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Madhu, Sharma A, Kaur A, Singh K, Upadhyay SK. Modulation in gene expression and enzyme activity suggested the roles of monodehydroascorbate reductase in development and stress response in bread wheat. Plant Sci 2024; 338:111902. [PMID: 37879539 DOI: 10.1016/j.plantsci.2023.111902] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/23/2023] [Accepted: 10/17/2023] [Indexed: 10/27/2023]
Abstract
Monodehydroascorbate reductase (MDHAR) is a crucial enzymatic antioxidant of the ascorbate-glutathione pathway involved in reactive oxygen species scavenging. Herein, we identified 15 TaMDHAR genes in bread wheat. Phylogenetic analysis revealed their clustering into three groups, which are also related to the subcellular localization in the peroxisome matrix, peroxisome membrane, and chloroplast. Each TaMDHAR protein consisted of two conserved domains; Pyr_redox and Pyr_redox_2 of the pyridine nucleotide disulfide oxidoreductase family. The occurrence of diverse groups of cis-regulatory elements in the promoter region and their interaction with numerous transcription factors suggest assorted functions of TaMDHARs in growth and development and in light, phytohormones, and stress responses. Expression analysis in various tissues further revealed their importance in vegetative and reproductive development. In addition, the differential gene expression and enhanced enzyme activity during drought, heat, and salt treatments exposed their role in abiotic stress response. Interaction of MDHARs with various antioxidant enzymes and biochemicals related to the ascorbate-glutathione cycle exposed their synchronized functioning. Interaction with auxin indicated the probability of cross-talk between antioxidants and auxin signaling. The miR168a, miR169, miR172 and others interaction with various TaMDHARs further directed their association with developmental processes and stress responses. The current study provides extensive information about the importance of TaMDHARs, moreover, the precise role of each gene needs to be established in future studies.
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Affiliation(s)
- Madhu
- Department of Botany, Panjab University, Chandigarh 160014, India
| | - Alok Sharma
- Department of Botany, Panjab University, Chandigarh 160014, India
| | - Amandeep Kaur
- Department of Botany, Panjab University, Chandigarh 160014, India
| | - Kashmir Singh
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
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2
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Zerpa-Catanho D, Clough SJ, Ming R. Characterization and analysis of the promoter region of monodehydroascorbate reductase 4 (CpMDAR4) in papaya. Plant Reprod 2022; 35:233-264. [PMID: 35920937 DOI: 10.1007/s00497-022-00447-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Differential spatial and temporal expression patterns due to regulatory cis-elements and two different isoforms are detected among CpMDAR4 alleles in papaya. The aim of this research was to study the effects of cis-element differences between the X, Y and Yh alleles on the expression of CpMDAR4, a potential candidate gene for sex differentiation in papaya, using a transcriptional reporter system in a model species Arabidopsis thaliana. Possible effects of a retrotransposon insertion in the Y and Yh alleles on the transcription and expression of CpMDAR4 alleles in papaya flowers were also examined. When comparing promoters and cis-regulatory elements among genes in the non-recombining region of the sex chromosomes, paired genes exhibited differences. Our results showed that differences in the promoter sequences of the CpMDAR4 alleles drove the expression of a reporter gene to different flower tissues in Arabidopsis. β-glucuronidase staining analysis of T2 and T3 lines for constructs containing 5' deletions of native Y and Yh allele promoters showed the loss of specific expression of the reporter gene in the anthers, confirming the existence and location of cis-regulatory element POLLEN1LELAT52. The expression analysis of CpMDAR4 alleles in papaya flowers also showed that all alleles are actively expressed in different flower tissues, with the existence of a shorter truncated isoform, with unknown function, for the Y and Yh alleles due to an LTR-RT insertion in the Y and Yh chromosomes. The observed expression patterns in Arabidopsis thaliana flowers and the expression patterns of CpMDAR4 alleles in papaya flowers suggest that MDAR4 might have a role on development of reproductive organs in papaya, and that it constitutes an important candidate for sex differentiation.
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Affiliation(s)
| | - Steven J Clough
- Department of Crop Sciences, University of Illinois, Urbana, IL, 61801, USA
- United States Department of Agriculture, Agricultural Research Service, Urbana, IL, 61801, USA
| | - Ray Ming
- Department of Plant Biology, University of Illinois, Urbana, IL, 61801, USA.
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Wu LB, Feng Y, Zeibig F, Alam MS, Frei M. High Throughput Analyses of Ascorbate-turnover Enzyme Activities in Rice ( Oryza sativa L.) Seedlings. Bio Protoc 2021; 11:e4190. [PMID: 34761063 DOI: 10.21769/bioprotoc.4190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 11/02/2022] Open
Abstract
Ascorbate (Vitamin C) fulfills various functions in plant photosynthesis and abiotic stress tolerance. The four key enzymes involved in the ascorbate-turnover pathway are ascorbate peroxidase, ascorbate oxidase, monodehydroascorbate reductase, and dehydroascorbate reductase. Several reports have shown the pivotal roles of these enzymes in plant development and stress tolerance. Therefore, reliable and rapid assay protocols are required for researchers to investigate their enzymatic activities during plant development and stress responses. Previously published methods for analyzing these enzymatic activities rely on cuvette spectrophotometers, which can only handle one sample per test, leading to a prolonged investigation. In this protocol, we employed a 96-well microplate reader to analyze at least eight samples with two technical replicates simultaneously. We analyzed two rice (Oryza sativa L.) genotypes with distinct ascorbate oxidase and dehydroascorbate reductase activities to demonstrate the assay process, including plant growth, sample preparation, reaction setup, and data analysis. Our protocol provides a high throughput method for investigating ascorbate turnover-related enzymatic activities in plants.
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Affiliation(s)
- Lin-Bo Wu
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding, Justus Liebig University Giessen, Giessen, Germany
| | - Yanru Feng
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding, Justus Liebig University Giessen, Giessen, Germany
| | - Frederike Zeibig
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding, Justus Liebig University Giessen, Giessen, Germany
| | - Muhammad Shahedul Alam
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding, Justus Liebig University Giessen, Giessen, Germany
| | - Michael Frei
- Department of Agronomy and Crop Physiology, Institute for Agronomy and Plant Breeding, Justus Liebig University Giessen, Giessen, Germany
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Chen JR, Ueno H, Matsumura H, Urasaki N, Lee CY, Chen FC, Chin SW, Liu CC, Chiu CT, Tarora K, Li JY, Lee CY, Ku HM. Genomic characterization of a rare Carica papaya X chromosome mutant reveals a candidate monodehydroascorbate reductase 4 gene involved in all-hermaphrodite phenomenon. Mol Genet Genomics 2021; 296:1323-1335. [PMID: 34609588 DOI: 10.1007/s00438-021-01822-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 09/11/2021] [Indexed: 11/27/2022]
Abstract
Sex form is one of the most important characteristics in papaya cultivation in which hermaphrodite is the preferable form. Self-pollination of H*-TSS No.7, an inbred line derived from a rare X chromosome mutant SR*, produced all-hermaphrodite progeny. The recessive lethal allele controlling the all-hermaphrodite phenomenon was proposed to be the recessive Germination suppressor (gs) locus. This study employed next-generation sequencing technology and genome comparison to identify the candidate Gs gene. One specific gene, monodehydroascorbate reductase 4 (MDAR4) harboring a unique polymorphic 3 bp deletion in H*-TSS No.7 was identified. The function of MDAR4 is known to be involved in the hydrogen peroxide (H2O2) scavenging pathway and is associated with seed germination. Furthermore, MDAR4 showed higher expression in the imbibed seeds than that in the dry seeds indicating its potential role in the seed germination. Perhaps this is the very first report providing the evidences that MDAR4 is the candidate of Gs locus in H*-TSS No.7. In addition, Gs allele-specific markers were developed which would be facilitated for breeding all-hermaphrodite lines.
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Affiliation(s)
- Jen-Ren Chen
- Taiwan Seed Improvement and Propagation Station, No 6 Xingzhong St, Xinshe Dist, Taichung, 426, Taiwan
| | - Hiroki Ueno
- Vegetable and Floriculture Science, The National Agriculture and Food Research Organization, 360 Kusawa, Ano, Tsu, Mie, 514-2392, Japan
| | - Hideo Matsumura
- Gene Research Center, Shinshu University, Tokida 3-15-1, Ueda, Nagano, 386-8567, Japan
| | - Naoya Urasaki
- Okinawa Prefectural Agriculture Research Center, Itoman, Okinawa, 901-0336, Japan
| | - Chen-Yu Lee
- Department of Plant Industry, National Pingtung University of Science and Technology, No 1, Shuefu Rd, Neipu, Pingtung, 912, Taiwan
| | - Fure-Chyi Chen
- Department of Plant Industry, National Pingtung University of Science and Technology, No 1, Shuefu Rd, Neipu, Pingtung, 912, Taiwan
| | - Shih-Wen Chin
- Department of Plant Industry, National Pingtung University of Science and Technology, No 1, Shuefu Rd, Neipu, Pingtung, 912, Taiwan
| | - Chun-Chi Liu
- Institute of Genomics and Bioinformatics, National Chung Hsing University, No 145 Xingda Rd, South Dist, Taichung, 402, Taiwan
| | - Chan-Tai Chiu
- Taiwan Seed Improvement and Propagation Station, No 6 Xingzhong St, Xinshe Dist, Taichung, 426, Taiwan
| | - Kazuhiko Tarora
- Okinawa Prefectural Agriculture Research Center, Itoman, Okinawa, 901-0336, Japan
| | - Jing-Yi Li
- Dashu District, Known-You Seed Co. Ltd, No 114-6, Zhuliao Road, Kaohsiung, 840, Taiwan
| | - Chieh Ying Lee
- Dashu District, Known-You Seed Co. Ltd, No 114-6, Zhuliao Road, Kaohsiung, 840, Taiwan
| | - Hsin-Mei Ku
- Agronomy Department, National Chung Hsing University, No 145 Xingda Rd, South Dist, Taichung, 402, Taiwan.
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Maynard D, Kumar V, Sproï J, Dietz KJ. 12-Oxophytodienoic Acid Reductase 3 (OPR3) Functions as NADPH-Dependent α,β-Ketoalkene Reductase in Detoxification and Monodehydroascorbate Reductase in Redox Homeostasis. Plant Cell Physiol 2020; 61:584-595. [PMID: 31834385 DOI: 10.1093/pcp/pcz226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) 12-oxophytodienoic acid reductase isoform 3 (OPR3) is involved in the synthesis of jasmonic acid (JA) by reducing the α,β-unsaturated double bond of the cyclopentenone moiety in 12-oxophytodienoic acid (12-OPDA). Recent research revealed that JA synthesis is not strictly dependent on the peroxisomal OPR3. The ability of OPR3 to reduce trinitrotoluene suggests that the old yellow enzyme homolog OPR3 has additional functions. Here, we show that OPR3 catalyzes the reduction of a wide spectrum of electrophilic species that share a reactivity toward the major redox buffers glutathione (GSH) and ascorbate (ASC). Furthermore, we show that 12-OPDA reacts with ASC to form an ASC-12-OPDA adduct, but in addition OPR3 has the ability to regenerate ASC from monodehydroascorbate. The presented data characterize OPR3 as a bifunctional enzyme with NADPH-dependent α,β-ketoalkene double-bond reductase and monodehydroascorbate reductase activities (MDHAR). opr3 mutants showed a slightly less-reduced ASC pool in leaves in line with the MDHAR activity of OPR3 in vitro. These functions link redox homeostasis as mediated by ASC and GSH with OPR3 activity and metabolism of reactive electrophilic species.
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Affiliation(s)
- Daniel Maynard
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Universit�tsstr. 25, Bielefeld 33615, Germany
| | - Vijay Kumar
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Universit�tsstr. 25, Bielefeld 33615, Germany
| | - Jens Sproï
- Department of Chemistry, Industrial Organic Chemistry and Biotechnology, University of Bielefeld, Universit�tsstra�e 25, D-33615 Bielefeld, Germany
| | - Karl-Josef Dietz
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Universit�tsstr. 25, Bielefeld 33615, Germany
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Yeh HL, Lin TH, Chen CC, Cheng TX, Chang HY, Lee TM. Monodehydroascorbate Reductase Plays a Role in the Tolerance of Chlamydomonas reinhardtii to Photooxidative Stress. Plant Cell Physiol 2019; 60:2167-2179. [PMID: 31198969 DOI: 10.1093/pcp/pcz110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 05/21/2019] [Indexed: 05/26/2023]
Abstract
Monodehydroascorbate reductase (MDAR; EC 1.6.5.4) is one of the key enzymes in the conversion of oxidized ascorbate (AsA) back to reduced AsA in plants. This study investigated the role of MDAR in the tolerance of Chlamydomonas reinhardtii P.A. Dangeard to photooxidative stress by overexpression and downregulation of the CrMDAR1 gene. For overexpression of CrMDAR1 driven by a HSP70A:RBCS2 fusion promoter, the cells survived under very high-intensity light stress (VHL, 1,800 μmol�m-2�s-1), while the survival of CC-400 and vector only control (vector without insert) cells decreased for 1.5 h under VHL stress. VHL increased lipid peroxidation of CC-400 but did not alter lipid peroxidation in CrMDAR1 overexpression lines. Additionally, overexpression of CrMDAR1 showed an increase in viability, CrMDAR1 transcript abundance, enzyme activity and the AsA: dehydroascorbate (DHA) ratio. Next, MDAR was downregulated to examine the essential role of MDAR under high light condition (HL, 1,400 μmol�m-2�s-1). The CrMDAR1 knockdown amiRNA line exhibited a low MDAR transcript abundance and enzyme activity and the survival decreased under HL conditions. Additionally, HL illumination decreased CrMDAR1 transcript abundance, enzyme activity and AsA:DHA ratio of CrMDAR1-downregulation amiRNA lines. Methyl viologen (an O2�- generator), H2O2 and NaCl treatment could induce an increase in CrMDAR1 transcript level. It represents reactive oxygen species are one of the factor inducing CrMDAR1 gene expression. In conclusion, MDAR plays a role in the tolerance of Chlamydomonas cells to photooxidative stress.
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Affiliation(s)
- Hui-Ling Yeh
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Tsen-Hung Lin
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chi-Chih Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Tian-Xing Cheng
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Hsin-Yang Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan
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Liu J, Sun X, Xu F, Zhang Y, Zhang Q, Miao R, Zhang J, Liang J, Xu W. Suppression of OsMDHAR4 enhances heat tolerance by mediating H 2O 2-induced stomatal closure in rice plants. Rice (N Y) 2018; 11:38. [PMID: 29951703 PMCID: PMC6021276 DOI: 10.1186/s12284-018-0230-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/19/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND Monodehydroascorbate reductase (MDAR or MDHAR), which is responsible for growth, development and stress response in plants, is a key enzyme in the maintenance of the ascorbate acid (AsA) pool through the AsA-glutathione (AsA-GSH) cycle. High temperature affects a broad spectrum of cellular components and metabolism including AsA-GSH cycle in plants. In rice, however, the detailed roles of OsMDHAR4 in resistance against heat stress remains unclear. RESULTS Here, we report that OsMDHAR4 protein was localized to the chloroplasts. OsMDHAR4 expression was detected in all tissues surveyed and peaked in leaf blade. OsMDHAR4 was responsive to multiple stresses and was relatively strongly induced by heat treatment. In comparison with wild type, the osmdhar4 mutant exhibited improved tolerance to heat stress, whereas OsMDHAR4 overexpression lines exhibited enhanced sensitivity to heat stress. Moreover, we found that suppression of OsMDHAR4 promoted stomatal closure and hydrogen peroxide accumulation, and overexpression of OsMDHAR4 increased stomatal opening and decreased hydrogen peroxide content in rice leaves. CONCLUSIONS Taken together, these results indicated that OsMDHAR4 negatively regulates tolerance to heat stress by mediating H2O2-induced stomatal closure in rice.
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Affiliation(s)
- Jianping Liu
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Xinjiao Sun
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Feiyun Xu
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Yingjiao Zhang
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Qian Zhang
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Rui Miao
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China
| | - Jianhua Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, China.
| | - Jiansheng Liang
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Weifeng Xu
- Center for Plant Water-use and Nutrition Regulation and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop, Fujian Agriculture and Forestry University, Jinshan Fuzhou, 350002, China.
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Sudan J, Negi B, Arora S. Oxidative stress induced expression of monodehydroascorbate reductase gene in Eleusine coracana. Physiol Mol Biol Plants 2015; 21:551-8. [PMID: 26600681 PMCID: PMC4646862 DOI: 10.1007/s12298-015-0327-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 10/02/2015] [Accepted: 10/06/2015] [Indexed: 05/22/2023]
Abstract
Abiotic stresses constitute a serious threats to the world food security as they cause significant economic losses in terms of reduction in crop productivity and also greatly limit the geographical locations where crops can be grown. Exposure to abiotic stress causes over-production of reactive oxygen species, leading to oxidative stress in plants. Induction of oxidative stress is primarily responsible for a variety of detrimental changes in the cellular physiology. However, plants have evolved intricate anti-oxidative defence machinery, for their survival under stress. Plant defence strategies for stress tolerance rely on the expression of anti-oxidative genes required for scavenging the toxic reactive oxygen species. Monodehydroascorbate reductase is one of the key anti-oxidant enzyme responsible for scavenging reactive oxygen species. In the present study, efforts have been made to understand the role of monodehydroascorbate reductase in finger millet under different abiotic stresses (drought, salt and UV radiation). The study establishes a differential link between mdar gene expression and enzyme activity under oxidative stress that is validated under different types of imposed stresses. Alteration in correlation between gene expression and enzyme activities under varying magnitude of oxidative stress is elucidated.
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Affiliation(s)
- Jebi Sudan
- Department of Molecular Biology & Genetic Engineering, College of Basic Sciences & Humanities, G.B. Pant University of Agriculture & Technology, Pantnagar, Uttarakhand 263145 India
| | - Bhawana Negi
- Department of Molecular Biology & Genetic Engineering, College of Basic Sciences & Humanities, G.B. Pant University of Agriculture & Technology, Pantnagar, Uttarakhand 263145 India
| | - Sandeep Arora
- Department of Molecular Biology & Genetic Engineering, College of Basic Sciences & Humanities, G.B. Pant University of Agriculture & Technology, Pantnagar, Uttarakhand 263145 India
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Sayantan D. Amendment in phosphorus levels moderate the chromium toxicity in Raphanus sativus L. as assayed by antioxidant enzymes activities. Ecotoxicol Environ Saf 2013; 95:161-170. [PMID: 23810367 DOI: 10.1016/j.ecoenv.2013.05.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 05/18/2013] [Accepted: 05/29/2013] [Indexed: 06/02/2023]
Abstract
Chromium (Z=24), a d-block element, is a potent carcinogen, whereas phosphorus is an essential and limiting nutrient for the plant growth and development. This study undertakes the role of phosphorus in moderating the chromium toxicity in Raphanus sativus L., as both of them compete with each other during the uptake process. Two-factor complete randomized experiment (5 chromium × 5 phosphorus concentrations) was conducted for twenty eight days in green house. The individuals of R. sativus were grown in pots supplied with all essential nutrients. The toxic effects of chromium and the moderation of toxicity due to phosphorus amendment were determined as accumulation of chromium, nitrogen, phosphorus in root tissues and their effects were also examined in the changes in biomass, chlorophyll and antioxidant enzyme levels. Cr and N accumulation were almost doubled at the highest concentration of Cr supply, without any P amendment, whereas at the highest P concentration (125 mM), the accumulation was reduced to almost half. A significant reduction in toxic effects of Cr was determined as there was three-fold increase in total chlorophyll and biomass at the highest P amendment. Antioxidant enzymes like superoxide dismutase, catalase, peroxidase and lipid peroxidation were analyzed at various levels of Cr each amended with five levels of P. It was observed that at highest level of P amendment, the reduction percentage in toxicity was 33, 44, 39 and 44, correspondingly. Conclusively, the phosphorus amendment moderates the toxicity caused by the supplied chromium in R. sativus. This finding can be utilized to develop a novel technology for the amelioration of chromium stressed fields.
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Affiliation(s)
- D Sayantan
- Laboratory of Environment and Biotechnology, Department of Botany, Patna Science College, Patna University, Patna 800005, Bihar, India.
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