Srivastava Ashish Kumar, Pandey Manish, Ghate Tejashree, Kumar Vikash, Upadhyay Munish Kumar, Majumdar Arnab, Sanjukta Abhay Kumar, Agrawal Ashish Kumar, Bose Sutapa, Srivastava Sudhakar, Suprasanna Penna
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, 400 085, India; Homi Bhabha National Institute, Mumbai, 400094, India.
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, 400 085, India.
Environ Pollut. 2021 May 1;276:116719. doi: 10.1016/j.envpol.2021.116719. Epub 2021 Feb 13.
Arsenic (As) is a ubiquitous environmental carcinogen that enters the human food chain mainly through rice grains. In the present study, we evaluated the potential of thiourea (TU; non-physiological reactive oxygen species scavenger) in mitigating the negative effects of arsenic (As) stress in indica rice variety IR64, with the overall aim to reduce grain As accumulation. At seedling stage, As + TU treatment induced the formation of more numerous and longer crown roots compared with As alone. The As accumulation in main root, crown root, lower leaf and upper leaf was significantly reduced to 0.1-, 0.14-, 0.16-, 0.14-fold, respectively in As + TU treated seedlings compared with those of As alone. This reduced As accumulation was also coincided with light-dependent suppression in the expression levels of aquaporins and photosynthesis-related genes in As + TU treated roots. In addition, the foliar-supplemented TU under As-stress maintained reducing redox conditions which decreased the rate of As accumulation in flag leaves and, eventually grain As by 0.53-fold compared with those of As treatment. The agronomic feasibility of TU was validated under naturally As contaminated sites of Nadia (West Bengal, India). The tiller numbers and crop productivity (kg seed/ha) of TU-sprayed plants were increased by 1.5- and 1.18-fold, respectively; while, grain As accumulation was reduced by 0.36-fold compared with those of water-sprayed control. Thus, this study established TU application as a sustainable solution for cultivating rice in As-contaminated field conditions.
砷（As）是一种普遍存在的环境致癌物，主要通过米粒进入人类食物链。在本研究中，我们评估了硫脲（TU；非生理性活性氧清除剂）减轻籼稻品种IR64中砷（As）胁迫负面影响的潜力，总体目标是减少籽粒中砷的积累。在幼苗期，与单独施加砷相比，砷+硫脲处理诱导形成了更多且更长的冠根。与单独施加砷的幼苗相比，砷+硫脲处理的幼苗主根、冠根、下部叶片和上部叶片中的砷积累分别显著降低至0.1倍、0.14倍、0.16倍、0.14倍。这种砷积累的减少也与砷+硫脲处理的根中 aquaporins 和光合作用相关基因表达水平的光依赖性抑制相一致。此外，在砷胁迫下叶面补充硫脲维持了还原氧化条件，与砷处理相比，旗叶中砷的积累速率降低，最终籽粒中的砷降低了0.53倍。硫脲在印度西孟加拉邦纳迪亚天然砷污染地点的农艺可行性得到了验证。喷施硫脲的植株分蘖数和作物生产力（kg种子/公顷）分别提高了1.5倍和1.18倍；而与喷水对照相比，籽粒中砷的积累减少了0.36倍。因此，本研究确立了在砷污染田间条件下应用硫脲是种植水稻的可持续解决方案。
