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Wittmann D, Geigenberger P, Grimm B. NTRC and TRX-f Coordinately Affect the Levels of Enzymes of Chlorophyll Biosynthesis in a Light-Dependent Manner. Cells 2023; 12:1670. [PMID: 37371140 DOI: 10.3390/cells12121670] [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: 03/29/2023] [Revised: 05/02/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Redox regulation of plastid gene expression and different metabolic pathways promotes many activities of redox-sensitive proteins. We address the question of how the plastid redox state and the contributing reducing enzymes control the enzymes of tetrapyrrole biosynthesis (TBS). In higher plants, this metabolic pathway serves to produce chlorophyll and heme, among other essential end products. Because of the strictly light-dependent synthesis of chlorophyll, tight control of TBS requires a diurnal balanced supply of the precursor 5-aminolevulinic acid (ALA) to prevent the accumulation of photoreactive metabolic intermediates in darkness. We report on some TBS enzymes that accumulate in a light intensity-dependent manner, and their contents decrease under oxidizing conditions of darkness, low light conditions, or in the absence of NADPH-dependent thioredoxin reductase (NTRC) and thioredoxin f1 (TRX-f1). Analysis of single and double trxf1 and ntrc mutants revealed a decreased content of the early TBS enzymes glutamyl-tRNA reductase (GluTR) and 5-aminolevulinic acid dehydratase (ALAD) instead of an exclusive decrease in enzyme activity. This effect was dependent on light conditions and strongly attenuated after transfer to high light intensities. Thus, it is suggested that a deficiency of plastid-localized thiol-redox transmitters leads to enhanced degradation of TBS enzymes rather than being directly caused by lower catalytic activity. The effects of the proteolytic activity of the Clp protease on TBS enzymes were studied by using Clp subunit-deficient mutants. The simultaneous lack of TRX and Clp activities in double mutants confirms the Clp-induced degradation of some TBS proteins in the absence of reductive activity of TRXs. In addition, we verified previous observations that decreased chlorophyll and heme levels in ntrc could be reverted to WT levels in the ntrc/Δ2cp triple mutant. The decreased synthesis of 5-aminolevulinic acid and porphobilinogen in ntrc was completely restored in ntrc/Δ2cp and correlated with WT-like levels of GluTR, ALAD, and other TBS proteins.
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Affiliation(s)
- Daniel Wittmann
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Peter Geigenberger
- Department Biology I, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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2
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Han H, Zhou Y, Liu H, Chen X, Wang Q, Zhuang H, Sun X, Ling Q, Zhang H, Wang B, Wang J, Tang Y, Wang H, Liu H. Transcriptomics and Metabolomics Analysis Provides Insight into Leaf Color and Photosynthesis Variation of the Yellow-Green Leaf Mutant of Hami Melon ( Cucumis melo L.). PLANTS (BASEL, SWITZERLAND) 2023; 12:1623. [PMID: 37111847 PMCID: PMC10143263 DOI: 10.3390/plants12081623] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 06/16/2023]
Abstract
Leaf color mutants are ideal materials for studying the regulatory mechanism of chloroplast development and photosynthesis. We isolated a cucumis melo spontaneous mutant (MT), which showed yellow-green leaf phenotype in the whole growing period and could be inherited stably. We compared its leaves with the wild type (WT) in terms of cytology, physiology, transcriptome and metabolism. The results showed that the thylakoid grana lamellae of MT were loosely arranged and fewer in number than WT. Physiological experiments also showed that MT had less chlorophyll content and more accumulation of reactive oxygen species (ROS) than WT. Furthermore, the activity of several key enzymes in C4 photosynthetic carbon assimilation pathway was more enhanced in MT than WT. Transcriptomic and metabolomic analyses showed that differential expression genes and differentially accumulated metabolites in MT were mainly co-enriched in the pathways related to photosystem-antenna proteins, central carbon metabolism, glutathione metabolism, phenylpropanoid biosynthesis and flavonoid metabolism. We also analyzed several key proteins in photosynthesis and chloroplast transport by Western blot. In summary, the results may provide a new insight into the understanding of how plants respond to the impaired photosynthesis by regulating chloroplast development and photosynthetic carbon assimilation pathways.
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Affiliation(s)
- Hongwei Han
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yuan Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huifang Liu
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xianjun Chen
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qiang Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hongmei Zhuang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Xiaoxia Sun
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
| | - Qihua Ling
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200030, China
| | - Huijun Zhang
- School of Life Science, Huaibei Normal University, Huaibei 235000, China
| | - Baike Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Juan Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Yaping Tang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Hao Wang
- Key Laboratory of Horticulture Crop Genomics and Genetic Improvement in Xinjiang, Institute of Horticultural Crops, Xinjiang Academy of Agricultural Sciences, Urumqi 830002, China
| | - Huiying Liu
- Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Corps, Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China; (H.H.)
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3
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Function of ALA Content in Porphyrin Metabolism Regulation of Ananas comosus var. bracteatus. Int J Mol Sci 2023; 24:ijms24065274. [PMID: 36982348 PMCID: PMC10049405 DOI: 10.3390/ijms24065274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/23/2023] [Accepted: 03/01/2023] [Indexed: 03/12/2023] Open
Abstract
Chlorophyll and heme are essential molecules for photosynthesis and respiration, which are competing branches of the porphyrin metabolism pathway. Chlorophyll and heme balance regulation is very important for the growth and development of plants. The chimeric leaves of Ananas comosus var. bracteatus were composed of central photosynthetic tissue (PT) and marginal albino tissue (AT), which were ideal materials for the study of porphyrin metabolism mechanisms. In this study, the regulatory function of ALA content on porphyrin metabolism (chlorophyll and heme balance) was revealed by comparing PT and AT, 5-Aminolevulinic Acid (ALA) exogenous supply, and interference of hemA expression. The AT remained similar in porphyrin metabolism flow level to the PT by keeping an equal ALA content in both tissues, which was very important for the normal growth of the chimeric leaves. As the chlorophyll biosynthesis in AT was significantly inhibited, the porphyrin metabolism flow was directed more toward the heme branch. Both tissues had similar Mg2+ contents; however, Fe2+ content was significantly increased in the AT. The chlorophyll biosynthesis inhibition in the white tissue was not due to a lack of Mg2+ and ALA. A 1.5-fold increase in ALA content inhibited chlorophyll biosynthesis while promoting heme biosynthesis and hemA expression. The doubling of ALA content boosted chlorophyll biosynthesis while decreasing hemA expression and heme content. HemA expression interference resulted in a higher ALA content and a lower chlorophyll content, while the heme content remained at a relatively low and stable level. Conclusively, a certain amount of ALA was important for the stability of porphyrin metabolism and the normal growth of plants. The ALA content appears to be able to regulate chlorophyll and heme content by bidirectionally regulating porphyrin metabolism branch direction.
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Lin N, Wang M, Jiang J, Zhou Q, Yin J, Li J, Lian J, Xue Y, Chai Y. Downregulation of Brassica napus MYB69 ( BnMYB69) increases biomass growth and disease susceptibility via remodeling phytohormone, chlorophyll, shikimate and lignin levels. FRONTIERS IN PLANT SCIENCE 2023; 14:1157836. [PMID: 37077631 PMCID: PMC10108680 DOI: 10.3389/fpls.2023.1157836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/07/2023] [Indexed: 05/03/2023]
Abstract
MYB transcription factors are major actors regulating plant development and adaptability. Brassica napus is a staple oil crop and is hampered by lodging and diseases. Here, four B. napus MYB69 (BnMYB69s) genes were cloned and functionally characterized. They were dominantly expressed in stems during lignification. BnMYB69 RNA interference (BnMYB69i) plants showed considerable changes in morphology, anatomy, metabolism and gene expression. Stem diameter, leaves, roots and total biomass were distinctly larger, but plant height was significantly reduced. Contents of lignin, cellulose and protopectin in stems were significantly reduced, accompanied with decrease in bending resistance and Sclerotinia sclerotiorum resistance. Anatomical detection observed perturbation in vascular and fiber differentiation in stems, but promotion in parenchyma growth, accompanied with changes in cell size and cell number. In shoots, contents of IAA, shikimates and proanthocyanidin were reduced, while contents of ABA, BL and leaf chlorophyll were increased. qRT-PCR revealed changes in multiple pathways of primary and secondary metabolisms. IAA treatment could recover many phenotypes and metabolisms of BnMYB69i plants. However, roots showed trends opposite to shoots in most cases, and BnMYB69i phenotypes were light-sensitive. Conclusively, BnMYB69s might be light-regulated positive regulators of shikimates-related metabolisms, and exert profound influences on various internal and external plant traits.
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Affiliation(s)
- Na Lin
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Mu Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Jiayi Jiang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Qinyuan Zhou
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Jiaming Yin
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Jiana Li
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
- Engineering Research Center of South Upland Agriculture, Ministry of Education, Academy of Agricultural Science, Southwest University, Chongqing, China
| | - Jianping Lian
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Yufei Xue
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
| | - Yourong Chai
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China
- Engineering Research Center of South Upland Agriculture, Ministry of Education, Academy of Agricultural Science, Southwest University, Chongqing, China
- *Correspondence: Yourong Chai,
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Sinha N, Eirich J, Finkemeier I, Grimm B. Glutamate 1-semialdehyde aminotransferase is connected to GluTR by GluTR-binding protein and contributes to the rate-limiting step of 5-aminolevulinic acid synthesis. THE PLANT CELL 2022; 34:4623-4640. [PMID: 35972388 PMCID: PMC9614494 DOI: 10.1093/plcell/koac237] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 07/28/2022] [Indexed: 06/01/2023]
Abstract
Tetrapyrroles play fundamental roles in crucial processes including photosynthesis, respiration, and catalysis. In plants, 5-aminolevulinic acid (ALA) is the common precursor of tetrapyrroles. ALA is synthesized from activated glutamate by the enzymes glutamyl-tRNA reductase (GluTR) and glutamate-1-semialdehyde aminotransferase (GSAAT). ALA synthesis is recognized as the rate-limiting step in this pathway. We aimed to explore the contribution of GSAAT to the control of ALA synthesis and the formation of a protein complex with GluTR. In Arabidopsis thaliana, two genes encode GSAAT isoforms: GSA1 and GSA2. A comparison of two GSA knockout mutants with the wild-type revealed the correlation of reduced GSAAT activity and ALA-synthesizing capacity in leaves with lower chlorophyll content. Growth and green pigmentation were more severely impaired in gsa2 than in gsa1, indicating the predominant role of GSAAT2 in ALA synthesis. Interestingly, GluTR accumulated to higher levels in gsa2 than in the wild-type and was mainly associated with the plastid membrane. We propose that the GSAAT content modulates the amount of soluble GluTR available for ALA synthesis. Several different biochemical approaches revealed the GSAAT-GluTR interaction through the assistance of GluTR-binding protein (GBP). A modeled structure of the tripartite protein complex indicated that GBP mediates the stable association of GluTR and GSAAT for adequate ALA synthesis.
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Affiliation(s)
- Neha Sinha
- Institute of Biology/Plant Physiology, Humboldt-University Berlin, 10115 Berlin, Germany
| | - Jürgen Eirich
- Institute for Plant Biology and Biotechnology, Plant Physiology, Westfälische Wilhelms-Universität, 48149 Muenster, Germany
| | - Iris Finkemeier
- Institute for Plant Biology and Biotechnology, Plant Physiology, Westfälische Wilhelms-Universität, 48149 Muenster, Germany
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6
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Song X, Li N, Zhang Y, Liang Y, Zhou R, Yu T, Shen S, Feng S, Zhang Y, Li X, Lin H, Wang X. Transcriptomics and Genomics Analysis Uncover the Differentially Expressed Chlorophyll and Carotenoid-Related Genes in Celery. Int J Mol Sci 2022; 23:ijms23168986. [PMID: 36012264 PMCID: PMC9409461 DOI: 10.3390/ijms23168986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Celery (Apium graveolens L.), a plant from Apiaceae, is one of the most important vegetables and is grown worldwide. Carotenoids can capture light energy and transfer it to chlorophyll, which plays a central role in photosynthesis. Here, by performing transcriptomics and genomics analysis, we identified and conducted a comprehensive analysis of chlorophyll and carotenoid-related genes in celery and six representative species. Significantly, different contents and gene expression patterns were found among three celery varieties. In total, 237 and 290 chlorophyll and carotenoid-related genes were identified in seven species. No notable gene expansion of chlorophyll biosynthesis was detected in examined species. However, the gene encoding ζ-carotene desaturase (ZDS) enzyme in carotenoid was expanded in celery. Comparative genomics and RNA-seq analyses revealed 16 and 5 key genes, respectively, regulating chlorophyll and carotenoid. An intriguing finding is that chlorophyll and carotenoid-related genes were coordinately regulated by transcriptional factors, which could be distinctively classified into positive- and negative-regulation groups. Six CONSTANS (CO)-like transcription factors co-regulated chlorophyll and carotenoid-related genes were identified in celery. In conclusion, this study provides new insights into the regulation of chlorophyll and carotenoid by transcription factors.
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Affiliation(s)
- Xiaoming Song
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Nan Li
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Yingchao Zhang
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Yi Liang
- Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing 100097, China
| | - Rong Zhou
- Department of Food Science, Aarhus University, 8200 Aarhus, Denmark
| | - Tong Yu
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Shaoqin Shen
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Shuyan Feng
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Yu Zhang
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Xiuqing Li
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB E3B 4Z7, Canada
| | - Hao Lin
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
- Correspondence: (H.L.); (X.W.)
| | - Xiyin Wang
- Center for Genomics and Bio-Computing, School of Life Sciences, North China University of Science and Technology, Tangshan 063210, China
- Correspondence: (H.L.); (X.W.)
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7
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Jiang Y, Zhu Q, Yang H, Zhi T, Ren C. Phenylalanine suppresses cell death caused by loss of fumarylacetoacetate hydrolase in Arabidopsis. Sci Rep 2022; 12:13546. [PMID: 35941360 PMCID: PMC9360007 DOI: 10.1038/s41598-022-17819-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 08/01/2022] [Indexed: 11/23/2022] Open
Abstract
Fumarylacetoacetate hydrolase (FAH) catalyzes the final step of Tyrosine (Tyr) degradation pathway essential to animals and the deficiency of FAH causes an inborn lethal disease. In plants, a role of this pathway was unknown until we found that mutation of Short-day Sensitive Cell Death1 (SSCD1), encoding Arabidopsis FAH, results in cell death under short day. Phenylalanine (Phe) could be converted to Tyr and then degraded in both animals and plants. Phe ingestion in animals worsens the disease caused by FAH defect. However, in this study we found that Phe represses cell death caused by FAH defect in plants. Phe treatment promoted chlorophyll biosynthesis and suppressed the up-regulation of reactive oxygen species marker genes in the sscd1 mutant. Furthermore, the repression of sscd1 cell death by Phe could be reduced by α-aminooxi-β-phenylpropionic acid but increased by methyl jasmonate, which inhibits or activates Phe ammonia-lyase catalyzing the first step of phenylpropanoid pathway, respectively. In addition, we found that jasmonate signaling up-regulates Phe ammonia-lyase 1 and mediates the methyl jasmonate enhanced repression of sscd1 cell death by Phe. These results uncovered the relation between chlorophyll biosynthesis, phenylpropanoid pathway and jasmonate signaling in regulating the cell death resulting from loss of FAH in plants.
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Affiliation(s)
- Yihe Jiang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Qi Zhu
- College of Horticulture, Hunan Agricultural University, Changsha, 410128, China
| | - Hua Yang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.,Crop Gene Engineering Key Laboratory of Hunan Province, Hunan Agricultural University, Changsha, 410128, China
| | - Tiantian Zhi
- Crop Gene Engineering Key Laboratory of Hunan Province, Hunan Agricultural University, Changsha, 410128, China.,College of Life Sciences and Resources and Environment, Yichun University, Yichun, 336000, China
| | - Chunmei Ren
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China. .,Crop Gene Engineering Key Laboratory of Hunan Province, Hunan Agricultural University, Changsha, 410128, China.
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8
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Liao HS, Chung YH, Hsieh MH. Glutamate: A multifunctional amino acid in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 318:111238. [PMID: 35351313 DOI: 10.1016/j.plantsci.2022.111238] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/15/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Glutamate (Glu) is a versatile metabolite and a signaling molecule in plants. Glu biosynthesis is associated with the primary nitrogen assimilation pathway. The conversion between Glu and 2-oxoglutarate connects Glu metabolism to the tricarboxylic acid cycle, carbon metabolism, and energy production. Glu is the predominant amino donor for transamination reactions in the cell. In addition to protein synthesis, Glu is a building block for tetrapyrroles, glutathione, and folate. Glu is the precursor of γ-aminobutyric acid that plays an important role in balancing carbon/nitrogen metabolism and various cellular processes. Glu can conjugate to the major auxin indole 3-acetic acid (IAA), and IAA-Glu is destined for oxidative degradation. Glu also conjugates with isochorismate for the production of salicylic acid. Accumulating evidence indicates that Glu functions as a signaling molecule to regulate plant growth, development, and defense responses. The ligand-gated Glu receptor-like proteins (GLRs) mediate some of these responses. However, many of the Glu signaling events are GLR-independent. The receptor perceiving extracellular Glu as a danger signal is still unknown. In addition to GLRs, Glu may act on receptor-like kinases or receptor-like proteins to trigger immune responses. Glu metabolism and Glu signaling may entwine to regulate growth, development, and defense responses in plants.
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Affiliation(s)
- Hong-Sheng Liao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Hsin Chung
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Hsiun Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; Department of Life Sciences, National Central University, Taoyuan 32001, Taiwan.
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9
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Luo T, Zhou Z, Deng Y, Fan Y, Qiu L, Chen R, Yan H, Zhou H, Lakshmanan P, Wu J, Chen Q. Transcriptome and metabolome analyses reveal new insights into chlorophyll, photosynthesis, metal ion and phenylpropanoids related pathways during sugarcane ratoon chlorosis. BMC PLANT BIOLOGY 2022; 22:222. [PMID: 35484490 PMCID: PMC9052583 DOI: 10.1186/s12870-022-03588-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Ratoon sugarcane is susceptible to chlorosis, characterized by chlorophyll loss, poor growth, and a multitude of nutritional deficiency mainly occurring at young stage. Chlorosis would significantly reduce the cane production. The molecular mechanism underlying this phenomenon remains unknown. We analyzed the transcriptome and metabolome of chlorotic and non-chlorotic sugarcane leaves of the same age from the same field to gain molecular insights into this phenomenon. RESULTS The agronomic traits, such as plant height and the number of leaf, stalk node, and tillers declined in chlorotic sugarcane. Chlorotic leaves had substantially lower chlorophyll content than green leaves. A total of 11,776 differentially expressed genes (DEGs) were discovered in transcriptome analysis. In the KEGG enriched chlorophyll metabolism pathway, sixteen DEGs were found, eleven of which were down-regulated. Two photosynthesis pathways were also enriched with 32 genes downregulated and four genes up-regulated. Among the 81 enriched GO biological processes, there were four categories related to metal ion homeostasis and three related to metal ion transport. Approximately 400 metabolites were identified in metabolome analysis. The thirteen differentially expressed metabolites (DEMs) were all found down-regulated. The phenylpropanoid biosynthesis pathway was enriched in DEGs and DEMs, indicating a potentially vital role for phenylpropanoids in chlorosis. CONCLUSIONS Chlorophyll production, metal ion metabolism, photosynthesis, and some metabolites in the phenylpropanoid biosynthesis pathway were considerably altered in chlorotic ratoon sugarcane leaves. Our finding revealed the relation between chlorosis and these pathways, which will help expand our mechanistic understanding of ratoon sugarcane chlorosis.
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Affiliation(s)
- Ting Luo
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Zhongfeng Zhou
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Yuchi Deng
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Yegeng Fan
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Lihang Qiu
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Rongfa Chen
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Haifeng Yan
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Huiwen Zhou
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China
| | - Prakash Lakshmanan
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China
- Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, 400716, China
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, QLD, St Lucia, 4067, Australia
| | - Jianming Wu
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, China.
- Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, Guangxi, China.
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Nanning, Guangxi, China.
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning, Guangxi, China.
| | - Qi Chen
- Nanning New Technology Entrepreneur Center, Nanning, Guangxi, China
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10
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Shan D, Wang C, Song H, Bai Y, Zhang H, Hu Z, Wang L, Shi K, Zheng X, Yan T, Sun Y, Zhu Y, Zhang T, Zhou Z, Guo Y, Kong J. The MdMEK2-MdMPK6-MdWRKY17 pathway stabilizes chlorophyll levels by directly regulating MdSUFB in apple under drought stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:814-828. [PMID: 34469599 DOI: 10.1111/tpj.15480] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/16/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Drought stress severely limits plant growth and production in apple (Malus domestica Borkh.). To breed water-deficit-tolerant apple cultivars that maintain high yields under slight or moderate drought stress, it is important to uncover the mechanisms underlying the transcriptional regulation of chlorophyll metabolism in apple. To explore this mechanism, we generated transgenic 'Gala3' apple plants with overexpression or knockdown of MdWRKY17, which encodes a transcription factor whose expression is significantly induced by water deficit. Under moderate drought stress, we observed significantly higher chlorophyll contents and photosynthesis rates in overexpression transgenic plants than in controls, whereas these were dramatically lower in the knockdown lines. MdWRKY17 directly regulates MdSUFB expression, as demonstrated by in vitro and in vivo experiments. MdSUFB, a key component of the sulfur mobilization (SUF) system that assembles Fe-S clusters, is essential for inhibiting chlorophyll degradation and stabilizing electron transport during photosynthesis, leading to higher chlorophyll levels in transgenic apple plants overexpressing MdWRKY17. The activated MdMEK2-MdMPK6 cascade by water-deficit stress fine-tunes the MdWRKY17-MdSUFB pathway by phosphorylating MdWRKY17 under water-deficit stress. This fine-tuning of the MdWRKY17-MdSUFB regulatory pathway is important for balancing plant survival and yield losses (chlorophyll degradation and reduced photosynthesis) under slight or moderate drought stress. The phosphorylation by MdMEK2-MdMPK6 activates the MdWRKY17-MdSUFB pathway at S66 (identified by LC-MS), as demonstrated by in vitro and in vivo experiments. Our findings reveal that the MdMEK2-MdMPK6-MdWRKY17-MdSUFB pathway stabilizes chlorophyll levels under moderate drought stress, which could facilitate the breeding of apple varieties that maintain high yields under drought stress.
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Affiliation(s)
- Dongqian Shan
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Chanyu Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Handong Song
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yixue Bai
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Haixia Zhang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Zehui Hu
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Lin Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Kun Shi
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xiaodong Zheng
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Tianci Yan
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yanzhao Sun
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yunpeng Zhu
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Tong Zhang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Zhaoyang Zhou
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yan Guo
- College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jin Kong
- College of Horticulture, China Agricultural University, Beijing, 100193, China
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11
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Lee J, Choi B, Yun A, Son N, Ahn G, Cha JY, Kim WY, Hwang I. Long-term abscisic acid promotes golden2-like1 degradation through constitutive photomorphogenic 1 in a light intensity-dependent manner to suppress chloroplast development. PLANT, CELL & ENVIRONMENT 2021; 44:3034-3048. [PMID: 34129248 DOI: 10.1111/pce.14130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/12/2021] [Accepted: 06/12/2021] [Indexed: 05/14/2023]
Abstract
Abiotic stress, a serious threat to plants, occurs for extended periods in nature. Abscisic acid (ABA) plays a critical role in abiotic stress responses in plants. Therefore, stress responses mediated by ABA have been studied extensively, especially in short-term responses. However, long-term stress responses mediated by ABA remain largely unknown. To elucidate the mechanism by which plants respond to prolonged abiotic stress, we used long-term ABA treatment that activates the signalling against abiotic stress such as dehydration and investigated mechanisms underlying the responses. Long-term ABA treatment activates constitutive photomorphogenic 1 (COP1). Active COP1 mediates the ubiquitination of golden2-like1 (GLK1) for degradation, contributing to lowering expression of photosynthesis-associated genes such as glutamyl-tRNA reductase (HEMA1) and protochlorophyllide oxidoreductase A (PORA), resulting in the suppression of chloroplast development. Moreover, COP1 activation and GLK1 degradation upon long-term ABA treatment depend on light intensity. Additionally, plants with COP1 mutation or exposed to higher light intensity were more sensitive to salt stress. Collectively, our results demonstrate that long-term treatment of ABA leads to activation of COP1 in a light intensity-dependent manner for GLK1 degradation to suppress chloroplast development, which we propose to constitute a mechanism of balancing normal growth and stress responses upon the long-term abiotic stress.
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Affiliation(s)
- Juhun Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Bongsoo Choi
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Areum Yun
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Namil Son
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Gyeongik Ahn
- Division of Applied Life Science (BK21Plus), RILS & IALS, Gyeongsang National University, Jinju, Republic of Korea
| | - Joon-Yung Cha
- Division of Applied Life Science (BK21Plus), RILS & IALS, Gyeongsang National University, Jinju, Republic of Korea
| | - Woe-Yeon Kim
- Division of Applied Life Science (BK21Plus), RILS & IALS, Gyeongsang National University, Jinju, Republic of Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
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12
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DeTar RA, Barahimipour R, Manavski N, Schwenkert S, Höhner R, Bölter B, Inaba T, Meurer J, Zoschke R, Kunz HH. Loss of inner-envelope K+/H+ exchangers impairs plastid rRNA maturation and gene expression. THE PLANT CELL 2021; 33:2479-2505. [PMID: 34235544 PMCID: PMC8364240 DOI: 10.1093/plcell/koab123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/30/2021] [Indexed: 05/08/2023]
Abstract
The inner-envelope K+ EFFLUX ANTIPORTERS (KEA) 1 and 2 are critical for chloroplast development, ion homeostasis, and photosynthesis. However, the mechanisms by which changes in ion flux across the envelope affect organelle biogenesis remained elusive. Chloroplast development requires intricate coordination between the nuclear genome and the plastome. Many mutants compromised in plastid gene expression (PGE) display a virescent phenotype, that is delayed greening. The phenotypic appearance of Arabidopsis thaliana kea1 kea2 double mutants fulfills this criterion, yet a link to PGE has not been explored. Here, we show that a simultaneous loss of KEA1 and KEA2 results in maturation defects of the plastid ribosomal RNAs. This may be caused by secondary structure changes of rRNA transcripts and concomitant reduced binding of RNA-processing proteins, which we documented in the presence of skewed ion homeostasis in kea1 kea2. Consequently, protein synthesis and steady-state levels of plastome-encoded proteins remain low in mutants. Disturbance in PGE and other signs of plastid malfunction activate GENOMES UNCOUPLED 1-dependent retrograde signaling in kea1 kea2, resulting in a dramatic downregulation of GOLDEN2-LIKE transcription factors to halt expression of photosynthesis-associated nuclear-encoded genes (PhANGs). PhANG suppression delays the development of fully photosynthesizing kea1 kea2 chloroplasts, probably to avoid progressing photo-oxidative damage. Overall, our results reveal that KEA1/KEA2 function impacts plastid development via effects on RNA-metabolism and PGE.
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Affiliation(s)
- Rachael Ann DeTar
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Rouhollah Barahimipour
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Nikolay Manavski
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Serena Schwenkert
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Ricarda Höhner
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
| | - Bettina Bölter
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Takehito Inaba
- Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Jörg Meurer
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA
- Plant Sciences, Department I, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
- Author for correspondence:
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Hou Z, Pang X, Hedtke B, Grimm B. In vivo functional analysis of the structural domains of FLUORESCENT (FLU). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:360-376. [PMID: 33901334 DOI: 10.1111/tpj.15293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/12/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
The control of chlorophyll (Chl) synthesis in angiosperms depends on the light-operating enzyme protochlorophyllide oxidoreductase (POR). The interruption of Chl synthesis during darkness requires suppression of the synthesis of 5-aminolevulinic acid (ALA), the first precursor molecule specific for Chl synthesis. The inactivation of glutamyl-tRNA reductase (GluTR), the first enzyme in tetrapyrrole biosynthesis, accomplished the decreased ALA synthesis by the membrane-bound protein FLUORESCENT (FLU) and prevents overaccumulation of protochlorophyllide (Pchlide) in the dark. We set out to elucidate the molecular mechanism of FLU-mediated inhibition of ALA synthesis, and explored the role of each of the three structural domains of mature FLU, the transmembrane, coiled-coil and tetratricopeptide repeat (TPR) domains, in this process. Efforts to rescue the FLU knock-out mutant with truncated FLU peptides revealed that, on its own, the TPR domain is insufficient to inactivate GluTR, although tight binding of the TPR domain to GluTR was detected. A truncated FLU peptide consisting of transmembrane and TPR domains also failed to inactivate GluTR in the dark. Similarly, suppression of ALA synthesis could not be achieved by combining the coiled-coil and TPR domains. Interaction studies revealed that binding of GluTR and POR to FLU is essential for inhibiting ALA synthesis. These results imply that all three FLU domains are required for the repression of ALA synthesis, in order to avoid the overaccumulation of Pchlide in the dark. Only complete FLU ensures the formation of a membrane-bound ternary complex consisting at least of FLU, GluTR and POR to repress ALA synthesis.
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Affiliation(s)
- Zhiwei Hou
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Xiaoqing Pang
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Boris Hedtke
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
| | - Bernhard Grimm
- Humboldt Universität zu Berlin, Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Philippstrasse 13, Berlin, 10115, Germany
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14
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Ikeda Y, Zalabák D, Kubalová I, Králová M, Brenner WG, Aida M. Interpreting Cytokinin Action as Anterograde Signaling and Beyond. FRONTIERS IN PLANT SCIENCE 2021; 12:641257. [PMID: 33854521 PMCID: PMC8039514 DOI: 10.3389/fpls.2021.641257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/08/2021] [Indexed: 05/22/2023]
Abstract
Among the major phytohormones, the cytokinin exhibits unique features for its ability to positively affect the developmental status of plastids. Even early on in its research, cytokinins were known to promote plastid differentiation and to reduce the loss of chlorophyll in detached leaves. Since the discovery of the components of cytokinin perception and primary signaling, the genes involved in photosynthesis and plastid differentiation have been identified as those directly targeted by type-B response regulators. Furthermore, cytokinins are known to modulate versatile cellular processes such as promoting the division and differentiation of cells and, in concert with auxin, initiating the de novo formation of shoot apical meristem (SAM) in tissue cultures. Yet how cytokinins precisely participate in such diverse cellular phenomena, and how the associated cellular processes are coordinated as a whole, remains unclear. A plausible presumption that would account for the coordinated gene expression is the tight and reciprocal communication between the nucleus and plastid. The fact that cytokinins affect plastid developmental status via gene expression in both the nucleus and plastid is interpreted here to suggest that cytokinin functions as an initiator of anterograde (nucleus-to-plastid) signaling. Based on this viewpoint, we first summarize the physiological relevance of cytokinins to the coordination of plastid differentiation with de novo shoot organogenesis in tissue culture systems. Next, the role of endogenous cytokinins in influencing plastid differentiation within the SAM of intact plants is discussed. Finally, a presumed plastid-derived signal in response to cytokinins for coupled nuclear gene expression is proposed.
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Affiliation(s)
- Yoshihisa Ikeda
- Centre of the Region Haná for Biotechnological and Agricultural Research, Czech Advanced Technology and Research Institute, Palacký University, Olomouc, Czechia
| | - David Zalabák
- Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany AS CR, Olomouc, Czechia
| | - Ivona Kubalová
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Michaela Králová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Czech Advanced Technology and Research Institute, Palacký University, Olomouc, Czechia
| | - Wolfram G. Brenner
- General and Applied Botany, Institute of Biology, Universität Leipzig, Leipzig, Germany
| | - Mitsuhiro Aida
- International Research Organization for Advanced Science and Technology (IROAST), Kumamoto University, Kumamoto, Japan
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15
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Regulation of the Photon Spectrum on Growth and Nutritional Attributes of Baby-Leaf Lettuce at Harvest and during Postharvest Storage. PLANTS 2021; 10:plants10030549. [PMID: 33799394 PMCID: PMC8000317 DOI: 10.3390/plants10030549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 12/04/2022]
Abstract
The photon flux density (PFD) and spectrum regulate the growth, quality attributes, and postharvest physiology of leafy vegetables grown indoors. However, limited information is available on how a photon spectrum enriched with a broad range of different wavebands regulates these factors. To determine this, we grew baby-leaf lettuce ‘Rouxai’ under a PFD of 200 µmol m−2 s−1 provided by warm-white (WW; control) light-emitting diodes (LEDs) supplemented with either 30 µmol m−2 s−1 of ultraviolet-A (+UV30) or 50 µmol m−2 s−1 of blue (+B50), green (+G50), red (+R50), or WW (+WW50) light. We then quantified growth attributes and accumulated secondary metabolites at harvest and during storage in darkness at 5 °C. Additional +G50 light increased shoot fresh and dry weight by 53% and 59% compared to the control. Relative chlorophyll concentration increased under +UV30, +G50, and especially +B50. At harvest, +B50 increased total phenolic content (TPC) by 25% and anthocyanin content (TAC) by 2.0-fold. Additionally, +G50 increased antiradical activity (DPPH) by 29%. After each day of storage, TPC decreased by 2.9 to 7.1% and DPPH by 3.0 to 6.2%, while TAC degradation was less pronounced. Principal component analysis indicated a distinct effect of +G50 on the lettuce at harvest. However, concentrations of metabolites before and during storage were usually greatest under the +B50 and +R50 treatments.
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Shimizu T, Masuda T. The Role of Tetrapyrrole- and GUN1-Dependent Signaling on Chloroplast Biogenesis. PLANTS 2021; 10:plants10020196. [PMID: 33494334 PMCID: PMC7911674 DOI: 10.3390/plants10020196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/14/2022]
Abstract
Chloroplast biogenesis requires the coordinated expression of the chloroplast and nuclear genomes, which is achieved by communication between the developing chloroplasts and the nucleus. Signals emitted from the plastids, so-called retrograde signals, control nuclear gene expression depending on plastid development and functionality. Genetic analysis of this pathway identified a set of mutants defective in retrograde signaling and designated genomes uncoupled (gun) mutants. Subsequent research has pointed to a significant role of tetrapyrrole biosynthesis in retrograde signaling. Meanwhile, the molecular functions of GUN1, the proposed integrator of multiple retrograde signals, have not been identified yet. However, based on the interactions of GUN1, some working hypotheses have been proposed. Interestingly, GUN1 contributes to important biological processes, including plastid protein homeostasis, through transcription, translation, and protein import. Furthermore, the interactions of GUN1 with tetrapyrroles and their biosynthetic enzymes have been revealed. This review focuses on our current understanding of the function of tetrapyrrole retrograde signaling on chloroplast biogenesis.
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17
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Tian D, Yang F, Niu Y, Lin Y, Chen Z, Li G, Luo Q, Wang F, Wang M. Loss function of SL (sekiguchi lesion) in the rice cultivar Minghui 86 leads to enhanced resistance to (hemi)biotrophic pathogens. BMC PLANT BIOLOGY 2020; 20:507. [PMID: 33148178 PMCID: PMC7640399 DOI: 10.1186/s12870-020-02724-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 10/26/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND Serotonin, originally identified as a neurotransmitter in mammals, functions as an antioxidant to scavenge cellular ROS in plants. In rice, the conversion of tryptamine to serotonin is catalyzed by SL (sekiguchi lesion), a member of cytochrome P450 monooxygenase family. The sl mutant, originated from rice cultivar Sekiguchi-asahi, exhibits spontaneous lesions, whereas its immune responses to pathogens have not been clearly characterized. RESULTS Here we identified three allelic mutants of SL in an indica rice restore line Minghui 86 (MH86), named as sl-MH-1, - 2 and - 3, all of which present the typical lesions under normal growth condition. Compared with those in MH86, the serotonin content in sl-MH-1 is dramatically decreased, whereas the levels of tryptamine and L-trytophan are significantly increased. The sl-MH-1 mutant accumulates high H2O2 level at its lesion sites and is more sensitive to exogenous H2O2 treatment than the wild type. When treated with the reductant vitamin C (Vc), the lesion formation on sl-MH-1 leaves could be efficiently suppressed. In addition, sl-MH-1 displayed more resistant to both the blast fungus and blight bacteria, Pyricularia oryzae (P. oryzae, teleomorph: Magnaporthe oryzae) and Xanthomonas oryzae pv. Oryzae (Xoo), respectively. The pathogen-associated molecular patterns (PAMPs)-triggered immunity (PTI) responses, like reactive oxygen species (ROS) burst and callose deposition, were enhanced in sl-MH-1. Moreover, loss function of SL resulted in higher resting levels of the defense hormones, salicylic acid and jasmonic acid. The RNA-seq analysis indicated that after P. oryzae infection, transcription of the genes involved in reduction-oxidation regulation was the most markedly changed in sl-MH-1, compared with MH86. CONCLUSIONS Our results indicate that SL, involving in the final step of serotonin biosynthesis, negatively regulates rice resistance against (hemi)biotrophic pathogens via compromising the PTI responses and defense hormones accumulation.
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Affiliation(s)
- Dagang Tian
- Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China
| | - Fang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Yuqing Niu
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Yan Lin
- Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China
| | - Zaijie Chen
- Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China
| | - Gang Li
- Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China
| | - Qiong Luo
- Ministry of Education Key Laboratory of Agriculture Biodiversity for Plant Disease Management, Yunnan Agricultural University, Kunming, 650201, China
| | - Feng Wang
- Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, Fujian, China.
| | - Mo Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China.
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Okamoto H, Ducreux LJM, Allwood JW, Hedley PE, Wright A, Gururajan V, Terry MJ, Taylor MA. Light Regulation of Chlorophyll and Glycoalkaloid Biosynthesis During Tuber Greening of Potato S. tuberosum. FRONTIERS IN PLANT SCIENCE 2020; 11:753. [PMID: 32760410 PMCID: PMC7372192 DOI: 10.3389/fpls.2020.00753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Potato, S. tuberosum, is one of the most important global crops, but has high levels of waste due to tuber greening under light, which is associated with the accumulation of neurotoxic glycoalkaloids. However, unlike the situation in de-etiolating seedlings, the mechanisms underlying tuber greening are not well understood. Here, we have investigated the effect of monochromatic blue, red, and far-red light on the regulation of chlorophyll and glycoalkaloid accumulation in potato tubers. Blue and red wavelengths were effective for induction and accumulation of chlorophyll, carotenoids and the two major potato glycoalkaloids, α-solanine and α-chaconine, whereas none of these accumulated in darkness or under far-red light. Key genes in chlorophyll biosynthesis (HEMA1, encoding the rate-limiting enzyme glutamyl-tRNA reductase, GSA, CHLH and GUN4) and six genes (HMG1, SQS, CAS1, SSR2, SGT1 and SGT2) required for glycoalkaloid synthesis were also induced under white, blue, and red light but not in darkness or under far-red light. These data suggest a role for both cryptochrome and phytochrome photoreceptors in chlorophyll and glycoalkaloid accumulation. The contribution of phytochrome was further supported by the observation that far-red light could inhibit white light-induced chlorophyll and glycoalkaloid accumulation and associated gene expression. Transcriptomic analysis of tubers exposed to white, blue, and red light showed that light induction of photosynthesis and tetrapyrrole-related genes grouped into three distinct groups with one group showing a generally progressive induction by light at both 6 h and 24 h, a second group showing induction at 6 h in all light treatments, but induction only by red and white light at 24 h and a third showing just a very moderate light induction at 6 h which was reduced to the dark control level at 24 h. All glycoalkaloid synthesis genes showed a group one profile consistent with what was seen for the most light regulated chlorophyll synthesis genes. Our data provide a molecular framework for developing new approaches to reducing waste due to potato greening.
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Affiliation(s)
- Haruko Okamoto
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | | | - J. William Allwood
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
| | - Pete E. Hedley
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
| | - Alison Wright
- Branston Ltd., Lincoln, United Kingdom
- B-hive Innovations Ltd., Lincoln, United Kingdom
| | - Vidyanath Gururajan
- Branston Ltd., Lincoln, United Kingdom
- B-hive Innovations Ltd., Lincoln, United Kingdom
| | - Matthew J. Terry
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Mark A. Taylor
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
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Peng R, Sun W, Jin X, Yu L, Chen C, Yue Z, Dong Y. Analysis of 2,4-epibrassinolide created an enhancement tolerance on Cd toxicity in Solanum nigrum L. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:16784-16797. [PMID: 32141006 DOI: 10.1007/s11356-020-08228-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 02/25/2020] [Indexed: 06/10/2023]
Abstract
Contamination of soils with cadmium (Cd) is a serious problem worldwide. Solanum nigrum L. is reported as a Cd hyperaccumulator, but its enrichment capacity is limited. 2,4-Epibrassinolide (2,4-EBL) plays important roles in plant response to various stresses. Little is known about its effect on Cd tolerance in S. nigrum. Current study was performed to demonstrate effects of 2,4-EBL on plant growth, photosynthesis activity, activities of antioxidants, and Cd concentration in plants by nutrient solution contaminated with Cd. Results revealed that S. nigrum exhibited toxicity to Cd stress, including reducing plant height, root length, and chlorophyll content and increasing malondialdehyde (MDA) content. Exogenous application of 2,4-EBL significantly enhanced the contents of proline and soluble sugar and decreased the MDA content. Meanwhile, the levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) markedly increased compared with the control. Interesting, 2,4-EBL promoted photosynthesis by increasing the chlorophyll content, Fv/Fm. And increase in chlorophyll content is caused by increased expression of synthetic genes and decreased expression of degraded genes. 2,4-EBL also decreased accumulation of Cd in S. nigrum compared with single Cd stress. According to the present results, 2,4-EBL can effectively be used to alleviate the damage of Cd stress in S. nigrum and probably in other solanaceae.
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Affiliation(s)
- Ruonan Peng
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China
| | - Weiyue Sun
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China
| | - Xiaoxia Jin
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China.
| | - Lijie Yu
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China
| | - Chao Chen
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China
| | - Zhonghui Yue
- Institute of Life Science and Technology, Harbin Normal University, Harbin, 150025, Heilongjiang, China
| | - Yanlong Dong
- Horticulture Branch, Heilongjiang Academy of Agricultural Sciences, Harbin, 150069, Heilongjiang, China
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Abstract
Etiolated seedlings accumulate the chlorophyll biosynthesis intermediate protochlorophyllide (Pchlide) and measuring Pchlide can be important for characterizing photomorphogenic mutants that may be affected in chloroplast development. In this chapter we outline a simple and sensitive method for quantifying Pchlide in extracts of Arabidopsis seedlings using fluorescence spectroscopy. This method can be easily adapted to study chloroplast development in a wide range of plant species.
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Wen Z, Mei Y, Zhou J, Cui Y, Wang D, Wang NN. SAUR49 Can Positively Regulate Leaf Senescence by Suppressing SSPP in Arabidopsis. PLANT & CELL PHYSIOLOGY 2020; 61:644-658. [PMID: 31851355 DOI: 10.1093/pcp/pcz231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 12/12/2019] [Indexed: 05/22/2023]
Abstract
The involvement of SMALL AUXIN-UP RNA (SAUR) proteins in leaf senescence has been more and more acknowledged, but the detailed mechanisms remain unclear. In the present study, we performed yeast two-hybrid assays and identified SAUR49 as an interactor of SENESCENCE SUPPRESSED PROTEIN PHOSPHATASE (SSPP), which is a PP2C protein phosphatase that negatively regulates Arabidopsis leaf senescence by suppressing the leucine-rich repeat receptor-like protein kinase SENESCENCE-ASSOCIATED RECEPTOR-LIKE KINASE (SARK), as reported previously by our group. The interaction between SAUR49 and SSPP was further confirmed in planta. Functional characterization revealed that SAUR49 is a positive regulator of leaf senescence. The accumulation level of SAUR49 protein increased during natural leaf senescence in Arabidopsis. The transcript level of SAUR49 was upregulated during SARK-induced premature leaf senescence but downregulated during SSPP-mediated delayed leaf senescence. Overexpression of SAUR49 significantly accelerated both natural and dark-induced leaf senescence in Arabidopsis. More importantly, SAUR49 overexpression completely reversed SSPP-induced delayed leaf senescence. In addition, overexpression of SAUR49 reversed the decreased plasma membrane H+-ATPase activity mediated by SSPP. Taken together, the results showed that SAUR49 functions in accelerating the leaf senescence process via the activation of SARK-mediated leaf senescence signaling by suppressing SSPP. We further identified four other SSPP-interacting SAURs, SAUR30, SAUR39, SAUR41 and SAUR72, that may act redundantly with SAUR49 in regulating leaf senescence. All these observations indicated that certain members of the SAUR family may serve as an important hub that integrates various hormonal and environmental signals with senescence signals in Arabidopsis.
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Affiliation(s)
- Zewen Wen
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yuanyuan Mei
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jie Zhou
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yanjiao Cui
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Dan Wang
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ning Ning Wang
- Tianjin Key Laboratory of Protein Sciences, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China
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Alameldin HF, Oh S, Hernandez AP, Montgomery BL. Nuclear-encoded sigma factor 6 (SIG6) is involved in the block of greening response in Arabidopsis thaliana. AMERICAN JOURNAL OF BOTANY 2020; 107:329-338. [PMID: 32002990 DOI: 10.1002/ajb2.1423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/24/2019] [Indexed: 05/22/2023]
Abstract
PREMISE Light is critical in the ability of plants to accumulate chlorophyll. When exposed to far-red (FR) light and then grown in white light in the absence of sucrose, wild-type seedlings fail to green in a response known as the FR block of greening (BOG). This response is controlled by phytochrome A through repression of protochlorophyllide reductase-encoding (POR) genes by FR light coupled with irreversible plastid damage. Sigma (SIG) factors are nuclear-encoded proteins that contribute to plant greening and plastid development through regulating gene transcription in chloroplasts and impacting retrograde signaling from the plastid to nucleus. SIGs are regulated by phytochromes, and the expression of some SIG factors is reduced in phytochrome mutant lines, including phyA. Given the association of phyA with the FR BOG and its regulation of SIG factors, we investigated the potential regulatory role of SIG factors in the FR BOG response. METHODS We examined FR BOG responses in sig mutants, phytochrome-deficient lines, and mutant lines for several phy-associated factors. We quantified chlorophyll levels and examined expression of key BOG-associated genes. RESULTS Among six sig mutants, only the sig6 mutant significantly accumulated chlorophyll after FR BOG treatment, similar to the phyA mutant. SIG6 appears to control protochlorophyllide accumulation by contributing to the regulation of tetrapyrrole biosynthesis associated with glutamyl-tRNA reductase (HEMA1) function, select phytochrome-interacting factor genes (PIF4 and PIF6), and PENTA1, which regulates PORA mRNA translation after FR exposure. CONCLUSIONS Regulation of SIG6 plays a significant role in plant responses to FR exposure during the BOG response.
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Affiliation(s)
- Hussien F Alameldin
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Agricultural Genetic Engineering Research Institute (AGERI), Agriculture Research Center (ARC), Giza, 12619, Egypt
| | - Sookyung Oh
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Alexandra P Hernandez
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Beronda L Montgomery
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
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Gao S, Gao W, Liao X, Xiong C, Yu G, Yang Q, Yang C, Ye Z. The tomato WV gene encoding a thioredoxin protein is essential for chloroplast development at low temperature and high light intensity. BMC PLANT BIOLOGY 2019; 19:265. [PMID: 31221088 PMCID: PMC6585109 DOI: 10.1186/s12870-019-1829-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 05/13/2019] [Indexed: 05/31/2023]
Abstract
BACKGROUND Chloroplast biogenesis, a complex process in higher plants, is the key to photoautotrophic growth in plants. White virescent (wv) mutants have been used to unfold the molecular mechanisms underlying the regulation of chloroplast development and chloroplast gene expression in plants. However, most of genes controlling white virescent phenotype still remain unknown. RESULTS In this study, we identified a temperature- and light intensity-sensitive mutant, named as wv. The content of chlorophyll was dramatically decreased in the immature leaves of wv mutant under the conditions of low temperature and high-light intensity. TEM observation showed that the chloroplasts in the young leaves of wv mutant lacked an organized thylakoid membrane, whereas crescent-shaped chloroplasts with well-developed stromal and stacked grana thylakoids in the mature leaves were developed. Immunoblot analyses suggested that proteins of photosynthetic complexes were decreased substantially in wv mutants. Based on map-based cloning and transgenic analysis, we determined that the wv phenotype was caused by single base mutation in the first intron of WV gene, which encoded a thioredoxin protein with 365 amino acids. qRT-PCR analysis revealed that the expression of WV gene was significantly down-regulated in wv mutant. In addition, knockdown of WV gene through RNAi also resulted in white virescent young leaves, suggesting that the mutation possibly blocks the differentiation of chloroplasts through inhibiting the expression of WV gene. Furthermore, the expression of WV peaked in apical buds and gradually decreased along with the developmental stage, which was consistent with the wv mutant phenotype. Expression analysis of chloroplast-encoded genes by qRT-PCR showed that the wv mutation affected the expression pattern of chloroplast-encoded PEP dependent genes. CONCLUSION Our results suggested that wv mutant was sensitive to low temperature and light intensity. WV gene was essential for chloroplast differentiation. A single base mutation in the first intron resulted in down-regulation of WV gene expression, which inhibited the expression of chloroplast-encoded genes, thereby blocking chloroplast formation and chlorophyll synthesis.
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Affiliation(s)
- Shenghua Gao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Hubei Key Laboratory of Vegetable Germplasm Enhancement and Genetic Improvement, Cash Crops Research Institute, Hubei Academy of Agricultural Sciences, Wuhan, 430070, Hubei, China
| | - Wenjing Gao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Xiaoli Liao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Cheng Xiong
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Gang Yu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Qihong Yang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Changxian Yang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
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24
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Sineshchekov VA, Belyaeva OB. Regulation of Chlorophyll Biogenesis by Phytochrome A. BIOCHEMISTRY (MOSCOW) 2019; 84:491-508. [DOI: 10.1134/s0006297919050043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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25
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Sineshchekov VA, Belyaeva OB. Regulation of Chlorophyll Biogenesis by Phytochrome A. BIOCHEMISTRY (MOSCOW) 2019; 84:491-508. [DOI: https:/doi.org/10.1134/s0006297919050043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 12/18/2023]
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26
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Zhi T, Zhou Z, Qiu B, Zhu Q, Xiong X, Ren C. Loss of fumarylacetoacetate hydrolase causes light-dependent increases in protochlorophyllide and cell death in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:622-638. [PMID: 30666736 DOI: 10.1111/tpj.14235] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 05/10/2023]
Abstract
Fumarylacetoacetate hydrolase (FAH) catalyses the final step of the tyrosine degradation pathway, which is essential to animals but was of unknown importance in plants until we found that mutation of Short-day Sensitive Cell Death1 (SSCD1), encoding Arabidopsis FAH, results in cell death under short-day conditions. The sscd1 mutant accumulates succinylacetone (SUAC), an abnormal metabolite caused by loss of FAH. Succinylacetone is an inhibitor of δ-aminolevulinic acid (ALA) dehydratase (ALAD), which is involved in chlorophyll (Chl) biosynthesis. In this study, we investigated whether sscd1 cell death is mediated by Chl biosynthesis and found that ALAD activity is repressed in sscd1 and that protochlorophyllide (Pchlide), an intermediate of Chl biosynthesis, accumulates at lower levels in etiolated sscd1 seedlings. However, it was interesting that Pchlide in sscd1 might increase after transfer from light to dark and that HEMA1 and CHLH are upregulated in the light-dark transition before Pchlide levels increased. Upon re-illumination after Pchlide levels had increased, reactive oxygen species marker genes, including singlet oxygen-induced genes, are upregulated, and the sscd1 cell death phenotype appears. In addition, Arabidopsis WT seedlings treated with SUAC mimic sscd1 in decline of ALAD activity and accumulation of Pchlide as well as cell death. These results demonstrate that increase in Pchlide causes cell death in sscd1 upon re-illumination and suggest that a decline in the Pchlide pool due to inhibition of ALAD activity by SUAC impairs the repression of ALA synthesis from the light-dark transition by feedback control, resulting in activation of the Chl biosynthesis pathway and accumulation of Pchlide in the dark.
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Affiliation(s)
- Tiantian Zhi
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Zhou Zhou
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Bo Qiu
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, 410083, China
| | - Qi Zhu
- College of Horticulture and Landscape, Hunan Agricultural University, Changsha, 410128, China
| | - Xingyao Xiong
- College of Horticulture and Landscape, Hunan Agricultural University, Changsha, 410128, China
| | - Chunmei Ren
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
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27
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Hou Z, Yang Y, Hedtke B, Grimm B. Fluorescence in blue light (FLU) is involved in inactivation and localization of glutamyl-tRNA reductase during light exposure. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:517-529. [PMID: 30362619 DOI: 10.1111/tpj.14138] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 10/13/2018] [Accepted: 10/18/2018] [Indexed: 06/08/2023]
Abstract
Fluorescent in blue light (FLU) is a negative regulator involved in dark repression of 5-aminolevulinic acid (ALA) synthesis and interacts with glutamyl-tRNA reductase (GluTR), the rate-limiting enzyme of tetrapyrrole biosynthesis. In this study, we investigated FLU's regulatory function in light-exposed FLU-overexpressing (FLUOE) Arabidopsis lines and under fluctuating light intensities in wild-type (WT) and flu seedlings. FLUOE lines suppress ALA synthesis in the light, resulting in reduced chlorophyll content, but more strongly in low and high light than in medium growth light. This situation indicates that FLU's impact on chlorophyll biosynthesis depends on light intensity. FLU overexpressors contain strongly increased amounts of mainly membrane-associated GluTR. These findings correlate with FLU-dependent localization of GluTR to plastidic membranes and concomitant inhibition, such that only the soluble GluTR fraction is active. The overaccumulation of membrane-associated GluTR indicates that FLU binding enhances GluTR stability. Interestingly, under fluctuating light, the leaves of flu mutants contain less chlorophyll compared with WT and become necrotic. We propose that FLU is basically required for fine-tuned ALA synthesis. FLU not only mediates dark repression of ALA synthesis, but functions also to control balanced ALA synthesis under variable light intensities to ensure the adequate supply of chlorophyll.
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Affiliation(s)
- Zhiwei Hou
- Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Yanyu Yang
- Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Boris Hedtke
- Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Bernhard Grimm
- Lebenswissenschaftliche Fakultät, Institut für Biologie, AG Pflanzenphysiologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
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Schmied J, Hou Z, Hedtke B, Grimm B. Controlled Partitioning of Glutamyl-tRNA Reductase in Stroma- and Membrane-Associated Fractions Affects the Synthesis of 5-Aminolevulinic Acid. PLANT & CELL PHYSIOLOGY 2018; 59:2204-2213. [PMID: 30032295 DOI: 10.1093/pcp/pcy143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
The synthesis of 5-aminolevulinic acid (ALA) determines adequate amounts of metabolites for the tetrapyrrole biosynthetic pathway. Glutamyl-tRNA reductase (GluTR) catalyzes the rate-limiting step of ALA synthesis and was previously considered to be exclusively localized in the chloroplast stroma of light-exposed plants. To assess the intraplastidic localization of GluTR, we developed a fast separation protocol of soluble and membrane-bound proteins and reassessed the subplastidal allocation of GluTR in stroma and membrane fractions of Arabidopsis plants grown under different light regimes as well as during de-etiolation and dark incubations. Under the examined conditions, the amount of stroma-localized GluTR correlated with the ALA synthesis rate. The transfer to dark repression of ALA synthesis resulted in a loss of soluble GluTR. Arabidopsis mutants lacking one of the GluTR-interacting factors FLUORESCENT (FLU), the GluTR-binding protein (GBP) or ClpC, a chaperone of the Clp protease system, were applied to examine the amount of GluTR and its distribution to the stroma or membrane in darkness and light. Taking into consideration the different compartmental allocation of GluTR, its stability and ALA synthesis rates, the post-translational impact of these regulatory factors on GluTR activity and plastidic sublocalization is discussed.
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Affiliation(s)
- Judith Schmied
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Zhiwei Hou
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Boris Hedtke
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
| | - Bernhard Grimm
- Humboldt-Universität zu Berlin Institute of Biology/Plant Physiology, Philippstr.13, Building 12, Berlin, Germany
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29
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Yu X, Wang X, Hyldgaard B, Zhu Z, Zhou R, Kjaer KH, Ouzounis T, Lou Q, Li J, Cai Q, Rosenqvist E, Ottosen CO, Chen J. Allopolyploidization in Cucumis contributes to delayed leaf maturation with repression of redundant homoeologous genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:393-404. [PMID: 29421854 DOI: 10.1111/tpj.13865] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 05/25/2023]
Abstract
The important role of polyploidy in plant evolution is widely recognized. However, many questions remain to be explored to address how polyploidy affects the phenotype of the plant. To shed light on the phenotypic and molecular impacts of allopolyploidy, we investigated the leaf development of a synthesized allotetraploid (Cucumis × hytivus), with an emphasis on chlorophyll development. Delayed leaf maturation was identified in C. × hytivus, based on delayed leaf expansion, initial chlorophyll deficiency in the leaves and disordered sink-source transition. Anatomical observations also revealed disturbed chloroplast development in C. ×hytivus. The determination of chlorophyll biosynthesis intermediates suggested that the chlorophyll biosynthesis pathway of C. × hytivus is blocked at the site at which uroporphyrinogen III is catalysed to coproporphyrinogen III. Three chlorophyll biosynthesis-related genes, HEMA1, HEME2 and POR, were significantly repressed in C. × hytivus. Sequence alignment showed both synonymous and non-synonymous substitutions in the HEMA1, HEME2 and POR genes of the parents. Cloning of the chlorophyll biosynthetic genes suggested the retention of homoeologs. In addition, a chimeric clone of the HEMA1 gene that consisted of homologous genes from the parents was identified in C. × hytivus. Overall, our results showed that allopolyploidization in Cucumis has resulted in disturbed chloroplast development and reduced chlorophyll biosynthesis caused by the repressed expression of duplicated homologous genes, which further led to delayed leaf maturation in the allotetraploid, C. × hytivus. The preferential retention/loss of certain types of genes and non-reciprocal homoeologous recombination were also supported in the present study, which provides new insights into the impact of allopolyploidy.
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Affiliation(s)
- Xiaqing Yu
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xixi Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | | | - Zaobing Zhu
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Rong Zhou
- Vegetable Research Institute, Jiangsu Academy of Agricultural Science, Jiangsu, Nanjing, China
| | | | - Theoharis Ouzounis
- Horticulture and Product Physiology Group, Wageningen University, Wageningen, The Netherlands
| | - Qunfeng Lou
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Ji Li
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Qingsheng Cai
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Eva Rosenqvist
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Jinfeng Chen
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- State Key Lab for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
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30
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Wang M, Lee J, Choi B, Park Y, Sim HJ, Kim H, Hwang I. Physiological and Molecular Processes Associated with Long Duration of ABA Treatment. FRONTIERS IN PLANT SCIENCE 2018; 9:176. [PMID: 29515601 PMCID: PMC5826348 DOI: 10.3389/fpls.2018.00176] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/30/2018] [Indexed: 05/27/2023]
Abstract
Plants need to respond to various environmental stresses such as abiotic stress for proper development and growth. The responses to abiotic stress can be biochemically demanding, resulting in a trade-off that negatively affects plant growth and development. Thus, plant stress responses must be fine-tuned depending on the stress severity and duration. Abscisic acid, a phytohormone, plays a key role in responses to abiotic stress. Here, we investigated time-dependent physiological and molecular responses to long-term ABA treatment in Arabidopsis as an approach to gain insight into the plant responses to long-term abiotic stress. Upon ABA treatment, the amount of cellular ABA increased to higher levels, reaching to a peak at 24 h after treatment (HAT), and then gradually decreased with time whereas ABA-GE was maintained at lower levels until 24 HAT and then abruptly increased to higher levels at 48 HAT followed by a gradual decline at later time points. Many genes involved in dehydration stress responses, ABA metabolism, chloroplast biogenesis, and chlorophyll degradation were strongly expressed at early time points with a peak at 24 or 48 HAT followed by gradual decreases in induction fold or even suppression at later time points. At the physiological level, long-term ABA treatment caused leaf yellowing, reduced chlorophyll levels, and inhibited chloroplast division in addition to the growth suppression whereas short-term ABA treatment did not affect chlorophyll levels. Our results indicate that the duration of ABA treatment is a crucial factor in determining the mode of ABA-mediated signaling and plant responses: active mobilization of cellular resources at early time points and suppressive responses at later time points.
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Affiliation(s)
- Mei Wang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, China
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Juhun Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Bongsoo Choi
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Youngmin Park
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
| | - Hee-Jung Sim
- Center for Genome Engineering, Institute for Basic Science, Daejeon, South Korea
- Environmental Toxicology Research Center, Gyeongnam Department of Environmental Toxicology and Chemistry, Korea Institute of Toxicology, Jinju, South Korea
| | - Hyeran Kim
- Department of Biological Sciences, Kangwon National University, Chuncheon, South Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
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Dong B, Wang H, Liu T, Cheng P, Chen Y, Chen S, Guan Z, Fang W, Jiang J, Chen F. Whole genome duplication enhances the photosynthetic capacity of Chrysanthemum nankingense. Mol Genet Genomics 2017; 292:1247-1256. [DOI: 10.1007/s00438-017-1344-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 06/23/2017] [Indexed: 11/25/2022]
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Page MT, McCormac AC, Smith AG, Terry MJ. Singlet oxygen initiates a plastid signal controlling photosynthetic gene expression. THE NEW PHYTOLOGIST 2017; 213:1168-1180. [PMID: 27735068 PMCID: PMC5244666 DOI: 10.1111/nph.14223] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/19/2016] [Indexed: 05/20/2023]
Abstract
Retrograde signals from the plastid regulate photosynthesis-associated nuclear genes and are essential to successful chloroplast biogenesis. One model is that a positive haem-related signal promotes photosynthetic gene expression in a pathway that is abolished by the herbicide norflurazon. Far-red light (FR) pretreatment and transfer to white light also results in plastid damage and loss of photosynthetic gene expression. Here, we investigated whether norflurazon and FR pretreatment affect the same retrograde signal. We used transcriptome analysis and real-time reverse transcription-polymerase chain reaction (RT-PCR) to analyse the effects of these treatments on nuclear gene expression in various Arabidopsis (Arabidopsis thaliana) retrograde signalling mutants. Results showed that the two treatments inhibited largely different nuclear gene sets, suggesting that they affected different retrograde signals. Moreover, FR pretreatment resulted in singlet oxygen (1 O2 ) production and a rapid inhibition of photosynthetic gene expression. This inhibition was partially blocked in the executer1executer2 mutant, which is impaired in 1 O2 signalling. Our data support a new model in which a 1 O2 retrograde signal, generated by chlorophyll precursors, inhibits expression of key photosynthetic and chlorophyll synthesis genes to prevent photo-oxidative damage during de-etiolation. Such a signal would provide a counterbalance to the positive haem-related signal to fine tune regulation of chloroplast biogenesis.
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Affiliation(s)
- Mike T. Page
- Biological SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Alex C. McCormac
- Biological SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
| | - Alison G. Smith
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Matthew J. Terry
- Biological SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
- Institute for Life SciencesUniversity of SouthamptonSouthamptonSO17 1BJUK
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Bohne AV, Schwenkert S, Grimm B, Nickelsen J. Roles of Tetratricopeptide Repeat Proteins in Biogenesis of the Photosynthetic Apparatus. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:187-227. [PMID: 27017009 DOI: 10.1016/bs.ircmb.2016.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Biosynthesis of the photosynthetic apparatus is a complex operation, which includes the concerted synthesis and assembly of lipids, pigments and metal cofactors, and dozens of proteins. Research conducted in recent years has shown that these processes, as well as the stabilization and repair of this molecular machinery, are facilitated by transiently acting regulatory proteins, many of which belong to the superfamily of helical repeat proteins. Here, we focus on one of its families in photoautotrophic model organisms, the tetratricopeptide repeat (TPR) proteins, which participate in almost all of these steps and are crucial for biogenesis of the thylakoid membrane.
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Affiliation(s)
- A-V Bohne
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany
| | - S Schwenkert
- Botany, Ludwig-Maximilians-University, Munich, Germany
| | - B Grimm
- Institute of Biology/Plant Physiology, Humboldt University, Berlin, Germany
| | - J Nickelsen
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany.
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The Arabidopsis glutamyl-tRNA reductase (GluTR) forms a ternary complex with FLU and GluTR-binding protein. Sci Rep 2016; 6:19756. [PMID: 26794057 PMCID: PMC4726326 DOI: 10.1038/srep19756] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/17/2015] [Indexed: 11/09/2022] Open
Abstract
Tetrapyrrole biosynthesis is an essential and tightly regulated process, and glutamyl-tRNA reductase (GluTR) is a key target for multiple regulatory factors at the post-translational level. By binding to the thylakoid membrane protein FLUORESCENT (FLU) or the soluble stromal GluTR-binding protein (GBP), the activity of GluTR is down- or up-regulated. Here, we reconstructed a ternary complex composed of the C-terminal tetratricopepetide-repeat domain of FLU, GBP, and GluTR, crystallized and solved the structure of the complex at 3.2 Å. The overall structure resembles the shape of merged two binary complexes as previously reported, and shows a large conformational change within GluTR. We also demonstrated that GluTR binds tightly with GBP but does not bind to GSAM under the same condition. These findings allow us to suggest a biological role of the ternary complex for the regulation of plant GluTR.
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Fan M, Gao S, Ren J, Yang Q, Li H, Yang C, Ye Z. Overexpression of SlRBZ Results in Chlorosis and Dwarfism through Impairing Chlorophyll, Carotenoid, and Gibberellin Biosynthesis in Tomato. FRONTIERS IN PLANT SCIENCE 2016; 7:907. [PMID: 27446137 PMCID: PMC4916219 DOI: 10.3389/fpls.2016.00907] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/08/2016] [Indexed: 05/19/2023]
Abstract
ZFPs play important roles in many biological processes, including plant development, stress response, and phytohormone response. RanBP2-type zinc finger transcription factors have been characterized in animals and humans. However, their functions remain largely unknown in plants. In this study, we identified a RanBP2-type zinc finger protein gene (SlRBZ) in tomato. SlRBZ was constitutively expressed in roots, stems, leaves, flowers, and fruits. The SlRBZ-GFP fused protein was localized in the nucleus. Overexpression of SlRBZ resulted in chlorosis and dwarf phenotypes in tomato. Determination of physiological index showed that chlorophyll, carotenoid, and GAs contents were evidently decreased in transgenic plants. Furthermore, the qRT-PCR and RNA-Seq analyses demonstrated that the transcription of the genes involved in these biosynthesis pathways obviously decreased in SlRBZ-OE plants. In addition, ultrastructural observation by transmission electron microscopy indicated that plastids could not develop into mature chloroplasts with normal chloroplast membrane and thylakoid membrane system in SlRBZ-OE plants. The results suggest that overexpression of SlRBZ may impair the biosynthesis of chlorophyll, carotenoid, and gibberellin through blocking chloroplast development, resulting in chlorosis and dwarfism in tomato.
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Affiliation(s)
- Mingqin Fan
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
- School of Biology and Food Engineering, Fuyang Teachers CollegeFuyang, China
| | - Shenghua Gao
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
| | - Junling Ren
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
| | - Qihong Yang
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
| | - Hanxia Li
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
| | - Changxian Yang
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
- *Correspondence: Changxian Yang
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology (MOE), Key Laboratory of Horticultural Crop Biology and Genetic Improvement (Central Region), MOA, Huazhong Agricultural UniversityWuhan, China
- Zhibiao Ye
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Oryza sativa Chloroplast Signal Recognition Particle 43 (OscpSRP43) Is Required for Chloroplast Development and Photosynthesis. PLoS One 2015; 10:e0143249. [PMID: 26600124 PMCID: PMC4657901 DOI: 10.1371/journal.pone.0143249] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/02/2015] [Indexed: 12/26/2022] Open
Abstract
A rice chlorophyll-deficient mutant w67 was isolated from an ethyl methane sulfonate (EMS)-induced IR64 (Oryza sativa L. ssp. indica) mutant bank. The mutant exhibited a distinct yellow-green leaf phenotype in the whole plant growth duration with significantly reduced levels of chlorophyll and carotenoid, impaired chloroplast development and lowered capacity of photosynthesis compared with the wild-type IR64. Expression of a number of genes associated with chlorophyll metabolism, chloroplast biogenesis and photosynthesis was significantly altered in the mutant. Genetic analysis indicated that the yellow-green phenotype was controlled by a single recessive nuclear gene located on the short arm of chromosome 3. Using map-based strategy, the mutation was isolated and predicted to encode a chloroplast signal recognition particle 43 KD protein (cpSRP43) with 388 amino acid residuals. A single base substitution from A to T at position 160 resulted in a premature stop codon. OscpSRP43 was constitutively expressed in various organs with the highest level in the leaf. Functional complementation could rescue the mutant phenotype and subcellular localization showed that the cpSRP43:GFP fusion protein was targeted to the chloroplast. The data suggested that Oryza sativa cpSRP43 (OscpSRP43) was required for the normal development of chloroplasts and photosynthesis in rice.
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Sun XE, Feng XX, Li C, Zhang ZP, Wang LJ. Study on salt tolerance with YHem1 transgenic canola (Brassica napus). PHYSIOLOGIA PLANTARUM 2015; 154:223-42. [PMID: 25220348 DOI: 10.1111/ppl.12282] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 07/27/2014] [Accepted: 08/09/2014] [Indexed: 05/08/2023]
Abstract
5-Aminolevulinic acid (5-ALA) has been suggested for improving plant salt tolerance via exogenous application. In this study, we used a transgenic canola (Brassica napus), which contained a constituted gene YHem1 and biosynthesized more 5-ALA, to study salt stress responses. In a long-term pot experiment, the transgenic plants produced higher yield under 200 mmol L(-1) NaCl treatment than the wild type (WT). In a short-term experiment, the YHem1 transformation accelerated endogenous 5-ALA metabolism, leading to more chlorophyll accumulation, higher diurnal photosynthetic rates and upregulated expression of the gene encoding Rubisco small subunit. Furthermore, the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase, were significantly higher in the transgenic plants than the WT, while the levels of O2 ·(-) and malondialdehyde were lower than the latter. Additionally, the Na(+) content was higher in the transgenic leaves than that in the WT under salinity, but K(+) and Cl(-) were significantly lower. The levels of N, P, Cu, and S in the transgenic plants were also significantly lower than those in the WT, but the Fe content was significantly improved. As the leaf Fe content was decreased by salinity, it was suggested that the stronger salt tolerance of the transgenic plants was related to the higher Fe acquisition. Lastly, YHem1 transformation improved the leaf proline content, but salinity decreased rather than increased it. The content of free amino acids and soluble sugars was similarly decreased as salinity increased, but it was higher in the transgenic plants than that in the WT.
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Affiliation(s)
- Xin-E Sun
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Xin-Xin Feng
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Cui Li
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhi-Ping Zhang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Liang-Ju Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
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Regulation and function of tetrapyrrole biosynthesis in plants and algae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:968-85. [PMID: 25979235 DOI: 10.1016/j.bbabio.2015.05.007] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/21/2015] [Accepted: 05/07/2015] [Indexed: 12/20/2022]
Abstract
Tetrapyrroles are macrocyclic molecules with various structural variants and multiple functions in Prokaryotes and Eukaryotes. Present knowledge about the metabolism of tetrapyrroles reflects the complex evolution of the pathway in different kingdoms of organisms, the complexity of structural and enzymatic variations of enzymatic steps, as well as a wide range of regulatory mechanisms, which ensure adequate synthesis of tetrapyrrole end-products at any time of development and environmental condition. This review intends to highlight new findings of research on tetrapyrrole biosynthesis in plants and algae. In the course of the heme and chlorophyll synthesis in these photosynthetic organisms, glutamate, one of the central and abundant metabolites, is converted into highly photoreactive tetrapyrrole intermediates. Thereby, several mechanisms of posttranslational control are thought to be essential for a tight regulation of each enzymatic step. Finally, we wish to discuss the potential role of tetrapyrroles in retrograde signaling and point out perspectives of the formation of macromolecular protein complexes in tetrapyrrole biosynthesis as an efficient mechanism to ensure a fine-tuned metabolic flow in the pathway. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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Nagahatenna DSK, Langridge P, Whitford R. Tetrapyrrole-based drought stress signalling. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:447-59. [PMID: 25756609 PMCID: PMC5054908 DOI: 10.1111/pbi.12356] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 01/05/2015] [Accepted: 01/31/2015] [Indexed: 05/07/2023]
Abstract
Tetrapyrroles such as chlorophyll and heme play a vital role in primary plant metabolic processes such as photosynthesis and respiration. Over the past decades, extensive genetic and molecular analyses have provided valuable insights into the complex regulatory network of the tetrapyrrole biosynthesis. However, tetrapyrroles are also implicated in abiotic stress tolerance, although the mechanisms are largely unknown. With recent reports demonstrating that modified tetrapyrrole biosynthesis in plants confers wilting avoidance, a component physiological trait to drought tolerance, it is now timely that this pathway be reviewed in the context of drought stress signalling. In this review, the significance of tetrapyrrole biosynthesis under drought stress is addressed, with particular emphasis on the inter-relationships with major stress signalling cascades driven by reactive oxygen species (ROS) and organellar retrograde signalling. We propose that unlike the chlorophyll branch, the heme branch of the pathway plays a key role in mediating intracellular drought stress signalling and stimulating ROS detoxification under drought stress. Determining how the tetrapyrrole biosynthetic pathway is involved in stress signalling provides an opportunity to identify gene targets for engineering drought-tolerant crops.
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Affiliation(s)
- Dilrukshi S. K. Nagahatenna
- Australian Centre for Plant Functional GenomicsSchool of Agriculture, Food and WineUniversity of AdelaideGlen OsmondSAAustralia
| | - Peter Langridge
- Australian Centre for Plant Functional GenomicsSchool of Agriculture, Food and WineUniversity of AdelaideGlen OsmondSAAustralia
| | - Ryan Whitford
- Australian Centre for Plant Functional GenomicsSchool of Agriculture, Food and WineUniversity of AdelaideGlen OsmondSAAustralia
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Pale-green phenotype of atl31atl6 double mutant leaves is caused by disruption of 5-aminolevulinic acid biosynthesis in Arabidopsis thaliana. PLoS One 2015; 10:e0117662. [PMID: 25706562 PMCID: PMC4338271 DOI: 10.1371/journal.pone.0117662] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/29/2014] [Indexed: 11/19/2022] Open
Abstract
Arabidopsis ubiquitin ligases ATL31 and homologue ATL6 control the carbon/nitrogen nutrient and pathogen responses. A mutant with the loss-of-function of both atl31 and atl6 developed light intensity-dependent pale-green true leaves, whereas the single knockout mutants did not. Plastid ultrastructure and Blue Native-PAGE analyses revealed that pale-green leaves contain abnormal plastid structure with highly reduced levels of thylakoid proteins. In contrast, the pale-green leaves of the atl31/atl6 mutant showed normal Fv/Fm. In the pale-green leaves of the atl31/atl6, the expression of HEMA1, which encodes the key enzyme for 5-aminolevulinic acid synthesis, the rate-limiting step in chlorophyll biosynthesis, was markedly down-regulated. The expression of key transcription factor GLK1, which directly promotes HEMA1 transcription, was also significantly decreased in atl31/atl6 mutant. Finally, application of 5-aminolevulinic acid to the atl31/atl6 mutants resulted in recovery to a green phenotype. Taken together, these findings indicate that the 5-aminolevulinic acid biosynthesis step was inhibited through the down-regulation of chlorophyll biosynthesis-related genes in the pale-green leaves of atl31/atl6 mutant.
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Hills AC, Khan S, López-Juez E. Chloroplast Biogenesis-Associated Nuclear Genes: Control by Plastid Signals Evolved Prior to Their Regulation as Part of Photomorphogenesis. FRONTIERS IN PLANT SCIENCE 2015; 6:1078. [PMID: 26697036 PMCID: PMC4674571 DOI: 10.3389/fpls.2015.01078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/18/2015] [Indexed: 05/20/2023]
Abstract
The assembly of photosynthetically competent chloroplasts occurs in angiosperm seedlings when first exposed to light, and is due to the control by light of photosynthesis-associated nuclear genes (PhANGs), also dependent upon plastid-to-nucleus "biogenic" communication signals. The relationship between light- and plastid signal-regulation of PhANGs is close but poorly understood. In contrast, many conifers green in the dark and the promoter of a pine PhANG, Lhcb, is active in the dark in tobacco. Here, we show that the activity of this promoter in tobacco is sensitive to plastid photobleaching, or to the inhibition of plastid translation in the light or the dark, and the same interventions reduce expression of the native gene in pine seedlings, demonstrating classic plastid biogenic signaling in gymnosperms. Furthermore, Arabidopsis mutations causing defective plastid biogenesis suppress the effect in darkness of mutations in COP1 and DET1, repressors of photomorphogenesis, for the expression of several PhANGs but not a photosynthesis-unrelated, light-regulated gene. GLK transcriptional regulators mediate the response of LHCB but not of other tested PhANGs. We propose the ability to suppress PhANG response to positive plastid biogenic signals in the dark may have contributed to the evolution of light-controlled chloroplast biogenesis.
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Apitz J, Schmied J, Lehmann MJ, Hedtke B, Grimm B. GluTR2 Complements a hema1 Mutant Lacking Glutamyl-tRNA Reductase 1, but is Differently Regulated at the Post-Translational Level. ACTA ACUST UNITED AC 2014; 55:645-57. [DOI: 10.1093/pcp/pcu016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Dalal VK, Tripathy BC. Modulation of chlorophyll biosynthesis by water stress in rice seedlings during chloroplast biogenesis. PLANT, CELL & ENVIRONMENT 2012; 35:1685-703. [PMID: 22494411 DOI: 10.1111/j.1365-3040.2012.02520.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
To understand the impact of water stress on the greening process, water stress was applied to 6-day-old etiolated seedlings of a drought-sensitive cultivar of rice (Oryza sativa), Pusa Basmati-1 by immersing their roots in 40 mm polyethylene glycol (PEG) 6000 (-0.69 MPa) or 50 mm PEG 6000 (-1.03 MPa) dissolved in half-strength Murashige and Skoog (MS)-nutrient-solution, 16 h prior to transfer to cool-white-fluorescent + incandescent light. Chlorophyll (Chl) accumulation substantially declined in developing water-stressed seedlings. Reduced Chl synthesis was due to decreased accumulation of chlorophyll biosynthetic intermediates, that is, glutamate-1-semialdehyde (GSA), 5-aminolevulinic acid, Mg-protoporphyrin IX monomethylester and protochlorophyllide. Although 5-aminolevulinic acid synthesis decreased, the gene expression and protein abundance of the enzyme responsible for its synthesis, GSA aminotransferase, increased, suggesting its crucial role in the greening process in stressful environment. The biochemical activities of Chl biosynthetic enzymes, that is, 5-aminolevulinic acid dehydratase, porphobilinogen deaminase, coproporphyrinogen III oxidase, porphyrinogen IX oxidase, Mg-chelatase and protochlorophyllide oxidoreductase, were down-regulated due to their reduced protein abundance/gene expression in water-stressed seedlings. Down-regulation of protochlorophyllide oxidoreductase resulted in impaired Shibata shift. Our results demonstrate that reduced synthesis of early intermediates, that is, GSA and 5-aminolevulinic acid, could modulate the gene expression of later enzymes of Chl biosynthesis pathway.
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Affiliation(s)
- Vijay K Dalal
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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Zhang ZP, Yao QH, Wang LJ. Expression of yeast Hem1 controlled by Arabidopsis HemA1 promoter enhances leaf photosynthesis in transgenic tobacco. Mol Biol Rep 2011; 38:4369-79. [PMID: 21110104 DOI: 10.1007/s11033-010-0564-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Accepted: 11/17/2010] [Indexed: 10/18/2022]
Abstract
A gene encoding aminolevulinate synthase (ALA-S) in yeast (Saccharomyces cerevisiae YHem1) was introduced into the genome of tobacco (Nicoliana tabacum) under the control of Arabidopsis thaliana HemA1 gene promoter (AtHemA1 P). All transgenic lines transcribed the YHem1 gene, especially under light condition. The capacity to synthesize ALA and therefore chlorophyll was increased in transformed plants. Determination of gas exchange suggested that transgenic plants had significantly higher level of net photosynthetic rate (P ( n )), stomatal conductance (G ( s )) and transpiration rate (T ( r )), compared to the wild type (WT). Analysis with a modulated chlorophyll fluorometer demonstrated that the genetic transformation also caused a significant increase in photochemical efficiency of PSII ([Formula: see text]), actual photochemical efficiency (Ф ( PSII )), photochemical quenching (qP), electron transfer rate (ETR) and the energy proportion in photochemistry (Pc), but decrease in proportion in heat dissipation (Hd). Chlorophyll-a fast fluorescence measurement and JIP-test indicated that photosynthetic performance index on cross section basis (PI ( CS )) and electron transport flux (ET ( o ) /CS) of transgenic tobacco were increased remarkably. And the probability that a trapped exciton can move a electron into the electron transport chain beyond Q ( A ) (-) (Ψ ( o )) and the density of active reaction centers (RC/CS) were also increased obviously in transgenic tobacco. These results imply that transgenic tobacco plants expressing YHem1 gene had higher photosynthetic capacity and energy conversion efficiency than the WT plants.
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Affiliation(s)
- Zhi-Ping Zhang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
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Schmied J, Hedtke B, Grimm B. Overexpression of HEMA1 encoding glutamyl-tRNA reductase. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:1372-9. [PMID: 21272955 DOI: 10.1016/j.jplph.2010.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/17/2010] [Accepted: 12/18/2010] [Indexed: 05/28/2023]
Abstract
5-Aminolevulinic acid (ALA) synthesis has been shown to be the rate limiting step of tetrapyrrole biosynthesis. Glutamyl-tRNA reductase (GluTR) is the first committed enzyme of plant ALA synthesis and is controlled by interacting regulators, such as heme and the FLU protein. Induced inactivation of the HEMA1 gene encoding GluTR by RNAi expression in tobacco resulted in a reduced activity of Mg chelatase and Fe chelatase indicating a feed-forward regulatory mechanism that links ALA synthesis posttranslationally with late enzymes of tetrapyrrole biosynthesis (Hedtke et al., 2007). Here, the regulatory impact of GluTR was investigated by overexpression of AtHEMA1 in Arabidopsis and tobacco plants. Light-dependent ALA synthesis cannot benefit from an up to 7-fold induced expression of GluTR in Arabidopsis. While constitutive AtHEMA1 overexpression in tobacco stimulates ALA synthesis by 50-90% during light-exposed growth of seedlings, no increase in heme and chlorophyll contents is observed. HEMA1 overexpression in etiolated and dark-grown Arabidopsis and tobacco seedlings leads to additional accumulation of protochlorophyllide. As excessive accumulation of GluTR does not correlate with increased ALA formation, it is hypothesized that ALA synthesis is additionally limited by other effectors that balance the allocation of ALA with the activity of enzymes of chlorophyll and heme biosynthesis.
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Affiliation(s)
- Judith Schmied
- Institute of Biology, Plant Physiology, Humboldt University Berlin, Philippstrasse 13, Berlin, Germany
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Tanaka R, Kobayashi K, Masuda T. Tetrapyrrole Metabolism in Arabidopsis thaliana. THE ARABIDOPSIS BOOK 2011; 9:e0145. [PMID: 22303270 PMCID: PMC3268503 DOI: 10.1199/tab.0145] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Higher plants produce four classes of tetrapyrroles, namely, chlorophyll (Chl), heme, siroheme, and phytochromobilin. In plants, tetrapyrroles play essential roles in a wide range of biological activities including photosynthesis, respiration and the assimilation of nitrogen/sulfur. All four classes of tetrapyrroles are derived from a common biosynthetic pathway that resides in the plastid. In this article, we present an overview of tetrapyrrole metabolism in Arabidopsis and other higher plants, and we describe all identified enzymatic steps involved in this metabolism. We also summarize recent findings on Chl biosynthesis and Chl breakdown. Recent advances in this field, in particular those on the genetic and biochemical analyses of novel enzymes, prompted us to redraw the tetrapyrrole metabolic pathways. In addition, we also summarize our current understanding on the regulatory mechanisms governing tetrapyrrole metabolism. The interactions of tetrapyrrole biosynthesis and other cellular processes including the plastid-to-nucleus signal transduction are discussed.
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Affiliation(s)
- Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | | | - Tatsuru Masuda
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
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Sobotka R, Tichy M, Wilde A, Hunter CN. Functional assignments for the carboxyl-terminal domains of the ferrochelatase from Synechocystis PCC 6803: the CAB domain plays a regulatory role, and region II is essential for catalysis. PLANT PHYSIOLOGY 2011; 155:1735-47. [PMID: 21081693 PMCID: PMC3091120 DOI: 10.1104/pp.110.167528] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/09/2010] [Indexed: 05/20/2023]
Abstract
Ferrochelatase (FeCH) catalyzes the insertion of Fe(2+) into protoporphyrin, forming protoheme. In photosynthetic organisms, FeCH and magnesium chelatase lie at a biosynthetic branch point where partitioning down the heme and chlorophyll (Chl) pathways occurs. Unlike their mammalian, yeast, and other bacterial counterparts, cyanobacterial and algal FeCHs as well as FeCH2 isoform from plants possess a carboxyl-terminal Chl a/b-binding (CAB) domain with a conserved Chl-binding motif. The CAB domain is connected to the FeCH catalytic core by a proline-rich linker sequence (region II). In order to dissect the regulatory, catalytic, and structural roles of the region II and CAB domains, we analyzed a FeCH ΔH347 mutant that retains region II but lacks the CAB domain and compared it with the ΔH324-FeCH mutant that lacks both these domains. We found that the CAB domain is not required for catalytic activity but is essential for dimerization of FeCH; its absence causes aberrant accumulation of Chl-protein complexes under high light accompanied by high levels of the Chl precursor chlorophyllide. Thus, the CAB domain appears to serve mainly a regulatory function, possibly in balancing Chl biosynthesis with the synthesis of cognate apoproteins. Region II is essential for the catalytic function of the plastid-type FeCH enzyme, although the low residual activity of the ΔH324-FeCH is more than sufficient to furnish the cellular demand for heme. We propose that the apparent surplus of FeCH activity in the wild type is critical for cell viability under high light due to a regulatory role of FeCH in the distribution of Chl into apoproteins.
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Affiliation(s)
- Roman Sobotka
- Institute of Microbiology, Department of Autotrophic Microorganisms, 379 81 Trebon, Czech Republic.
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Zhang ZP, Yao QH, Wang LJ. Expression of yeast Hem1 gene controlled by Arabidopsis HemA1 promoter improves salt tolerance in Arabidopsis plants. BMB Rep 2010; 43:330-6. [PMID: 20510016 DOI: 10.5483/bmbrep.2010.43.5.330] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
5-Aminolevulinate (ALA) is well-known as an essential biosynthetic precursor of all tetrapyrrole compounds, which has been suggested to improve plant salt tolerance by exogenous application. In this work, the gene encoding aminolevulinate synthase (ALA-S) in yeast (Saccharomyces cerevisiae Hem1) was introduced into the genome of Arabidopsis controlled by the Arabidopsis thaliana HemA1 gene promoter. All transgenic lines were able to transcribe the YHem1 gene, especially under light condition. The chimeric protein (YHem1-EGFP) was found co-localizing with the mitochondria in onion epidermal cells. The transgenic Arabidopsis plants could synthesize more endogenous ALA with higher levels of metabolites including chlorophyll and heme. When the T(2) homozygous seeds were cultured under NaCl stress, their germination and seedling growth were much better than the wild type. Therefore, introduction of ALA-S gene led to higher level of ALA metabolism with more salt tolerance in higher plants.
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Solymosi K, Schoefs B. Etioplast and etio-chloroplast formation under natural conditions: the dark side of chlorophyll biosynthesis in angiosperms. PHOTOSYNTHESIS RESEARCH 2010; 105:143-66. [PMID: 20582474 DOI: 10.1007/s11120-010-9568-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Accepted: 05/30/2010] [Indexed: 05/03/2023]
Abstract
Chloroplast development is usually regarded as proceeding from proplastids. However, direct or indirect conversion pathways have been described in the literature, the latter involving the etioplast or the etio-chloroplast stages. Etioplasts are characterized by the absence of chlorophylls (Chl-s) and the presence of a unique inner membrane network, the prolamellar body (PLB), whereas etio-chloroplasts contain Chl-s and small PLBs interconnected with chloroplast thylakoids. As etioplast development requires growth in darkness for several days, this stage is generally regarded as a nonnatural pathway of chloroplast development occurring only under laboratory conditions. In this article, we have reviewed the data in favor of the involvement of etioplasts and etio-chloroplasts as intermediary stage(s) in chloroplast formation under natural conditions, the molecular aspects of PLB formation and we propose a dynamic model for its regulation.
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Affiliation(s)
- Katalin Solymosi
- Department of Plant Anatomy, Institute of Biology, Eötvös University, Pázmány P. s. 1/C, 1117 Budapest, Hungary.
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