title: Loss-of-function mutations in the APX1 gene result in enhanced selenium tolerance in Arabidopsis thaliana.
abstract: It is generally recognized that excess selenium (Se) has a negative effect on the growth and development of plants. Numerous studies have identified key genes involved in selenium tolerance in plants; however, our understanding of its molecular mechanisms is far from complete. In this study, we isolated an Arabidopsis selenium-resistant mutant from the mutant XVE pool lines because of its increased root growth and fresh weight in Se stress, and cloned the gene, which encodes the cytosolic ascorbate peroxidase (APX1). Two other APX1 gene knockout allelic lines were also selenium resistant, and the APX1-complementary COM1 restored the growth state of wild type under Se stress. In addition, these APX1 allelic lines accumulated more Se than did wild-type plants when subjected to Se stress. Further analysis revealed that the APX1-mediated Se tolerance was associated, at least in part, with the enhanced activities of antioxidant enzymes catalase, glutathione peroxidase and glutathione reductase. Moreover, enhanced Se resistance of the mutants was associated with glutathione (GSH), which had the higher expression level of GSH1 gene involved in GSH synthesis and consequently increased GSH content. Our results provide genetic evidence indicating that loss-of-function of APX1 results in tolerance to Se stress.
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China. jiangli@ustc.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.|School of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
authors.forename: Ziping
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
authors.forename: Qiuchen
authors.initials: Q
authors.lastname: Gao
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
authors.forename: Lingkun
authors.initials: L
authors.lastname: Ci
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
authors.forename: Shuqing
authors.initials: S
authors.lastname: Cao
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Han
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
authors.forename: Weiyan
authors.initials: W
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D003001:Cloning, Molecular; D055786:Gene Knockout Techniques; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D000073658:Loss of Function Mutation; D012643:Selenium / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C555290:APX1 protein, Arabidopsis; D060387:Ascorbate Peroxidases; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D012643:Selenium
keywords: APX1 gene; glutathione; glutathione peroxidase; mutant apx1-3; selenite