National Botanical Research Institute, Lucknow, UP, India.
Chemosphere. 2011 Feb;82(7):986-95. doi: 10.1016/j.chemosphere.2010.10.070. Epub 2010 Nov 13.
World wide arsenic (As) contamination of rice has raised much concern as it is the staple crop for millions. Four most commonly cultivated rice cultivars, Triguna, IR-36, PNR-519 and IET-4786, of the West Bengal region were taken for a hydroponic study to examine the effect of arsenate (As(V)) and arsenite (As(III)) on growth response, expression of genes and antioxidants vis-à-vis As accumulation. The rice genotypes responded differentially under As(V) and As(III) stress in terms of gene expression and antioxidant defences. Some of the transporters were up-regulated in all rice cultivars at lower doses of As species, except IET-4786. Phytochelatin synthase, GST and γ-ECS showed considerable variation in their expression pattern in all genotypes, however in IET-4786 they were generally down-regulated in higher As(III) stress. Similarly, most of antioxidants such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) increased significantly in Triguna, IR-36 and PNR-519 and decreased in IET-4786. Our study suggests that Triguna, IR-36 and PNR-519 are tolerant rice cultivars accumulating higher arsenic; however IET-4786 is susceptible to As-stress and accumulates less arsenic than other cultivars.
全世界范围内，由于大米是数百万人的主食，其受到砷污染的情况引发了广泛关注。本研究选取印度西孟加拉邦地区种植的四种主要水稻品种（Triguna、IR-36、PNR-519 和 IET-4786）进行水培实验，以考察砷酸盐（As(V)）和亚砷酸盐（As(III)）对生长反应、基因表达和抗氧化剂的影响，进而评估砷的积累情况。在砷(V)和砷(III)胁迫下，这些水稻基因型在基因表达和抗氧化防御方面表现出不同的反应。在较低浓度的砷物种处理下，除 IET-4786 外，所有水稻品种中的一些转运蛋白都被上调。在所有基因型中，谷胱甘肽 S-转移酶和γ-ECS 表现出相当大的差异，但在高砷(III)胁迫下，IET-4786 中的表达通常被下调。同样，大多数抗氧化剂，如超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）、愈创木酚过氧化物酶（GPX）、过氧化氢酶（CAT）、单脱氢抗坏血酸还原酶（MDHAR）和脱氢抗坏血酸还原酶（DHAR），在 Triguna、IR-36 和 PNR-519 中显著增加，而在 IET-4786 中则减少。本研究表明，Triguna、IR-36 和 PNR-519 是耐砷的水稻品种，积累了较高的砷；而 IET-4786 对砷胁迫敏感，积累的砷比其他品种少。
