - David B Medeiros
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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3
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Qin Z, Wang T, Zhao Y, Ma C, Shao Q. Molecular Machinery of Lipid Droplet Degradation and Turnover in Plants. Int J Mol Sci 2023; 24:16039. [PMID: 38003229 PMCID: PMC10671748 DOI: 10.3390/ijms242216039] [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: 09/11/2023] [Revised: 10/23/2023] [Accepted: 10/29/2023] [Indexed: 11/26/2023] Open
Abstract
Lipid droplets (LDs) are important organelles conserved across eukaryotes with a fascinating biogenesis and consumption cycle. Recent intensive research has focused on uncovering the cellular biology of LDs, with emphasis on their degradation. Briefly, two major pathways for LD degradation have been recognized: (1) lipolysis, in which lipid degradation is catalyzed by lipases on the LD surface, and (2) lipophagy, in which LDs are degraded by autophagy. Both of these pathways require the collective actions of several lipolytic and proteolytic enzymes, some of which have been purified and analyzed for their in vitro activities. Furthermore, several genes encoding these proteins have been cloned and characterized. In seed plants, seed germination is initiated by the hydrolysis of stored lipids in LDs to provide energy and carbon equivalents for the germinating seedling. However, little is known about the mechanism regulating the LD mobilization. In this review, we focus on recent progress toward understanding how lipids are degraded and the specific pathways that coordinate LD mobilization in plants, aiming to provide an accurate and detailed outline of the process. This will set the stage for future studies of LD dynamics and help to utilize LDs to their full potential.
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Affiliation(s)
| | | | | | - Changle Ma
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
| | - Qun Shao
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
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4
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Lei P, Yu F, Liu X. Recent advances in cellular degradation and nuclear control of leaf senescence. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5472-5486. [PMID: 37453102 DOI: 10.1093/jxb/erad273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Senescence is the final stage of plant growth and development, and is a highly regulated process at the molecular, cellular, and organismal levels. When triggered by age, hormonal, or environmental cues, plants actively adjust their metabolism and gene expression to execute the progression of senescence. Regulation of senescence is vital for the reallocation of nutrients to sink organs, to ensure reproductive success and adaptations to stresses. Identification and characterization of hallmarks of leaf senescence are of great importance for understanding the molecular regulatory mechanisms of plant senescence, and breeding future crops with more desirable senescence traits. Tremendous progress has been made in elucidating the genetic network underpinning the metabolic and cellular changes in leaf senescence. In this review, we focus on three hallmarks of leaf senescence - chlorophyll and chloroplast degradation, loss of proteostasis, and activation of senescence-associated genes (SAGs), and discuss recent findings of the molecular players and the crosstalk of senescence pathways.
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Affiliation(s)
- Pei Lei
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Fei Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
- Institute of Future Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiayan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
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5
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Barros JAS, Chatt EC, Augustine RC, McLoughlin F, Li F, Otegui MS, Vierstra RD. Autophagy during maize endosperm development dampens oxidative stress and promotes mitochondrial clearance. PLANT PHYSIOLOGY 2023; 193:1395-1415. [PMID: 37335933 PMCID: PMC10517192 DOI: 10.1093/plphys/kiad340] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 06/21/2023]
Abstract
The selective turnover of macromolecules by autophagy provides a critical homeostatic mechanism for recycling cellular constituents and for removing superfluous and damaged organelles, membranes, and proteins. To better understand how autophagy impacts seed maturation and nutrient storage, we studied maize (Zea mays) endosperm in its early and middle developmental stages via an integrated multiomic approach using mutants impacting the core macroautophagy factor AUTOPHAGY (ATG)-12 required for autophagosome assembly. Surprisingly, the mutant endosperm in these developmental windows accumulated normal amounts of starch and Zein storage proteins. However, the tissue acquired a substantially altered metabolome, especially for compounds related to oxidative stress and sulfur metabolism, including increases in cystine, dehydroascorbate, cys-glutathione disulfide, glucarate, and galactarate, and decreases in peroxide and the antioxidant glutathione. While changes in the associated transcriptome were mild, the proteome was strongly altered in the atg12 endosperm, especially for increased levels of mitochondrial proteins without a concomitant increase in mRNA abundances. Although fewer mitochondria were seen cytologically, a heightened number appeared dysfunctional based on the accumulation of dilated cristae, consistent with attenuated mitophagy. Collectively, our results confirm that macroautophagy plays a minor role in the accumulation of starch and storage proteins during maize endosperm development but likely helps protect against oxidative stress and clears unneeded/dysfunctional mitochondria during tissue maturation.
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Affiliation(s)
- Jessica A S Barros
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elizabeth C Chatt
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Robert C Augustine
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Fionn McLoughlin
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Faqiang Li
- Department of Genetics, University of Wisconsin, Madison, WI 53706, USA
| | - Marisa S Otegui
- Department of Botany, University of Wisconsin, Madison, WI 53706, USA
- Center for Quantitative Cell Imaging, University of Wisconsin, Madison, WI 53706, USA
| | - Richard D Vierstra
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
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6
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Erlichman OA, Weiss S, Abu Arkia M, Ankary-Khaner M, Soroka Y, Jasinska W, Rosental L, Brotman Y, Avin-Wittenberg T. Autophagy in maternal tissues contributes to Arabidopsis seed development. PLANT PHYSIOLOGY 2023; 193:611-626. [PMID: 37313772 DOI: 10.1093/plphys/kiad350] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/15/2023]
Abstract
Seeds are an essential food source, providing nutrients for germination and early seedling growth. Degradation events in the seed and the mother plant accompany seed development, including autophagy, which facilitates cellular component breakdown in the lytic organelle. Autophagy influences various aspects of plant physiology, specifically nutrient availability and remobilization, suggesting its involvement in source-sink interactions. During seed development, autophagy affects nutrient remobilization from mother plants and functions in the embryo. However, it is impossible to distinguish between the contribution of autophagy in the source (i.e. the mother plant) and the sink tissue (i.e. the embryo) when using autophagy knockout (atg mutant) plants. To address this, we employed an approach to differentiate between autophagy in source and sink tissues. We investigated how autophagy in the maternal tissue affects seed development by performing reciprocal crosses between wild type and atg mutant Arabidopsis (Arabidopsis thaliana) plants. Although F1 seedlings possessed a functional autophagy mechanism, etiolated F1 plants from maternal atg mutants displayed reduced growth. This was attributed to altered protein but not lipid accumulation in the seeds, suggesting autophagy differentially regulates carbon and nitrogen remobilization. Surprisingly, F1 seeds of maternal atg mutants exhibited faster germination, resulting from altered seed coat development. Our study emphasizes the importance of examining autophagy in a tissue-specific manner, revealing valuable insights into the interplay between different tissues during seed development. It also sheds light on the tissue-specific functions of autophagy, offering potential for research into the underlying mechanisms governing seed development and crop yield.
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Affiliation(s)
- Ori Avraham Erlichman
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Shahar Weiss
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Maria Abu Arkia
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Moria Ankary-Khaner
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Yoram Soroka
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Weronika Jasinska
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Leah Rosental
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Yariv Brotman
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
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7
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Khan D, Cai N, Zhu W, Li L, Guan M, Pu X, Chen Q. The role of phytomelatonin receptor 1-mediated signaling in plant growth and stress response. FRONTIERS IN PLANT SCIENCE 2023; 14:1142753. [PMID: 36968396 PMCID: PMC10036441 DOI: 10.3389/fpls.2023.1142753] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Phytomelatonin is a pleiotropic signaling molecule that regulates plant growth, development, and stress response. In plant cells, phytomelatonin is synthesized from tryptophan via several consecutive steps that are catalyzed by tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N-acyltransferase (SNAT), and N-acetylserotonin methyltransferase (ASMT) and/or caffeic acid-3-O-methyltransferase (COMT). Recently, the identification of the phytomelatonin receptor PMTR1 in Arabidopsis has been considered a turning point in plant research, with the function and signal of phytomelatonin emerging as a receptor-based regulatory strategy. In addition, PMTR1 homologs have been identified in several plant species and have been found to regulate seed germination and seedling growth, stomatal closure, leaf senescence, and several stress responses. In this article, we review the recent evidence in our understanding of the PMTR1-mediated regulatory pathways in phytomelatonin signaling under environmental stimuli. Based on structural comparison of the melatonin receptor 1 (MT1) in human and PMTR1 homologs, we propose that the similarity in the three-dimensional structure of the melatonin receptors probably represents a convergent evolution of melatonin recognition in different species.
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Affiliation(s)
| | | | | | | | | | - Xiaojun Pu
- *Correspondence: Xiaojun Pu, ; ; Qi Chen, ;
| | - Qi Chen
- *Correspondence: Xiaojun Pu, ; ; Qi Chen, ;
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8
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Praveen A, Dubey S, Singh S, Sharma VK. Abiotic stress tolerance in plants: a fascinating action of defense mechanisms. 3 Biotech 2023; 13:102. [PMID: 36866326 PMCID: PMC9971429 DOI: 10.1007/s13205-023-03519-w] [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: 09/15/2022] [Accepted: 02/13/2023] [Indexed: 03/02/2023] Open
Abstract
Climate fluctuation mediated abiotic stress consequences loss in crop yields. These stresses have a negative impact on plant growth and development by causing physiological and molecular changes. In this review, we have attempted to outline recent studies (5 years) associated with abiotic stress resistance in plants. We investigated the various factors that contribute to coping with abiotic challenges, such as transcription factors (TFs), microRNAs (miRNAs), epigenetic changes, chemical priming, transgenic breeding, autophagy, and non-coding RNAs. Stress responsive genes are regulated mostly by TFs, and these can be used to enhance stress resistance in plants. Plants express some miRNA during stress imposition that act on stress-related target genes to help them survive. Epigenetic alterations govern gene expression and facilitate stress tolerance. Chemical priming enhances growth in plants by modulating physiological parameters. Transgenic breeding enables identification of genes involved in precise plant responses during stressful situations. In addition to protein coding genes, non-coding RNAs also influence the growth of the plant by causing alterations at gene expression levels. For achieving sustainable agriculture for a rising world population, it is crucial to develop abiotic-resistant crops with anticipated agronomical traits. To achieve this objective, understanding the diverse mechanisms by which plants protect themselves against abiotic stresses is imperative. This review emphasizes on recent progress and future prospects for abiotic stress tolerance and productivity in plants.
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Affiliation(s)
- Afsana Praveen
- Department of Biotechnology and Microbiology, School of Sciences, Noida International University, Yamuna Expressway, Sector 17A, Gautam Budh Nagar, Uttar Pradesh 203201 India
| | - Sonali Dubey
- National Botanical Research Institute, Uttar Pradesh, Lukhnow, 226001 India
| | - Shilpy Singh
- Department of Biotechnology and Microbiology, School of Sciences, Noida International University, Yamuna Expressway, Sector 17A, Gautam Budh Nagar, Uttar Pradesh 203201 India
| | - Varun Kumar Sharma
- Department of Biotechnology and Microbiology, School of Sciences, Noida International University, Yamuna Expressway, Sector 17A, Gautam Budh Nagar, Uttar Pradesh 203201 India
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9
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Li L, Lee CP, Ding X, Qin Y, Wijerathna-Yapa A, Broda M, Otegui MS, Millar AH. Defects in autophagy lead to selective in vivo changes in turnover of cytosolic and organelle proteins in Arabidopsis. THE PLANT CELL 2022; 34:3936-3960. [PMID: 35766863 PMCID: PMC9516138 DOI: 10.1093/plcell/koac185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/21/2022] [Indexed: 05/26/2023]
Abstract
Identification of autophagic protein cargo in plants in autophagy-related genes (ATG) mutants is complicated by changes in protein synthesis and protein degradation. To detect autophagic cargo, we measured protein degradation rate in shoots and roots of Arabidopsis (Arabidopsis thaliana) atg5 and atg11 mutants. These data show that less than a quarter of proteins changing in abundance are probable cargo and revealed roles of ATG11 and ATG5 in degradation of specific glycolytic enzymes and of other cytosol, chloroplast, and ER-resident proteins, and a specialized role for ATG11 in degradation of proteins from mitochondria and chloroplasts. Protein localization in transformed protoplasts and degradation assays in the presence of inhibitors confirm a role for autophagy in degrading glycolytic enzymes. Autophagy induction by phosphate (Pi) limitation changed metabolic profiles and the protein synthesis and degradation rates of atg5 and atg11 plants. A general decrease in the abundance of amino acids and increase in secondary metabolites in autophagy mutants was consistent with altered catabolism and changes in energy conversion caused by reduced degradation rate of specific proteins. Combining measures of changes in protein abundance and degradation rates, we also identify ATG11 and ATG5-associated protein cargo of low Pi-induced autophagy in chloroplasts and ER-resident proteins involved in secondary metabolism.
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Affiliation(s)
- Lei Li
- Authors for correspondence (L.L.) and (A.H.M)
| | - Chun Pong Lee
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, Crawley, WA 6009, Australia
| | - Xinxin Ding
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Yu Qin
- Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Akila Wijerathna-Yapa
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, Crawley, WA 6009, Australia
| | - Martyna Broda
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, Crawley, WA 6009, Australia
| | - Marisa S Otegui
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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10
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Barros JAS, Cavalcanti JHF, Pimentel KG, Medeiros DB, Silva JCF, Condori-Apfata JA, Lapidot-Cohen T, Brotman Y, Nunes-Nesi A, Fernie AR, Avin-Wittenberg T, Araújo WL. The significance of WRKY45 transcription factor in metabolic adjustments during dark-induced leaf senescence. PLANT, CELL & ENVIRONMENT 2022; 45:2682-2695. [PMID: 35818668 DOI: 10.1111/pce.14393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Plants are constantly exposed to environmental changes that affect their performance. Metabolic adjustments are crucial to controlling energy homoeostasis and plant survival, particularly during stress. Under carbon starvation, coordinated reprogramming is initiated to adjust metabolic processes, which culminate in premature senescence. Notwithstanding, the regulatory networks that modulate transcriptional control during low energy remain poorly understood. Here, we show that the WRKY45 transcription factor is highly induced during both developmental and dark-induced senescence. The overexpression of Arabidopsis WRKY45 resulted in an early senescence phenotype characterized by a reduction of maximum photochemical efficiency of photosystem II and chlorophyll levels in the later stages of darkness. The detailed metabolic characterization showed significant changes in amino acids coupled with the accumulation of organic acids in WRKY45 overexpression lines during dark-induced senescence. Furthermore, the markedly upregulation of alternative oxidase (AOX1a, AOX1d) and electron transfer flavoprotein/ubiquinone oxidoreductase (ETFQO) genes suggested that WRKY45 is associated with a dysregulation of mitochondrial signalling and the activation of alternative respiration rather than amino acids catabolism regulation. Collectively our results provided evidence that WRKY45 is involved in the plant metabolic reprogramming following carbon starvation and highlight the potential role of WRKY45 in the modulation of mitochondrial signalling pathways.
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Affiliation(s)
- Jessica A S Barros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - João Henrique F Cavalcanti
- Instituto de Educação, Agricultura e Ambiente, Universidade Federal do Amazonas, Humaitá, Amazonas, Brazil
| | - Karla G Pimentel
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - David B Medeiros
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - José C F Silva
- Departamento de Bioquímica e Biologia Molecular/BIOAGRO, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Jorge A Condori-Apfata
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Taly Lapidot-Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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11
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Desjardins SM, Laamanen CA, Basiliko N, Senhorinho GNA, Scott JA. Dark stress for improved lipid quantity and quality in bioprospected acid-tolerant green microalgae. FEMS Microbiol Lett 2022; 369:6615457. [PMID: 35746875 DOI: 10.1093/femsle/fnac057] [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: 11/03/2021] [Revised: 05/26/2022] [Accepted: 06/18/2022] [Indexed: 11/14/2022] Open
Abstract
The cost of microalgae cultivation is one of the largest limitations to achieving sustainable, large-scale microalgae production of commercially desirable lipids. Utilizing CO2 as a 'free' carbon source from waste industrial flue gas emissions can offer wide-ranging cost savings. However, these gas streams typically create acidic environments, in which most microalgae cannot survive due to the concentration of CO2 and the presence of other acidic gasses such as NO2 and SO2. To address this situation, we investigated growth of a mixed acid-tolerant green microalgal culture (91% dominated by a single Coccomyxa sp. taxon) bioprospected at pH 2.8 from an acid mine drainage impacted water body. The culture was grown at pH 2.5 and fed with a simulated flue gas containing 6% CO2 and 94% N2. On reaching the end of the exponential growth phase, the culture was exposed to either continued light-dark cycle conditions or continual dark conditions. After three days in the dark, the biomass consisted of 28% of lipids, which was 42% higher than at the end of the exponential phase and 55% higher than the maximum lipid content achieved under light/dark conditions. The stress caused by being continually in the dark also favoured the production of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs; 19.47% and 21.04%, respectively, after 7 days) compared to 7-days of light-dark treatment (1.94% and 9.53%, respectively) and showed an increase in nitrogen content (C:N ratio of 6.4) compared to light-dark treatment (C:N ratio of 11.9). The results of the research indicate that use of acid tolerant microalgae overcomes issues using flue gasses that will create an acidic environment and that applying dark stress is a low-cost stressor stimulates production of desirable dietary lipids.
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Affiliation(s)
- Sabrina M Desjardins
- School of Engineering, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada
| | - Corey A Laamanen
- School of Engineering, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada
| | - Nathan Basiliko
- Department of Biology, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada
| | - Gerusa N A Senhorinho
- School of Engineering, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada
| | - John A Scott
- School of Engineering, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON P3E 2C6, Canada
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12
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Alseekh S, Zhu F, Vallarino JG, Sokolowska EM, Yoshida T, Bergmann S, Wendenburg R, Bolze A, Skirycz A, Avin-Wittenberg T, Fernie AR. Autophagy modulates the metabolism and growth of tomato fruit during development. HORTICULTURE RESEARCH 2022; 9:uhac129. [PMID: 35928403 PMCID: PMC9343920 DOI: 10.1093/hr/uhac129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Although autophagy is a conserved mechanism operating across eukaryotes, its effects on crops and especially their metabolism has received relatively little attention. Indeed, whilst a few recent studies have used systems biology tools to look at the consequences of lack of autophagy in maize these focused on leaf tissues rather than the kernels. Here we utilized RNA interference (RNAi) to generate tomato plants that were deficient in the autophagy-regulating protease ATG4. Plants displayed an early senescence phenotype yet relatively mild changes in the foliar metabolome and were characterized by a reduced fruit yield phenotype. Metabolite profiling indicated that metabolites of ATG4-RNAi tomato leaves just exhibited minor alterations while that of fruit displayed bigger difference compared to the WT. In detail, many primary metabolites exhibited decreases in the ATG4-RNAi lines, such as proline, tryptophan and phenylalanine, while the representative secondary metabolites (quinic acid and 3-trans-caffeoylquinic acid) were present at substantially higher levels in ATG4-RNAi green fruits than in WT. Moreover, transcriptome analysis indicated that the most prominent differences were in the significant upregulation of organelle degradation genes involved in the proteasome or chloroplast vesiculation pathways, which was further confirmed by the reduced levels of chloroplastic proteins in the proteomics data. Furthermore, integration analysis of the metabolome, transcriptome and proteome data indicated that ATG4 significantly affected the lipid metabolism, chlorophyll binding proteins and chloroplast biosynthesis. These data collectively lead us to propose a more sophisticated model to explain the cellular co-ordination of the process of autophagy.
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Affiliation(s)
| | | | - José G Vallarino
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | | | - Takuya Yoshida
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Susan Bergmann
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Regina Wendenburg
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Antje Bolze
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Aleksandra Skirycz
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Boyce Thompson Institute, 14850, Ithaca, US
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13
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Xu C, Fan J. Links between autophagy and lipid droplet dynamics. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2848-2858. [PMID: 35560198 DOI: 10.1093/jxb/erac003] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/06/2022] [Indexed: 06/15/2023]
Abstract
Autophagy is a catabolic process in which cytoplasmic components are delivered to vacuoles or lysosomes for degradation and nutrient recycling. Autophagy-mediated degradation of membrane lipids provides a source of fatty acids for the synthesis of energy-rich, storage lipid esters such as triacylglycerol (TAG). In eukaryotes, storage lipids are packaged into dynamic subcellular organelles, lipid droplets. In times of energy scarcity, lipid droplets can be degraded via autophagy in a process termed lipophagy to release fatty acids for energy production via fatty acid β-oxidation. On the other hand, emerging evidence suggests that lipid droplets are required for the efficient execution of autophagic processes. Here, we review recent advances in our understanding of metabolic interactions between autophagy and TAG storage, and discuss mechanisms of lipophagy. Free fatty acids are cytotoxic due to their detergent-like properties and their incorporation into lipid intermediates that are toxic at high levels. Thus, we also discuss how cells manage lipotoxic stresses during autophagy-mediated mobilization of fatty acids from lipid droplets and organellar membranes for energy generation.
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Affiliation(s)
- Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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14
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Magen S, Seybold H, Laloum D, Avin-Wittenberg T. Metabolism and autophagy in plants - A perfect match. FEBS Lett 2022; 596:2133-2151. [PMID: 35470431 DOI: 10.1002/1873-3468.14359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 01/18/2023]
Abstract
Autophagy is a eukaryotic cellular transport mechanism that delivers intracellular macromolecules, proteins, and even organelles to a lytic organelle (vacuole in yeast and plants/lysosome in animals) for degradation and nutrient recycling. The process is mediated by highly conserved Autophagy-Related (ATG) proteins. In plants, autophagy maintains cellular homeostasis under favorable conditions, guaranteeing normal plant growth and fitness. Severe stress such as nutrient starvation and plant senescence further induce it, thus ensuring plant survival under unfavorable conditions by providing nutrients through the removal of damaged or aged proteins, or organelles. In this article, we examine the interplay between metabolism and autophagy, focusing on the different aspects of this reciprocal relationship. We show that autophagy has a strong influence on a range of metabolic processes, whereas, at the same time, even single metabolites can activate autophagy. We highlight the involvement of ATG genes in metabolism, examine the role of the macronutrients carbon and nitrogen, as well as various micronutrients, and take a closer look at how the interaction between autophagy and metabolism impacts on plant phenotypes and yield.
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Affiliation(s)
- Sahar Magen
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Heike Seybold
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Daniel Laloum
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Israel
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15
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Laloum D, Magen S, Soroka Y, Avin-Wittenberg T. Exploring the Contribution of Autophagy to the Excess-Sucrose Response in Arabidopsis thaliana. Int J Mol Sci 2022; 23:ijms23073891. [PMID: 35409249 PMCID: PMC8999498 DOI: 10.3390/ijms23073891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/13/2022] [Accepted: 03/29/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is an essential intracellular eukaryotic recycling mechanism, functioning in, among others, carbon starvation. Surprisingly, although autophagy-deficient plants (atg mutants) are hypersensitive to carbon starvation, metabolic analysis revealed that they accumulate sugars under such conditions. In plants, sugars serve as both an energy source and as signaling molecules, affecting many developmental processes, including root and shoot formation. We thus set out to understand the interplay between autophagy and sucrose excess, comparing wild-type and atg mutant seedlings. The presented work showed that autophagy contributes to primary root elongation arrest under conditions of exogenous sucrose and glucose excess but not during fructose or mannitol treatment. Minor or no alterations in starch and primary metabolites were observed between atg mutants and wild-type plants, indicating that the sucrose response relates to its signaling and not its metabolic role. Extensive proteomic analysis of roots performed to further understand the mechanism found an accumulation of proteins essential for ROS reduction and auxin maintenance, which are necessary for root elongation, in atg plants under sucrose excess. The analysis also suggested mitochondrial and peroxisomal involvement in the autophagy-mediated sucrose response. This research increases our knowledge of the complex interplay between autophagy and sugar signaling in plants.
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16
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Mugume Y, Ding G, Dueñas ME, Liu M, Lee YJ, Nikolau BJ, Bassham DC. Complex Changes in Membrane Lipids Associated with the Modification of Autophagy in Arabidopsis. Metabolites 2022; 12:metabo12020190. [PMID: 35208263 PMCID: PMC8876039 DOI: 10.3390/metabo12020190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/26/2022] [Accepted: 02/11/2022] [Indexed: 12/28/2022] Open
Abstract
Autophagy is a conserved mechanism among eukaryotes that degrades and recycles cytoplasmic components. Autophagy is known to influence the plant metabolome, including lipid content; however, its impact on the plant lipidome is not fully understood, and most studies have analyzed a single or few mutants defective in autophagy. To gain more insight into the effect of autophagy on lipid concentrations and composition, we quantitatively profiled glycerolipids from multiple Arabidopsis thaliana mutants altered in autophagy and compared them with wild-type seedlings under nitrogen replete (+N; normal growth) and nitrogen starvation (−N; autophagy inducing) conditions. Mutants include those in genes of the core autophagy pathway, together with other genes that have been reported to affect autophagy. Using Matrix-Assisted Laser Desorption/Ionization—Mass Spectrometry (MALDI-MS), we imaged the cellular distribution of specific lipids in situ and demonstrated that autophagy and nitrogen treatment did not affect their spatial distribution within Arabidopsis seedling leaves. We observed changes, both increases and decreases, in the relative amounts of different lipid species in the mutants compared to WT both in +N and −N conditions, although more changes were seen in −N conditions. The relative amounts of polyunsaturated and very long chain lipids were significantly reduced in autophagy-disrupted mutants compared to WT plants. Collectively, our results provide additional evidence that autophagy affects plant lipid content and that autophagy likely affects lipid properties such as chain length and unsaturation.
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Affiliation(s)
- Yosia Mugume
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA;
| | - Geng Ding
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (G.D.); (B.J.N.)
| | - Maria Emilia Dueñas
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; (M.E.D.); (Y.-J.L.)
| | - Meiling Liu
- Department of Statistics, Iowa State University, Ames, IA 50011, USA;
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Young-Jin Lee
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; (M.E.D.); (Y.-J.L.)
| | - Basil J. Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (G.D.); (B.J.N.)
- Center for Metabolic Biology, Iowa State University, Ames, IA 50011, USA
| | - Diane C. Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA;
- Correspondence: ; Tel.: +1-515-294-7461
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17
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Yang Y, Xiang Y, Niu Y. An Overview of the Molecular Mechanisms and Functions of Autophagic Pathways in Plants. PLANT SIGNALING & BEHAVIOR 2021; 16:1977527. [PMID: 34617497 PMCID: PMC9208794 DOI: 10.1080/15592324.2021.1977527] [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: 07/28/2021] [Revised: 08/29/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
Autophagy is an evolutionarily conserved pathway for the degradation of damaged or toxic components. Under normal conditions, autophagy maintains cellular homeostasis. It can be triggered by senescence and various stresses. In the process of autophagy, autophagy-related (ATG) proteins not only function as central signal regulators but also participate in the development of complex survival mechanisms when plants suffer from adverse environments. Therefore, ATGs play significant roles in metabolism, development and stress tolerance. In the past decade, both the molecular mechanisms of autophagy and a large number of components involved in the assembly of autophagic vesicles have been identified. In recent studies, an increasing number of components, mechanisms, and receptors have appeared in the autophagy pathway. In this paper, we mainly review the recent progress of research on the molecular mechanisms of plant autophagy, as well as its function under biotic stress and abiotic stress.
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Affiliation(s)
- Yang Yang
- Moe Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences,Lanzhou University, Lanzhou, China
| | - Yun Xiang
- Moe Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences,Lanzhou University, Lanzhou, China
| | - Yue Niu
- Moe Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences,Lanzhou University, Lanzhou, China
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18
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Wijerathna-Yapa A, Signorelli S, Fenske R, Ganguly DR, Stroeher E, Li L, Pogson BJ, Duncan O, Millar AH. Autophagy mutants show delayed chloroplast development during de-etiolation in carbon limiting conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:459-477. [PMID: 34365695 DOI: 10.1111/tpj.15452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
Autophagy is a conserved catabolic process that plays an essential role under nutrient starvation conditions and influences different developmental processes. We observed that seedlings of autophagy mutants (atg2, atg5, atg7, and atg9) germinated in the dark showed delayed chloroplast development following illumination. The delayed chloroplast development was characterized by a decrease in photosynthetic and chlorophyll biosynthetic proteins, lower chlorophyll content, reduced chloroplast size, and increased levels of proteins involved in lipid biosynthesis. Confirming the biological impact of these differences, photosynthetic performance was impaired in autophagy mutants 12 h post-illumination. We observed that while gene expression for photosynthetic machinery during de-etiolation was largely unaffected in atg mutants, several genes involved in photosystem assembly were transcriptionally downregulated. We also investigated if the delayed chloroplast development could be explained by lower lipid import to the chloroplast or lower triglyceride (TAG) turnover. We observed that the limitations in the chloroplast lipid import imposed by trigalactosyldiacylglycerol1 are unlikely to explain the delay in chloroplast development. However, we found that lower TAG mobility in the triacylglycerol lipase mutant sugardependent1 significantly affected de-etiolation. Moreover, we showed that lower levels of carbon resources exacerbated the slow greening phenotype whereas higher levels of carbon resources had an opposite effect. This work suggests a lack of autophagy machinery limits chloroplast development during de-etiolation, and this is exacerbated by limited lipid turnover (lipophagy) that physically or energetically restrains chloroplast development.
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Affiliation(s)
- Akila Wijerathna-Yapa
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Santiago Signorelli
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
- Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Uruguay
| | - Ricarda Fenske
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Diep R Ganguly
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Elke Stroeher
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - Lei Li
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
- Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, 300071, Tianjin, PR China
| | - Barry J Pogson
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, School of Molecular Science, The University of Western Australia, 6009, Crawley, WA, Australia
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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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Gomez RE, Lupette J, Chambaud C, Castets J, Ducloy A, Cacas JL, Masclaux-Daubresse C, Bernard A. How Lipids Contribute to Autophagosome Biogenesis, a Critical Process in Plant Responses to Stresses. Cells 2021; 10:1272. [PMID: 34063958 PMCID: PMC8224036 DOI: 10.3390/cells10061272] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/03/2021] [Accepted: 05/17/2021] [Indexed: 01/18/2023] Open
Abstract
Throughout their life cycle, plants face a tremendous number of environmental and developmental stresses. To respond to these different constraints, they have developed a set of refined intracellular systems including autophagy. This pathway, highly conserved among eukaryotes, is induced by a wide range of biotic and abiotic stresses upon which it mediates the degradation and recycling of cytoplasmic material. Central to autophagy is the formation of highly specialized double membrane vesicles called autophagosomes which select, engulf, and traffic cargo to the lytic vacuole for degradation. The biogenesis of these structures requires a series of membrane remodeling events during which both the quantity and quality of lipids are critical to sustain autophagy activity. This review highlights our knowledge, and raises current questions, regarding the mechanism of autophagy, and its induction and regulation upon environmental stresses with a particular focus on the fundamental contribution of lipids. How autophagy regulates metabolism and the recycling of resources, including lipids, to promote plant acclimation and resistance to stresses is further discussed.
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Affiliation(s)
- Rodrigo Enrique Gomez
- Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS, Université de Bordeaux, F-33140 Villenave d’Ornon, France; (R.E.G.); (J.L.); (C.C.); (J.C.)
| | - Josselin Lupette
- Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS, Université de Bordeaux, F-33140 Villenave d’Ornon, France; (R.E.G.); (J.L.); (C.C.); (J.C.)
| | - Clément Chambaud
- Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS, Université de Bordeaux, F-33140 Villenave d’Ornon, France; (R.E.G.); (J.L.); (C.C.); (J.C.)
| | - Julie Castets
- Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS, Université de Bordeaux, F-33140 Villenave d’Ornon, France; (R.E.G.); (J.L.); (C.C.); (J.C.)
| | - Amélie Ducloy
- Institut Jean-Pierre Bourgin, UMR 1318 AgroParisTech-INRAE, Université Paris-Saclay, 78000 Versailles, France; (A.D.); (J.-L.C.); (C.M.-D.)
| | - Jean-Luc Cacas
- Institut Jean-Pierre Bourgin, UMR 1318 AgroParisTech-INRAE, Université Paris-Saclay, 78000 Versailles, France; (A.D.); (J.-L.C.); (C.M.-D.)
| | - Céline Masclaux-Daubresse
- Institut Jean-Pierre Bourgin, UMR 1318 AgroParisTech-INRAE, Université Paris-Saclay, 78000 Versailles, France; (A.D.); (J.-L.C.); (C.M.-D.)
| | - Amélie Bernard
- Laboratoire de Biogenèse Membranaire, UMR 5200, CNRS, Université de Bordeaux, F-33140 Villenave d’Ornon, France; (R.E.G.); (J.L.); (C.C.); (J.C.)
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