Yang Xu, Li Jiachun, Zheng Yuze, Li Huashou, Qiu Rongliang
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
J Environ Sci (China). 2023 Apr;126:602-611. doi: 10.1016/j.jes.2022.05.053. Epub 2022 Jun 10.
Salt-tolerant rice (sea rice) is a key cultivar for increasing rice yields in salinity soil. The co-existence of salinity and cadmium (Cd) toxicities in the plant-soil system has become a great challenge for sustainable agriculture, especially in some estuaries and coastal areas. However, little information is available on the Cd accumulating features of sea rice under the co-stress of Cd and salinity. In this work, a hydroponic experiment with combined Cd (0, 0.2, 0.8 mg/L Cd) and saline (0, 0.6%, and 1.2% NaCl, W/V) levels and a pot experiment were set to evaluate the Cd toxic risks of sea rice. The hydroponic results showed that more Cd accumulated in sea rice than that in the reported high-Cd-accumulating rice, Chang Xianggu. It indicated an interesting synergistic effect between Cd and Na levels in sea rice, and the Cd level rose significantly with a concomitant increase in Na level in both shoot (r = 0.54, p < 0.01) and root (r = 0.66, p < 0.01) of sea rice. Lower MDA content was found in sea rice, implying that the salt addition probably triggered the defensive ability against oxidative stress. The pot experiment indicated that the coexistent Cd and salinity stress further inhibited the rice growth and rice yield, and the Cd concentration in rice grain was below 0.2 mg/kg. Collectively, this work provides a general understanding of the co-stress of Cd and salinity on the growth and Cd accumulation of sea rice. Additional work is required to precisely identify the phytoremediation potential of sea rice in Cd-polluted saline soil.
耐盐水稻（海水稻）是提高盐碱地水稻产量的关键品种。植物 - 土壤系统中盐分和镉（Cd）毒性的共存已成为可持续农业面临的巨大挑战，特别是在一些河口和沿海地区。然而，关于海水稻在镉和盐分共同胁迫下的镉积累特征的信息却很少。在这项研究中，设置了一个镉（0、0.2、0.8 mg/L Cd）和盐分（0、0.6%和1.2% NaCl，W/V）水平组合的水培实验以及一个盆栽实验，以评估海水稻的镉毒性风险。水培结果表明，海水稻积累的镉比报道的高镉积累水稻品种长香谷更多。这表明海水稻中镉和钠水平之间存在有趣的协同效应，在海水稻的地上部（r = 0.54，p < 0.01）和根部（r = 0.66，p < 0.01），镉水平均随着钠水平的升高而显著上升。在海水稻中发现较低的丙二醛含量，这意味着添加盐分可能触发了对氧化应激的防御能力。盆栽实验表明，镉和盐分胁迫共同进一步抑制了水稻生长和产量，且水稻籽粒中的镉浓度低于0.2 mg/kg。总体而言，这项研究提供了对镉和盐分共同胁迫对海水稻生长和镉积累影响的总体认识。还需要进一步的研究来准确确定海水稻在镉污染盐碱土壤中的植物修复潜力。
