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Aubry S, Fankhauser N, Ovinnikov S, Pružinská A, Stirnemann M, Zienkiewicz K, Herrfurth C, Feussner I, Hörtensteiner S. Pheophorbide a May Regulate Jasmonate Signaling during Dark-Induced Senescence. PLANT PHYSIOLOGY 2020; 182:776-791. [PMID: 31753845 PMCID: PMC6997679 DOI: 10.1104/pp.19.01115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 10/31/2019] [Indexed: 05/17/2023]
Abstract
Chlorophyll degradation is one of the most visible signs of leaf senescence. During senescence, chlorophyll is degraded in the multistep pheophorbide a oxygenase (PAO)/phyllobilin pathway. This pathway is tightly regulated at the transcriptional level, allowing coordinated and efficient remobilization of nitrogen toward sink organs. Using a combination of transcriptome and metabolite analyses during dark-induced senescence of Arabidopsis (Arabidopsis thaliana) mutants deficient in key steps of the PAO/phyllobilin pathway, we show an unanticipated role for one of the pathway intermediates, i.e. pheophorbide a Both jasmonic acid-related gene expression and jasmonic acid precursors specifically accumulated in pao1, a mutant deficient in PAO. We propose that pheophorbide a, the last intact porphyrin intermediate of chlorophyll degradation and a unique pathway "bottleneck," has been recruited as a signaling molecule of chloroplast metabolic status. Our work challenges the assumption that chlorophyll breakdown is merely a result of senescence, and proposes that the flux of pheophorbide a through the pathway acts in a feed-forward loop that remodels the nuclear transcriptome and controls the pace of chlorophyll degradation in senescing leaves.
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Affiliation(s)
- Sylvain Aubry
- Institute of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Niklaus Fankhauser
- Department for Clinical Research, Clinical Trials Unit, University of Bern, 3012 Bern, Switzerland
| | - Serguei Ovinnikov
- Institute of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Adriana Pružinská
- The Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, Western Australia 6009
| | - Marina Stirnemann
- Institute of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
| | - Krzysztof Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
- Göttingen Metabolomics and Lipidomics Laboratory, Göttingen Center for Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Cornelia Herrfurth
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
- Göttingen Metabolomics and Lipidomics Laboratory, Göttingen Center for Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, 37077 Göttingen, Germany
- Göttingen Metabolomics and Lipidomics Laboratory, Göttingen Center for Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
- Department of Plant Biochemistry, Göttingen Center for Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
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Trejo-Arellano MS, Mehdi S, de Jonge J, Dvorák Tomastíková E, Köhler C, Hennig L. Dark-Induced Senescence Causes Localized Changes in DNA Methylation. PLANT PHYSIOLOGY 2020; 182:949-961. [PMID: 31792150 PMCID: PMC6997673 DOI: 10.1104/pp.19.01154] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/14/2019] [Indexed: 05/04/2023]
Abstract
Senescence occurs in a programmed manner to dismantle the vegetative tissues and redirect nutrients towards metabolic pathways supporting reproductive success. External factors can trigger the senescence program as an adaptive strategy, indicating that this terminal program is controlled at different levels. It has been proposed that epigenetic factors accompany the reprogramming of the senescent genome; however, the mechanism and extent of this reprogramming remain unknown. Using bisulphite conversion followed by sequencing, we assessed changes in the methylome of senescent Arabidopsis (Arabidopsis thaliana) leaves induced by darkness and monitored their effect on gene and transposable element (TE) expression with transcriptome sequencing. Upon dark-induced senescence, genes controlling chromatin silencing were collectively down-regulated. As a consequence, the silencing of TEs was impaired, causing in particular young TEs to become preferentially reactivated. In parallel, heterochromatin at chromocenters was decondensed. Despite the disruption of the chromatin maintenance network, the global DNA methylation landscape remained highly stable, with localized changes mainly restricted to CHH methylation. Together, our data show that the terminal stage of plant life is accompanied by global changes in chromatin structure but only localized changes in DNA methylation, adding another example of the dynamics of DNA methylation during plant development.
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Affiliation(s)
- Minerva S Trejo-Arellano
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
| | - Saher Mehdi
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
| | - Jennifer de Jonge
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
| | - Eva Dvorák Tomastíková
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
| | - Claudia Köhler
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
| | - Lars Hennig
- Swedish University of Agricultural Sciences, Department of Plant Biology and Linnean Center for Plant Biology, SE-75007 Uppsala, Sweden
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Süssenbacher I, Menghini D, Scherzer G, Salinger K, Erhart T, Moser S, Vergeiner C, Hörtensteiner S, Kräutler B. Cryptic chlorophyll breakdown in non-senescent green Arabidopsis thaliana leaves. PHOTOSYNTHESIS RESEARCH 2019; 142:69-85. [PMID: 31172355 DOI: 10.1007/s11120-019-00649-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
Chlorophyll (Chl) breakdown is a diagnostic visual process of leaf senescence, which furnishes phyllobilins (PBs) by the PAO/phyllobilin pathway. As Chl breakdown disables photosynthesis, it appears to have no role in photoactive green leaves. Here, colorless PBs were detected in green, non-senescent leaves of Arabidopsis thaliana. The PBs from the green leaves had structures entirely consistent with the PAO/phyllobilin pathway and the mutation of a single Chl catabolic enzyme completely abolished PBs with the particular modification. Hence, the PAO/phyllobilin pathway was active in the absence of visible senescence and expression of genes encoding Chl catabolic enzymes was observed in green Arabidopsis leaves. PBs accumulated to only sub-% amounts compared to the Chls present in the green leaves, excluding a substantial contribution of Chl breakdown from rapid Chl turnover associated with photosystem II repair. Indeed, Chl turnover was shown to involve a Chl a dephytylation and Chl a reconstitution cycle. However, non-recyclable pheophytin a is also liberated in the course of photosystem II repair, and is proposed here to be scavenged and degraded to the observed PBs. Hence, a cryptic form of the established pathway of Chl breakdown is indicated to play a constitutive role in photoactive leaves.
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Affiliation(s)
- Iris Süssenbacher
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Damian Menghini
- Institute of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Gerhard Scherzer
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Kathrin Salinger
- Institute of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Theresia Erhart
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Simone Moser
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Clemens Vergeiner
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria.
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Karg CA, Schilling CM, Allmendinger L, Moser S. Isolation, characterization, and antioxidative activity of a dioxobilin-type phylloxanthobilin from savoy cabbage. J PORPHYR PHTHALOCYA 2019. [DOI: 10.1142/s1088424619500718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The degradation of the green pigment chlorophyll in plants is known to yield phyllobilins as highly abundant linear tetrapyrroles. Recently, a split path of the degradation pathway has been discovered, leading to so-called dioxobilin-type (or type-II) phyllobilins. The first characterized type-II phyllobilin was colorless featuring four deconjugated pyrrole units. Similar to the type-I branch, for which yellow oxidation products of the colorless phyllobilins – the type-I phylloxanthobilins – are known, a type-II phylloxanthobilin has recently been characterized from senescent leaves of grapevine. Type-I phylloxanthobilins appear to be actively produced in the plant, are known to possess interesting chemical properties, and were shown to act as potent antioxidants that can protect cells from oxidative stress. Here we report the isolation and structural characterization of a type-II phylloxanthobilin from de-greened leaves of savoy cabbage, which turned out to be structurally closely related to bilirubin. Bilirubin is known to possess high antioxidative activity; in addition, savoy cabbage is considered to promote health benefits due to its high content in antioxidants. We therefore investigated the in vitro antioxidative potential of the newly identified type-II phylloxanthobilin using two different approaches, both of which revealed an even higher antioxidative activity for the type-II phylloxanthobilin from savoy cabbage compared to bilirubin.
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Affiliation(s)
- Cornelia A. Karg
- Pharmaceutical Biology, Pharmacy Department, Ludwig-Maximilians University of Munich, Butenandtstraße, 5-13, D-81337 Munich, Germany
| | - Charlotte M. Schilling
- Pharmaceutical Biology, Pharmacy Department, Ludwig-Maximilians University of Munich, Butenandtstraße, 5-13, D-81337 Munich, Germany
| | - Lars Allmendinger
- Pharmaceutical Chemistry, Pharmacy Department, Ludwig-Maximilians University of Munich, Butenandtstraße, 5-13, D-81337 Munich, Germany
| | - Simone Moser
- Pharmaceutical Biology, Pharmacy Department, Ludwig-Maximilians University of Munich, Butenandtstraße, 5-13, D-81337 Munich, Germany
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Cytotoxic Effects of Chlorophyllides in Ethanol Crude Extracts from Plant Leaves. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:9494328. [PMID: 31379971 PMCID: PMC6662445 DOI: 10.1155/2019/9494328] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/03/2019] [Accepted: 06/09/2019] [Indexed: 12/13/2022]
Abstract
Chlorophyllide (chlide) is a natural catabolic product of chlorophyll (Chl), produced through the activity of chlorophyllase (chlase). The growth inhibitory and antioxidant effects of chlide from different plant leaf extracts have not been reported. The aim of this study is to demonstrate that chlide in crude extracts from leaves has the potential to exert cytotoxic effects on cancer cell lines. The potential inhibitory and antioxidant effects of chlide in crude extracts from 10 plant leaves on breast cancer cells (MCF7 and MDA-MB-231), hepatocellular carcinoma cells (Hep G2), colorectal adenocarcinoma cells (Caco2), and glioblastoma cells (U-118 MG) were studied using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays. The results of the MTT assay showed that chlide in crude extracts from sweet potato were the most effective against all cancer cell lines tested. U-118 MG cells were the most sensitive, while Caco2 cells were the most resistant to the tested crude extracts. The cytotoxic effects of chlide and Chl in crude extracts from sweet potato and of commercial chlorophyllin (Cu-chlin), in descending order, were as follows: chlide > Chl > Cu-chlin. Notably, the IC50 of sweet potato in U-118 MG cells was 45.65 μg/mL while those of Chl and Cu-chlin exceeded 200 μg/mL. In the DPPH assay, low concentrations (100 μg/mL) of chlide and Cu-chlin from crude extracts of sweet potato presented very similar radical scavenging activity to vitamin B2. The concentration of chlide was negatively correlated with DPPH activity. The current study was the first to demonstrate that chlide in crude extracts from leaves have potential cytotoxicity in cancer cell lines. Synergism between chlide and other compounds from leaf crude extracts may contribute to its cytotoxicity.
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Karg CA, Wang P, Vollmar AM, Moser S. Re-opening the stage for Echinacea research - Characterization of phylloxanthobilins as a novel anti-oxidative compound class in Echinacea purpurea. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 60:152969. [PMID: 31153733 DOI: 10.1016/j.phymed.2019.152969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/19/2019] [Accepted: 05/22/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Phylloxanthobilins are tetrapyrrolic natural products that arise from the degradation of chlorophyll. Phylloxanthobilins have been discovered roughly 10 years ago in the leaves of deciduous trees, and are now considered a compound class with high and still unexplored potential of bioactivities. To date, however, there are no reports on the occurrence of phylloxanthobilins in parts of a medicinal plant used for pharmaceutical preparations. PURPOSE The relevance of Echinacea purpurea as medicinal plant is undoubtedly high, and a large variety of pharmaceutical preparations is available on the market, mostly for the treatment of the common cold. Nevertheless, its phytochemical profiling has been limited to analysis for previously characterized substances, and this has not explained all its pharmacological efficacies. We therefore set out to investigate the occurrence of phylloxanthobilins in Echinacea purpurea. METHODS Phylloxanthobilins in leaf extracts of Echinacea purpurea were detected using analytical HPLC. Identified phyllobilins were purified from plant material and characterized by UV/Vis, mass spectrometry, MS/MS, and confirmed by co-injections with previously published phyllobilins from different sources. The anti-oxidant activity of selected isolated phylloxanthobilins was assessed by an in vitro ferric reducing antioxidant power (FRAP) assay; in addition, the ability to scavenge ROS in cells caused by hydrogen peroxide stimulation was determined by measuring H2DCF-DA fluorescence and by assessing cellular GSH levels. RESULTS In extracts of Echinacea purpurea leaves, an unprecedented diversity of phylloxanthobilins was detected; surprisingly, not only in senescent yellow leaves, but also in green leaves with no visible chlorophyll degradation. Six phylloxanthobilins were identified and structurally characterized. The uptake of phylloxanthobilins by human endothelial kidney cells was demonstrated. When investigating the anti-oxidative activity of these natural products, a potent in vitro activity was demonstrated; in addition, phylloxanthobilins possess intracellular ROS scavenging ability and can prevent oxidative stress as assessed by total cellular GSH levels. CONCLUSION Phylloxanthobilins are important constituents of Echinacea purpurea extracts, and our first exploratory studies hint towards promising bioactivities of these natural products, which may be relevant for understanding Echinacea efficacies.
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Affiliation(s)
- Cornelia A Karg
- Pharmaceutical Biology, Department Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Pengyu Wang
- Pharmaceutical Biology, Department Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Angelika M Vollmar
- Pharmaceutical Biology, Department Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Simone Moser
- Pharmaceutical Biology, Department Pharmacy, Ludwig-Maximilians University of Munich, Butenandtstraße 5-13, Munich 81377, Germany.
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Chen Z, Lu X, Xuan Y, Tang F, Wang J, Shi D, Fu S, Ren J. Transcriptome analysis based on a combination of sequencing platforms provides insights into leaf pigmentation in Acer rubrum. BMC PLANT BIOLOGY 2019; 19:240. [PMID: 31170934 PMCID: PMC6555730 DOI: 10.1186/s12870-019-1850-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 05/28/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Red maple (Acer rubrum L.) is one of the most common and widespread trees with colorful leaves. We found a mutant with red, yellow, and green leaf phenotypes in different branches, which provided ideal materials with the same genetic relationship, and little interference from the environment, for the study of complex metabolic networks that underly variations in the coloration of leaves. We applied a combination of NGS and SMRT sequencing to various red maple tissues. RESULTS A total of 125,448 unigenes were obtained, of which 46 and 69 were thought to be related to the synthesis of anthocyanins and carotenoids, respectively. In addition, 88 unigenes were presumed to be involved in the chlorophyll metabolic pathway. Based on a comprehensive analysis of the pigment gene expression network, the mechanisms of leaf color were investigated. The massive accumulation of Cy led to its higher content and proportion than other pigments, which caused the redness of leaves. Yellow coloration was the result of the complete decomposition of chlorophyll pigments, the unmasking of carotenoid pigments, and a slight accumulation of Cy. CONCLUSIONS This study provides a systematic analysis of color variations in the red maple. Moreover, mass sequence data obtained by deep sequencing will provide references for the controlled breeding of red maple.
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Affiliation(s)
- Zhu Chen
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
| | - Xiaoyu Lu
- College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036 Anhui China
| | - Yun Xuan
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
| | - Fei Tang
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
| | - Jingjing Wang
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
| | - Dan Shi
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
| | - Songling Fu
- College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei, 230036 Anhui China
| | - Jie Ren
- Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, Hefei, 230031 China
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Jiang J, Hu J, Tan R, Han Y, Li Z. Expression of IbVPE1 from sweet potato in Arabidopsis affects leaf development, flowering time and chlorophyll catabolism. BMC PLANT BIOLOGY 2019; 19:184. [PMID: 31060496 PMCID: PMC6503384 DOI: 10.1186/s12870-019-1789-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 04/18/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Since their discovery, vacuolar processing enzymes (VPEs) have consistently been investigated as programmed cell death (PCD) initiators and participants in plant development and responses to biotic or abiotic stresses, in part due to similarities with the apoptosis regulator caspase-1. However, recent studies show additional functions of VPE in tomatoes, specifically in sucrose accumulation and fruit ripening. RESULTS Herein, we evaluated the functions of VPE from sweetpotato, initially in expression pattern analyses of IbVPE1 during development and senescence. Subsequently, we identified physiological functions by overexpressing IbVPE1 in Arabidopsis thaliana, and showed reduced leaf sizes and numbers and early flowering, and elucidated the underlying molecular mechanisms. CONCLUSIONS The present data demonstrate functions of the VPE gene family in development and senescence and in regulation of flowering times, leaf sizes and numbers, and senescence phenotypes in Arabidopsis thaliana.
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Affiliation(s)
- Jiaojiao Jiang
- Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou, 221116 China
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, Jiangsu Normal University, Xuzhou, China
| | - Jianzhong Hu
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186 South Korea
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, Jiangsu Normal University, Xuzhou, China
| | - Rujiao Tan
- Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou, 221116 China
| | - Yonghua Han
- Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou, 221116 China
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, Jiangsu Normal University, Xuzhou, China
| | - Zongyun Li
- Institute of Integrative Plant Biology, School of Life Science, Jiangsu Normal University, Xuzhou, 221116 China
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, Jiangsu Normal University, Xuzhou, China
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Wang Q, Ni J, Shah F, Liu W, Wang D, Yao Y, Hu H, Huang S, Hou J, Fu S, Wu L. Overexpression of the Stress-Inducible SsMAX2 Promotes Drought and Salt Resistance via the Regulation of Redox Homeostasis in Arabidopsis. Int J Mol Sci 2019; 20:ijms20040837. [PMID: 30781340 PMCID: PMC6412474 DOI: 10.3390/ijms20040837] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/12/2019] [Accepted: 02/12/2019] [Indexed: 12/30/2022] Open
Abstract
Recent studies have demonstrated that strigolactones (SLs) also participate in the regulation of stress adaptation; however, the regulatory mechanism remains elusive. In this study, the homolog of More Axillary Branches 2, which encodes a key component in SL signaling, in the perennial oil plant Sapium sebiferum was identified and functionally characterized in Arabidopsis. The results showed that the expression of SsMAX2 in S. sebiferum seedlings was stress-responsive, and SsMAX2 overexpression (OE) in Arabidopsis significantly promoted resistance to drought, osmotic, and salt stresses. Moreover, SsMAX2 OE lines exhibited decreased chlorophyll degradation, increased soluble sugar and proline accumulation, and lower water loss ratio in response to the stresses. Importantly, anthocyanin biosynthesis and the activities of several antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), were enhanced in the SsMAX2 OE lines, which further led to a significant reduction in hydrogen peroxide levels. Additionally, the SsMAX2 OE lines exhibited higher expression level of several abscisic acid (ABA) biosynthesis genes, suggesting potential interactions between SL and ABA in the regulation of stress adaptation. Overall, we provide physiological and biochemical evidence demonstrating the pivotal role of SsMAX2 in the regulation of osmotic, drought, and salt stress resistance and show that MAX2 can be a genetic target to improve stress tolerance.
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Affiliation(s)
- Qiaojian Wang
- College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230000, Anhui, China.
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Jun Ni
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Faheem Shah
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Wenbo Liu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Dongdong Wang
- College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230000, Anhui, China.
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Yuanyuan Yao
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Hao Hu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Shengwei Huang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Jinyan Hou
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
| | - Songling Fu
- College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230000, Anhui, China.
| | - Lifang Wu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230000, Anhui, China.
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Abstract
Phytol, the prenyl side chain of chlorophyll, is derived from geranylgeraniol by reduction of three double bonds. Recent results demonstrated that the conversion of geranylgeraniol to phytol is linked to chlorophyll synthesis, which is catalyzed by protein complexes associated with the thylakoid membranes. One of these complexes contains light harvesting chlorophyll binding like proteins (LIL3), enzymes of chlorophyll synthesis (protoporphyrinogen oxidoreductase, POR; chlorophyll synthase, CHLG) and geranylgeranyl reductase (GGR). Phytol is not only employed for the synthesis of chlorophyll, but also for tocopherol (vitamin E), phylloquinol (vitamin K) and fatty acid phytyl ester production. Previously, it was believed that phytol is derived from reduction of geranylgeranyl-diphosphate originating from the 4-methylerythritol-5-phosphate (MEP) pathway. The identification and characterization of two kinases, VTE5 and VTE6, involved in phytol and phytyl-phosphate phosphorylation, respectively, indicated that most phytol employed for tocopherol synthesis is derived from reduction of geranylgeranylated chlorophyll to (phytol-) chlorophyll. After hydrolysis from chlorophyll, free phytol is phosphorylated by the two kinases, and phytyl-diphosphate employed for the synthesis of tocopherol and phylloquinol. The reason why some chloroplast lipids, i.e. chlorophyll, tocopherol and phylloquinol, are derived from phytol, while others, i.e. carotenoids and tocotrienols (in some plant species) are synthesized from geranylgeraniol, remains unclear.
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Soltabayeva A, Srivastava S, Kurmanbayeva A, Bekturova A, Fluhr R, Sagi M. Early Senescence in Older Leaves of Low Nitrate-Grown Atxdh1 Uncovers a Role for Purine Catabolism in N Supply. PLANT PHYSIOLOGY 2018; 178:1027-1044. [PMID: 30190419 PMCID: PMC6236613 DOI: 10.1104/pp.18.00795] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/25/2018] [Indexed: 05/19/2023]
Abstract
The nitrogen (N)-rich ureides allantoin and allantoate, which are products of purine catabolism, play a role in N delivery in Leguminosae. Here, we examined their role as an N source in nonlegume plants using Arabidopsis (Arabidopsis thaliana) plants mutated in XANTHINE DEHYDROGENASE1 (AtXDH1), a catalytic bottleneck in purine catabolism. Older leaves of the Atxdh1 mutant exhibited early senescence, lower soluble protein, and lower organic N levels as compared with wild-type older leaves when grown with 1 mm nitrate but were comparable to the wild type under 5 mm nitrate. Similar nitrate-dependent senescence phenotypes were evident in the older leaves of allantoinase (Ataln) and allantoate amidohydrolase (Ataah) mutants, which also are impaired in purine catabolism. Under low-nitrate conditions, xanthine accumulated in older leaves of Atxdh1, whereas allantoin accumulated in both older and younger leaves of Ataln but not in wild-type leaves, indicating the remobilization of xanthine-degraded products from older to younger leaves. Supporting this notion, ureide transporter expression was enhanced in older leaves of the wild type in low-nitrate as compared with high-nitrate conditions. Elevated transcripts and proteins of AtXDH and AtAAH were detected in low-nitrate-grown wild-type plants, indicating regulation at protein and transcript levels. The higher nitrate reductase activity in Atxdh1 leaves compared with wild-type leaves indicated a need for nitrate assimilation products. Together, these results indicate that the absence of remobilized purine-degraded N from older leaves of Atxdh1 caused senescence symptoms, a result of higher chloroplastic protein degradation in older leaves of low-nitrate-grown plants.
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Affiliation(s)
- Aigerim Soltabayeva
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Sudhakar Srivastava
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Assylay Kurmanbayeva
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Aizat Bekturova
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
| | - Robert Fluhr
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Moshe Sagi
- Plant Stress Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel
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Naumann M, Hubberten HM, Watanabe M, Hänsch R, Schöttler MA, Hoefgen R. Sulfite Reductase Co-suppression in Tobacco Reveals Detoxification Mechanisms and Downstream Responses Comparable to Sulfate Starvation. FRONTIERS IN PLANT SCIENCE 2018; 9:1423. [PMID: 30374361 PMCID: PMC6196246 DOI: 10.3389/fpls.2018.01423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/07/2018] [Indexed: 05/30/2023]
Abstract
Sulfite reductase (SIR) is a key enzyme in higher plants in the assimilatory sulfate reduction pathway. SIR, being exclusively localized in plastids, catalyzes the reduction of sulfite (SO3 2-) to sulfide (S2-) and is essential for plant life. We characterized transgenic plants leading to co-suppression of the SIR gene in tobacco (Nicotiana tabacum cv. Samsun NN). Co-suppression resulted in reduced but not completely extinguished expression of SIR and in a reduction of SIR activity to about 20-50% of the activity in control plants. The reduction of SIR activity caused chlorotic and necrotic phenotypes in tobacco leaves, but with varying phenotype strength even among clones and increasing from young to old leaves. In transgenic plants compared to control plants, metabolite levels upstream of SIR accumulated, such as sulfite, sulfate and thiosulfate. The levels of downstream metabolites were reduced, such as cysteine, glutathione (GSH) and methionine. This metabolic signature resembles a sulfate deprivation phenotype as corroborated by the fact that O-acetylserine (OAS) accumulated. Further, chlorophyll contents, photosynthetic electron transport, and the contents of carbohydrates such as starch, sucrose, fructose, and glucose were reduced. Amino acid compositions were altered in a complex manner due to the reduction of contents of cysteine, and to some extent methionine. Interestingly, sulfide levels remained constant indicating that sulfide homeostasis is crucial for plant performance and survival. Additionally, this allows concluding that sulfide does not act as a signal in this context to control sulfate uptake and assimilation. The accumulation of upstream compounds hints at detoxification mechanisms and, additionally, a control exerted by the downstream metabolites on the sulfate uptake and assimilation system. Co-suppression lines showed increased sensitivity to additionally imposed stresses probably due to the accumulation of reactive compounds because of insufficient detoxification in combination with reduced GSH levels.
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Affiliation(s)
- Marcel Naumann
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Division of Quality of Plant Products, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | | | - Mutsumi Watanabe
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Nara Institute of Science and Technology, Ikoma, Japan
| | - Robert Hänsch
- Department of Plant Biology, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Rainer Hoefgen
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
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Das A, Christ B, Hörtensteiner S. Characterization of the pheophorbide a oxygenase/phyllobilin pathway of chlorophyll breakdown in grasses. PLANTA 2018; 248:875-892. [PMID: 29951845 DOI: 10.1007/s00425-018-2946-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
Although the PAO/phyllobilin pathway of chlorophyll breakdown is active in grass leaf senescence, the abundance of phyllobilins is far below the amount of degraded chlorophyll. The yellowing of fully developed leaves is the most prominent visual symptom of plant senescence. Thereby, chlorophyll is degraded via the so-called pheophorbide a oxygenase (PAO)/phyllobilin pathway to a species-specific set of phyllobilins, linear tetrapyrrolic products of chlorophyll breakdown. Here, we investigated the diversity and abundance of phyllobilins in cereal and forage crops, i.e. barley, rice, ryegrass, sorghum and wheat, using liquid chromatography-mass spectrometry. A total of thirteen phyllobilins were identified, among them four novel, not yet described ones, pointing to a rather high diversity of phyllobilin-modifying activities present in the Gramineae. Along with these phyllobilins, barley orthologs of known Arabidopsis thaliana chlorophyll catabolic enzymes were demonstrated to localize in the chloroplast, and two of them, i.e. PAO and pheophytin pheophorbide hydrolase, complemented respective Arabidopsis mutants. These data confirm functionality of the PAO/phyllobilin pathway in grasses. Interestingly, when comparing phyllobilin abundance with amounts of degraded chlorophyll in senescent leaves, in most analyzed grass species only minor fractions of chlorophyll were recovered as phyllobilins, opposite to A. thaliana where phyllobilin quantities match degraded chlorophyll rather well. These data show that, despite the presence and activity of the PAO/phyllobilin pathway in barley (and other cereals), phyllobilins do not accumulate stoichiometrically, implying possible degradation of chlorophyll beyond the phyllobilin level.
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Affiliation(s)
- Aditi Das
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Bastien Christ
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland
- Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
| | - Stefan Hörtensteiner
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland.
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Durgud M, Gupta S, Ivanov I, Omidbakhshfard MA, Benina M, Alseekh S, Staykov N, Hauenstein M, Dijkwel PP, Hörtensteiner S, Toneva V, Brotman Y, Fernie AR, Mueller-Roeber B, Gechev TS. Molecular Mechanisms Preventing Senescence in Response to Prolonged Darkness in a Desiccation-Tolerant Plant. PLANT PHYSIOLOGY 2018; 177:1319-1338. [PMID: 29789435 PMCID: PMC6053018 DOI: 10.1104/pp.18.00055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/09/2018] [Indexed: 05/28/2023]
Abstract
The desiccation-tolerant plant Haberlea rhodopensis can withstand months of darkness without any visible senescence. Here, we investigated the molecular mechanisms of this adaptation to prolonged (30 d) darkness and subsequent return to light. H. rhodopensis plants remained green and viable throughout the dark treatment. Transcriptomic analysis revealed that darkness regulated several transcription factor (TF) genes. Stress- and autophagy-related TFs such as ERF8, HSFA2b, RD26, TGA1, and WRKY33 were up-regulated, while chloroplast- and flowering-related TFs such as ATH1, COL2, COL4, RL1, and PTAC7 were repressed. PHYTOCHROME INTERACTING FACTOR4, a negative regulator of photomorphogenesis and promoter of senescence, also was down-regulated. In response to darkness, most of the photosynthesis- and photorespiratory-related genes were strongly down-regulated, while genes related to autophagy were up-regulated. This occurred concomitant with the induction of SUCROSE NON-FERMENTING1-RELATED PROTEIN KINASES (SnRK1) signaling pathway genes, which regulate responses to stress-induced starvation and autophagy. Most of the genes associated with chlorophyll catabolism, which are induced by darkness in dark-senescing species, were either unregulated (PHEOPHORBIDE A OXYGENASE, PAO; RED CHLOROPHYLL CATABOLITE REDUCTASE, RCCR) or repressed (STAY GREEN-LIKE, PHEOPHYTINASE, and NON-YELLOW COLORING1). Metabolite profiling revealed increases in the levels of many amino acids in darkness, suggesting increased protein degradation. In darkness, levels of the chloroplastic lipids digalactosyldiacylglycerol, monogalactosyldiacylglycerol, phosphatidylglycerol, and sulfoquinovosyldiacylglycerol decreased, while those of storage triacylglycerols increased, suggesting degradation of chloroplast membrane lipids and their conversion to triacylglycerols for use as energy and carbon sources. Collectively, these data show a coordinated response to darkness, including repression of photosynthetic, photorespiratory, flowering, and chlorophyll catabolic genes, induction of autophagy and SnRK1 pathways, and metabolic reconfigurations that enable survival under prolonged darkness.
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Affiliation(s)
- Meriem Durgud
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Institute of Molecular Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department of Plant Physiology and Molecular Biology, University of Plovdiv, Plovdiv 4000, Bulgaria
| | - Saurabh Gupta
- Department Molecular Biology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Ivan Ivanov
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Institute of Molecular Biology and Biotechnology, Plovdiv 4000, Bulgaria
| | - M Amin Omidbakhshfard
- Department Molecular Biology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
- Department Willmitzer, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Maria Benina
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
| | - Saleh Alseekh
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department Willmitzer, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Nikola Staykov
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Institute of Molecular Biology and Biotechnology, Plovdiv 4000, Bulgaria
| | - Mareike Hauenstein
- Department of Plant and Microbial Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Paul P Dijkwel
- Institute of Fundamental Sciences, Massey University, 4474 Palmerston North, New Zealand
| | - Stefan Hörtensteiner
- Department of Plant and Microbial Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Valentina Toneva
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Institute of Molecular Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department of Plant Physiology and Molecular Biology, University of Plovdiv, Plovdiv 4000, Bulgaria
| | - Yariv Brotman
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva, Israel
| | - Alisdair R Fernie
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department Willmitzer, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Bernd Mueller-Roeber
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department Molecular Biology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Tsanko S Gechev
- Center of Plant Systems Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Institute of Molecular Biology and Biotechnology, Plovdiv 4000, Bulgaria
- Department of Plant Physiology and Molecular Biology, University of Plovdiv, Plovdiv 4000, Bulgaria
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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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Bresson J, Bieker S, Riester L, Doll J, Zentgraf U. A guideline for leaf senescence analyses: from quantification to physiological and molecular investigations. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:769-786. [PMID: 28992225 DOI: 10.1093/jxb/erx246] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Leaf senescence is not a chaotic breakdown but a dynamic process following a precise timetable. It enables plants to economize with their resources and control their own viability and integrity. The onset as well as the progression of leaf senescence are co-ordinated by a complex genetic network that continuously integrates developmental and environmental signals such as biotic and abiotic stresses. Therefore, studying senescence requires an integrative and multi-scale analysis of the dynamic changes occurring in plant physiology and metabolism. In addition to providing an automated and standardized method to quantify leaf senescence at the macroscopic scale, we also propose an analytic framework to investigate senescence at physiological, biochemical, and molecular levels throughout the plant life cycle. We have developed protocols and suggested methods for studying different key processes involved in senescence, including photosynthetic capacities, membrane degradation, redox status, and genetic regulation. All methods presented in this review were conducted on Arabidopsis thaliana Columbia-0 and results are compared with senescence-related mutants. This guideline includes experimental design, protocols, recommendations, and the automated tools for leaf senescence analyses that could also be applied to other species.
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Affiliation(s)
- Justine Bresson
- ZMBP, General Genetics, University of Tübingen, Auf der Morgenstelle 32, Tübingen, Germany
| | - Stefan Bieker
- ZMBP, General Genetics, University of Tübingen, Auf der Morgenstelle 32, Tübingen, Germany
| | - Lena Riester
- ZMBP, General Genetics, University of Tübingen, Auf der Morgenstelle 32, Tübingen, Germany
| | - Jasmin Doll
- ZMBP, General Genetics, University of Tübingen, Auf der Morgenstelle 32, Tübingen, Germany
| | - Ulrike Zentgraf
- ZMBP, General Genetics, University of Tübingen, Auf der Morgenstelle 32, Tübingen, Germany
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67
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Kuai B, Chen J, Hörtensteiner S. The biochemistry and molecular biology of chlorophyll breakdown. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:751-767. [PMID: 28992212 DOI: 10.1093/jxb/erx322] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Chlorophyll breakdown is one of the most obvious signs of leaf senescence and fruit ripening. The resulting yellowing of leaves can be observed every autumn, and the color change of fruits indicates their ripening state. During these processes, chlorophyll is broken down in a multistep pathway, now termed the 'PAO/phyllobilin' pathway, acknowledging the core enzymatic breakdown step catalysed by pheophorbide a oxygenase, which determines the basic linear tetrapyrrole structure of the products of breakdown that are now called 'phyllobilins'. This review provides an update on the PAO/phyllobilin pathway, and focuses on recent biochemical and molecular progress in understanding phyllobilin-modifying reactions as the basis for phyllobilin diversity, on the evolutionary diversity of the pathway, and on the transcriptional regulation of the pathway genes.
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Affiliation(s)
- Benke Kuai
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Junyi Chen
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, China
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zurich, Zollikerstrasse, Zurich, Switzerland
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Wan Y, Mao M, Wan D, Yang Q, Yang F, Li G, Wang R. Identification of the WRKY gene family and functional analysis of two genes in Caragana intermedia. BMC PLANT BIOLOGY 2018; 18:31. [PMID: 29426284 PMCID: PMC5807834 DOI: 10.1186/s12870-018-1235-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 01/14/2018] [Indexed: 05/20/2023]
Abstract
BACKGROUND WRKY transcription factors, one of the largest families of transcriptional regulators in plants, play important roles in plant development and various stress responses. The WRKYs of Caragana intermedia are still not well characterized, although many WRKYs have been identified in various plant species. RESULTS We identified 53 CiWRKY genes from C. intermedia transcriptome data, 28 of which exhibited complete open reading frames (ORFs). These CiWRKYs were divided into three groups via phylogenetic analysis according to their WRKY domains and zinc finger motifs. Conserved domain analysis showed that the CiWRKY proteins contain a highly conserved WRKYGQK motif and two variant motifs (WRKYGKK and WKKYEEK). The subcellular localization of CiWRKY26 and CiWRKY28-1 indicated that these two proteins localized exclusively to nuclei, supporting their role as transcription factors. The expression patterns of the 28 CiWRKYs with complete ORFs were examined through quantitative real-time PCR (qRT-PCR) in various tissues and under different abiotic stresses (drought, cold, salt, high-pH and abscisic acid (ABA)). The results showed that each CiWRKY responded to at least one stress treatment. Furthermore, overexpression of CiWRKY75-1 and CiWRKY40-4 in Arabidopsis thaliana suppressed the drought stress tolerance of the plants and delayed leaf senescence, respectively. CONCLUSIONS Fifty-three CiWRKY genes from the C. intermedia transcriptome were identified and divided into three groups via phylogenetic analysis. The expression patterns of the 28 CiWRKYs under different abiotic stresses suggested that each CiWRKY responded to at least one stress treatment. Overexpression of CiWRKY75-1 and CiWRKY40-4 suppressed the drought stress tolerance of Arabidopsis and delayed leaf senescence, respectively. These results provide a basis for the molecular mechanism through which CiWRKYs mediate stress tolerance.
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Affiliation(s)
- Yongqing Wan
- College of Life Sciences, Inner Mongolia Key Laboratory of Plant Stress Physiology and Molecular Biology, Inner Mongolia Agricultural University, Hohhot, China
| | - Mingzhu Mao
- College of Life Sciences, Inner Mongolia Key Laboratory of Plant Stress Physiology and Molecular Biology, Inner Mongolia Agricultural University, Hohhot, China
| | - Dongli Wan
- Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Key Laboratory of Grassland Ecology and Restoration, Ministry of Agriculture, Hohhot, China
| | - Qi Yang
- College of Life Sciences, Inner Mongolia Key Laboratory of Plant Stress Physiology and Molecular Biology, Inner Mongolia Agricultural University, Hohhot, China
| | - Feiyun Yang
- College of Food Science and Engineering, Inner Mongolia Agricultural University, Hohhot, China
| | - Guojing Li
- College of Life Sciences, Inner Mongolia Key Laboratory of Plant Stress Physiology and Molecular Biology, Inner Mongolia Agricultural University, Hohhot, China
| | - Ruigang Wang
- College of Life Sciences, Inner Mongolia Key Laboratory of Plant Stress Physiology and Molecular Biology, Inner Mongolia Agricultural University, Hohhot, China
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Przybyla-Toscano J, Roland M, Gaymard F, Couturier J, Rouhier N. Roles and maturation of iron-sulfur proteins in plastids. J Biol Inorg Chem 2018; 23:545-566. [PMID: 29349662 PMCID: PMC6006212 DOI: 10.1007/s00775-018-1532-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/14/2017] [Indexed: 12/28/2022]
Abstract
One reason why iron is an essential element for most organisms is its presence in prosthetic groups such as hemes or iron–sulfur (Fe–S) clusters, which are notably required for electron transfer reactions. As an organelle with an intense metabolism in plants, chloroplast relies on many Fe–S proteins. This includes those present in the electron transfer chain which will be, in fact, essential for most other metabolic processes occurring in chloroplasts, e.g., carbon fixation, nitrogen and sulfur assimilation, pigment, amino acid, and vitamin biosynthetic pathways to cite only a few examples. The maturation of these Fe–S proteins requires a complex and specific machinery named SUF (sulfur mobilisation). The assembly process can be split in two major steps, (1) the de novo assembly on scaffold proteins which requires ATP, iron and sulfur atoms, electrons, and thus the concerted action of several proteins forming early acting assembly complexes, and (2) the transfer of the preformed Fe–S cluster to client proteins using a set of late-acting maturation factors. Similar machineries, having in common these basic principles, are present in the cytosol and in mitochondria. This review focuses on the currently known molecular details concerning the assembly and roles of Fe–S proteins in plastids.
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Affiliation(s)
- Jonathan Przybyla-Toscano
- Université de Lorraine, Interactions Arbres-Microorganismes, UMR1136, 54500, Vandoeuvre-lès-Nancy, France
| | - Mélanie Roland
- Université de Lorraine, Interactions Arbres-Microorganismes, UMR1136, 54500, Vandoeuvre-lès-Nancy, France
| | - Frédéric Gaymard
- Biochimie et Physiologie Moléculaire des Plantes, CNRS/INRA/Université Montpellier 2, SupAgro Campus, 34060, Montpellier, France
| | - Jérémy Couturier
- Université de Lorraine, Interactions Arbres-Microorganismes, UMR1136, 54500, Vandoeuvre-lès-Nancy, France
| | - Nicolas Rouhier
- Université de Lorraine, Interactions Arbres-Microorganismes, UMR1136, 54500, Vandoeuvre-lès-Nancy, France.
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Zer H, Margulis K, Georg J, Shotland Y, Kostova G, Sultan LD, Hess WR, Keren N. Resequencing of a mutant bearing an iron starvation recovery phenotype defines Slr1658 as a new player in the regulatory network of a model cyanobacterium. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:235-245. [PMID: 29161470 DOI: 10.1111/tpj.13770] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Photosynthetic microorganisms encounter an erratic nutrient environment characterized by periods of iron limitation and sufficiency. Surviving in such an environment requires mechanisms for handling these transitions. Our study identified a regulatory system involved in the process of recovery from iron limitation in cyanobacteria. We set out to study the role of bacterioferritin co-migratory proteins during transitions in iron bioavailability in the cyanobacterium Synechocystis sp. PCC 6803 using knockout strains coupled with physiological and biochemical measurements. One of the mutants displayed slow recovery from iron limitation. However, we discovered that the cause of the phenotype was not the intended knockout but rather the serendipitous selection of a mutation in an unrelated locus, slr1658. Bioinformatics analysis suggested similarities to two-component systems and a possible regulatory role. Transcriptomic analysis of the recovery from iron limitation showed that the slr1658 mutation had an extensive effect on the expression of genes encoding regulatory proteins, proteins involved in the remodeling and degradation of the photosynthetic apparatus and proteins modulating electron transport. Most significantly, expression of the cyanobacterial homologue of the cyclic electron transport protein PGR5 was upregulated 1000-fold in slr1658 disruption mutants. pgr5 transcripts in the Δslr1658 mutant retained these high levels under a range of stress and recovery conditions. The results suggest that slr1658 is part of a regulatory operon that, among other aspects, affects the regulation of alternative electron flow. Disruption of its function has deleterious results under oxidative stress promoting conditions.
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Affiliation(s)
- Hagit Zer
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Ketty Margulis
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Jens Georg
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Yoram Shotland
- Department of Chemical Engineering, Shamoon College of Engineering, Beer Sheva, 84100, Israel
| | - Gergana Kostova
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Laure D Sultan
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
| | - Wolfgang R Hess
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, D-79104, Freiburg, Germany
| | - Nir Keren
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem, Israel
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Das A, Guyer L, Hörtensteiner S. Chlorophyll and Chlorophyll Catabolite Analysis by HPLC. Methods Mol Biol 2018; 1744:223-235. [PMID: 29392669 DOI: 10.1007/978-1-4939-7672-0_18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The most obvious event of leaf senescence is the loss of chlorophyll. Chlorophyll degradation proceeds in a well-characterized pathway that, although being common to higher plants, yields a species-specific set of chlorophyll catabolites, termed phyllobilins. Analysis of chlorophyll degradation and phyllobilin accumulation by high-performance liquid chromatography (HPLC) is a valuable tool to investigate senescence processes in plants. In this chapter, methods for the extraction, separation, and quantification of chlorophyll and its degradation products are described. Because of their different physicochemical properties, chlorin-type pigments (chlorophylls and magnesium-free pheo-pigments) and phyllobilins (linear tetrapyrroles) are analyzed separately. Specific spectral properties and polarity differences allow the identification of the different classes of known chlorins and phyllobilins. The methods provided facilitate the analysis of chlorophyll degradation and the identification of chlorophyll catabolites in a wide range of plant species, in different tissues, and under a variety of physiological conditions that involve loss of chlorophyll.
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Affiliation(s)
- Aditi Das
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Luzia Guyer
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Stefan Hörtensteiner
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.
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72
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Zhao M, Guo B, Onakpa MM, Wong T, Wakasa K, Che CT, Warpeha K. Activity of Icacinol from Icacina trichantha on Seedling Growth of Oryza sativa and Arabidopsis thaliana. JOURNAL OF NATURAL PRODUCTS 2017; 80:3314-3318. [PMID: 29227099 PMCID: PMC6639824 DOI: 10.1021/acs.jnatprod.7b00668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Broadleaf weeds are very costly for crop growers. Additional herbicidal compounds need to be obtained, especially from natural sources. Extracts of Icacina trichantha were evaluated for responses in germinating seeds and seedlings of rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana). An ethyl acetate fraction of I. trichantha tuber and a diterpenoid constituent, icacinol (1), were found to have impacts on germination and growth of seedlings. The seed germination inhibitory activity on rice was minimal, but significant on Arabidopsis. While rice indicated some growth delay in leaf expansion in the presence of 1, the effects appeared temporary; chlorophyll and anthocyanins were not significantly altered compared to DMSO controls. Rice seedlings attained biomass similar to DMSO controls, and rice grains per panicle were not significantly different from the DMSO controls. On the other hand, Arabidopsis exhibited damage to leaf expansion, reduced chlorophyll, and increased anthocyanins in aerial portions of the seedlings. Icacinol (1) may be a suitable chemical agent to investigate further for the treatment of eudicot weeds.
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Affiliation(s)
- Ming Zhao
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, College of Pharmacy, Nanjing University of Chinese Medicine , Nanjing 210023, People's Republic of China
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States
| | - Brian Guo
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States
| | - Michael M Onakpa
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States
- Department of Physiology and Pharmacology, Faculty of Veterinary Medicine, University of Abuja , Abuja 920001, Nigeria
| | - Tiffany Wong
- Department of Biological Sciences, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Kyo Wakasa
- Genome Research Center, Tokyo University of Agriculture, NODAI Research Institute , Tokyo 156-8502, Japan
| | - Chun-Tao Che
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States
| | - Katherine Warpeha
- Department of Biological Sciences, University of Illinois at Chicago , Chicago, Illinois 60607, United States
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Chlorophyll degradation in aqueous mediums induced by light and UV-B irradiation: An UHPLC-ESI-MS study. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.05.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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74
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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: 37] [Impact Index Per Article: 5.3] [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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75
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Roca M, Ríos JJ, Chahuaris A, Pérez-Gálvez A. Non-fluorescent and yellow chlorophyll catabolites in Japanese plum fruits (Prunus salicina, Lindl.). Food Res Int 2017; 100:332-338. [DOI: 10.1016/j.foodres.2017.07.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/09/2017] [Accepted: 07/13/2017] [Indexed: 12/11/2022]
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76
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Mao C, Lu S, Lv B, Zhang B, Shen J, He J, Luo L, Xi D, Chen X, Ming F. A Rice NAC Transcription Factor Promotes Leaf Senescence via ABA Biosynthesis. PLANT PHYSIOLOGY 2017; 174:1747-1763. [PMID: 28500268 PMCID: PMC5490923 DOI: 10.1104/pp.17.00542] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/09/2017] [Indexed: 05/17/2023]
Abstract
It is well known that abscisic acid (ABA)-induced leaf senescence and premature leaf senescence negatively affect the yield of rice (Oryza sativa). However, the molecular mechanism underlying this relationship, especially the upstream transcriptional network that modulates ABA level during leaf senescence, remains largely unknown. Here, we demonstrate a rice NAC transcription factor, OsNAC2, that participates in ABA-induced leaf senescence. Overexpression of OsNAC2 dramatically accelerated leaf senescence, whereas its knockdown lines showed a delay in leaf senescence. Chromatin immunoprecipitation-quantitative PCR, dual-luciferase, and yeast one-hybrid assays demonstrated that OsNAC2 directly activates expression of chlorophyll degradation genes, OsSGR and OsNYC3 Moreover, ectopic expression of OsNAC2 leads to an increase in ABA levels via directly up-regulating expression of ABA biosynthetic genes (OsNCED3 and OsZEP1) as well as down-regulating the ABA catabolic gene (OsABA8ox1). Interestingly, OsNAC2 is upregulated by a lower level of ABA but downregulated by a higher level of ABA, indicating a feedback repression of OsNAC2 by ABA. Additionally, reduced OsNAC2 expression leads to about 10% increase in the grain yield of RNAi lines. The novel ABA-NAC-SAGs regulatory module might provide a new insight into the molecular action of ABA to enhance leaf senescence and elucidates the transcriptional network of ABA production during leaf senescence in rice.
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Affiliation(s)
- Chanjuan Mao
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Songchong Lu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Bo Lv
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Bin Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jiabin Shen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jianmei He
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Liqiong Luo
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Dandan Xi
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xu Chen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Feng Ming
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China
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77
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Wei B, Zhang W, Chao J, Zhang T, Zhao T, Noctor G, Liu Y, Han Y. Functional analysis of the role of hydrogen sulfide in the regulation of dark-induced leaf senescence in Arabidopsis. Sci Rep 2017; 7:2615. [PMID: 28572670 PMCID: PMC5454012 DOI: 10.1038/s41598-017-02872-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/20/2017] [Indexed: 12/19/2022] Open
Abstract
There is growing evidence that hydrogen sulfide (H2S) is involved in many physiological processes in plants, but the role of H2S in dark-induced leaf senescence remains unknown. In this work, we found that H2S not only inhibited chlorophyll degradation but also caused the accumulation of photoreactive pheide a in detached leaves under extended darkness. Despite this, transcript levels of senescence-associated genes (SAGs) were less affected in H2S-treated detached leaves compared with those in H2S-untreated detached leaves. Furthermore, cell death/rapid bleaching occurred in both H2S-treated detached and attached leaves after transfer from extended darkness to light. Unlike the lack of effect of H2S on SAG transcripts in darkened detached leaves, exogenous H2S induced higher SAG transcript levels in attached leaves than untreated attached leaves. Genetic evidence further underlined the positive correlation between SAG expression in attached leaves and H2S. In addition, effects of H2S on SAG expression in attached leaves were compromised in the S-nitrosoglutathione reductase-deficient mutant, gsnor1. Taken together, our results suggest that H2S suppresses chlorophyll degradation of detached leaves by regulating a dark-dependent reaction, and that this gas positively modulates SAG expression in attached leaves under prolonged darkness in a GSNOR1-dependent manner.
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Affiliation(s)
- Bo Wei
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Wei Zhang
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Jin Chao
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Tianru Zhang
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Tingting Zhao
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China
| | - Graham Noctor
- Institute of Plant Sciences Paris Saclay, Université Paris-Sud, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Evry, Paris Diderot, Sorbonne Paris-Cité, Université Paris-Saclay, 91405, Orsay, France
| | - Yongsheng Liu
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
| | - Yi Han
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
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78
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Kucharewicz W, Distelfeld A, Bilger W, Müller M, Munné-Bosch S, Hensel G, Krupinska K. Acceleration of leaf senescence is slowed down in transgenic barley plants deficient in the DNA/RNA-binding protein WHIRLY1. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:983-996. [PMID: 28338757 PMCID: PMC5441857 DOI: 10.1093/jxb/erw501] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
WHIRLY1 in barley was isolated as a potential regulator of the senescence-associated gene HvS40. In order to investigate whether the plastid-nucleus-located DNA/RNA-binding protein WHIRLY1 plays a role in regulation of leaf senescence, primary foliage leaves from transgenic barley plants with an RNAi-mediated knockdown of the WHIRLY1 gene were characterized by typical senescence parameters, namely pigment contents, function and composition of the photosynthetic apparatus, as well as expression of selected genes known to be either down- or up-regulated during leaf senescence. When the plants were grown at low light intensity, senescence progression was similar between wild-type and RNAi-W1 plants. Likewise, dark-induced senescence of detached leaves was not affected by reduction of WHIRLY1. When plants were grown at high light intensity, however, senescence was induced prematurely in wild-type plants but was delayed in RNAi-W1 plants. This result suggests that WHIRLY1 plays a role in light sensing and/or stress communication between chloroplasts and the nucleus.
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Affiliation(s)
| | - Assaf Distelfeld
- Department of Molecular Biology and Ecology of Plants, University of Tel Aviv, Tel Aviv, Israel
| | - Wolfgang Bilger
- Institute of Botany, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Maren Müller
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Götz Hensel
- Plant Reproductive Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland/OT Gatersleben, Germany
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of Kiel, Kiel, Germany
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79
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80
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Liu T, Zhang L, Chen G, Shi T. Identifying and Characterizing the Circular RNAs during the Lifespan of Arabidopsis Leaves. FRONTIERS IN PLANT SCIENCE 2017; 8:1278. [PMID: 28785273 PMCID: PMC5517402 DOI: 10.3389/fpls.2017.01278] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/06/2017] [Indexed: 05/20/2023]
Abstract
Leaf growth and senescence are controlled by tight genetic factors involved regulation at multiple levels. Circular RNAs (circRNAs) have recently been reported as the microRNA sponge to accomplish corresponding regulatory roles. This study aims to explore the expression profile and functional role of circRNAs in Arabidopsis leaf growth and senescence. We used publically available RNA-seq data of Arabidopsis leaves to identify the circular RNA expression profile and used quantitative real-time PCR to validate our identified circRNAs. The functions of circRNAs were explored using distinct bioinformatics methods including analysis of network, gene ontology and KEGG pathway. We identified 168 circRNAs, including 40 novel circRNAs, in Arabidopsis thaliana leaves, with 158 (94.1%) circRNAs arising from the exons of genes. Real-time PCRs were used to verify 4 highly expressed circRNAs and they all showed consistent expression patterns with the RNA-seq results. Interestingly, 6 and 35 circRNAs were differentially expressed at G- to -M stage and M- to -S stage, respectively. The circRNAs display an upregulation trend during the lifespan of Arabidopsis leaves. Moreover, the expression of circRNAs during senescence is independent of host gene expression to a certain degree. The gene ontology (GO) and KEGG pathway analysis of the targeted mRNA of circRNA-miRNA-mRNA network showed that the circRNAs may be involved in plant hormone signal transduction, Porphyrin and chlorophyll metabolism during leaves senescence. Our comprehensive analysis of the expression profile of circRNAs and their potential functions during leaf growth and senescence suggest that circRNAs may function as new post-transcriptional regulators in the senescence of Arabidopsis leaves.
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Affiliation(s)
| | | | - Geng Chen
- *Correspondence: Tieliu Shi, Geng Chen,
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81
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Vergara-Domínguez H, Ríos JJ, Gandul-Rojas B, Roca M. Chlorophyll catabolism in olive fruits (var. Arbequina and Hojiblanca) during maturation. Food Chem 2016; 212:604-11. [DOI: 10.1016/j.foodchem.2016.06.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/03/2016] [Accepted: 06/07/2016] [Indexed: 12/29/2022]
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82
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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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83
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Erhart T, Mittelberger C, Vergeiner C, Scherzer G, Holzner B, Robatscher P, Oberhuber M, Kräutler B. Chlorophyll Catabolites in Senescent Leaves of the Plum Tree (Prunus domestica). Chem Biodivers 2016; 13:1441-1453. [PMID: 27533340 PMCID: PMC5123584 DOI: 10.1002/cbdv.201600181] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/10/2016] [Indexed: 12/28/2022]
Abstract
In cold extracts of senescent leaves of the plum tree (Prunus domestica ssp. domestica), six colorless non-fluorescent chlorophyll catabolites (NCCs) were characterized, named Pd-NCCs. In addition, several minor NCC fractions were tentatively classified. The structure of the most polar one of the NCCs, named Pd-NCC-32, featured an unprecedented twofold glycosidation pattern. Three of the NCCs are also functionalized at their 32 -position by a glucopyranosyl group. In addition, two of these glycosidated NCCs carry a dihydroxyethyl group at their 18-position. In the polar Pd-NCC-32, the latter group is further glycosidated at the terminal 182 -position. Four other major Pd-NCCs and one minor Pd-NCC were identified with five NCCs from higher plants known to belong to the 'epi'-series. In addition, tentative structures were derived for two minor fractions, classified as yellow chlorophyll catabolites, which represented (formal) oxidation products of two of the observed Pd-NCCs. The chlorophyll catabolites in leaves of plum feature the same basic structural pattern as those found in leaves of apple and pear trees.
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Affiliation(s)
- Theresia Erhart
- Institute of Organic Chemistry and Center of Molecular BiosciencesUniversity of InnsbruckInnrain 80/82AT‐6020Innsbruck
| | - Cecilia Mittelberger
- Laimburg Research Centre for Agriculture and ForestryLaimburg 6 – Pfatten (Vadena)IT‐39040Auer (Ora)BZ
| | - Clemens Vergeiner
- Institute of Organic Chemistry and Center of Molecular BiosciencesUniversity of InnsbruckInnrain 80/82AT‐6020Innsbruck
| | - Gerhard Scherzer
- Institute of Organic Chemistry and Center of Molecular BiosciencesUniversity of InnsbruckInnrain 80/82AT‐6020Innsbruck
| | - Barbara Holzner
- Laimburg Research Centre for Agriculture and ForestryLaimburg 6 – Pfatten (Vadena)IT‐39040Auer (Ora)BZ
| | - Peter Robatscher
- Laimburg Research Centre for Agriculture and ForestryLaimburg 6 – Pfatten (Vadena)IT‐39040Auer (Ora)BZ
| | - Michael Oberhuber
- Laimburg Research Centre for Agriculture and ForestryLaimburg 6 – Pfatten (Vadena)IT‐39040Auer (Ora)BZ
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center of Molecular BiosciencesUniversity of InnsbruckInnrain 80/82AT‐6020Innsbruck
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84
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Christ B, Hauenstein M, Hörtensteiner S. A liquid chromatography-mass spectrometry platform for the analysis of phyllobilins, the major degradation products of chlorophyll in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:505-518. [PMID: 27349589 DOI: 10.1111/tpj.13253] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 05/08/2023]
Abstract
During senescence, chlorophyll is broken down to a set of structurally similar, but distinct linear tetrapyrrolic compounds termed phyllobilins. Structure identification of phyllobilins from over a dozen plant species revealed that modifications at different peripheral positions may cause complex phyllobilin composition in a given species. For example, in Arabidopsis thaliana wild-type, eight different phyllobilins have structurally been characterized to date. Accurate phyllobilin identification and quantification, which classically have been performed by high performance liquid chromatography (HPLC) and UV/vis detection, are, however, hampered because of their similar physiochemical properties and vastly differing abundances in plant extracts. Here we established a rapid method for phyllobilin identification and quantification that couples ultra-HPLC with high-resolution/high-precision tandem mass spectrometry. Using Arabidopsis wild-type and mutant lines that are deficient in specific phyllobilin-modifying reactions, we identified a total of 16 phyllobilins, among them two that have not been described before in Arabidopsis. The single and collision-induced dissociation tandem mass spectrometry data of all 16 Arabidopsis phyllobilins were collected in a mass spectrometry library, which is available to the scientific community. The library allows rapid detection and quantification of phyllobilins within and across Arabidopsis genotypes and we demonstrate its potential use for high-throughput approaches and genome-wide association studies in chlorophyll breakdown. By extending the library with phyllobilin data from other plant species in the future, we aim providing a tool for chlorophyll metabolite analysis as a measure of senescence for practical applications, such as post-harvest quality control.
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Affiliation(s)
- Bastien Christ
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Mareike Hauenstein
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Stefan Hörtensteiner
- Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
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85
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Hauenstein M, Christ B, Das A, Aubry S, Hörtensteiner S. A Role for TIC55 as a Hydroxylase of Phyllobilins, the Products of Chlorophyll Breakdown during Plant Senescence. THE PLANT CELL 2016; 28:2510-2527. [PMID: 27655840 PMCID: PMC5134989 DOI: 10.1105/tpc.16.00630] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/08/2016] [Accepted: 09/19/2016] [Indexed: 05/04/2023]
Abstract
Chlorophyll degradation is the most obvious hallmark of leaf senescence. Phyllobilins, linear tetrapyrroles that are derived from opening of the chlorin macrocycle by the Rieske-type oxygenase PHEOPHORBIDE a OXYGENASE (PAO), are the end products of chlorophyll degradation. Phyllobilins carry defined modifications at several peripheral positions within the tetrapyrrole backbone. While most of these modifications are species-specific, hydroxylation at the C32 position is commonly found in all species analyzed to date. We demonstrate that this hydroxylation occurs in senescent chloroplasts of Arabidopsis thaliana. Using bell pepper (Capsicum annuum) chromoplasts, we establish that phyllobilin hydroxylation is catalyzed by a membrane-bound, molecular oxygen-dependent, and ferredoxin-dependent activity. As these features resemble the requirements of PAO, we considered membrane-bound Rieske-type oxygenases as potential candidates. Analysis of mutants of the two Arabidopsis Rieske-type oxygenases (besides PAO) uncovered that phyllobilin hydroxylation depends on TRANSLOCON AT THE INNER CHLOROPLAST ENVELOPE55 (TIC55). Our work demonstrates a catalytic activity for TIC55, which in the past has been considered as a redox sensor of protein import into plastids. Given the wide evolutionary distribution of both PAO and TIC55, we consider that chlorophyll degradation likely coevolved with land plants.
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Affiliation(s)
- Mareike Hauenstein
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Bastien Christ
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Aditi Das
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
| | - Sylvain Aubry
- Institute of Plant Biology, University of Zurich, CH-8008 Zurich, Switzerland
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86
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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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87
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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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88
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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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89
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Li H, Pu H. Crystal structure of methylesterase family member 16 (MES16) from Arabidopsis thaliana. Biochem Biophys Res Commun 2016; 474:226-231. [PMID: 27109476 DOI: 10.1016/j.bbrc.2016.04.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 04/20/2016] [Indexed: 11/19/2022]
Abstract
Methylesterase family member 16 (MES16) is an integral component of chlorophyll breakdown. It catalyzes the demethylation of fluorescent chlorophyll catabolite (FCC) and pheophorbide in vitro, and specifically demethylates FCC in vivo. Here we report the crystal structure of MES16 from Arabidopsis thaliana at 2.8 Å resolution. The structure confirm that MES16 is a member of the α/β-hydrolase superfamily with Ser-87, His-239, and Asp-211 as the catalytic triad. Our biochemical studies reveal that MES16 has esterase activity with methyl-indole acetic acid as the substrate, and the catalytically essential role of Ser-87 has been demonstrated.
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Affiliation(s)
- Hongmei Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.
| | - Hua Pu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, People's Republic of China; University of Chinese Academy of Sciences, College of Life Science, Beijing, 101048, People's Republic of China
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90
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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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91
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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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92
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Grabski K, Baranowski N, Skórko-Glonek J, Tukaj Z. Chlorophyll catabolites in conditioned media of green microalga Desmodesmus subspicatus. JOURNAL OF APPLIED PHYCOLOGY 2016; 28:889-896. [PMID: 27057086 PMCID: PMC4789205 DOI: 10.1007/s10811-015-0618-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 05/05/2015] [Accepted: 05/05/2015] [Indexed: 05/08/2023]
Abstract
Although the appearance of coloured chlorophyll degradation products of higher plants is well known, knowledge about such compounds produced and released particularly by planktonic algae is still limited. Colourless conditioned media (CM) obtained from autotrophic cultures of unicellular green alga Desmosdemus subspicatus turn red after acidification. The accumulation of red pigments in the medium and the growth rate of algae were inversely correlated. The red, crude solution isolated from CM by dialysis and ion exchange chromatography, and next purified by means of high-performance liquid chromatography, appeared to be a mixture of three compounds with characteristic UV/VIS absorption maxima near 330 and 505 nm. Electrospray ionization (ESI) mass spectrometry analysis revealed that the molecular mass of the most polar and most abundant compound was 637 Da and molecular masses of two other ones were 641 and 607 Da. Addition of 15 N isotope to the culture medium and subsequent mass spectrometry measurements revealed the occurrence of four nitrogen atoms per each molecule. The data suggest that red pigments isolated from algal-conditioned media are chlorophyll degradation compounds, the production of which depends on light intensity, and are released mainly during the stationary phase of growth.
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Affiliation(s)
- Krzysztof Grabski
- />Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Natalia Baranowski
- />Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Joanna Skórko-Glonek
- />Department of Biochemistry, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Zbigniew Tukaj
- />Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
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93
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Harris CJ, Baulcombe DC. Chlorophyll Content Assay to Quantify the Level of Necrosis Induced by Different R Gene/Elicitor Combinations after Transient Expression. Bio Protoc 2015; 5:e1670. [PMID: 28748201 DOI: 10.21769/bioprotoc.1670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
This assay can be used to rapidly and accurately quantify levels of leaf necrosis induced after transient expression of R genes and elicitor combinations (Harris et al., 2013). It is based on the inverse correlation between level of necrosis and chlorophyll content in leaf tissue. It is adapted from the calculations described by (Strain et al., 1971).
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Affiliation(s)
- C Jake Harris
- Plant Sciences Department, Cambridge University, Cambridge, UK
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94
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Sztatelman O, Grzyb J, Gabryś H, Banaś AK. The effect of UV-B on Arabidopsis leaves depends on light conditions after treatment. BMC PLANT BIOLOGY 2015; 15:281. [PMID: 26608826 PMCID: PMC4660668 DOI: 10.1186/s12870-015-0667-2] [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] [Received: 08/10/2015] [Accepted: 11/17/2015] [Indexed: 05/11/2023]
Abstract
BACKGROUND Ultraviolet B (UV-B) irradiation can influence many cellular processes. Irradiation with high UV-B doses causes chlorophyll degradation, a decrease in the expression of genes associated with photosynthesis and its subsequent inhibition. On the other hand, sublethal doses of UV-B are used in post-harvest technology to prevent yellowing in storage. To address this inconsistency the effect of short, high-dose UV-B irradiation on detached Arabidopsis thaliana leaves was examined. RESULTS Two different experimental models were used. After short treatment with a high dose of UV-B the Arabidopsis leaves were either put into darkness or exposed to constant light for up to 4 days. UV-B inhibited dark-induced chlorophyll degradation in Arabidopsis leaves in a dose-dependent manner. The expression of photosynthesis-related genes, chlorophyll content and photosynthetic efficiency were higher in UV-B -treated leaves left in darkness. UV-B treatment followed by constant light caused leaf yellowing and induced the expression of senescence-related genes. Irrespective of light treatment a high UV-B dose led to clearly visible cell death 3 days after irradiation. CONCLUSIONS High doses of UV-B have opposing effects on leaves depending on their light status after UV treatment. In darkened leaves short UV-B treatment delays the appearance of senescence symptoms. When followed by light treatment, the same doses of UV-B result in chlorophyll degradation. This restricts the potential usability of UV treatment in postharvest technology to crops which are stored in darkness.
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Affiliation(s)
- Olga Sztatelman
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland.
- Current address: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, 02-106, Poland.
| | - Joanna Grzyb
- Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warszawa, 02-668, Poland.
| | - Halina Gabryś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland.
| | - Agnieszka Katarzyna Banaś
- Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland.
- The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland.
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95
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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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96
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Chou YL, Ko CY, Yen CC, Chen LFO, Shaw JF. A Novel Recombinant Chlorophyllase1 from Chlamydomonas reinhardtii for the Production of Chlorophyllide Derivatives. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:9496-9503. [PMID: 26478543 DOI: 10.1021/acs.jafc.5b02787] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Natural chlorophyll metabolites have exhibited physiological activity in vitro. In this study, a recombinant chlorophyllase1 gene from Chlamydomonas reinhardtii (CrCLH1) was isolated and characterized. Recombinant CrCLH1 can perform chlorophyll dephytylation and produce chlorophyllide and phytol. In a transient assay, the subcellular localization of CrCLH1-green fluorescent protein was determined to be outside the chloroplast. Biochemical analyses of the activity of recombinant CrCLH1 indicated that its optimal pH value and temperature are 6.0 and 40 °C, respectively. Enzyme kinetic data revealed that the recombinant CrCLH1 had a higher catalytic efficiency for chlorophyll a than for chlorophyll b and bacteriochlorophyll a. According to high-performance liquid chromatography analysis of chlorophyll hydrolysis, recombinant CrCLH1 catalyzed the conversion of chlorophyll a to pheophorbide a at pH 5. Therefore, recombinant CrCLH1 can be used as a biocatalyst to produce chlorophyllide derivatives.
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Affiliation(s)
- Yi-Li Chou
- Department of Biological Science and Technology, I-Shou University , Kaohsiung 82445, Taiwan
| | - Chia-Yun Ko
- Institute of Plant and Microbial Biology, Academia Sinica , Taipei 11529, Taiwan
| | - Chih-Chung Yen
- Institute of Genomics and Bioinformatics, National Chung Hsing University , Taichung 40227, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University , Taichung 40227, Taiwan
| | - Long-Fang O Chen
- Institute of Plant and Microbial Biology, Academia Sinica , Taipei 11529, Taiwan
| | - Jei-Fu Shaw
- Department of Biological Science and Technology, I-Shou University , Kaohsiung 82445, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University , Taichung 40227, Taiwan
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97
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Zhu X, Chen J, Xie Z, Gao J, Ren G, Gao S, Zhou X, Kuai B. Jasmonic acid promotes degreening via MYC2/3/4- and ANAC019/055/072-mediated regulation of major chlorophyll catabolic genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:597-610. [PMID: 26407000 DOI: 10.1111/tpj.13030] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/04/2015] [Accepted: 09/08/2015] [Indexed: 05/18/2023]
Abstract
Degreening caused by rapid chlorophyll (Chl) degradation is a characteristic event during green organ senescence or maturation. Pheophorbide a oxygenase gene (PAO) encodes a key enzyme of Chl degradation, yet its transcriptional regulation remains largely unknown. Using yeast one-hybrid screening, coupled with in vitro and in vivo assays, we revealed that Arabidopsis MYC2/3/4 basic helix-loop-helix proteins directly bind to PAO promoter. Overexpression of the MYCs significantly enhanced the transcriptional activity of PAO promoter in Arabidopsis protoplasts, and methyl jasmonate (MeJA) treatment greatly induced PAO expression in wild-type Arabidopsis plants, but the induction was abolished in myc2 myc3 myc4. In addition, MYC2/3/4 proteins could promote the expression of another Chl catabolic enzyme gene, NYC1, as well as a key regulatory gene of Chl degradation, NYE1/SGR1, by directly binding to their promoters. More importantly, the myc2 myc3 myc4 triple mutant showed a severe stay-green phenotype, whereas the lines overexpressing the MYCs showed accelerated leaf yellowing upon MeJA treatment. These results suggest that MYC2/3/4 proteins may mediate jasmonic acid (JA)-induced Chl degradation by directly activating these Chl catabolic genes (CCGs). Three NAC family proteins, ANAC019/055/072, downstream from MYC2/3/4 proteins, could also directly promote the expression of a similar set of CCGs (NYE1/SGR1, NYE2/SGR2 and NYC1) during Chl degradation. In particular, anac019 anac055 anac072 triple mutant displayed a severe stay-green phenotype after MeJA treatment. Finally, we revealed that MYC2 and ANAC019 may interact with each other and synergistically enhance NYE1 expression. Together, our study reveals a hierarchical and coordinated regulatory network of JA-induced Chl degradation.
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Affiliation(s)
- Xiaoyu Zhu
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Junyi Chen
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Zuokun Xie
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Jiong Gao
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Guodong Ren
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Shan Gao
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xin Zhou
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Benke Kuai
- State Key Laboratory of Genetic Engineering and Fudan Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Shanghai Key Laboratory of Bio-Energy Crops, Shanghai University, Shanghai, 200444, China
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98
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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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99
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Xiao HJ, Liu KK, Li DW, Arisha MH, Chai WG, Gong ZH. Cloning and characterization of the pepper CaPAO gene for defense responses to salt-induced leaf senescence. BMC Biotechnol 2015; 15:100. [PMID: 26498743 PMCID: PMC4619409 DOI: 10.1186/s12896-015-0213-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/06/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pheophorbide a oxygenase (PAO) is an important enzyme in the chlorophyll catabolism pathway and is involved in leaf senescence. It opens the porphyrin macrocycle of pheophorbide a and finally forms the primary fluorescent chlorophyll catabolite. Previous studies have demonstrated the function of PAO during cell death. However, the characterizaton of PAO during leaf senescence induced by environmental factors is not well understood. METHODS Homology-based cloning and RACE techniques were used to obtain the full-length cDNA of the CaPAO gene. CaPAO expression was determined by quantitative real-time PCR. Function of CaPAO gene were studied using virus-induced gene silencing and transgenic techniques with tobacco plants (Nicotiana tabacum). RESULTS A novel PAO gene CaPAO was isolated from pepper (Capsicum annuum L.). The full-length CaPAO cDNA is comprised of 1838 bp, containing an open reading frame of 1614 bp, and encodes a 537 amino acid protein. This deduced protein belongs to the Rieske-type iron-sulfur superfamily, containing a conserved Rieske cluster. CaPAO expression, as determined by quantitative real-time PCR, was higher in leaves than roots, stems and flowers. It was upregulated by abscisic acid, methyl jasmonate and salicylic acid. Moreover, CaPAO was significantly induced by high salinity and osmotic stress treatments and also was regulated by Phytophthora capsici. The virus-induced gene silencing technique was used to silence the CaPAO gene in pepper plants. After 3 days of high salt treatment, the chlorophyll breakdown of CaPAO-silenced pepper plants was retarded. RD29A promoter-inducible expression vector was constructed and transferred into tobacco plant. After 7 days of salt treatment, the leaves of transgenic plants were severely turned into yellow, the lower leaves showed necrotic symptom and chlorophyll content was significantly lower than that in the control plants. CONCLUSIONS The expression of CaPAO gene was induced in natural senescence and various stresses. The CaPAO gene may be related to defense responses to various stresses and play an important role in salt-induced leaf senescence.
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Affiliation(s)
- Huai-Juan Xiao
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
- College of Horticulture, Henan Agricultural University, Zhengzhou, Henan, P. R. China.
| | - Ke-Ke Liu
- College of Horticulture, Henan Agricultural University, Zhengzhou, Henan, P. R. China.
| | - Da-Wei Li
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
| | - Mohamed Hamed Arisha
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
- Faculty of Agriculture, Zagazig University, Zagazig, Sharkia P. R. Egypt.
| | - Wei-Guo Chai
- Institute of Vegetables, Hangzhou Academy of Agricultural Sciences, Hangzhou, Zhejiang, P. R. China.
| | - Zhen-Hui Gong
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P. R. China.
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100
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Vom Dorp K, Hölzl G, Plohmann C, Eisenhut M, Abraham M, Weber APM, Hanson AD, Dörmann P. Remobilization of Phytol from Chlorophyll Degradation Is Essential for Tocopherol Synthesis and Growth of Arabidopsis. THE PLANT CELL 2015; 27:2846-59. [PMID: 26452599 PMCID: PMC4682318 DOI: 10.1105/tpc.15.00395] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 09/08/2015] [Accepted: 09/17/2015] [Indexed: 05/18/2023]
Abstract
Phytol from chlorophyll degradation can be phosphorylated to phytyl-phosphate and phytyl-diphosphate, the substrate for tocopherol (vitamin E) synthesis. A candidate for the phytyl-phosphate kinase from Arabidopsis thaliana (At1g78620) was identified via a phylogeny-based approach. This gene was designated VITAMIN E DEFICIENT6 (VTE6) because the leaves of the Arabidopsis vte6 mutants are tocopherol deficient. The vte6 mutant plants are incapable of photoautotrophic growth. Phytol and phytyl-phosphate accumulate, and the phytyl-diphosphate content is strongly decreased in vte6 leaves. Phytol feeding and enzyme assays with Arabidopsis and recombinant Escherichia coli cells demonstrated that VTE6 has phytyl-P kinase activity. Overexpression of VTE6 resulted in increased phytyl-diphosphate and tocopherol contents in seeds, indicating that VTE6 encodes phytyl-phosphate kinase. The severe growth retardation of vte6 mutants was partially rescued by introducing the phytol kinase mutation vte5. Double mutant plants (vte5 vte6) are tocopherol deficient and contain more chlorophyll, but reduced amounts of phytol and phytyl-phosphate compared with vte6 mutants, suggesting that phytol or phytyl-phosphate are detrimental to plant growth. Therefore, VTE6 represents the missing phytyl-phosphate kinase, linking phytol release from chlorophyll with tocopherol synthesis. Moreover, tocopherol synthesis in leaves depends on phytol derived from chlorophyll, not on de novo synthesis of phytyl-diphosphate from geranylgeranyl-diphosphate.
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Affiliation(s)
- Katharina Vom Dorp
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Georg Hölzl
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Christian Plohmann
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS) Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Marion Eisenhut
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS) Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Marion Abraham
- Leibniz Institute for Baltic Sea Research, 18119 Rostock, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS) Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Andrew D Hanson
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32611
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
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