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Derrien V, André E, Bernad S. Peroxidase activity of rice (Oryza sativa) hemoglobin: distinct role of tyrosines 112 and 151. J Biol Inorg Chem 2023; 28:613-626. [PMID: 37507628 DOI: 10.1007/s00775-023-02014-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023]
Abstract
Five non-symbiotic hemoglobins (nsHb) have been identified in rice (Oryza sativa). Previous studies have shown that stress conditions can induce their overexpression, but the role of those globins is still unclear. To better understand the functions of nsHb, the reactivity of rice Hb1 toward hydrogen peroxide (H2O2) has been studied in vitro. Our results show that recombinant rice Hb1 dimerizes through dityrosine cross-links in the presence of H2O2. By site-directed mutagenesis, we suggest that tyrosine 112 located in the FG loop is involved in this dimerization. Interestingly, this residue is not conserved in the sequence of the five rice non-symbiotic hemoglobins. Stopped-flow spectrophotometric experiments have been performed to measure the catalytic constants of rice Hb and its variants using the oxidation of guaiacol. We have shown that Tyrosine112 is a residue that enhances the peroxidase activity of rice Hb1, since its replacement by an alananine leads to a decrease of guaiacol oxidation. In contrast, tyrosine 151, a conserved residue which is buried inside the heme pocket, reduces the protein reactivity. Indeed, the variant Tyr151Ala exhibits a higher peroxidase activity than the wild type. Interestingly, this residue affects the heme coordination and the replacement of the tyrosine by an alanine leads to the loss of the distal ligand. Therefore, even if the amino acid at position 151 does not participate to the formation of the dimer, this residue modulates the peroxidase activity and plays a role in the hexacoordinated state of the heme.
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Affiliation(s)
- Valérie Derrien
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, Avenue Jean Perrin. Bat 350, 91405, Orsay, France.
| | - Eric André
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, Avenue Jean Perrin. Bat 350, 91405, Orsay, France
| | - Sophie Bernad
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, Avenue Jean Perrin. Bat 350, 91405, Orsay, France
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2
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Fu ZW, Feng YR, Gao X, Ding F, Li JH, Yuan TT, Lu YT. Salt stress-induced chloroplastic hydrogen peroxide stimulates pdTPI sulfenylation and methylglyoxal accumulation. THE PLANT CELL 2023; 35:1593-1616. [PMID: 36695476 PMCID: PMC10118271 DOI: 10.1093/plcell/koad019] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 01/24/2023] [Indexed: 06/17/2023]
Abstract
High salinity, an adverse environmental factor affecting about 20% of irrigated arable land worldwide, inhibits plant growth and development by causing oxidative stress, damaging cellular components, and disturbing global metabolism. However, whether and how reactive oxygen species disturb the metabolism of salt-stressed plants remain elusive. Here, we report that salt-induced hydrogen peroxide (H2O2) inhibits the activity of plastid triose phosphate isomerase (pdTPI) to promote methylglyoxal (MG) accumulation and stimulates the sulfenylation of pdTPI at cysteine 74. We also show that MG is a key factor limiting the plant growth, as a decrease in MG levels completely rescued the stunted growth and repressed salt stress tolerance of the pdtpi mutant. Furthermore, targeting CATALASE 2 into chloroplasts to prevent salt-induced overaccumulation of H2O2 conferred salt stress tolerance, revealing a role for chloroplastic H2O2 in salt-caused plant damage. In addition, we demonstrate that the H2O2-mediated accumulation of MG in turn induces H2O2 production, thus forming a regulatory loop that further inhibits the pdTPI activity in salt-stressed plants. Our findings, therefore, illustrate how salt stress induces MG production to inhibit the plant growth.
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Affiliation(s)
- Zheng-Wei Fu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Yu-Rui Feng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Xiang Gao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Feng Ding
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Jian-Hui Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Ting-Ting Yuan
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
| | - Ying-Tang Lu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430072, China
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Becana M, Yruela I, Sarath G, Catalán P, Hargrove MS. Plant hemoglobins: a journey from unicellular green algae to vascular plants. THE NEW PHYTOLOGIST 2020; 227:1618-1635. [PMID: 31960995 DOI: 10.1111/nph.16444] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 12/24/2019] [Indexed: 05/17/2023]
Abstract
Globins (Glbs) are widely distributed in archaea, bacteria and eukaryotes. They can be classified into proteins with 2/2 or 3/3 α-helical folding around the heme cavity. Both types of Glbs occur in green algae, bryophytes and vascular plants. The Glbs of angiosperms have been more intensively studied, and several protein structures have been solved. They can be hexacoordinate or pentacoordinate, depending on whether a histidine is coordinating or not at the sixth position of the iron atom. The 3/3 Glbs of class 1 and the 2/2 Glbs (also called class 3 in plants) are present in all angiosperms, whereas the 3/3 Glbs of class 2 have been only found in early angiosperms and eudicots. The three Glb classes are expected to play different roles. Class 1 Glbs are involved in hypoxia responses and modulate NO concentration, which may explain their roles in plant morphogenesis, hormone signaling, cell fate determination, nutrient deficiency, nitrogen metabolism and plant-microorganism symbioses. Symbiotic Glbs derive from class 1 or class 2 Glbs and transport O2 in nodules. The physiological roles of class 2 and class 3 Glbs are poorly defined but could involve O2 and NO transport and/or metabolism, respectively. More research is warranted on these intriguing proteins to determine their non-redundant functions.
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Affiliation(s)
- Manuel Becana
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080, Zaragoza, Spain
| | - Inmaculada Yruela
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080, Zaragoza, Spain
- Group of Biochemistry, Biophysics and Computational Biology (BIFI-Unizar) Joint Unit to CSIC, Edificio I+D Campus Río Ebro, 50018, Zaragoza, Spain
| | - Gautam Sarath
- Wheat, Sorghum, and Forage Research Unit, USDA-ARS, East Campus, University of Nebraska-Lincoln, Lincoln, NE, 86583, USA
| | - Pilar Catalán
- Group of Biochemistry, Biophysics and Computational Biology (BIFI-Unizar) Joint Unit to CSIC, Edificio I+D Campus Río Ebro, 50018, Zaragoza, Spain
- Escuela Politécnica Superior de Huesca, Universidad de Zaragoza, 22071, Huesca, Spain
| | - Mark S Hargrove
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
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4
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Li D, Wei J, Peng Z, Ma W, Yang Q, Song Z, Sun W, Yang W, Yuan L, Xu X, Chang W, Rengel Z, Shen J, Reiter RJ, Cui X, Yu D, Chen Q. Daily rhythms of phytomelatonin signaling modulate diurnal stomatal closure via regulating reactive oxygen species dynamics in Arabidopsis. J Pineal Res 2020; 68:e12640. [PMID: 32064655 DOI: 10.1111/jpi.12640] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/06/2020] [Accepted: 02/11/2020] [Indexed: 12/26/2022]
Abstract
Melatonin is a well-studied neurohormone oscillating in a 24-h cycle in vertebrates. Phytomelatonin is widespread in plant kingdom, but it remains elusive whether this newly characterized putative hormone underlies the regulation by daily rhythms. Here, we report phytomelatonin signaling, as reflected by changes in endogenous concentrations of phytomelatonin and expression of genes associated with biosynthesis of phytomelatonin (AtSNAT1, AtCOMT1, and AtASMT) and its receptor (AtPMTR1), shows 24-h oscillations in Arabidopsis. The variation of reactive oxygen species (ROS) production and scavenging and expression of ROS-related genes significantly decrease in pmtr1 and snat and increase in PMTR1-OE seedlings, indicating the rhythmicity in phytomelatonin signaling is required for maintenance of ROS dynamics. Additionally, the ROS signaling feedback influences the expression of AtSNAT1, AtCOMT1, AtASMT, and AtPMTR1, suggesting the phytomelatonin and ROS signaling are coordinately interrelated. The pmtr1 mutant plants lose diurnal stomatal closure, with stomata remaining open during daytime as well as nighttime and mutants showing more water loss and drought sensitivity when compared with the wild-type Col-0 plants. Taken together, our results suggest that PMTR1-regulated ROS signaling peaks in the afternoon and may transmit the darkness signals to trigger stomatal closure, which might be essential for high water-use efficiency and drought tolerance.
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Affiliation(s)
- Dongxu Li
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Jian Wei
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Zhongping Peng
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Wenna Ma
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Qian Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Zhongbang Song
- Yunnan Academy of Tobacco Agricultural Sciences, Kunming, China
| | - Wei Sun
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Wei Yang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Li Yuan
- Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Xiaodong Xu
- Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, China
| | - Wei Chang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Zed Rengel
- Faculty of Science, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
| | - Jianbo Shen
- Key Laboratory of Plant-Soil Interactions, Department of Plant Nutrition, Ministry of Education, China Agricultural University, Beijing, China
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX, USA
| | - Xiuming Cui
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Dashi Yu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Qi Chen
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
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Yan H, Sheng M, Wang C, Liu Y, Yang J, Liu F, Xu W, Su Z. AtSPX1-mediated transcriptional regulation during leaf senescence in Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 283:238-246. [PMID: 31128694 DOI: 10.1016/j.plantsci.2019.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
Leaf senescence is the final stage of leaf growth, a highly coordinated and complicated process. Phosphorus as an essential macronutrient for plant growth is remobilized from senescing leaves to other vigorous parts of the plant. In this study, through data mining, we found some phosphate starvation induced genes such as AtSPX1, were significantly induced in aging leaves in Arabidopsis. We applied a reverse genetics approach to investigate the phenotypes of transgenic plants and mutant plants, and the results showed that the overexpression of AtSPX1 accelerated leaf senescence, suppressed Pi accumulation, promoted SA production and H2O2 levels in leaves, while the mutant lines of AtSPX1 showed slightly delayed leaf senescence. We conducted RNA-seq-based transcriptome analysis together with GO and GSEA enrichment analyses for transgenic vs. wild-type plants to elucidate the possible underlying regulatory mechanism. The 558 genes that were up-regulated in the overexpression plants 35S::AtSPX1/WT, were significantly enriched in the process of leaf senescence, Pi starvation responses and SA signaling pathways, as were the target genes of some transcription factors such as WRKYs and NACs. In a word, we characterized AtSPX1 as a key regulator, which mediated the crosstalks among leaf senescence, Pi starvation and SA signaling pathways in Arabidopsis thaliana.
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Affiliation(s)
- Hengyu Yan
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Minghao Sheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Chunchao Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yue Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jiaotong Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Fengxia Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wenying Xu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
| | - Zhen Su
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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Quantitative proteomics analysis reveals resistance differences of banana cultivar 'Brazilian' to Fusarium oxysporum f. sp. cubense races 1 and 4. J Proteomics 2019; 203:103376. [PMID: 31078632 DOI: 10.1016/j.jprot.2019.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 12/29/2022]
Abstract
Banana Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases in banana production. Foc is classified into three physiological races. However, the resistance mechanisms of banana against different Foc races are poorly understood. In this study, we performed a comparative proteomics analysis to investigate the resistance mechanisms of 'Brazilian' against Foc1 and Foc4. The proteomes of 'Brazilian' roots inoculated with Foc1 and Foc4 and mock inoculated control at 48 h were analyzed using TMT based quantitative analysis technique. A total of 7325 unique protein species were identified, of which 689, 744, and 1222 protein species were differentially accumulated in Foc1 vs. CK, Foc4 vs. CK, and Foc1 vs. Foc4, respectively. The differential accumulations of candidate protein species were further confirmed by RT-qPCR, PRM, and physiological and biochemical assays. Bioinformatics analysis revealed that the differentially abundance protein species (DAPS) related to pattern recognition receptors, plant cell wall modification, redox homeostasis, and defense responses were differentially accumulated after Foc1 and Foc4 infection, suggesting that 'Brazilian' differed in resistance to the two Foc races. Our study lay the foundation for an in-depth understanding of the interaction between bananas and Foc at the proteome level. SIGNIFICANCE: The banana fusarium wilt disease is one of the most destructive disease of banana and is caused by Fusarium oxysporum f. sp. cubense (Foc). Foc is classified into three physiological races, namely, Foc1, Foc2, and Foc4. Among these races, Foc1 and Foc4 are widely distributed in south China and significantly lose yield. Although both physiological races (Foc1 and Foc4) can invade the Cavendish banana cultivar 'Brazilian', they have significant pathogenicity differences. Unfortunately, how the resistance differences are produced between two races is still largely unclear to date. In this study, we addressed this issue by performing TMT-based comparative quantitative proteomics analysis of 'Brazilian' roots after inoculation with Foc1 and Foc4 as well as sterile water as the control. We revealed that the series of protein species associated with pattern recognition receptors, plant cell wall modification, redox homeostasis, pathogenesis, phytohormones and signal transduction, plant secondary metabolites and programmed cell death etc. were involved in the response to Foc infection. Notably, the potential role of lipid signaling in banana defense against Foc are not reported previously but rather unveiled for the first time in this study. The current study represents the most extensive analysis of the protein profile of 'Brazilian' in response to Foc inoculation and includes for the first time the results from comparison quantitative proteomics analysis between plants inoculated with a pathogenic strain Foc4 and a nonpathogenic strain Foc1 of 'Brazilian', which will lay the foundation for an in-depth understanding of the interaction between bananas and Foc at the proteome level.
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Analysis of potential strategies for cadmium stress tolerance revealed by transcriptome analysis of upland cotton. Sci Rep 2019; 9:86. [PMID: 30643161 PMCID: PMC6331580 DOI: 10.1038/s41598-018-36228-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 11/19/2018] [Indexed: 12/17/2022] Open
Abstract
In recent years, heavy metal pollution has become a more serious global problem, and all countries are actively engaged in finding methods to remediate heavy metal-contaminated soil. We conducted transcriptome sequencing of the roots of cotton grown under three different cadmium concentrations, and analysed the potential strategies for coping with cadmium stress. Through Gene Ontology analysis, we found that most of the genes differentially regulated under cadmium stress were associated with catalytic activity and binding action, especially metal iron binding, and specific metabolic and cellular processes. The genes responsive to cadmium stress were mainly related to membrane and response to stimulus. The KEGG pathways enriched differentially expressed genes were associated with secondary metabolite production, Starch and sucrose metabolism, flavonoid biosynthesis, phenylalanina metalism and biosynthesis, in order to improve the activity of antioxidant system, repair systems and transport system and reduction of cadmium toxicity. There are three main mechanisms by which cotton responds to cadmium stress: thickening of physical barriers, oxidation resistance and detoxification complexation. Meanwhile, identified a potential cotton-specific stress response pathway involving brassinolide, and ethylene signaling pathways. Further investigation is needed to define the specific molecular mechanisms underlying cotton tolerance to cadmium stress. In this study potential coping strategies of cotton root under cadmium stress were revealed. Our findings can guide the selection of cotton breeds that absorb high levels of cadmium.
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Ipomoea pes-caprae IpASR Improves Salinity and Drought Tolerance in Transgenic Escherichia coli and Arabidopsis. Int J Mol Sci 2018; 19:ijms19082252. [PMID: 30071625 PMCID: PMC6121548 DOI: 10.3390/ijms19082252] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 07/26/2018] [Accepted: 07/30/2018] [Indexed: 01/03/2023] Open
Abstract
Ipomoea pes-caprae L. is an extremophile halophyte with strong adaptability to seawater and drought. It is widely used in the ecological restoration of coastal areas or degraded islands in tropical and subtropical regions. In this study, a new abscisic acid, stressandripening (ASR) gene, IpASR, was reported, and is mainly associated with biological functions involved in salt and drought tolerance. Sequence analysis of IpASR showed that this protein contains an ABA/WDS (abscisic acid/water deficit stress) domain, which is a common feature of all plant ASR members. Overexpression of IpASR improved Escherichia coli growth performance compared with the control under abiotic stress treatment. The transgenic overexpressing IpASR Arabidopsis showed higher tolerance to salt and drought stress than the wild type and lower accumulation of hydrogen peroxide (H2O2) and superoxide (O2−) accompanied by increased antioxidant enzyme activity in vivo. IpASR exhibits transcription factor’s activity. Therefore, the overexpression of IpASR in Arabidopsis is supposed to influence the expression of some genes involved in anti-oxidative and abiotic stresses. The results indicate that IpASR is involved in the plant response to salt and drought and probably acts as a reactive oxygen species scavenger or transcription factor, and therefore influences physiological processes associated with various abiotic stresses in plants.
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Shankar A, Fernandes JL, Kaur K, Sharma M, Kundu S, Pandey GK. Rice phytoglobins regulate responses under low mineral nutrients and abiotic stresses in Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2018; 41:215-230. [PMID: 29044557 DOI: 10.1111/pce.13081] [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: 12/22/2016] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 06/07/2023]
Abstract
Just like animals, plants also contain haemoglobins (known as phytoglobins in plants). Plant phytoglobins (Pgbs) have been categorized into 6 different classes, namely, Phytogb0 (Pgb0), Phytogb1 (Pgb1), Phytogb2 (Pgb2), SymPhytogb (sPgb), Leghaemoglobin (Lb), and Phytogb3 (Pgb3). Among the 6 Phytogbs, sPgb and Lb have been functionally characterized, whereas understanding of the roles of other Pgbs is still evolving. In our present study, we have explored the function of 2 rice Pgbs (OsPgb1.1 and OsPgb1.2). OsPgb1.1, OsPgb1.2, OsPgb1.3, and OsPgb1.4 displayed increased level of transcript upon salt, drought, cold, and ABA treatment. The overexpression (OX) lines of OsPgb1.2 in Arabidopsis showed a tolerant phenotype in terms of better root growth in low potassium (K+ ) conditions. The expression of the known K+ gene markers such as LOX2, HAK5, and CAX3 was much higher in the OsPgb1.2 OX as compared to wild type. Furthermore, the OsPgb1.2 OX lines showed a decrease in reactive oxygen species (ROS) production and conversely an increase in the K+ content, both in root and shoot, as compared to wild type in K+ limiting condition. Our results indicated the potential involvement of OsPgb1.2 in signalling networks triggered by the nutrient deficiency stresses.
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Affiliation(s)
- Alka Shankar
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Joel Lars Fernandes
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Kanwaljeet Kaur
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Manisha Sharma
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
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10
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Zhang H, Zheng J, Su H, Xia K, Jian S, Zhang M. Molecular Cloning and Functional Characterization of the Dehydrin ( IpDHN) Gene From Ipomoea pes-caprae. FRONTIERS IN PLANT SCIENCE 2018; 9:1454. [PMID: 30364314 PMCID: PMC6193111 DOI: 10.3389/fpls.2018.01454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/12/2018] [Indexed: 05/02/2023]
Abstract
Dehydrin (DHN) genes can be rapidly induced to offset water deficit stresses in plants. Here, we reported on a dehydrin gene (IpDHN) related to salt tolerance isolated from Ipomoea pes-caprae L. (Convolvulaceae). The IpDHN protein shares a relatively high homology with Arabidopsis dehydrin ERD14 (At1g76180). IpDHN was shown to have a cytoplasmic localization pattern. Quantitative RT-PCR analyses indicated that IpDHN was differentially expressed in most organs of I. pes-caprae plants, and its expression level increased after salt, osmotic stress, oxidative stress, cold stress and ABA treatments. Analysis of the 974-bp promoter of IpDHN identified distinct cis-acting regulatory elements, including an MYB binding site (MBS), ABRE (ABA responding)-elements, Skn-1 motif, and TC-rich repeats. The induced expression of IpDHN in Escherichia coli indicated that IpDHN might be involved in salt, drought, osmotic, and oxidative stresses. We also generated transgenic Arabidopsis lines that over-expressed IpDHN. The transgenic Arabidopsis plants showed a significant enhancement in tolerance to salt/drought stresses, as well as less accumulation of hydrogen peroxide (H2O2) and the superoxide radical (O2 -), accompanied by increasing activity of the antioxidant enzyme system in vivo. Under osmotic stresses, the overexpression of IpDHN in Arabidopsis can elevate the expression of ROS-related and stress-responsive genes and can improve the ROS-scavenging ability. Our results indicated that IpDHN is involved in cellular responses to salt and drought through a series of pleiotropic effects that are likely involved in ROS scavenging and therefore influence the physiological processes of microorganisms and plants exposed to many abiotic stresses.
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Affiliation(s)
- Hui Zhang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jiexuan Zheng
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Huaxiang Su
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kuaifei Xia
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Shuguang Jian
- Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Mei Zhang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- *Correspondence: Mei Zhang,
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Singh N, Bhatla SC. Signaling through reactive oxygen and nitrogen species is differentially modulated in sunflower seedling root and cotyledon in response to various nitric oxide donors and scavengers<sup/>. PLANT SIGNALING & BEHAVIOR 2017; 12:e1365214. [PMID: 28862537 PMCID: PMC5640198 DOI: 10.1080/15592324.2017.1365214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 08/04/2017] [Indexed: 05/04/2023]
Abstract
Sodium nitroprusside (SNP), diethylenetriamine NONOate (DETA), S-nitroso-n-acetyl-D,L- penicillamine (SNAP), and 4-(p-methoxyphenyl)-1,3,2- Oxathiazolylium-5-olate (CAY) exhibit differential NO releasing ability in aqueous solution and hemoglobin is a more efficient NO quencher than cPTIO in solution. DETA releases 16% more NO compared with SNP in solution. Various NO donors (SNP, DETA, SNAP, and CAY) also bring about a differential but concentration-dependent increase in endogenous NO in seedling cotyledons and roots. Two-day old, dark-grown seedling roots exhibit 95%, 77%, 59% and 45% increase in NO content in presence of each of 500 µM of DETA, SNAP, CAY and SNP, respectively, relative to control. NO accumulation in the tissue system as a response to NO donors is reflected in terms of corresponding peroxynitrite accumulation. Release of cyanide and free iron as byproducts of SNP dissociation in solution limits its usefulness as an NO donor. SNP leads to profuse ROS generation in sunflower seedling roots. Light is not a pre-requisite for NO generation from SNP. Present work also demonstrates the usefulness of hemoglobin over cPTIO as NO scavenger. Hemoglobin brings about increasing NO quenching with its increasing concentration from 2.5 to 10 µM. Greater sensitivity of the root system to the NO donor/scavenger treatments is evident, it being in direct contact with the molecules in the incubation/ growth medium. This differential effect does not seem to be significantly transmitted to the cotyledons (long-distance signaling).
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Affiliation(s)
- Neha Singh
- Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi, India
| | - Satish C. Bhatla
- Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi, India
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12
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Abstract
Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (
Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the
nshb genes, consisting of
hb1,
hb2,
hb3,
hb4 and
hb5, and a single copy of the
thb gene exist in
Oryza sativa var. indica and
O.
sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O
2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O
2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O
2-transport, O
2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice
nshb and
thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice
nshbs and
thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the
cis-elements and
trans-acting factors that regulate the expression of rice
hb genes, and the partial understanding of the evolution of rice Hbs.
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Affiliation(s)
- Raúl Arredondo-Peter
- Laboratorio de Biofísica y Biología Molecular, Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, 62210, Mexico
| | - Jose F Moran
- Instituto de Agrobiotecnología, IdAB-CSIC-Universidad Pública de Navarra-Gobierno de Navarra, Navarre, E-31192, Spain
| | - Gautam Sarath
- Grain, Forage and Bioenergy Research Unit, USDA-ARS, University of Nebraska-Lincoln, Lincoln, NE, 68583-0937, USA
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13
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Shi H, Chen Y, Qian Y, Chan Z. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation. FRONTIERS IN PLANT SCIENCE 2015; 6:893. [PMID: 26539205 PMCID: PMC4611175 DOI: 10.3389/fpls.2015.00893] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/08/2015] [Indexed: 05/15/2023]
Abstract
As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.
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Affiliation(s)
- Haitao Shi
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan UniversityHaikou, China
- *Correspondence: Haitao Shi, ; Zhulong Chan,
| | - Yinhua Chen
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan UniversityHaikou, China
| | - Yongqiang Qian
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of ForestryBeijing, China
| | - Zhulong Chan
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- *Correspondence: Haitao Shi, ; Zhulong Chan,
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14
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Huseynova IM, Sultanova NF, Aliyev JA. Histochemical visualization of ROS and antioxidant response to viral infections of vegetable crops grown in Azerbaijan. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:26-35. [PMID: 24661407 DOI: 10.1016/j.plaphy.2014.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 03/01/2014] [Indexed: 06/03/2023]
Abstract
Extremes of environmental conditions, such as biotic stresses, strongly affect plant growth and development and may adversely affect photosynthetic process. Virus infection is especially problematic in crops, because unlike other diseases, its impact cannot be reduced by phytosanitary treatments. The vegetable crops (Solanum lycopеrsicum L, Cucurbita melo L., Cucumis sativus L., Piper longum L., Solánum melongéna L., Vicia faba L.) showing virus-like symptoms were collected from fields located in the main crop production provinces of Azerbaijan. Infection of the plants were confirmed by Enzyme-linked immunosorbent assay using commercial kits for the following viruses: Tomato yellow leaf curl virus, Tomato mosaic virus, Tomato chlorosis virus, Melon necrotic spot virus and Cucumber mosaic virus, Bean common mosaic virus and Bean yellow mosaic virus. Generation sites of superoxide and hydrogen peroxide radicals and activities of enzymes involved in the detoxification of reactive oxygen species (catalase, glutathione reductase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase) were examined in uninfected leaves and in leaves infected with viruses. High accumulation of superoxide and hydrogen peroxide radicals was visualized in infected leaves as a purple discoloration of nitro blue tetrazolium and 3,3'-diaminobenzidine tetrahydrochloride. It was found that the activities of APX and CAT significantly increased in all infected samples compared with non-infected ones. Dynamics of GR and Cu/Zn-SOD activities differed from those of CAT and APX, and slightly increased in stressed samples. Electrophoretic mobility profiling of APX, GPX and CAT isoenzymes was also studied.
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Affiliation(s)
- Irada M Huseynova
- Department of Fundamental Problems of Biological Productivity, Institute of Botany, Azerbaijan National Academy of Sciences, 40 Badamdar Highway, Baku AZ1073, Azerbaijan
| | - Nargiz F Sultanova
- Department of Fundamental Problems of Biological Productivity, Institute of Botany, Azerbaijan National Academy of Sciences, 40 Badamdar Highway, Baku AZ1073, Azerbaijan
| | - Jalal A Aliyev
- Department of Fundamental Problems of Biological Productivity, Institute of Botany, Azerbaijan National Academy of Sciences, 40 Badamdar Highway, Baku AZ1073, Azerbaijan.
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15
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Shi H, Wang X, Ye T, Chen F, Deng J, Yang P, Zhang Y, Chan Z. The Cysteine2/Histidine2-Type Transcription Factor ZINC FINGER OF ARABIDOPSIS THALIANA6 Modulates Biotic and Abiotic Stress Responses by Activating Salicylic Acid-Related Genes and C-REPEAT-BINDING FACTOR Genes in Arabidopsis. PLANT PHYSIOLOGY 2014; 165:1367-1379. [PMID: 24834923 PMCID: PMC4081343 DOI: 10.1104/pp.114.242404] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/15/2014] [Indexed: 05/18/2023]
Abstract
The cysteine2/histidine2-type zinc finger proteins are a large family of transcription regulators, and some of them play essential roles in plant responses to biotic and abiotic stress. In this study, we found that expression of C2H2-type ZINC FINGER OF ARABIDOPSIS THALIANA6 (AtZAT6) was transcriptionally induced by salt, dehydration, cold stress treatments, and pathogen infection, and AtZAT6 was predominantly located in the nucleus. AtZAT6-overexpressing plants exhibited improved resistance to pathogen infection, salt, drought, and freezing stresses, while AtZAT6 knockdown plants showed decreased stress resistance. AtZAT6 positively modulates expression levels of stress-related genes by directly binding to the TACAAT motifs in the promoter region of pathogen-related genes (ENHANCED DISEASE SUSCEPTIBILITY1, PHYTOALEXIN DEFICIENT4, PATHOGENESIS-RELATED GENE1 [PR1], PR2, and PR5) and abiotic stress-responsive genes (C-REPEAT-BINDING FACTOR1 [CBF1], CBF2, and CBF3). Moreover, overexpression of AtZAT6 exhibited pleiotrophic phenotypes with curly leaves and small-sized plant at vegetative stage and reduced size of floral organs and siliques at the reproductive stage. Modulation of AtZAT6 also positively regulates the accumulation of salicylic acid and reactive oxygen species (hydrogen peroxide and superoxide radical). Taken together, our findings indicated that AtZAT6 plays important roles in plant development and positively modulates biotic and abiotic stress resistance by activating the expression levels of salicylic acid-related genes and CBF genes.
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Affiliation(s)
- Haitao Shi
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Xin Wang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Tiantian Ye
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Fangfang Chen
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Jiao Deng
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Pingfang Yang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Yansheng Zhang
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
| | - Zhulong Chan
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China (H.S., X.W., T.Y., F.C., J.D., P.Y., Y.Z., Z.C.); andUniversity of Chinese Academy of Sciences, Beijing 100039, China (X.W., T.Y., J.D.)
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16
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Reeder BJ, Hough MA. The structure of a class 3 nonsymbiotic plant haemoglobin from Arabidopsis thaliana reveals a novel N-terminal helical extension. ACTA ACUST UNITED AC 2014; 70:1411-8. [PMID: 24816109 DOI: 10.1107/s1399004714004878] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/03/2014] [Indexed: 12/25/2022]
Abstract
Plant nonsymbiotic haemoglobins fall into three classes, each with distinct properties but all with largely unresolved physiological functions. Here, the first crystal structure of a class 3 nonsymbiotic plant haemoglobin, that from Arabidopsis thaliana, is reported to 1.77 Å resolution. The protein forms a homodimer, with each monomer containing a two-over-two α-helical domain similar to that observed in bacterial truncated haemoglobins. A novel N-terminal extension comprising two α-helices plays a major role in the dimer interface, which occupies the periphery of the dimer-dimer face, surrounding an open central cavity. The haem pocket contains a proximal histidine ligand and an open sixth iron-coordination site with potential for a ligand, in this structure hydroxide, to form hydrogen bonds to a tyrosine or a tryptophan residue. The haem pocket appears to be unusually open to the external environment, with another cavity spanning the entrance of the two haem pockets. The final 23 residues of the C-terminal domain are disordered in the structure; however, these domains in the functional dimer are adjacent and include the only two cysteine residues in the protein sequence. It is likely that these residues form disulfide bonds in vitro and it is conceivable that this C-terminal region may act in a putative complex with a partner molecule in vivo.
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Affiliation(s)
- Brandon J Reeder
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, England
| | - Michael A Hough
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, England
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17
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Perturbation of auxin homeostasis by overexpression of wild-type IAA15 results in impaired stem cell differentiation and gravitropism in roots. PLoS One 2013; 8:e58103. [PMID: 23472140 PMCID: PMC3589423 DOI: 10.1371/journal.pone.0058103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 02/03/2013] [Indexed: 12/23/2022] Open
Abstract
Aux/IAAs interact with auxin response factors (ARFs) to repress their transcriptional activity in the auxin signaling pathway. Previous studies have focused on gain-of-function mutations of domain II and little is known about whether the expression level of wild-type Aux/IAAs can modulate auxin homeostasis. Here we examined the perturbation of auxin homeostasis by ectopic expression of wild-type IAA15. Root gravitropism and stem cell differentiation were also analyzed. The transgenic lines were less sensitive to exogenous auxin and exhibited low-auxin phenotypes including failures in gravity response and defects in stem cell differentiation. Overexpression lines also showed an increase in auxin concentration and reduced polar auxin transport. These results demonstrate that an alteration in the expression of wild-type IAA15 can disrupt auxin homeostasis.
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18
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Matilla AJ, Rodríguez-Gacio MDC. Non-symbiotic hemoglobins in the life of seeds. PHYTOCHEMISTRY 2013; 87:7-15. [PMID: 23286879 DOI: 10.1016/j.phytochem.2012.11.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 11/13/2012] [Accepted: 11/21/2012] [Indexed: 06/01/2023]
Abstract
Non-symbiotic hemoglobins (nsHbs), ancestors of symbiotic-Hbs, are hexacoordinated dimeric proteins, for which the crystal structure is well described. According to the extent of hexacoordination, nsHbs are classified as belonging to class-1 (nsHbs1) or class-2 (nsHbs2). The nsHbs1 show weak hexacoordination, moderate rates of O(2)-binding, very small rates of O(2) dissociation, and a remarkably high affinity for O(2), all suggesting a function involving O(2) scavenging. In contrast, the nsHbs2 exhibit strong hexacoordination, low rates of O(2)-binding and moderately low O(2) dissociation and affinity, suggesting a sensing role for sustained low (μM) levels of O(2). The existence of spatial and specific expression of nsHbs1 suggests that nsHbs play tissue-specific rather than housekeeping functions. The permeation of O(2) into seeds is usually prevented during the desiccation phase and early imbibition, generating an internal hypoxic environment that leads to ATP limitation. During evolution, the seed has acquired mechanisms to prevent or reduce this hypoxic stress. The nsHbs1/NO cycle appear to be involved in modulating the redox state in the seed and in maintaining an active metabolism. Under O(2) deficit, NADH and NO are synthesized in the seed and nsHbs1 scavenges O(2), which is used to transform NO into NO(3)(-) with concomitant formation of Fe(3+)-nsHbs1. Expression of nsHbs1 is not detectable in dry viable seeds. However, in the seeds cross-talk occurs between nsHbs1 and NO during germination. This review considers the current status of our knowledge of seed nsHbs and considers key issues of further work to better understand their role in seed physiology.
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Affiliation(s)
- Angel J Matilla
- Department of Plant Physiology, University of Santiago de Compostela, 15782 Santiago de Compostela, A Coruña, Spain.
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19
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Mukhi N, Dhindwal S, Uppal S, Kumar P, Kaur J, Kundu S. X-ray crystallographic structural characteristics of Arabidopsis hemoglobin I and their functional implications. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1944-56. [PMID: 23485912 DOI: 10.1016/j.bbapap.2013.02.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/16/2013] [Accepted: 02/19/2013] [Indexed: 11/24/2022]
Abstract
Genome of the model dicot flowering plant, Arabidopsis thaliana, a popular tool for understanding molecular biology of plant physiology, encodes all three classes of plant hemoglobins that differ in their sequence, ligand binding and spectral properties. As such these globins are of considerable attention. Crystal structures of few members of plant class I nonsymbiotic hemoglobin have been described earlier. Here we report the crystal structure of Arabidopsis class I hemoglobin (AHb1) to 2.2Ǻ and compare its key features with the structures of similar nonsymbiotic hemoglobin from other species. Crystal structure of AHb1 is homologous to the related members with similar globin fold and heme pocket architecture. The structure is homodimeric in the asymmetric unit with both distal and proximal histidines coordinating to the heme iron atom. Residues lining the dimeric interface are also conserved in AHb1 with the exception of additional electrostatic interaction between H112 and E113 of each subunit and that involving Y119 through two water molecules. In addition, differences in heme pocket non-covalent interactions, a novel Ser residue at F7 position, Xe binding site variability, internal cavity topology differences, CD loop conformation and stability and other such properties might explain kinetic variability in AHb1. Detailed cavity analysis of AHb1 showed the presence of a novel long tunnel connecting the distal pockets of both the monomers. Presence of such tunnel, along with conformational heterogeneity observed in the two chains, might suggest cooperative ligand binding and support its role in NO scavenging. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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Affiliation(s)
- Nitika Mukhi
- Department of Genetics, University of Delhi South Campus, New Delhi, India
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20
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Shi YC, Fu YP, Liu WQ. NADPH oxidase in plasma membrane is involved in stomatal closure induced by dehydroascorbate. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 51:26-30. [PMID: 22153236 DOI: 10.1016/j.plaphy.2011.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/23/2011] [Indexed: 05/31/2023]
Abstract
Stoma is surrounded by two guard cells, and regulates the contents of water and CO(2) in plant, its opening and closing was affected by various factors. Recently, dehydroascorbate was found to induce stomata closure and H(2)O(2) generation. However, the mechanism of H(2)O(2) production is not clear. DPI and imidazole inhibit the flavoprotein and the b(-type) cytochrome components of the NADPH oxidase complex. Application of DPI or imidazole with DHA together impaired stomatal closure and elevation of H(2)DCF-DA fluorescent intensity induced by DHA in guard cells. CoCl(2) and PD98059, as the blocker of calcium channel and the inhibitor of MAPKKK, both impaired stomatal closure induced by DHA. The results suggested that DHA-induced H(2)O(2) generation via activation of NADPH oxidase, and thus resulting in stomatal closure. Moreover, Ca(2+) channel and MAPK cascades were involved in stomatal closure induced by DHA.
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Affiliation(s)
- Yong Chun Shi
- National Key Laboratory of Tobacco Planting, Physiology and Biochemistry, 450002 Zhengzhou, China
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21
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Violante-Mota F, Tellechea E, Moran JF, Sarath G, Arredondo-Peter R. Analysis of peroxidase activity of rice (Oryza sativa) recombinant hemoglobin 1: implications for in vivo function of hexacoordinate non-symbiotic hemoglobins in plants. PHYTOCHEMISTRY 2010; 71:21-26. [PMID: 19833360 DOI: 10.1016/j.phytochem.2009.09.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 08/07/2009] [Accepted: 09/15/2009] [Indexed: 05/28/2023]
Abstract
In plants, it has been proposed that hexacoordinate (class 1) non-symbiotic Hbs (nsHb-1) function in vivo as peroxidases. However, little is known about peroxidase activity of nsHb-1. We evaluated the peroxidase activity of rice recombinant Hb1 (a nsHb-1) by using the guaiacol/H2O2 system at pH 6.0 and compared it to that from horseradish peroxidase (HRP). Results showed that the affinity of rice Hb1 for H2O2 was 86-times lower than that of HRP (K(m)=23.3 and 0.27 mM, respectively) and that the catalytic efficiency of rice Hb1 for the oxidation of guaiacol using H2O2 as electron donor was 2838-times lower than that of HRP (k(cat)/K(m)=15.8 and 44,833 mM(-1) min(-1), respectively). Also, results from this work showed that rice Hb1 is not chemically modified and binds CO after incubation with high H2O2 concentration, and that it poorly protects recombinant Escherichia coli from H2O2 stress. These observations indicate that rice Hb1 inefficiently scavenges H2O2 as compared to a typical plant peroxidase, thus indicating that non-symbiotic Hbs are unlikely to function as peroxidases in planta.
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Affiliation(s)
- Fernando Violante-Mota
- Laboratorio de Biofísica y Biología Molecular, Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62210 Cuernavaca, Morelos, México
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22
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Abstract
The mechanisms involved in sensing oxidative signalling molecules, such as H2O2, in plant and animal cells are not completely understood. In the present study, we tested the postulate that oxidation of Met (methionine) to MetSO (Met sulfoxide) can couple oxidative signals to changes in protein phosphorylation. We demonstrate that when a Met residue functions as a hydrophobic recognition element within a phosphorylation motif, its oxidation can strongly inhibit peptide phosphorylation in vitro. This is shown to occur with recombinant soybean CDPKs (calcium-dependent protein kinases) and human AMPK (AMP-dependent protein kinase). To determine whether this effect may occur in vivo, we monitored the phosphorylation status of Arabidopsis leaf NR (nitrate reductase) on Ser534 using modification-specific antibodies. NR was a candidate protein for this mechanism because Met538, located at the P+4 position, serves as a hydrophobic recognition element for phosphorylation of Ser534 and its oxidation substantially inhibits phosphorylation of Ser534in vitro. Two lines of evidence suggest that Met oxidation may inhibit phosphorylation of NR-Ser534in vivo. First, phosphorylation of NR at the Ser534 site was sensitive to exogenous H2O2 and secondly, phosphorylation in normal darkened leaves was increased by overexpression of the cytosolic MetSO-repair enzyme PMSRA3 (peptide MetSO reductase A3). These results are consistent with the notion that oxidation of surface-exposed Met residues in kinase substrate proteins, such as NR, can inhibit the phosphorylation of nearby sites and thereby couple oxidative signals to changes in protein phosphorylation.
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23
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Jiang Y, Deyholos MK. Functional characterization of Arabidopsis NaCl-inducible WRKY25 and WRKY33 transcription factors in abiotic stresses. PLANT MOLECULAR BIOLOGY 2009; 69:91-105. [PMID: 18839316 DOI: 10.1007/s11103-008-9408-3] [Citation(s) in RCA: 361] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 09/22/2008] [Indexed: 05/17/2023]
Abstract
Previous microarray analyses of Arabidopsis roots identified two closely related WRKY transcription factors (WRKY25 and WRKY33) among the transcripts that increased in abundance following treatment with NaCl. Here, we report further characterization of these genes, which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling. Transcripts of both genes were detected in roots and leaves, while specific patterns of enrichment were observed in stems and floral buds for WRKY25 and WRKY33, respectively. We also identified upstream intergenic regions from each gene that were sufficient to confer stress-inducible expression on a reporter gene. However, the stress sensitivity of wrky25 null mutants did not differ from wild-type under any assay condition, while wrky33 null mutants and wrky25wrky33 double mutants showed only a moderate increase in NaCl-sensitivity, suggesting functional redundancy with other transcription factors. Nevertheless, overexpression of WRKY25 or WRKY33 was sufficient to increase Arabidopsis NaCl tolerance, while increasing sensitivity to ABA. Through microarray analyses of relevant genotypes, we identified 31 and 208 potential downstream targets of WRKY25 and WRKY33, respectively, most of which contained a W-box in their upstream regions.
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Affiliation(s)
- Yuanqing Jiang
- Department of Biological Sciences, University of Alberta, Edmonton, Canada T6G 2E9
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Hoy JA, Hargrove MS. The structure and function of plant hemoglobins. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:371-9. [PMID: 18321722 DOI: 10.1016/j.plaphy.2007.12.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Indexed: 05/24/2023]
Abstract
Plants, like humans, contain hemoglobin. Three distinct types of hemoglobin exist in plants: symbiotic, non-symbiotic, and truncated hemoglobins. Crystal structures and other structural and biophysical techniques have revealed important knowledge about ligand binding and conformational stabilization in all three types. In symbiotic hemoglobins (leghemoglobins), ligand binding regulatory mechanisms have been shown to differ dramatically from myoglobin and red blood cell hemoglobin. In the non-symbiotic hemoglobins found in all plants, crystal structures and vibrational spectroscopy have revealed the nature of the structural transition between the hexacoordinate and ligand-bound states. In truncated hemoglobins, the abbreviated globin is porous, providing tunnels that may assist in ligand binding, and the bound ligand is stabilized by more than one distal pocket residue. Research has implicated these plant hemoglobins in a number of possible functions differing among hemoglobin types, and possibly between plant species.
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Affiliation(s)
- Julie A Hoy
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50014, USA
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Gao X, Ren F, Lu YT. The Arabidopsis Mutant stg1 Identifies a Function for TBP-Associated Factor 10 in Plant Osmotic Stress Adaptation. ACTA ACUST UNITED AC 2006; 47:1285-94. [PMID: 16945932 DOI: 10.1093/pcp/pcj099] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Plant salt tolerance is a complex trait involving many genes. To identify new salt tolerance determinants during seed germination, we have screened a population of chemically inducible activation-tagged Arabidopsis mutants. A mutant, designated stg1 (salt tolerance during germination 1), was obtained. The stg1 mutant is less sensitive than the wild type to NaCl and osmotic stress inhibition of germination in the presence of the inducer. Germination assays on media containing various salts upon inducer application indicate that the stg1 mutation enhances tolerance to Na(+) and K(+). Under salt stress, stg1 maintains a higher K(+)/Na(+) ratio and accumulates less proline than the wild-type control, suggesting that its salt tolerance mechanisms are mainly involved in the regulation of ion balance. STG1 encodes a putative Arabidopsis TATA box-binding protein (TBP)-associated factor 10 (atTAF10), which constitutes the transcriptional factor IID (TFIID) complex. Overexpression of atTAF10 under the control of the 35S promoter in Arabidopsis improves seed tolerance to salt stress during germination and the knocked-down mutant is more sensitive to salt stress, indicating the transcription initiation factor as a physiological target of salt toxicity in plants.
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Affiliation(s)
- Xiang Gao
- Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
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Igamberdiev AU, Stoimenova M, Seregélyes C, Hill RD. Class-1 hemoglobin and antioxidant metabolism in alfalfa roots. PLANTA 2006; 223:1041-6. [PMID: 16284778 DOI: 10.1007/s00425-005-0145-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Accepted: 09/28/2005] [Indexed: 05/05/2023]
Abstract
In the course of nitric oxide (NO) scavenging, hemoglobin (Hb) turnover is linked to antioxidant metabolism and affects the cellular redox level. The influence of Hb presence on the ascorbate-glutathione cycle enzymes and the levels of H(2)O(2) and ascorbate was investigated in alfalfa root cultures transformed to over-express (Hb+) or down-regulate (Hb-) class-1 Hb. Hb+ lines had substantially increased ascorbate levels as well as elevated monodehydroascorbate reductase and ascorbate peroxidase activities. Hb- lines showed significant increases in dehydroascorbate reductase and glutathione reductase activities. The observed changes in ascorbate and ascorbate-glutathione cycle enzymes were pronounced both at high (40 kPa) and low (3 kPa) O(2) pressures. Hb- lines had significantly reduced levels of the NO- and H(2)O(2)-sensitive enzyme, aconitase, as compared to Hb+ lines. This reduced activity was likely due the higher levels of NO in Hb- lines, as treatment of plant extracts with the NO-donor DEANO also affected aconitase activity. The H(2)O(2) levels were not significantly different amongst the lines and showed no variation with change in oxygen partial pressure. In conclusion, the expression of class-1 Hb improves the antioxidant status through increased ascorbate levels and increased activity of enzymes involved in H(2)O(2) removal.
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Affiliation(s)
- Abir U Igamberdiev
- Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
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Perazzolli M, Romero-Puertas MC, Delledonne M. Modulation of nitric oxide bioactivity by plant haemoglobins. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:479-88. [PMID: 16377734 DOI: 10.1093/jxb/erj051] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Nitric oxide (NO) is a highly reactive signalling molecule that has numerous targets in plants. Both enzymatic and non-enzymatic synthesis of NO has been detected in several plant species, and NO functions have been characterized during diverse physiological processes such as plant growth, development, and resistance to biotic and abiotic stresses. This wide variety of effects reflects the basic signalling mechanisms that are utilized by virtually all mammalian and plant cells and suggests the necessity of detoxification mechanisms to control the level and functions of NO. During the last two years an increasing number of reports have implicated non-symbiotic haemoglobins as the key enzymatic system for NO scavenging in plants, indicating that the primordial function of haemoglobins may well be to protect against nitrosative stress and to modulate NO signalling functions. The biological relevance of plant haemoglobins during specific conditions of plant growth and stress, and the existence of further enzymatic and non-enzymatic NO scavenging systems, suggest the existence of precise NO modulation mechanisms in plants, as observed for different NO sources.
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Affiliation(s)
- Michele Perazzolli
- Università degli Studi di Verona. Dipartimento Scientifico e Tecnologico. Strada le Grazie, 15, I-37134 Verona, Italy
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