OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation
Rice is a major dietary source of the toxic metalloid arsenic (As). Reducing its accumulation in rice (Oryza sativa) grain is of critical importance to food safety. Rice roots take up arsenate and arsenite depending on the prevailing soil conditions. The first step of arsenate detoxification is its...
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| Format: | Article |
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American Society of Plant Biologists
2016
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| Online Access: | https://eprints.nottingham.ac.uk/43931/ |
| _version_ | 1848796799389663232 |
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| author | Shi, Shulin Wang, Tao Chen, Ziru Tang, Zhong Wu, Zhongchang Salt, David E. Chao, Dai-Yin Zhao, Fang-Jie |
| author_facet | Shi, Shulin Wang, Tao Chen, Ziru Tang, Zhong Wu, Zhongchang Salt, David E. Chao, Dai-Yin Zhao, Fang-Jie |
| author_sort | Shi, Shulin |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Rice is a major dietary source of the toxic metalloid arsenic (As). Reducing its accumulation in rice (Oryza sativa) grain is of critical importance to food safety. Rice roots take up arsenate and arsenite depending on the prevailing soil conditions. The first step of arsenate detoxification is its reduction to arsenite, but the enzyme(s) catalyzing this reaction in rice remains unknown. Here, we identify OsHAC1;1 and OsHAC1;2 as arsenate reductases in rice. OsHAC1;1 and OsHAC1;2 are able to complement an Escherichia coli mutant lacking the endogenous arsenate reductase and to reduce arsenate to arsenite. OsHAC1:1 and OsHAC1;2 are predominantly expressed in roots, with OsHAC1;1 being abundant in the epidermis, root hairs, and pericycle cells while OsHAC1;2 is abundant in the epidermis, outer layers of cortex, and endodermis cells. Expression of the two genes was induced by arsenate exposure. Knocking out OsHAC1;1 or OsHAC1;2 decreased the reduction of arsenate to arsenite in roots, reducing arsenite efflux to the external medium. Loss of arsenite efflux was also associated with increased As accumulation in shoots. Greater effects were observed in a double mutant of the two genes. In contrast, overexpression of either OsHAC1;1 or OsHAC1;2 increased arsenite efflux, reduced As accumulation, and enhanced arsenate tolerance. When grown under aerobic soil conditions, overexpression of either OsHAC1;1 or OsHAC1;2 also decreased As accumulation in rice grain, whereas grain As increased in the knockout mutants. We conclude that OsHAC1;1 and OsHAC1;2 are arsenate reductases that play an important role in restricting As accumulation in rice shoots and grain. |
| first_indexed | 2025-11-14T19:53:43Z |
| format | Article |
| id | nottingham-43931 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:53:43Z |
| publishDate | 2016 |
| publisher | American Society of Plant Biologists |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-439312020-05-04T18:22:26Z https://eprints.nottingham.ac.uk/43931/ OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation Shi, Shulin Wang, Tao Chen, Ziru Tang, Zhong Wu, Zhongchang Salt, David E. Chao, Dai-Yin Zhao, Fang-Jie Rice is a major dietary source of the toxic metalloid arsenic (As). Reducing its accumulation in rice (Oryza sativa) grain is of critical importance to food safety. Rice roots take up arsenate and arsenite depending on the prevailing soil conditions. The first step of arsenate detoxification is its reduction to arsenite, but the enzyme(s) catalyzing this reaction in rice remains unknown. Here, we identify OsHAC1;1 and OsHAC1;2 as arsenate reductases in rice. OsHAC1;1 and OsHAC1;2 are able to complement an Escherichia coli mutant lacking the endogenous arsenate reductase and to reduce arsenate to arsenite. OsHAC1:1 and OsHAC1;2 are predominantly expressed in roots, with OsHAC1;1 being abundant in the epidermis, root hairs, and pericycle cells while OsHAC1;2 is abundant in the epidermis, outer layers of cortex, and endodermis cells. Expression of the two genes was induced by arsenate exposure. Knocking out OsHAC1;1 or OsHAC1;2 decreased the reduction of arsenate to arsenite in roots, reducing arsenite efflux to the external medium. Loss of arsenite efflux was also associated with increased As accumulation in shoots. Greater effects were observed in a double mutant of the two genes. In contrast, overexpression of either OsHAC1;1 or OsHAC1;2 increased arsenite efflux, reduced As accumulation, and enhanced arsenate tolerance. When grown under aerobic soil conditions, overexpression of either OsHAC1;1 or OsHAC1;2 also decreased As accumulation in rice grain, whereas grain As increased in the knockout mutants. We conclude that OsHAC1;1 and OsHAC1;2 are arsenate reductases that play an important role in restricting As accumulation in rice shoots and grain. American Society of Plant Biologists 2016-11-04 Article PeerReviewed Shi, Shulin, Wang, Tao, Chen, Ziru, Tang, Zhong, Wu, Zhongchang, Salt, David E., Chao, Dai-Yin and Zhao, Fang-Jie (2016) OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation. Plant Physiology, 172 (3). pp. 1708-1719. ISSN 1532-2548 http://www.plantphysiol.org/content/172/3/1708 doi:10.1104/pp.16.01332 doi:10.1104/pp.16.01332 |
| spellingShingle | Shi, Shulin Wang, Tao Chen, Ziru Tang, Zhong Wu, Zhongchang Salt, David E. Chao, Dai-Yin Zhao, Fang-Jie OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title | OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title_full | OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title_fullStr | OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title_full_unstemmed | OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title_short | OsHAC1;1 and OsHAC1;2 function as arsenate reductases and regulate arsenic accumulation |
| title_sort | oshac1;1 and oshac1;2 function as arsenate reductases and regulate arsenic accumulation |
| url | https://eprints.nottingham.ac.uk/43931/ https://eprints.nottingham.ac.uk/43931/ https://eprints.nottingham.ac.uk/43931/ |