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Li C, Erhart T, Liu X, Kräutler B. Yellow Dioxobilin-Type Tetrapyrroles from Chlorophyll Breakdown in Higher Plants-A New Class of Colored Phyllobilins. Chemistry 2019; 25:4052-4057. [PMID: 30688378 PMCID: PMC6563717 DOI: 10.1002/chem.201806038] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Indexed: 11/11/2022]
Abstract
In senescent leaves chlorophyll (Chl) catabolites typically accumulate as colorless tetrapyrroles, classified as formyloxobilin-type (or type-I) or dioxobilin-type (type-II) phyllobilins (PBs). Yellow type-I Chl catabolites (YCCs) also occur in some senescent leaves, in which they are generated by oxidation of colorless type-I PBs. A yellow type-II PB was recently proposed to occur in extracts of fall leaves of grapevine (Vitis vinifera), tentatively identified by its mass and UV/Vis absorption characteristics. Here, the first synthesis of a yellow type-II Chl catabolite (DYCC) from its presumed natural colorless type-II precursor is reported. A homogenate of a Spatiphyllum wallisii leaf was used as "green" means of effective and selective oxidation. The synthetic DYCC was fully characterized and identified with the yellow grapevine leaf pigment. As related yellow type-I PBs do, the DYCC functions as a reversible photoswitch by undergoing selective photo-induced Z/E isomerization of its C15=C16 bond.
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Affiliation(s)
- Chengjie Li
- Institute of Organic Chemistry & Centre of, Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnrain 80/826020InnsbruckAustria
- Present address: Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular EngineeringEast China University of Science & TechnologyMeilong Rd 130200237ShanghaiChina
| | - Theresia Erhart
- Institute of Organic Chemistry & Centre of, Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Xiujun Liu
- Institute of Organic Chemistry & Centre of, Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnrain 80/826020InnsbruckAustria
- Present address: Research Center of Analysis and TestEast China University of Science & TechnologyMeilong Rd 130200237ShanghaiChina
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Centre of, Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnrain 80/826020InnsbruckAustria
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Chen Y, Shimoda Y, Yokono M, Ito H, Tanaka A. Mg-dechelatase is involved in the formation of photosystem II but not in chlorophyll degradation in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:1022-1031. [PMID: 30471153 DOI: 10.1111/tpj.14174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
The STAY-GREEN (SGR) gene encodes Mg-dechelatase which catalyzes the conversion of chlorophyll (Chl) a to pheophytin (Pheo) a. This reaction is the first and most important regulatory step in the Chl degradation pathway. Conversely, Pheo a is an indispensable molecule in photosystem (PS) II, suggesting the involvement of SGR in the formation of PSII. To investigate the physiological functions of SGR, we isolated Chlamydomonas sgr mutants by screening an insertion-mutant library. The sgr mutants had reduced maximum quantum efficiency of PSII (Fv /Fm ) and reduced Pheo a levels. These phenotypes were complemented by the introduction of the Chlamydomonas SGR gene. Blue Native polyacrylamide gel electrophoresis and immunoblotting analysis showed that although PSII levels were reduced in the sgr mutants, PSI and light-harvesting Chl a/b complex levels were unaffected. Under nitrogen starvation conditions, Chl degradation proceeded in the sgr mutants as in the wild type, indicating that ChlamydomonasSGR is not required for Chl degradation and primarily contributes to the formation of PSII. In contrast, in the Arabidopsis sgr triple mutant (sgr1 sgr2 sgrL), which completely lacks SGR activity, PSII was synthesized normally. These results suggest that the Arabidopsis SGR participates in Chl degradation while the ChlamydomonasSGR participates in PSII formation despite having the same catalytic property.
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Affiliation(s)
- Ying Chen
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Yousuke Shimoda
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Makio Yokono
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Hisashi Ito
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
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Ren J, Liu Z, Chen W, Xu H, Feng H. Anthocyanin Degrading and Chlorophyll Accumulation Lead to the Formation of Bicolor Leaf in Ornamental Kale. Int J Mol Sci 2019; 20:E603. [PMID: 30704122 PMCID: PMC6387137 DOI: 10.3390/ijms20030603] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/26/2019] [Accepted: 01/28/2019] [Indexed: 02/07/2023] Open
Abstract
Ornamental kale is a popular decorative plant. We identified a peculiar bicolor leaf double haploid line, with green margins and red centers. The development of bicolor leaves can be divided into three stages: S1, S2, and S3. To probe the reason for bicolor formation, we analyzed the anthocyanin and chlorophyll contents, detected the changes in indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellin 3 (GA3), sugar, and starch contents, and identified the differentially expressed genes (DEGs) using RNA-seq. Results showed that the bicolor leaf phenotype is gradually formed with anthocyanin degrading and chlorophyll accumulation. Anthocyanin content is lower in the green margin (S3_S) than in the red center (S3_C) part at S3. IAA content was positively correlated with anthocyanin content during the bicolor leaf development. During anthocyanin degrading from S1 to S2, cinnamate-4-hydroxylase (C4H) and transport inhibitor response 1 (TIR1) were downregulated, while lateral organ boundaries domain 39 (LBD39) was upregulated. Two peroxidases, two β-glucosidases (BGLU), LBD39, LBD37, detoxifying efflux carrier 35 (DTX35), three no apical meristem (NAC) transcription factors (TFs), and 15 WRKY DNA-binding protein (WRKY) TFs were downregulated in S3_S vs. S3_C. The bicolor phenotype was mainly linked to anthocyanin degrading and chlorophyll accumulation, and that anthocyanin degrading resulted from reduced anthocyanin biosynthesis and increased anthocyanin degradation.
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Affiliation(s)
- Jie Ren
- Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
| | - Zhiyong Liu
- Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
| | - Weishu Chen
- Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
| | - Hezi Xu
- Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
| | - Hui Feng
- Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
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Yang R, Hong Y, Ren Z, Tang K, Zhang H, Zhu JK, Zhao C. A Role for PICKLE in the Regulation of Cold and Salt Stress Tolerance in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2019; 10:900. [PMID: 31354770 PMCID: PMC6633207 DOI: 10.3389/fpls.2019.00900] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/26/2019] [Indexed: 05/10/2023]
Abstract
Arabidopsis PICKLE (PKL) is a putative CHD3-type chromatin remodeling factor with important roles in regulating plant growth and development as well as RNA-directed DNA methylation (RdDM). The role of PKL protein in plant abiotic stress response is still poorly understood. Here, we report that PKL is important for cold stress response in Arabidopsis. Loss-of-function mutations in the PKL gene lead to a chlorotic phenotype in seedlings under cold stress, which is caused by the alterations in the transcript levels of some chlorophyll metabolism-related genes. The pkl mutant also exhibits increased electrolyte leakage after freezing treatment. These results suggest that PKL is required for proper chilling and freezing tolerance in plants. Gene expression analysis shows that CBF3, encoding a key transcription factor involved in the regulation of cold-responsive genes, exhibits an altered transcript level in the pkl mutant under cold stress. Transcriptome data also show that PKL regulates the expression of a number of cold-responsive genes, including RD29A, COR15A, and COR15B, possibly through its effect on the expression of CBF3 gene. Mutation in PKL gene also results in decreased cotyledon greening rate and reduced primary root elongation under high salinity. Together, our results suggest that PKL regulates plant responses to cold and salt stress.
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Affiliation(s)
- Rong Yang
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- *Correspondence: Rong Yang,
| | - Yechun Hong
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhizhong Ren
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
| | - Kai Tang
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States
| | - Heng Zhang
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
| | - Jian-Kang Zhu
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States
| | - Chunzhao Zhao
- CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai, China
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, United States
- Chunzhao Zhao,
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Erhart T, Mittelberger C, Liu X, Podewitz M, Li C, Scherzer G, Stoll G, Valls J, Robatscher P, Liedl KR, Oberhuber M, Kräutler B. Novel Types of Hypermodified Fluorescent Phyllobilins from Breakdown of Chlorophyll in Senescent Leaves of Grapevine (Vitis vinifera). Chemistry 2018; 24:17268-17279. [PMID: 30079972 PMCID: PMC6282590 DOI: 10.1002/chem.201803128] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Indexed: 01/04/2023]
Abstract
The tetrapyrrolic chlorophyll catabolites (or phyllobilins, PBs) were analyzed in yellow fall leaves of the grape Chardonnay, a common Vitis vinifera white wine cultivar. The major fractions in leaf extracts of V. vinifera, tentatively assigned to PBs, were isolated and their structures elucidated. The dominant fraction is a dioxobilin-type non-fluorescent Chl-catabolite of a previously observed type. Two less polar fluorescent PBs were characterized as a novel dioxobilin-type fluorescent Chl-catabolite with a bicyclo-1',6'-glycosyl architecture, and its new fluorescent formyloxobilin-type analogue. The discovery of persistent hypermodified fluorescent PBs with the architecture of bicyclo-[17.3.1]-PBs (bcPBs), suggests the activity of an unknown enzyme that forges the 20-membered macroring at the tetrapyrrolic core of a fluorescent PB. bcPBs may play specific physiological roles in grapevine plants and represent endogenous anti-infective agents, as found similarly for other organic bicyclo-[n.3.1]-1',6'-glycosyl derivatives.
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Affiliation(s)
- Theresia Erhart
- Institute of Organic Chemistry & Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | | | - Xiujun Liu
- Institute of Organic Chemistry & Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
- Present address: Research Center of Analysis and TestEast China University of Science & TechnologyMeilong Rd 130200237ShanghaiChina
| | - Maren Podewitz
- Institute of General, Inorganic and Theoretical Chemistry & Centre of, Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Chengjie Li
- Institute of Organic Chemistry & Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
- Present address: Key Laboratory for Advanced Materials & Institute of, Fine Chemicals, School of Chemistry & Molecular EngineeringEast China University of Science & TechnologyMeilong Rd 130200237ShanghaiChina
| | - Gerhard Scherzer
- Institute of Organic Chemistry & Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Gertrud Stoll
- Laimburg Research CentreLaimburg 6-Pfatten (Vadena)39040Auer (Ora), BZItaly
| | - Josep Valls
- Laimburg Research CentreLaimburg 6-Pfatten (Vadena)39040Auer (Ora), BZItaly
- Present address: Faculté des Sciences Pharmaceutiques, Unité de Recherche Enologie EA 4577Université de Bordeaux33882Villenave d'OrnonFrance
| | - Peter Robatscher
- Laimburg Research CentreLaimburg 6-Pfatten (Vadena)39040Auer (Ora), BZItaly
| | - Klaus R. Liedl
- Institute of General, Inorganic and Theoretical Chemistry & Centre of, Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Michael Oberhuber
- Laimburg Research CentreLaimburg 6-Pfatten (Vadena)39040Auer (Ora), BZItaly
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
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Jin SW, Rahim MA, Afrin KS, Park JI, Kang JG, Nou IS. Transcriptome profiling of two contrasting ornamental cabbage (Brassica oleracea var. acephala) lines provides insights into purple and white inner leaf pigmentation. BMC Genomics 2018; 19:797. [PMID: 30400854 PMCID: PMC6219265 DOI: 10.1186/s12864-018-5199-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/23/2018] [Indexed: 12/04/2022] Open
Abstract
Background Ornamental cabbage (Brassica oleracea var. acephala) is an attractive landscape plant that remains colorful at low temperatures during winter. Its key feature is its inner leaf coloration, which can include red, pink, lavender, blue, violet and white. Some ornamental cabbages exhibit variation in leaf color pattern linked to leaf developmental stage. However, little is known about the molecular mechanism underlying changes in leaf pigmentation pattern between developmental stages. Results The transcriptomes of six ornamental cabbage leaf samples were obtained using Illumina sequencing technology. A total of 339.75 million high-quality clean reads were assembled into 46,744 transcripts and 46,744 unigenes. Furthermore, 12,771 genes differentially expressed across the different lines and stages were identified by pairwise comparison. We identified 74 and 13 unigenes as differentially expressed genes related to the anthocyanin biosynthetic pathway and chlorophyll metabolism, respectively. Among them, three unigenes (BoC4H2, BoUGT9, and BoGST21) and six unigenes (BoHEMA1, BoCRD1, BoPORC1, BoPORC2, BoCAO, and BoCLH1) were found as candidates for the genes encoding enzymes in the anthocyanin biosynthetic pathway and chlorophyll metabolism, respectively. In addition, two unigenes (BoRAX3 and BoTRB1) as MYB candidates, two unigenes (BoMUTE1, and BHLH168-like) as bHLH candidates were identified for purple pigmentation in ornamental cabbage. Conclusion Our results indicate that the purple inner leaves of purple ornamental cabbage result from a high level of anthocyanin biosynthesis, a high level of chlorophyll degradation and an extremely low level of chlorophyll biosynthesis, whereas the bicolor (purple/green) outer leaves are due to a moderate level of anthocyanin biosynthesis, a high level of chlorophyll degradation and a very low level of chlorophyll biosynthesis. In white ornamental cabbage, the white inner leaves are due to an extremely low level or absence of anthocyanin biosynthesis, a high level of chlorophyll degradation and a very low level of chlorophyll biosynthesis, whereas the bicolor (white/green) leaves are due to a high level of chlorophyll degradation and a low level of chlorophyll biosynthesis and absence of anthocyanin biosynthesis. These results provide insight into the molecular mechanisms underlying inner and bicolor leaf pigmentation in ornamental cabbage and offer a platform for assessing related ornamental species. Electronic supplementary material The online version of this article (10.1186/s12864-018-5199-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Si-Won Jin
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea
| | - Md Abdur Rahim
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea.,Department of Genetics and Plant Breeding, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh
| | - Khandker Shazia Afrin
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea
| | - Jong-In Park
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea
| | - Jong-Goo Kang
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea
| | - Ill-Sup Nou
- Department of Horticulture, Sunchon National University, Suncheon, 57922, Republic of Korea.
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Propagation of cell death in dropdead1, a sorghum ortholog of the maize lls1 mutant. PLoS One 2018; 13:e0201359. [PMID: 30199528 PMCID: PMC6130852 DOI: 10.1371/journal.pone.0201359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 07/14/2018] [Indexed: 02/08/2023] Open
Abstract
We describe dropdead1-1 (ded1), an EMS-induced recessive lesion mimic mutant of sorghum. It is characterized by the formation of spreading necrotic lesions that share many attributes with those associated with the maize lethal leaf spot1 (lls1) and Arabidopsis accelerated cell death1 (acd1) mutation. We show that as in lls1, ded1 lesions are initiated by wounding and require light for continued propagation, and that loss of chloroplast integrity is responsible for ded1 cell death. Consistent with these parallels, we demonstrate that ded1 is an ortholog of lls1 and encodes pheophorbide a oxidase (PaO) with 93% identity at the protein level. The mutant ded1 allele resulted from a stop codon-inducing single base pair change in exon 6 of the sorghum ortholog of lls1. The ded1 transcript was rapidly and transiently induced after wounding and substantially elevated in leaves containing ded1 lesions. Given that PaO is a key enzyme of the chlorophyll degradation pathway, its dysfunction would result in the accumulation of pheophorbide, a potent photosensitizer that results in the production of singlet oxygen. Consistent with this, cell death associated with ded1 lesions is most likely caused by singlet oxygen as our results exclude superoxide and H2O2 from this role. We explore the signal responsible for the propagation of lesions affecting both ded1 and lls1 lesions and find that both developmental age and ethylene increase the rate of lesion expansion in both mutants.
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58
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Zhang Y, Liu Z, Wang X, Wang J, Fan K, Li Z, Lin W. DELLA proteins negatively regulate dark-induced senescence and chlorophyll degradation in Arabidopsis through interaction with the transcription factor WRKY6. PLANT CELL REPORTS 2018; 37:981-992. [PMID: 29574486 DOI: 10.1007/s00299-018-2282-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/21/2018] [Indexed: 05/23/2023]
Abstract
DELLA proteins' negative regulation of dark-induced senescence and chlorophyll degradation in Arabidopsis is through interaction with WRKY6 and thus repression of its transcriptional activities on senescence-related genes. Senescence is an intricate and highly orchestrated process regulated by numerous endogenous and environmental signals. Gibberellins (GAs) and their signaling components DELLA proteins have been known to participate in the regulation of senescence. However, the mechanism of the GA-DELLA system involved in the senescence process remains largely unclear. Darkness is a known environmental factor that induces plant senescence. In this study, exogenous GA3 (an active form of GA) accelerated but paclobutrazol (a specific GA biosynthesis inhibitor) retarded dark-induced leaf yellowing in Arabidopsis. Moreover, the dark-triggered decrease in chlorophyll content, increase in cell membrane leakage, and upregulation of senescence-associated genes were notably impaired in both endogenous GA-decreased mutants ga3ox1/ga3ox2 and ga20ox1/ga20ox2 compared with those in wild-type Col-0. These effects of darkness were enhanced in the quintuple mutant of DELLA genes gai-t6/rga-t2/rgl1-1/rgl2-1/rgl3-1 and conversely attenuated in the gain-of-function mutant gai and transgenic plant 35S::TAP-RGAd17 compared with wild-type Ler. Subsequently, RGA interacted with the transcription factor WRKY6 in a yeast two-hybrid assay, as confirmed by bimolecular fluorescence complementation and pull-down analyses. In addition, mutation and overexpression of WRKY6 retarded and accelerated dark-induced senescence, respectively. Furthermore, transient expression assays in Arabidopsis protoplasts indicated that RGA and GAI weakened the transcriptional activities of WRKY6 on its downstream senescence-related genes, including SAG13 and SGR. Taken together, these results suggest that GAs positively and DELLAs negatively regulate dark-induced senescence and chlorophyll degradation in Arabidopsis. DELLAs function in this process, at least in part, by interacting with WRKY6.
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Affiliation(s)
- Yongqiang Zhang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China.
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province Universities, Fuzhou, 350002, People's Republic of China.
| | - Zhongjuan Liu
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province Universities, Fuzhou, 350002, People's Republic of China
| | - Xiaoyun Wang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China
| | - Jianfeng Wang
- State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, People's Republic of China
| | - Kai Fan
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province Universities, Fuzhou, 350002, People's Republic of China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China
| | - Zhaowei Li
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China
| | - Wenxiong Lin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China.
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province Universities, Fuzhou, 350002, People's Republic of China.
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Agriculture and Forestry University, Fuzhou, 350002, People's Republic of China.
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Moniruzzaman M, Gann ER, Wilhelm SW. Infection by a Giant Virus (AaV) Induces Widespread Physiological Reprogramming in Aureococcus anophagefferens CCMP1984 - A Harmful Bloom Algae. Front Microbiol 2018; 9:752. [PMID: 29725322 PMCID: PMC5917014 DOI: 10.3389/fmicb.2018.00752] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/03/2018] [Indexed: 01/05/2023] Open
Abstract
While viruses with distinct phylogenetic origins and different nucleic acid types can infect and lyse eukaryotic phytoplankton, “giant” dsDNA viruses have been found to be associated with important ecological processes, including the collapse of algal blooms. However, the molecular aspects of giant virus–host interactions remain largely unknown. Aureococcus anophagefferens virus (AaV), a giant virus in the Mimiviridae clade, is known to play a critical role in regulating the fate of brown tide blooms caused by the pelagophyte Aureococcus anophagefferens. To understand the physiological response of A. anophagefferens CCMP1984 upon AaV infection, we studied the transcriptomic landscape of this host–virus pair over an entire infection cycle using a RNA-sequencing approach. A massive transcriptional response of the host was evident as early as 5 min post-infection, with modulation of specific processes likely related to both host defense mechanism(s) and viral takeover of the cell. Infected Aureococcus showed a relative suppression of host-cell transcripts associated with photosynthesis, cytoskeleton formation, fatty acid, and carbohydrate biosynthesis. In contrast, host cell processes related to protein synthesis, polyamine biosynthesis, cellular respiration, transcription, and RNA processing were overrepresented compared to the healthy cultures at different stages of the infection cycle. A large number of redox active host-selenoproteins were overexpressed, which suggested that viral replication and assembly progresses in a highly oxidative environment. The majority (99.2%) of annotated AaV genes were expressed at some point during the infection cycle and demonstrated a clear temporal–expression pattern and an increasing relative expression for the majority of the genes through the time course. We detected a putative early promoter motif for AaV, which was highly similar to the early promoter elements of two other Mimiviridae members, indicating some degree of evolutionary conservation of gene regulation within this clade. This large-scale transcriptome study provides insights into the Aureococcus cells infected by a giant virus and establishes a foundation to test hypotheses regarding metabolic and regulatory processes critical for AaV and other Mimiviridae members.
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Affiliation(s)
- Mohammad Moniruzzaman
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States.,Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA, United States
| | - Eric R Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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Shifts in the Gut Metabolome and Clostridium difficile Transcriptome throughout Colonization and Infection in a Mouse Model. mSphere 2018; 3:mSphere00089-18. [PMID: 29600278 PMCID: PMC5874438 DOI: 10.1128/msphere.00089-18] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 12/12/2022] Open
Abstract
Clostridium difficile is a bacterial pathogen of global significance that is a major cause of antibiotic-associated diarrhea. Antibiotics deplete the indigenous gut microbiota and change the metabolic environment in the gut to one favoring C. difficile growth. Here we used metabolomics and transcriptomics to define the gut environment after antibiotics and during the initial stages of C. difficile colonization and infection. We show that amino acids, in particular, proline and branched-chain amino acids, and carbohydrates decrease in abundance over time and that C. difficile gene expression is consistent with their utilization by the bacterium in vivo. We employed an integrated approach to analyze the metabolome and transcriptome to identify associations between metabolites and transcripts. This highlighted the importance of key nutrients in the early stages of colonization, and the data provide a rationale for the development of therapies based on the use of bacteria that specifically compete for nutrients that are essential for C. difficile colonization and disease. Antibiotics alter the gut microbiota and decrease resistance to Clostridium difficile colonization; however, the mechanisms driving colonization resistance are not well understood. Loss of resistance to C. difficile colonization due to antibiotic treatment is associated with alterations in the gut metabolome, specifically, with increases in levels of nutrients that C. difficile can utilize for growth in vitro. To define the nutrients that C. difficile requires for colonization and pathogenesis in vivo, we used a combination of mass spectrometry and RNA sequencing (RNA Seq) to model the gut metabolome and C. difficile transcriptome throughout an acute infection in a mouse model at the following time points: 0, 12, 24, and 30 h. We also performed multivariate-based integration of the omics data to define the signatures that were most important throughout colonization and infection. Here we show that amino acids, in particular, proline and branched-chain amino acids, and carbohydrates decrease in abundance over time in the mouse cecum and that C. difficile gene expression is consistent with their utilization in vivo. This was also reinforced by the multivariate-based integration of the omics data where we were able to discriminate the metabolites and transcripts that support C. difficile physiology between the different time points throughout colonization and infection. This report illustrates how important the availability of amino acids and other nutrients is for the initial stages of C. difficile colonization and progression of disease. Future studies identifying the source of the nutrients and engineering bacteria capable of outcompeting C. difficile in the gut will be important for developing new targeted bacterial therapeutics. IMPORTANCEClostridium difficile is a bacterial pathogen of global significance that is a major cause of antibiotic-associated diarrhea. Antibiotics deplete the indigenous gut microbiota and change the metabolic environment in the gut to one favoring C. difficile growth. Here we used metabolomics and transcriptomics to define the gut environment after antibiotics and during the initial stages of C. difficile colonization and infection. We show that amino acids, in particular, proline and branched-chain amino acids, and carbohydrates decrease in abundance over time and that C. difficile gene expression is consistent with their utilization by the bacterium in vivo. We employed an integrated approach to analyze the metabolome and transcriptome to identify associations between metabolites and transcripts. This highlighted the importance of key nutrients in the early stages of colonization, and the data provide a rationale for the development of therapies based on the use of bacteria that specifically compete for nutrients that are essential for C. difficile colonization and disease.
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Abstract
Increases in ambient temperatures have been a severe threat to crop production in many countries around the world under climate change. Chloroplasts serve as metabolic centers and play a key role in physiological adaptive processes to heat stress. In addition to expressing heat shock proteins that protect proteins from heat-induced damage, metabolic reprogramming occurs during adaptive physiological processes in chloroplasts. Heat stress leads to inhibition of plant photosynthetic activity by damaging key components functioning in a variety of metabolic processes, with concomitant reductions in biomass production and crop yield. In this review article, we will focus on events through extensive and transient metabolic reprogramming in response to heat stress, which included chlorophyll breakdown, generation of reactive oxygen species (ROS), antioxidant defense, protein turnover, and metabolic alterations with carbon assimilation. Such diverse metabolic reprogramming in chloroplasts is required for systemic acquired acclimation to heat stress in plants.
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Affiliation(s)
- Qing-Long Wang
- The National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
| | - Juan-Hua Chen
- The National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
| | - Ning-Yu He
- The National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
| | - Fang-Qing Guo
- The National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
- CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology & Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
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Li C, Wurst K, Berghold J, Podewitz M, Liedl KR, Kräutler B. Pyro-Phyllobilins: Elusive Chlorophyll Catabolites Lacking a Critical Carboxylate Function of the Natural Chlorophylls. Chemistry 2018; 24:2987-2998. [PMID: 29244236 PMCID: PMC5861670 DOI: 10.1002/chem.201705331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Indexed: 11/17/2022]
Abstract
A β-keto ester grouping is a characteristic of ring E of the chlorophylls (Chls). Its presence has also reinforced the original identification of nonfluorescent Chl catabolites (NCCs) as colorless, amphiphilic phyllobilins (PBs). Polar NCCs were also detected in higher plants, in which a free carboxyl group replaced the ring E ester group. Such NCCs are surprisingly resistant to loss of this carboxyl unit, and NCCs lacking the latter, that is, pyro-NCCs (pyNCCs), have not been reported. Intrigued by the question of the natural occurrence of pyro-phyllobilins (pyPBs), we have prepared a representative pyNCC by decarboxylation of a natural NCC. We also converted the pyNCC into its yellow oxidation product, a pyro-YCC (pyYCC). The solution structures of pyNCC and of pyYCC, and a crystal structure of the pyYCC methyl ester (pyYCC-Me) were obtained. pyYCC-Me features the same remarkable H-bonded and π-stacked dimer structure as the corresponding natural yellow Chl catabolite (YCC) with the ring E methyl ester group. Indeed, the latter substituent has little effect on the structure, as well as on the unique self-assembly and photoswitch behavior of yellow PBs.
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Affiliation(s)
- Chengjie Li
- Institute of Organic Chemistry and Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
- Present address: Key Laboratory for Advanced Materials and Institute of, Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyMeilong Rd. 130200237ShanghaiP.R. China
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical ChemistryUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Joachim Berghold
- Institute of Organic Chemistry and Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Maren Podewitz
- Institute of General, Inorganic and Theoretical ChemistryUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Klaus R. Liedl
- Institute of General, Inorganic and Theoretical ChemistryUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular BiosciencesUniversity of InnsbruckInnrain 80/826020InnsbruckAustria
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63
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Guyer L, Salinger K, Krügel U, Hörtensteiner S. Catalytic and structural properties of pheophytinase, the phytol esterase involved in chlorophyll breakdown. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:879-889. [PMID: 29036670 PMCID: PMC5853334 DOI: 10.1093/jxb/erx326] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/21/2017] [Indexed: 05/22/2023]
Abstract
During leaf senescence and fruit ripening, chlorophyll is degraded in a multistep pathway into linear tetrapyrroles called phyllobilins. A key feature of chlorophyll breakdown is the removal of the hydrophobic phytol chain that renders phyllobilins water soluble, an important prerequisite for their ultimate storage in the vacuole of senescent cells. Chlorophyllases had been considered for more than a century to catalyze dephytylation in vivo; however, this was recently refuted. Instead, pheophytinase was discovered as a genuine in vivo phytol hydrolase. While chlorophyllase acts rather unspecifically towards different porphyrin substrates, pheophytinase was shown to specifically dephytylate pheophytin, namely Mg-free chlorophyll. The aim of this work was to elucidate in detail the biochemical and structural properties of pheophytinase. By testing different porphyrin substrates with recombinant pheophytinase from Arabidopsis thaliana we show that pheophytinase has high specificity for the acid moiety of the ester bond, namely the porphyrin ring, while the nature of the alcohol, namely the phytol chain in pheophytin, is irrelevant. In silico modelling of the 3-dimensional structure of pheophytinase and subsequent analysis of site-directed pheophytinase mutant forms allowed the identification of the serine, histidine, and aspartic acid residues that compose the catalytic triad, a classical feature of serine-type hydrolases to which both pheophytinase and chlorophyllase belong. Based on substantial structural differences in the models of Arabidopsis pheophytinase and chlorophyllase 1, we discuss potential differences in the catalytic properties of these two phytol hydrolases.
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Affiliation(s)
- Luzia Guyer
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
| | - Kathrin Salinger
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
| | - Undine Krügel
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
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Li WX, Yang SB, Lu Z, He ZC, Ye YL, Zhao BB, Wang L, Jin B. Cytological, physiological, and transcriptomic analyses of golden leaf coloration in Ginkgo biloba L. HORTICULTURE RESEARCH 2018; 5:12. [PMID: 29507736 PMCID: PMC5830439 DOI: 10.1038/s41438-018-0015-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/18/2017] [Accepted: 12/23/2017] [Indexed: 05/06/2023]
Abstract
Ginkgo biloba is grown worldwide as an ornamental plant for its golden leaf color. However, the regulatory mechanism of leaf coloration in G. biloba remains unclear. Here, we compared G. biloba gold-colored mutant leaves and normal green leaves in cytological, physiological and transcriptomic terms. We found that chloroplasts of the mutant were fewer and smaller, and exhibited ruptured thylakoid membranes, indistinct stromal lamellae and irregularly arranged vesicles. Physiological experiments also showed that the mutant had a lower chlorophyll, lower flavonoid and higher carotenoid contents (especially lutein). We further used transcriptomic sequencing to identify 116 differentially expressed genes (DEGs) and 46 transcription factors (TFs) involved in chloroplast development, chlorophyll metabolism, pigment biosynthesis and photosynthesis. Among these, the chlorophyll biosynthesis-related PPO showed down-regulation, while chlorophyll degradation-related NYC/NOL had up-regulated expression in mutant leaves. Z-ISO, ZDS, and LCYE, which are involved in carotenoid biosynthesis were up-regulated. Quantitative real-time PCR (RT-qPCR) further confirmed the altered expression levels of these genes at three stages. The alteration of PPO and NYC/NOL gene expression might affect chlorophyll biosynthesis and promote degradation of chlorophyll b to chlorophyll a, while the up-regulated genes Z-ISO, ZDS and LCYE enhanced carotenoid accumulation. Consequently, changes in the ratio of carotenoids to chlorophylls were the main factors driving the golden leaf coloration in the mutant G. biloba.
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Affiliation(s)
- Wei-xing Li
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Shun-bo Yang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Zhaogeng Lu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Zhi-chong He
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Yun-ling Ye
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Bei-bei Zhao
- College of Resource and Environment, Xizang Agriculture and Animal Husbandry College, Tibet, 860000 China
| | - Li Wang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
| | - Biao Jin
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009 China
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65
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Ohmiya A, Sasaki K, Nashima K, Oda-Yamamizo C, Hirashima M, Sumitomo K. Transcriptome analysis in petals and leaves of chrysanthemums with different chlorophyll levels. BMC PLANT BIOLOGY 2017; 17:202. [PMID: 29141585 PMCID: PMC5688696 DOI: 10.1186/s12870-017-1156-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/08/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Chlorophylls (Chls) are magnesium-containing tetrapyrrole macromolecules responsible for the green color in plants. The Chl metabolic pathway has been intensively studied and nearly all the enzymes involved in the pathway have been identified and characterized. Synthesis and activity of these enzymes are tightly regulated in tissue- and developmental stage-specific manners. Leaves contain substantial amounts of Chls because Chls are indispensable for photosynthesis. In contrast, petals generally contain only trace amounts of Chls, which if present would mask the bright petal color. Limited information is available about the mechanisms that control such tissue-specific accumulation of Chls. RESULTS To identify the regulatory steps that control Chl accumulation, we compared gene expression in petals and leaves of chrysanthemum cultivars with different Chl levels. Microarray and quantitative real-time PCR analyses showed that the expression levels of Chl biosynthesis genes encoding glutamyl-tRNA reductase, Mg-protoporphyrin IX chelatase, Mg-protoporphyrin IX monomethylester cyclase, and protochlorophyllide oxidoreductase were well associated with Chl content: their expression levels were lower in white petals than in green petals, and were highest in leaves. Among Chl catabolic genes, expression of STAY-GREEN, encoding Mg-dechelatase, which is a key enzyme controlling Chl degradation, was considerably higher in white and green petals than in leaves. We searched for transcription factor genes whose expression was well related to Chl level in petals and leaves and found three such genes encoding MYB113, CONSTANS-like 16, and DREB and EAR motif protein. CONCLUSIONS From our transcriptome analysis, we assume that a low rate of Chl biosynthesis and a high rate of Chl degradation lead to the absence of Chls in white chrysanthemum petals. We identified several candidate transcription factors that might affect Chl accumulation in chrysanthemum petals. Functional analysis of these transcription factors will provide a basis for future molecular studies of tissue-specific Chl accumulation.
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Affiliation(s)
- Akemi Ohmiya
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-0852 Japan
| | - Katsutomo Sasaki
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-0852 Japan
| | - Kenji Nashima
- Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-8605 Japan
- College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880 Japan
| | - Chihiro Oda-Yamamizo
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-0852 Japan
| | - Masumi Hirashima
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-0852 Japan
| | - Katsuhiko Sumitomo
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Fujimoto 2-1, Tsukuba, Ibaraki 305-0852 Japan
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Moser S, Scherzer G, Kräutler B. On the Nature of Isomeric Nonfluorescent Chlorophyll Catabolites in Leaves and Fruit - A Study with a Ubiquitous Phylloleucobilin and its Main Isomerization Product. Chem Biodivers 2017; 14. [DOI: 10.1002/cbdv.201700368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/15/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Simone Moser
- Institute of Organic Chemistry and Center for Molecular Biosciences; University of Innsbruck; Innrain 80/82 A-6020 Innsbruck Austria
| | - Gerhard Scherzer
- Institute of Organic Chemistry and Center for Molecular Biosciences; University of Innsbruck; Innrain 80/82 A-6020 Innsbruck Austria
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center for Molecular Biosciences; University of Innsbruck; Innrain 80/82 A-6020 Innsbruck Austria
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Li Z, Wu S, Chen J, Wang X, Gao J, Ren G, Kuai B. NYEs/SGRs-mediated chlorophyll degradation is critical for detoxification during seed maturation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:650-661. [PMID: 28873256 DOI: 10.1111/tpj.13710] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 08/12/2017] [Accepted: 09/01/2017] [Indexed: 05/25/2023]
Abstract
In the seed industry, chlorophyll (Chl) fluorescence is often used as a major non-invasive reporter of seed maturation and quality. Breakdown of Chl is a proactive process during the late stage of seed maturation, as well as during leaf senescence and fruit ripening. However, the biological significance of this process is still unclear. NYE1 and NYE2 are Mg-dechelatases, catalyzing the first rate-limiting step of Chl a degradation. Loss-of-function of both NYE1 and NYE2 not only results in a nearly complete retention of Chl during leaf senescence, but also produces green seeds in Arabidopsis. In this study, we showed that Chl retention in the nye1 nye2 double-mutant caused severe photo-damage to maturing seeds. Upon prolonged light exposure, green seeds of nye1 nye2 gradually bleached out and eventually lost their germination capacity. This organ-specific photosensitive phenotype is likely due to an over-accumulation of free Chl, which possesses photosensitizing properties and causes a burst of reactive oxygen species upon light exposure. As expected, a similar, albeit much milder, photosensitive phenotype was observed in the seeds of d1 d2, a green-seed mutant defective in NYE/SGR orthologous genes in soybean. Taken together, our data suggest that efficient NYEs-mediated Chl degradation is critical for detoxification during seed maturation.
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Affiliation(s)
- Zhongpeng Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Shouxin Wu
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Junyi Chen
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xiaoyan Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Jiong Gao
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Guodong Ren
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Benke Kuai
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
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Piao W, Han SH, Sakuraba Y, Paek NC. Rice 7-Hydroxymethyl Chlorophyll a Reductase Is Involved in the Promotion of Chlorophyll Degradation and Modulates Cell Death Signaling. Mol Cells 2017; 40:773-786. [PMID: 29047257 PMCID: PMC5682254 DOI: 10.14348/molcells.2017.0127] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 08/10/2017] [Accepted: 08/23/2017] [Indexed: 11/30/2022] Open
Abstract
The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen (1O2) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to reactive oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.
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Affiliation(s)
- Weilan Piao
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Su-Hyun Han
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Yasuhito Sakuraba
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Nam-Chon Paek
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
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Smolikova G, Dolgikh E, Vikhnina M, Frolov A, Medvedev S. Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos. Int J Mol Sci 2017; 18:E1993. [PMID: 28926960 PMCID: PMC5618642 DOI: 10.3390/ijms18091993] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 09/07/2017] [Accepted: 09/12/2017] [Indexed: 01/05/2023] Open
Abstract
The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN (SGR) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds.
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Affiliation(s)
- Galina Smolikova
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, St. Petersburg 199034, Russia.
| | - Elena Dolgikh
- All-Russia Institute for Agricultural Microbiology, St. Petersburg State University, St. Petersburg 199034, Russia.
| | - Maria Vikhnina
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
- Department of Biochemistry, St. Petersburg State University, St. Petersburg 199034, Russia.
| | - Andrej Frolov
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
| | - Sergei Medvedev
- Department of Plant Physiology and Biochemistry, St. Petersburg State University, St. Petersburg 199034, Russia.
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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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Lu G, Casaretto JA, Ying S, Mahmood K, Liu F, Bi YM, Rothstein SJ. Overexpression of OsGATA12 regulates chlorophyll content, delays plant senescence and improves rice yield under high density planting. PLANT MOLECULAR BIOLOGY 2017; 94:215-227. [PMID: 28342018 DOI: 10.1007/s11103-017-0604-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 03/15/2017] [Indexed: 05/19/2023]
Abstract
Agronomic traits controlling the formation, architecture and physiology of source and sink organs are main determinants of rice productivity. Semi-dwarf rice varieties with low tiller formation but high seed production per panicle and dark green and thick leaves with prolonged source activity are among the desirable traits to further increase the yield potential of rice. Here, we report the functional characterization of a zinc finger transcription factor, OsGATA12, whose overexpression causes increased leaf greenness, reduction of leaf and tiller number, and affects yield parameters. Reduced tillering allowed testing the transgenic plants under high density which resulted in significantly increased yield per area and higher harvest index compared to wild-type. We show that delayed senescence of transgenic plants and the corresponding longer stay-green phenotype is mainly due to increased chlorophyll and chloroplast number. Further, our work postulates that the increased greenness observed in the transgenic plants is due to more chlorophyll synthesis but most significantly to decreased chlorophyll degradation, which is supported by the reduced expression of genes involved in the chlorophyll degradation pathway. In particular we show evidence for the down-regulation of the STAY GREEN RICE gene and in vivo repression of its promoter by OsGATA12, which suggests a transcriptional repression function for a GATA transcription factor for prolonging the onset of senescence in cereals.
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Affiliation(s)
- Guangwen Lu
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - José A Casaretto
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada.
| | - Shan Ying
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Kashif Mahmood
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Fang Liu
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Yong-Mei Bi
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Steven J Rothstein
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
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van Wijk KJ, Kessler F. Plastoglobuli: Plastid Microcompartments with Integrated Functions in Metabolism, Plastid Developmental Transitions, and Environmental Adaptation. ANNUAL REVIEW OF PLANT BIOLOGY 2017; 68:253-289. [PMID: 28125283 DOI: 10.1146/annurev-arplant-043015-111737] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plastoglobuli (PGs) are plastid lipoprotein particles surrounded by a membrane lipid monolayer. PGs contain small specialized proteomes and metabolomes. They are present in different plastid types (e.g., chloroplasts, chromoplasts, and elaioplasts) and are dynamic in size and shape in response to abiotic stress or developmental transitions. PGs in chromoplasts are highly enriched in carotenoid esters and enzymes involved in carotenoid metabolism. PGs in chloroplasts are associated with thylakoids and contain ∼30 core proteins (including six ABC1 kinases) as well as additional proteins recruited under specific conditions. Systems analysis has suggested that chloroplast PGs function in metabolism of prenyl lipids (e.g., tocopherols, plastoquinone, and phylloquinone); redox and photosynthetic regulation; plastid biogenesis; and senescence, including recycling of phytol, remobilization of thylakoid lipids, and metabolism of jasmonate. These functionalities contribute to chloroplast PGs' role in responses to stresses such as high light and nitrogen starvation. PGs are thus lipid microcompartments with multiple functions integrated into plastid metabolism, developmental transitions, and environmental adaptation. This review provides an in-depth overview of PG experimental observations, summarizes the present understanding of PG features and functions, and provides a conceptual framework for PG research and the realization of opportunities for crop improvement.
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Affiliation(s)
- Klaas J van Wijk
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853;
| | - Felix Kessler
- Laboratory of Plant Physiology, University of Neuchâtel, 2000 Neuchâtel, Switzerland;
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Xu L, Yang P, Feng Y, Xu H, Cao Y, Tang Y, Yuan S, Liu X, Ming J. Spatiotemporal Transcriptome Analysis Provides Insights into Bicolor Tepal Development in Lilium "Tiny Padhye". FRONTIERS IN PLANT SCIENCE 2017; 8:398. [PMID: 28392796 PMCID: PMC5364178 DOI: 10.3389/fpls.2017.00398] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/08/2017] [Indexed: 05/24/2023]
Abstract
The bicolor Asiatic hybrid lily cultivar "Tiny Padhye" is an attractive variety because of its unique color pattern. During its bicolor tepal development, the upper tepals undergo a rapid color change from green to white, while the tepal bases change from green to purple. However, the molecular mechanisms underlying these changes remain largely uncharacterized. To systematically investigate the dynamics of the lily bicolor tepal transcriptome during development, we generated 15 RNA-seq libraries from the upper tepals (S2-U) and basal tepals (S1-D, S2-D, S3-D, and S4-D) of Lilium "Tiny Padhye." Utilizing the Illumina platform, a total of 295,787 unigenes were obtained from 713.12 million high-quality paired-end reads. A total of 16,182 unigenes were identified as differentially expressed genes during tepal development. Using Kyoto Encyclopedia of Genes and Genomes pathway analysis, candidate genes involved in the anthocyanin biosynthetic pathway (61 unigenes), and chlorophyll metabolic pathway (106 unigenes) were identified. Further analyses showed that most anthocyanin biosynthesis genes were transcribed coordinately in the tepal bases, but not in the upper tepals, suggesting that the bicolor trait of "Tiny Padhye" tepals is caused by the transcriptional regulation of anthocyanin biosynthetic genes. Meanwhile, the high expression level of chlorophyll degradation genes and low expression level of chlorophyll biosynthetic genes resulted in the absence of chlorophylls from "Tiny Padhye" tepals after flowering. Transcription factors putatively involved in the anthocyanin biosynthetic pathway and chlorophyll metabolism in lilies were identified using a weighted gene co-expression network analysis and their possible roles in lily bicolor tepal development were discussed. In conclusion, these extensive transcriptome data provide a platform for elucidating the molecular mechanisms of bicolor tepals in lilies and provide a basis for similar research in other closely related species.
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Affiliation(s)
- Leifeng Xu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Panpan Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
- Department of Ornamental Plants, College of Landscape Architecture, Nanjing Forestry UniversityNanjing, China
| | - Yayan Feng
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Hua Xu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Yuwei Cao
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Yuchao Tang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Suxia Yuan
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Xinyan Liu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
| | - Jun Ming
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural SciencesBeijing, China
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Transcriptomic Analysis of Leaf in Tree Peony Reveals Differentially Expressed Pigments Genes. Molecules 2017; 22:molecules22020324. [PMID: 28230761 PMCID: PMC6155769 DOI: 10.3390/molecules22020324] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 02/13/2017] [Indexed: 12/11/2022] Open
Abstract
Tree peony (Paeonia suffruticosa Andrews) is an important traditional flower in China. Besides its beautiful flower, the leaf of tree peony has also good ornamental value owing to its leaf color change in spring. So far, the molecular mechanism of leaf color change in tree peony is unclear. In this study, the pigment level and transcriptome of three different color stages of tree peony leaf were analyzed. The purplish red leaf was rich in anthocyanin, while yellowish green leaf was rich in chlorophyll and carotenoid. Transcriptome analysis revealed that 4302 differentially expressed genes (DEGs) were upregulated, and 4225 were downregulated in the purplish red leaf vs. yellowish green leaf. Among these DEGs, eight genes were predicted to participate in anthocyanin biosynthesis, eight genes were predicted involved in porphyrin and chlorophyll metabolism, and 10 genes were predicted to participate in carotenoid metabolism. In addition, 27 MYBs, 20 bHLHs, 36 WD40 genes were also identified from DEGs. Anthocyanidin synthase (ANS) is the key gene that controls the anthocyanin level in tree peony leaf. Protochlorophyllide oxido-reductase (POR) is the key gene which regulated the chlorophyll content in tree peony leaf.
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León J, Costa Á, Castillo MC. Nitric oxide triggers a transient metabolic reprogramming in Arabidopsis. Sci Rep 2016; 6:37945. [PMID: 27885260 PMCID: PMC5122866 DOI: 10.1038/srep37945] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/02/2016] [Indexed: 01/15/2023] Open
Abstract
Nitric oxide (NO) regulates plant growth and development as well as responses to stress that enhanced its endogenous production. Arabidopsis plants exposed to a pulse of exogenous NO gas were used for untargeted global metabolomic analyses thus allowing the identification of metabolic processes affected by NO. At early time points after treatment, NO scavenged superoxide anion and induced the nitration and the S-nitrosylation of proteins. These events preceded an extensive though transient metabolic reprogramming at 6 h after NO treatment, which included enhanced levels of polyamines, lipid catabolism and accumulation of phospholipids, chlorophyll breakdown, protein and nucleic acid turnover and increased content of sugars. Accordingly, lipid-related structures such as root cell membranes and leaf cuticle altered their permeability upon NO treatment. Besides, NO-treated plants displayed degradation of starch granules, which is consistent with the increased sugar content observed in the metabolomic survey. The metabolic profile was restored to baseline levels at 24 h post-treatment, thus pointing up the plasticity of plant metabolism in response to nitroxidative stress conditions.
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Affiliation(s)
- José León
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
| | - Álvaro Costa
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
| | - Mari-Cruz Castillo
- Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), CPI Edificio 8E, Avda. Ingeniero Fausto Elio s/n, 46022 Valencia, Spain
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Ghandchi FP, Caetano-Anolles G, Clough SJ, Ort DR. Investigating the Control of Chlorophyll Degradation by Genomic Correlation Mining. PLoS One 2016; 11:e0162327. [PMID: 27618630 PMCID: PMC5019398 DOI: 10.1371/journal.pone.0162327] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/19/2016] [Indexed: 11/18/2022] Open
Abstract
Chlorophyll degradation is an intricate process that is critical in a variety of plant tissues at different times during the plant life cycle. Many of the photoactive chlorophyll degradation intermediates are exceptionally cytotoxic necessitating that the pathway be carefully coordinated and regulated. The primary regulatory step in the chlorophyll degradation pathway involves the enzyme pheophorbide a oxygenase (PAO), which oxidizes the chlorophyll intermediate pheophorbide a, that is eventually converted to non-fluorescent chlorophyll catabolites. There is evidence that PAO is differentially regulated across different environmental and developmental conditions with both transcriptional and post-transcriptional components, but the involved regulatory elements are uncertain or unknown. We hypothesized that transcription factors modulate PAO expression across different environmental conditions, such as cold and drought, as well as during developmental transitions to leaf senescence and maturation of green seeds. To test these hypotheses, several sets of Arabidopsis genomic and bioinformatic experiments were investigated and re-analyzed using computational approaches. PAO expression was compared across varied environmental conditions in the three separate datasets using regression modeling and correlation mining to identify gene elements co-expressed with PAO. Their functions were investigated as candidate upstream transcription factors or other regulatory elements that may regulate PAO expression. PAO transcript expression was found to be significantly up-regulated in warm conditions, during leaf senescence, and in drought conditions, and in all three conditions significantly positively correlated with expression of transcription factor Arabidopsis thaliana activating factor 1 (ATAF1), suggesting that ATAF1 is triggered in the plant response to these processes or abiotic stresses and in result up-regulates PAO expression. The proposed regulatory network includes the freezing, senescence, and drought stresses modulating factor ATAF1 and various other transcription factors and pathways, which in turn act to regulate chlorophyll degradation by up-regulating PAO expression.
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Affiliation(s)
- Frederick P. Ghandchi
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Gustavo Caetano-Anolles
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Steven J. Clough
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Soybean/maize Germplasm, Pathology, and Genetics Research Unit, USDA/ARS, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Donald R. Ort
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Global Change and Photosynthesis Research Unit, USDA/ARS, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- * E-mail:
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Li CF, Xu YX, Ma JQ, Jin JQ, Huang DJ, Yao MZ, Ma CL, Chen L. Biochemical and transcriptomic analyses reveal different metabolite biosynthesis profiles among three color and developmental stages in 'Anji Baicha' (Camellia sinensis). BMC PLANT BIOLOGY 2016; 16:195. [PMID: 27609021 PMCID: PMC5015330 DOI: 10.1186/s12870-016-0885-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 08/31/2016] [Indexed: 05/02/2023]
Abstract
BACKGROUND The new shoots of the albino tea cultivar 'Anji Baicha' are yellow or white at low temperatures and turn green as the environmental temperatures increase during the early spring. 'Anji Baicha' metabolite profiles exhibit considerable variability over three color and developmental stages, especially regarding the carotenoid, chlorophyll, and theanine concentrations. Previous studies focused on physiological characteristics, gene expression differences, and variations in metabolite abundances in albino tea plant leaves at specific growth stages. However, the molecular mechanisms regulating metabolite biosynthesis in various color and developmental stages in albino tea leaves have not been fully characterized. RESULTS We used RNA-sequencing to analyze 'Anji Baicha' leaves at the yellow-green, albescent, and re-greening stages. The leaf transcriptomes differed considerably among the three stages. Functional classifications based on Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that differentially expressed unigenes were mainly related to metabolic pathways, biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, and carbon fixation in photosynthetic organisms. Chemical analyses revealed higher β-carotene and theanine levels, but lower chlorophyll a levels, in the albescent stage than in the green stage. Furthermore, unigenes involved in carotenoid, chlorophyll, and theanine biosyntheses were identified, and the expression patterns of the differentially expressed unigenes in these biosynthesis pathways were characterized. Through co-expression analyses, we identified the key genes in these pathways. These genes may be responsible for the metabolite biosynthesis differences among the different leaf color and developmental stages of 'Anji Baicha' tea plants. CONCLUSIONS Our study presents the results of transcriptomic and biochemical analyses of 'Anji Baicha' tea plants at various stages. The distinct transcriptome profiles for each color and developmental stage enabled us to identify changes to biosynthesis pathways and revealed the contributions of such variations to the albino phenotype of tea plants. Furthermore, comparisons of the transcriptomes and related metabolites helped clarify the molecular regulatory mechanisms underlying the secondary metabolic pathways in different stages.
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Affiliation(s)
- Chun-Fang Li
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
- School of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou China
| | - Yan-Xia Xu
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Jian-Qiang Ma
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Ji-Qiang Jin
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Dan-Juan Huang
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Ming-Zhe Yao
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Chun-Lei Ma
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Liang Chen
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou, China
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Gao S, Gao J, Zhu X, Song Y, Li Z, Ren G, Zhou X, Kuai B. ABF2, ABF3, and ABF4 Promote ABA-Mediated Chlorophyll Degradation and Leaf Senescence by Transcriptional Activation of Chlorophyll Catabolic Genes and Senescence-Associated Genes in Arabidopsis. MOLECULAR PLANT 2016; 9:1272-1285. [PMID: 27373216 DOI: 10.1016/j.molp.2016.06.006] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 05/17/2023]
Abstract
Chlorophyll (Chl) degradation is an integral process of leaf senescence, and NYE1/SGR1 has been demonstrated as a key regulator of Chl catabolism in diverse plant species. In this study, using yeast one-hybrid screening, we identified three abscisic acid (ABA)-responsive element (ABRE)-binding transcription factors, ABF2 (AREB1), ABF3, and ABF4 (AREB2), as the putative binding proteins of the NYE1 promoter. Through the transactivation analysis, electrophoretic mobility shift assay, and chromatin immunoprecipitation, we demonstrated that ABF2, ABF3, and ABF4 directly bound to and activated the NYE1 promoter in vitro and in vivo. ABA is a positive regulator of leaf senescence, and exogenously applied ABA can accelerate Chl degradation. The triple mutant of the ABFs, abf2abf3abf4, as well as two ABA-insensitive mutants, abi1-1 and snrk2.2/2.3/2.6, exhibited stay-green phenotypes after ABA treatment, along with decreased induction of NYE1 and NYE2 expression. In contrast, overexpression of ABF4 accelerated Chl degradation upon ABA treatment. Interestingly, ABF2/3/4 could also activate the expression of two Chl catabolic enzyme genes, PAO and NYC1, by directly binding to their promoters. In addition, abf2abf3abf4 exhibited a functional stay-green phenotype, and senescence-associated genes (SAGs), such as SAG29 (SWEET15), might be directly regulated by the ABFs. Taken together, our results suggest that ABF2, ABF3, and ABF4 likely act as key regulators in mediating ABA-triggered Chl degradation and leaf senescence in general in Arabidopsis.
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Affiliation(s)
- Shan Gao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jiong Gao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xiaoyu Zhu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yi Song
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Zhongpeng Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Guodong Ren
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xin Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Benke Kuai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China; Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200438, China.
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80
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Diaz-Mendoza M, Velasco-Arroyo B, Santamaria ME, González-Melendi P, Martinez M, Diaz I. Plant senescence and proteolysis: two processes with one destiny. Genet Mol Biol 2016; 39:329-38. [PMID: 27505308 PMCID: PMC5004835 DOI: 10.1590/1678-4685-gmb-2016-0015] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 05/10/2016] [Indexed: 01/03/2023] Open
Abstract
Senescence-associated proteolysis in plants is a complex and controlled process,
essential for mobilization of nutrients from old or stressed tissues, mainly leaves,
to growing or sink organs. Protein breakdown in senescing leaves involves many
plastidial and nuclear proteases, regulators, different subcellular locations and
dynamic protein traffic to ensure the complete transformation of proteins of high
molecular weight into transportable and useful hydrolysed products. Protease
activities are strictly regulated by specific inhibitors and through the activation
of zymogens to develop their proteolytic activity at the right place and at the
proper time. All these events associated with senescence have deep effects on the
relocation of nutrients and as a consequence, on grain quality and crop yield. Thus,
it can be considered that nutrient recycling is the common destiny of two processes,
plant senescence and, proteolysis. This review article covers the most recent
findings about leaf senescence features mediated by abiotic and biotic stresses as
well as the participants and steps required in this physiological process, paying
special attention to C1A cysteine proteases, their specific inhibitors, known as
cystatins, and their potential targets, particularly the chloroplastic proteins as
source for nitrogen recycling.
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Affiliation(s)
- Mercedes Diaz-Mendoza
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Blanca Velasco-Arroyo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
| | - M Estrella Santamaria
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Pablo González-Melendi
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Manuel Martinez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Isabel Diaz
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Madrid, Spain
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Lelandais G, Scheiber I, Paz-Yepes J, Lozano JC, Botebol H, Pilátová J, Žárský V, Léger T, Blaiseau PL, Bowler C, Bouget FY, Camadro JM, Sutak R, Lesuisse E. Ostreococcus tauri is a new model green alga for studying iron metabolism in eukaryotic phytoplankton. BMC Genomics 2016; 17:319. [PMID: 27142620 PMCID: PMC4855317 DOI: 10.1186/s12864-016-2666-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/26/2016] [Indexed: 11/17/2022] Open
Abstract
Background Low iron bioavailability is a common feature of ocean surface water and therefore micro-algae developed original strategies to optimize iron uptake and metabolism. The marine picoeukaryotic green alga Ostreococcus tauri is a very good model for studying physiological and genetic aspects of the adaptation of the green algal lineage to the marine environment: it has a very compact genome, is easy to culture in laboratory conditions, and can be genetically manipulated by efficient homologous recombination. In this study, we aimed at characterizing the mechanisms of iron assimilation in O. tauri by combining genetics and physiological tools. Specifically, we wanted to identify and functionally characterize groups of genes displaying tightly orchestrated temporal expression patterns following the exposure of cells to iron deprivation and day/night cycles, and to highlight unique features of iron metabolism in O. tauri, as compared to the freshwater model alga Chalamydomonas reinhardtii. Results We used RNA sequencing to investigated the transcriptional responses to iron limitation in O. tauri and found that most of the genes involved in iron uptake and metabolism in O. tauri are regulated by day/night cycles, regardless of iron status. O. tauri lacks the classical components of a reductive iron uptake system, and has no obvious iron regulon. Iron uptake appears to be copper-independent, but is regulated by zinc. Conversely, iron deprivation resulted in the transcriptional activation of numerous genes encoding zinc-containing regulation factors. Iron uptake is likely mediated by a ZIP-family protein (Ot-Irt1) and by a new Fea1-related protein (Ot-Fea1) containing duplicated Fea1 domains. The adaptation of cells to iron limitation involved an iron-sparing response tightly coordinated with diurnal cycles to optimize cell functions and synchronize these functions with the day/night redistribution of iron orchestrated by ferritin, and a stress response based on the induction of thioredoxin-like proteins, of peroxiredoxin and of tesmin-like methallothionein rather than ascorbate. We briefly surveyed the metabolic remodeling resulting from iron deprivation. Conclusions The mechanisms of iron uptake and utilization by O. tauri differ fundamentally from those described in C. reinhardtii. We propose this species as a new model for investigation of iron metabolism in marine microalgae. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2666-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gaëlle Lelandais
- CNRS, Institut Jacques Monod, Université Paris Diderot-Paris 7, F-75013, Paris, France
| | - Ivo Scheiber
- Department of Parasitology, Faculty of Science, Charles University in Prague, 12844, Prague, Czech Republic
| | - Javier Paz-Yepes
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005, Paris, France
| | - Jean-Claude Lozano
- Sorbonne Universités, University Pierre et Marie Curie, University of Paris VI, CNRS, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls-sur-Mer, France
| | - Hugo Botebol
- Sorbonne Universités, University Pierre et Marie Curie, University of Paris VI, CNRS, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls-sur-Mer, France
| | - Jana Pilátová
- Department of Parasitology, Faculty of Science, Charles University in Prague, 12844, Prague, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University in Prague, 12844, Prague, Czech Republic
| | - Thibaut Léger
- CNRS, Institut Jacques Monod, Université Paris Diderot-Paris 7, F-75013, Paris, France
| | - Pierre-Louis Blaiseau
- Sorbonne Universités, University Pierre et Marie Curie, University of Paris VI, CNRS, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls-sur-Mer, France
| | - Chris Bowler
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005, Paris, France
| | - François-Yves Bouget
- Sorbonne Universités, University Pierre et Marie Curie, University of Paris VI, CNRS, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls-sur-Mer, France
| | - Jean-Michel Camadro
- CNRS, Institut Jacques Monod, Université Paris Diderot-Paris 7, F-75013, Paris, France
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University in Prague, 12844, Prague, Czech Republic.
| | - Emmanuel Lesuisse
- CNRS, Institut Jacques Monod, Université Paris Diderot-Paris 7, F-75013, Paris, France.
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Kräutler B. Breakdown of Chlorophyll in Higher Plants--Phyllobilins as Abundant, Yet Hardly Visible Signs of Ripening, Senescence, and Cell Death. Angew Chem Int Ed Engl 2016; 55:4882-907. [PMID: 26919572 PMCID: PMC4950323 DOI: 10.1002/anie.201508928] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 01/06/2023]
Abstract
Fall colors have always been fascinating and are still a remarkably puzzling phenomenon associated with the breakdown of chlorophyll (Chl) in leaves. As discovered in recent years, nongreen bilin-type Chl catabolites are generated, which are known as the phyllobilins. Collaborative chemical-biological efforts have led to the elucidation of the key Chl-breakdown processes in senescent leaves and in ripening fruit. Colorless and largely photoinactive phyllobilins are rapidly produced from Chl, apparently primarily as part of a detoxification program. However, fluorescent Chl catabolites accumulate in some senescent leaves and in peels of ripe bananas and induce a striking blue glow. The structural features, chemical properties, and abundance of the phyllobilins in the biosphere suggest biological roles, which still remain to be elucidated.
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Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry & Center of Molecular Biosciences (CMBI), University of Innsbruck, 6020, Innsbruck, Austria.
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83
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Oda-Yamamizo C, Mitsuda N, Sakamoto S, Ogawa D, Ohme-Takagi M, Ohmiya A. The NAC transcription factor ANAC046 is a positive regulator of chlorophyll degradation and senescence in Arabidopsis leaves. Sci Rep 2016; 6:23609. [PMID: 27021284 PMCID: PMC4810360 DOI: 10.1038/srep23609] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 03/03/2016] [Indexed: 11/24/2022] Open
Abstract
Chlorophyll (Chl) degradation occurs during leaf senescence, embryo degreening, bud breaking, and fruit ripening. The Chl catabolic pathway has been intensively studied and nearly all the enzymes involved are identified and characterized; however, the molecular regulatory mechanisms of this pathway are largely unknown. In this study, we performed yeast one-hybrid screening using a transcription factor cDNA library to search for factors controlling the expression of Chl catabolic genes. We identified ANAC046 as a common regulator that directly binds to the promoter regions of NON-YELLOW COLORING1, STAY-GREEN1 (SGR1), SGR2, and PHEOPHORBIDE a OXYGENASE. Transgenic plants overexpressing ANAC046 exhibited an early-senescence phenotype and a lower Chl content in comparison with the wild-type plants, whereas loss-of-function mutants exhibited a delayed-senescence phenotype and a higher Chl content. Microarray analysis of ANAC046 transgenic plants showed that not only Chl catabolic genes but also senescence-associated genes were positively regulated by ANAC046. We conclude that ANAC046 is a positive regulator of Arabidopsis leaf senescence and exerts its effect by controlling the expression of Chl catabolic genes and senescence-associated genes.
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Affiliation(s)
- Chihiro Oda-Yamamizo
- National Agriculture and Food Research Organization (NARO), Institute of Floricultural Science, Tsukuba, Ibaraki 305-8519, Japan.,Research Fellow of Japanese Society for the Promotion of Science (JSPS), Tokyo 102-0083, Japan
| | - Nobutaka Mitsuda
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Shingo Sakamoto
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Daisuke Ogawa
- Horticultural Experiment Center, Wakayama Prefectural Agricultural Research Station, Gobo, Wakayama 644-0024, Japan
| | - Masaru Ohme-Takagi
- Institute for Environmental Science and Technology (IEST), Saitama University, Saitama, Saitama 338-8570, Japan
| | - Akemi Ohmiya
- National Agriculture and Food Research Organization (NARO), Institute of Floricultural Science, Tsukuba, Ibaraki 305-8519, Japan
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84
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Lira BS, Rosado D, Almeida J, de Souza AP, Buckeridge MS, Purgatto E, Guyer L, Hörtensteiner S, Freschi L, Rossi M. Pheophytinase Knockdown Impacts Carbon Metabolism and Nutraceutical Content Under Normal Growth Conditions in Tomato. PLANT & CELL PHYSIOLOGY 2016; 57:642-653. [PMID: 26880818 DOI: 10.1093/pcp/pcw021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/20/2016] [Indexed: 06/05/2023]
Abstract
Although chlorophyll (Chl) degradation is an essential biochemical pathway for plant physiology, our knowledge regarding this process still has unfilled gaps. Pheophytinase (PPH) was shown to be essential for Chl breakdown in dark-induced senescent leaves. However, the catalyzing enzymes involved in pigment turnover and fruit ripening-associated degreening are still controversial. Chl metabolism is closely linked to the biosynthesis of other isoprenoid-derived compounds, such as carotenoids and tocopherols, which are also components of the photosynthetic machinery. Chls, carotenoids and tocopherols share a common precursor, geranylgeranyl diphosphate, produced by the plastidial methylerythritol 4-phosphate (MEP) pathway. Additionally, the Chl degradation-derived phytol can be incorporated into tocopherol biosynthesis. In this context, tomato turns out to be an interesting model to address isoprenoid-metabolic cross-talk since fruit ripening combines degreening and an intensely active MEP leading to carotenoid accumulation. Here, we investigate the impact of PPH deficiency beyond senescence by the comprehensive phenotyping of SlPPH-knockdown tomato plants. In leaves, photosynthetic parameters indicate altered energy usage of excited Chl. As a mitigatory effect, photosynthesis-associated carotenoids increased while tocopherol content remained constant. Additionally, starch and soluble sugar profiles revealed a distinct pattern of carbon allocation in leaves that suggests enhanced sucrose exportation. The higher levels of carbohydrates in sink organs down-regulated carotenoid biosynthesis. Additionally, the reduction in Chl-derived phytol recycling resulted in decreased tocopherol content in transgenic ripe fruits. Summing up, tocopherol and carotenoid metabolism, together with the antioxidant capacity of the hydrophilic and hydrophobic fractions, were differentially affected in leaves and fruits of the transgenic plants. Thus, in tomato, PPH plays a role beyond senescence-associated Chl degradation that, when compromised, affects isoprenoid and carbon metabolism which ultimately alters the fruit's nutraceutical content.
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Affiliation(s)
- Bruno Silvestre Lira
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Daniele Rosado
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Juliana Almeida
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Amanda Pereira de Souza
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Eduardo Purgatto
- Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Luzia Guyer
- Institute of Plant Biology, University of Zurich, Zurich, Switzerland
| | | | - Luciano Freschi
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Magdalena Rossi
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
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85
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Kräutler B. Der Chlorophyllabbau in höheren Pflanzen - Phyllobiline als weitverbreitete, aber kaum sichtbare Zeichen von Reifung, Seneszenz und Zelltod. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201508928] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Bernhard Kräutler
- Institut für Organische Chemie & Centrum für MolekulareBiowissenschaften (CMBI); Universität Innsbruck; 6020 Innsbruck Österreich
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86
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Li C, Kräutler B. Transition metal complexes of phyllobilins - a new realm of bioinorganic chemistry. Dalton Trans 2016; 44:10116-27. [PMID: 25923782 PMCID: PMC4447063 DOI: 10.1039/c5dt00474h] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Phyllobilins may function as natural ligand molecules for biologically important transition metal ions, giving complexes with remarkable chemical and photophysical properties.
Natural cyclic tetrapyrroles feature outstanding capacity for binding transition metal ions, furnishing Nature with the important metallo-porphyrinoid ‘Pigments of Life’, such as heme, chlorophyll (Chl) and vitamin B12. In contrast, linear tetrapyrroles are not generally ascribed a biologically relevant ability for metal-binding. Indeed, when heme or Chl are degraded to natural linear tetrapyrroles, their central Fe- or Mg-ions are set free. Some linear tetrapyrroles are, however, effective multi-dentate ligands and their transition metal complexes have remarkable chemical properties. The focus of this short review is centred on such complexes of the linear tetrapyrroles derived from natural Chl-breakdown, called phyllobilins. These natural bilin-type compounds are massively produced in Nature and in highly visible processes. Colourless non-fluorescing Chl-catabolites (NCCs) and the related dioxobilin-type NCCs, which typically accumulate in leaves as ‘final’ products of Chl-breakdown, show low affinity for transition metal-ions. However, NCCs are oxidized in leaves to give less saturated coloured phyllobilins, such as yellow or pink Chl-catabolites (YCCs or PiCCs). YCCs and PiCCs are ligands for various biologically relevant transition metal-ions, such as Zn(ii)-, Ni(ii)- and Cu(ii)-ions. Complexation of Zn(ii)- and Cd(ii)-ions by the effectively tridentate PiCC produces blue metal-complexes that exhibit an intense red fluorescence, thus providing a tool for the sensitive detection of these metal ions. Outlined here are fundamental aspects of structure and metal coordination of phyllobilins, including a comparison with the corresponding properties of bilins. This knowledge may be valuable in the quest of finding possible biological roles of the phyllobilins. Thanks to their capacity for metal-ion coordination, phyllobilins could, e.g., be involved in heavy-metal transport and detoxification, and some of their metal-complexes could act as sensitizers for singlet oxygen or as plant toxins against pathogens.
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Affiliation(s)
- Chengjie Li
- Institute of Organic Chemistry & Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria.
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87
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Teixeira RN, Ligterink W, França-Neto JDB, Hilhorst HWM, da Silva EAA. Gene expression profiling of the green seed problem in Soybean. BMC PLANT BIOLOGY 2016; 16:37. [PMID: 26829931 PMCID: PMC4736698 DOI: 10.1186/s12870-016-0729-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 01/28/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND Due to the climate change of the past few decades, some agricultural areas in the world are now experiencing new climatic extremes. For soybean, high temperatures and drought stress can potentially lead to the "green seed problem", which is characterized by chlorophyll retention in mature seeds and is associated with lower oil and seed quality, thus negatively impacting the production of soybean seeds. RESULTS Here we show that heat and drought stress result in a "mild" stay-green phenotype and impaired expression of the STAY-GREEN 1 and STAY-GREEN 2 (D1, D2), PHEOPHORBIDASE 2 (PPH2) and NON-YELLOW COLORING 1 (NYC1_1) genes in soybean seeds of a susceptible soybean cultivar. We suggest that the higher expression of these genes in fully mature seeds of a tolerant cultivar allows these seeds to cope with stressful conditions and complete chlorophyll degradation. CONCLUSIONS The gene expression results obtained in this study represent a significant advance in understanding chlorophyll retention in mature soybean seeds produced under stressful conditions. This will open new research possibilities towards finding molecular markers for breeding programs to produce cultivars which are less susceptible to chlorophyll retention under the hot and dry climate conditions which are increasingly common in the largest soybean production areas of the world.
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Affiliation(s)
- Renake N Teixeira
- Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.
- Departamento de Produção e Melhoramento Vegetal, Faculdade de Ciências Agronômicas-UNESP, Universidade Estadual Paulista, Botucatu, SP, 18.610-307, Brazil.
| | - Wilco Ligterink
- Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.
| | - José de B França-Neto
- Empresa Brasileira de Pesquisa Agropecuária, Centro Nacional de Pesquisa de Soja, EMBRAPA Soja, Caixa-postal 231, Londrina, PR, 86001970, Brazil.
| | - Henk W M Hilhorst
- Wageningen Seed Lab, Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.
| | - Edvaldo A A da Silva
- Departamento de Produção e Melhoramento Vegetal, Faculdade de Ciências Agronômicas-UNESP, Universidade Estadual Paulista, Botucatu, SP, 18.610-307, Brazil.
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88
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Sakuraba Y, Han SH, Lee SH, Hörtensteiner S, Paek NC. Arabidopsis NAC016 promotes chlorophyll breakdown by directly upregulating STAYGREEN1 transcription. PLANT CELL REPORTS 2016; 35:155-66. [PMID: 26441053 DOI: 10.1007/s00299-015-1876-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 05/04/2023]
Abstract
The Arabidopsis transcriptional factor NAC016 directly activates chlorophyll degradation during leaf senescence by binding to the promoter of SGR1 and upregulating its transcription. During leaf senescence or abiotic stress in Arabidopsis thaliana, STAYGREEN1 (SGR1) promotes chlorophyll (Chl) degradation, acting with Chl catabolic enzymes, but the mechanism regulating SGR1 transcription remains largely unknown. Here, we show that the Arabidopsis senescence-associated NAC transcription factor NAC016 directly activates SGR1 transcription. Under senescence-promoting conditions, the expression of SGR1 was downregulated in nac016-1 mutants and upregulated in NAC016-overexpressing (NAC016-OX) plants. By yeast one-hybrid and chromatin immunoprecipitation assays, we found that NAC016 directly binds to the SGR1 promoter, which contains the NAC016-specific binding motif (termed the NAC016BM). Furthermore, nac016-1 SGR1-OX plants showed an early leaf yellowing phenotype, similar to SGR1-OX plants, confirming that NAC016 directly activates SGR1 expression in the leaf senescence regulatory cascade. Although we found that NAC016 activates SGR1 expression in senescing leaves, this transcriptional regulation is considerably weaker in maturing seeds; the seeds of sgr1-1 mutants (also known as nonyellowing1-1, nye1-1) stayed green, while the seeds of nac016-1 mutants turned from green to yellow normally. We also found that the abscisic acid (ABA) signaling-related transcription factor genes ABI5 and EEL and the ABA biosynthesis gene AAO3, which activate SGR1 expression directly or indirectly, were significantly downregulated in nac016-1 mutants and upregulated in NAC016-OX plants. However, the NAC016BM does not exist in their promoter regions, indicating that NAC016 may indirectly activate these ABA signaling and biosynthesis genes, probably by directly activating transcriptional cascades regulated by the NAC transcription factor NAP. The NAC016-mediated regulatory cascades of SGR1 and other Chl degradation-related genes are discussed.
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Affiliation(s)
- Yasuhito Sakuraba
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Su-Hyun Han
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Sang-Hwa Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
- CKD Research Institute, Yongin, 16995, Korea
| | | | - Nam-Chon Paek
- Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.
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89
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Zhang L, Kusaba M, Tanaka A, Sakamoto W. Protection of Chloroplast Membranes by VIPP1 Rescues Aberrant Seedling Development in Arabidopsis nyc1 Mutant. FRONTIERS IN PLANT SCIENCE 2016; 7:533. [PMID: 27200011 PMCID: PMC4848304 DOI: 10.3389/fpls.2016.00533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/04/2016] [Indexed: 05/07/2023]
Abstract
Chlorophylls (Chl) in photosynthetic apparatuses, along with other macromolecules in chloroplasts, are known to undergo degradation during leaf senescence. Several enzymes involved in Chl degradation, by which detoxification of Chl is safely implemented, have been identified. Chl degradation also occurs during embryogenesis and seedling development. Some genes encoding Chl degradation enzymes such as Chl b reductase (CBR) function during these developmental stages. Arabidopsis mutants lacking CBR (NYC1 and NOL) have been reported to exhibit reduced seed storability, compromised germination, and cotyledon development. In this study, we examined aberrant cotyledon development and found that NYC1 is solely responsible for this phenotype. We inferred that oxidative damage of chloroplast membranes caused the aberrant cotyledon. To test the inference, we attempted to trans-complement nyc1 mutant with overexpressing VIPP1 protein that is unrelated to Chl degradation but which supports chloroplast membrane integrity. VIPP1 expression actually complemented the aberrant cotyledon of nyc1, whereas stay-green phenotype during leaf senescence remained. The swollen chloroplasts observed in unfixed cotyledons of nyc1, which are characteristics of chloroplasts receiving envelope membrane damage, were recovered by overexpressing VIPP1. These results suggest that chloroplast membranes are a target for oxidative damage caused by the impairment in Chl degradation. Trans-complementation of nyc1 with VIPP1 also suggests that VIPP1 is useful for protecting chloroplasts against oxidative stress.
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Affiliation(s)
- Lingang Zhang
- Institute of Plant Science and Resources, Okayama UniversityOkayama, Japan
| | - Makoto Kusaba
- Graduate School of Science, Hiroshima UniversityHiroshima, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido UniversityHokkaido, Japan
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama UniversityOkayama, Japan
- *Correspondence: Wataru Sakamoto,
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90
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Tanoi K, Kobayashi NI. Leaf Senescence by Magnesium Deficiency. PLANTS (BASEL, SWITZERLAND) 2015; 4:756-72. [PMID: 27135350 PMCID: PMC4844269 DOI: 10.3390/plants4040756] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 11/11/2015] [Accepted: 12/02/2015] [Indexed: 01/03/2023]
Abstract
Magnesium ions (Mg(2+)) are the second most abundant cations in living plant cells, and they are involved in various functions, including photosynthesis, enzyme catalysis, and nucleic acid synthesis. Low availability of Mg(2+) in an agricultural field leads to a decrease in yield, which follows the appearance of Mg-deficient symptoms such as chlorosis, necrotic spots on the leaves, and droop. During the last decade, a variety of physiological and molecular responses to Mg(2+) deficiency that potentially link to leaf senescence have been recognized, allowing us to reconsider the mechanisms of Mg(2+) deficiency. This review focuses on the current knowledge about the physiological responses to Mg(2+) deficiency including a decline in transpiration, accumulation of sugars and starch in source leaves, change in redox states, increased oxidative stress, metabolite alterations, and a decline in photosynthetic activity. In addition, we refer to the molecular responses that are thought to be related to leaf senescence. With these current data, we give an overview of leaf senescence induced by Mg deficiency.
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Affiliation(s)
- Keitaro Tanoi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
| | - Natsuko I Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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91
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Süssenbacher I, Hörtensteiner S, Kräutler B. A Dioxobilin-Type Fluorescent Chlorophyll Catabolite as a Transient Early Intermediate of the Dioxobilin-Branch of Chlorophyll Breakdown in Arabidopsis thaliana. Angew Chem Int Ed Engl 2015; 54:13777-81. [PMID: 26426977 PMCID: PMC4678512 DOI: 10.1002/anie.201506299] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Indexed: 01/14/2023]
Abstract
Chlorophyll breakdown in higher plants occurs by the so called "PaO/phyllobilin" path. It generates two major types of phyllobilins, the characteristic 1-formyl-19-oxobilins and the more recently discovered 1,19-dioxobilins. The hypothetical branching point at which the original 1-formyl-19-oxobilins are transformed into 1,19-dioxobilins is still elusive. Here, we clarify this hypothetical crucial transition on the basis of the identification of the first natural 1,19-dioxobilin-type fluorescent chlorophyll catabolite (DFCC). This transient chlorophyll breakdown intermediate was isolated from leaf extracts of Arabidopsis thaliana at an early stage of senescence. The fleetingly existent DFCC was then shown to represent the direct precursor of the major nonfluorescent 1,19-dioxobilin that accumulated in fully senescent leaves.
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Affiliation(s)
- Iris Süssenbacher
- Institut für Organische Chemie und Centrum für Molekulare Biowissenschaften, Universität Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Stefan Hörtensteiner
- Institut für Pflanzenbiologie, Universität Zürich, Zollikerstrasse 107, 8008 Zürich (Switzerland)
| | - Bernhard Kräutler
- Institut für Organische Chemie und Centrum für Molekulare Biowissenschaften, Universität Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria).
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92
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Jibran R, Sullivan KL, Crowhurst R, Erridge ZA, Chagné D, McLachlan ARG, Brummell DA, Dijkwel PP, Hunter DA. Staying green postharvest: how three mutations in the Arabidopsis chlorophyll b reductase gene NYC1 delay degreening by distinct mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:6849-6862. [PMID: 26261268 DOI: 10.1093/jxb/erv390] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Stresses such as energy deprivation, wounding and water-supply disruption often contribute to rapid deterioration of harvested tissues. To uncover the genetic regulation behind such stresses, a simple assessment system was used to detect senescence mutants in conjunction with two rapid mapping techniques to identify the causal mutations. To demonstrate the power of this approach, immature inflorescences of Arabidopsis plants that contained ethyl methanesulfonate-induced lesions were detached and screened for altered timing of dark-induced senescence. Numerous mutant lines displaying accelerated or delayed timing of senescence relative to wild type were discovered. The underlying mutations in three of these were identified using High Resolution Melting analysis to map to a chromosomal arm followed by a whole-genome sequencing-based mapping method, termed 'Needle in the K-Stack', to identify the causal lesions. All three mutations were single base pair changes and occurred in the same gene, NON-YELLOW COLORING1 (NYC1), a chlorophyll b reductase of the short-chain dehydrogenase/reductase (SDR) superfamily. This was consistent with the mutants preferentially retaining chlorophyll b, although substantial amounts of chlorophyll b were still lost. The single base pair mutations disrupted NYC1 function by three distinct mechanisms, one by producing a termination codon, the second by interfering with correct intron splicing and the third by replacing a highly conserved proline with a non-equivalent serine residue. This non-synonymous amino acid change, which occurred in the NADPH binding domain of NYC1, is the first example of such a mutation in an SDR protein inhibiting a physiological response in plants.
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Affiliation(s)
- Rubina Jibran
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - Kerry L Sullivan
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Ross Crowhurst
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland 1142, New Zealand
| | - Zoe A Erridge
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - David Chagné
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Andrew R G McLachlan
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - David A Brummell
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
| | - Paul P Dijkwel
- Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand
| | - Donald A Hunter
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 11600, Palmerston North 4442, New Zealand
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93
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Bangerth KF. Basipetal auxin versus acropetal cytokinin transport, and their interaction with NO3 fertilisation in cotyledon senescence and sink:source relationships in cucumber (Cucumis sativus L.). PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:1135-1145. [PMID: 26084820 DOI: 10.1111/plb.12360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 06/15/2015] [Indexed: 06/04/2023]
Abstract
The paramount role of cytokinins (CKs) in initiation, as well as prevention, of senescence is well established. In recent years, experimental methods have become available to raise and lower the CK concentration and experimentally manipulate senescence. Decapitating the apical shoot and adding the synthetic auxin naphthylacetic acid to the cut stem reduced endogenous CKs to low levels. Conversely, if no auxin was applied, xylem and leaf CK levels increased dramatically, indicating that basipolar auxin transport is a key determinant in the synthesis of CKs and is potentially more important than NO(3). Manipulating the concentration of applied NO(3) caused considerable variation in leaf CK levels and concomitant changes in senescence. These and other results suggest that the frequently discussed decrease in nitrogen use efficiency (NUE) may be more highly regulated by CKs than by NO(3). Analysis of the re-metabolisation and re-allocation of chlorophyll, proteins, amino acids and starch in three different cucumber cultivars indirectly showed that these metabolites were significantly affected by the concentration of CKs in the leaves. Further research in this area may allow leaf senescence and plant yield to be more efficiently regulated by manipulating CKs and/or basipolar auxin transport instead of nitrate.
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Affiliation(s)
- K-F Bangerth
- Institut für Kulturpflanzenwissenschaften, University of Hohenheim, Stuttgart, Germany
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94
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Süssenbacher I, Hörtensteiner S, Kräutler B. Ein fluoreszierender Chlorophyll-Katabolit des Dioxobilin-Typs als transientes und frühes Zwischenprodukt des Dioxobilin-Astes des Chlorophyllabbaus inArabidopsis thaliana. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506299] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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95
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Gabruk M, Mysliwa-Kurdziel B. Light-Dependent Protochlorophyllide Oxidoreductase: Phylogeny, Regulation, and Catalytic Properties. Biochemistry 2015; 54:5255-62. [PMID: 26230427 DOI: 10.1021/acs.biochem.5b00704] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
This Current Topic focuses on light-dependent protochlorophyllide oxidoreductase (POR, EC 1.3.1.33). POR catalyzes the penultimate reaction of chlorophyll biosynthesis, i.e., the light-triggered reduction of protochlorophyllide to chlorophyllide. In this reaction, the chlorin ring of the chlorophyll molecule is formed, which is crucial for photosynthesis. POR is one of very few enzymes that are driven by light; however, it is unique in the need for its substrate to absorb photons to induce the conformational changes in the enzyme, which are required for its catalytic activation. Moreover, the enzyme is also involved in the negative feedback of the chlorophyll biosynthesis pathway and controls chlorophyll content via its light-dependent activity. Even though it has been almost 70 years since the first isolation of active POR complexes, our knowledge of them has markedly advanced in recent years. In this review, we summarize the current state of knowledge of POR, including the phylogenetic roots of POR, the mechanisms of the regulation of POR genes expression, the regulation of POR activity, the import of POR into plastids, the role of POR in PLB formation, and the molecular mechanism of protochlorophyllide reduction by POR. To the best of our knowledge, no previous review has compiled such a broad set of recent findings about POR.
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Affiliation(s)
- Michal Gabruk
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University , Gronostajowa 7, 30-387 Krakow, Poland
| | - Beata Mysliwa-Kurdziel
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University , Gronostajowa 7, 30-387 Krakow, Poland
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96
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Zhang Y, Liu Z, Chen Y, He JX, Bi Y. PHYTOCHROME-INTERACTING FACTOR 5 (PIF5) positively regulates dark-induced senescence and chlorophyll degradation in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 237:57-68. [PMID: 26089152 DOI: 10.1016/j.plantsci.2015.05.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 05/07/2023]
Abstract
Darkness is a known environmental factor that induces plant senescence. Here, Phytochrome-Interacting Factors (PIFs), several bHLH transcription factors involved in plant skotomorphogenesis, were examined for their roles in the regulation of dark-induced senescence and chlorophyll breakdown in Arabidopsis thaliana. After light-grown seedlings were transferred to darkness, green leaves turned yellow, and chlorophyll contents decreased, but membrane lipid peroxidation and cell death increased in wild-type Col-0. These responses were enhanced in overexpression line PIF5OX but decreased in mutant pif5-3. Darkness significantly induced expression of several genes involved in chlorophyll breakdown, including SGR, NYC1, NOL, and PAO, as well as genes encoding for transcription factors that have been shown to be required for dark-induced senescence, including WRKY22, NAP, EIN3, EIL1, and ORE1. These effects on gene expression were also enhanced in PIF5OX but decreased in pif5-3 relative to Col-0. Further analyses using ChIP-qPCR, EMSA, and protoplast transient assays indicated that PIF5 binds to the G-box motifs in the promoters of SGR, NYC1, and ORE1 genes and stimulate their expression. Collectively, our data indicate that PIF5 is a key factor that positively regulates dark-induced senescence upstream of ORE1 and regulates chlorophyll breakdown upstream of SGR and NYC1.
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Affiliation(s)
- Yongqiang Zhang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China; School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China
| | - Zhongjuan Liu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
| | - Yadi Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
| | - Jun-Xian He
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China.
| | - Yurong Bi
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.
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97
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Süssenbacher I, Kreutz CR, Christ B, Hörtensteiner S, Kräutler B. Hydroxymethylated Dioxobilins in SenescentArabidopsis thalianaLeaves: Sign of a Puzzling Biosynthetic Intermezzo of Chlorophyll Breakdown. Chemistry 2015; 21:11664-70. [DOI: 10.1002/chem.201501489] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 01/14/2023]
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98
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Tamiaki H, Tanaka T. Synthesis and physical properties of carbonylated chlorophyll derivatives. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.02.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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99
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Lai B, Hu B, Qin YH, Zhao JT, Wang HC, Hu GB. Transcriptomic analysis of Litchi chinensis pericarp during maturation with a focus on chlorophyll degradation and flavonoid biosynthesis. BMC Genomics 2015; 16:225. [PMID: 25887579 PMCID: PMC4376514 DOI: 10.1186/s12864-015-1433-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 03/06/2015] [Indexed: 01/06/2023] Open
Abstract
Background The fruit of litchi (Litchi chinensis) comprises a white translucent edible aril surrounded by a pericarp. The pericarp of litchi has been the focus of studies associated with fruit size, coloration, cracking and shelf life. However, research at the molecular level has been limited by the lack of genomic and transcriptomic information. In this study, an analysis of the transcriptome of litchi pericarp was performed to obtain information regarding the molecular mechanisms underlying the physiological changes in the pericarp, including those leading to fruit surface coloration. Results Coincident with the rapid break down of chlorophyll, but substantial increase of anthocyanins in litchi pericarp as fruit developed, two major physiological changes, degreening and pigmentation were visually apparent. In this study, a cDNA library of litchi pericarp with three different coloration stages was constructed. A total of 4.7 Gb of raw RNA-Seq data was generated and this was then de novo assembled into 51,089 unigenes with a mean length of 737 bp. Approximately 70% of the unigenes (34,705) could be annotated based on public protein databases and, of these, 3,649 genes were significantly differentially expressed between any two coloration stages, while 156 genes were differentially expressed among all three stages. Genes encoding enzymes involved in chlorophyll degradation and flavonoid biosynthesis were identified in the transcriptome dataset. The transcript expression patterns of the Stay Green (SGR) protein suggested a key role in chlorophyll degradation in the litchi pericarp, and this conclusion was supported by the result of an assay over-expressing LcSGR protein in tobacco leaves. We also found that the expression levels of most genes especially late anthocyanin biosynthesis genes were co-ordinated up-regulated coincident with the accumulation of anthocyanins, and that candidate MYB transcription factors that likely regulate flavonoid biosynthesis were identified. Conclusions This study provides a large collection of transcripts and expression profiles associated with litchi fruit maturation processes, including coloration. Since most of the unigenes were annotated, they provide a platform for litchi functional genomic research within this species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1433-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Biao Lai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Horticulture, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China. .,Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
| | - Bing Hu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Horticulture, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China. .,Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
| | - Yong-Hua Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Horticulture, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China.
| | - Jie-Tang Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Horticulture, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China.
| | - Hui-Cong Wang
- Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
| | - Gui-Bing Hu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Horticulture, South China Agricultural University, Guangzhou, 510642, Guangdong, People's Republic of China. .,Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
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Roiser M, Müller T, Kräutler B. Colorless chlorophyll catabolites in senescent florets of broccoli (Brassica oleracea var. italica). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:1385-92. [PMID: 25620234 PMCID: PMC4329831 DOI: 10.1021/jf5055326] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Typical postharvest storage of broccoli (Brassica oleracea var. italica) causes degreening of this common vegetable with visible loss of chlorophyll (Chl). As shown here, colorless Chl-catabolites are generated. In fresh extracts of degreening florets of broccoli, three colorless tetrapyrrolic Chl-catabolites accumulated and were detected by high performance liquid chromatography (HPLC): two "nonfluorescent" Chl-catabolites (NCCs), provisionally named Bo-NCC-1 and Bo-NCC-2, and a colorless 1,19-dioxobilin-type "nonfluorescent" Chl-catabolite (DNCC), named Bo-DNCC. Analysis by nuclear magnetic resonance spectroscopy and mass spectrometry of these three linear tetrapyrroles revealed their structures. In combination with a comparison of their HPL-chromatographic properties, this allowed their identification with three known catabolites from two other brassicacea, namely two NCCs from oil seed rape (Brassica napus) and a DNCC from degreened leaves of Arabidopsis thaliana.
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