Yang Xiao-Rong, Huang Yong-Chun, Liu Zhong-Qi, Huang Yi-Zong, Cheng Liu-Long, Zhang Chang-Bo
Research Center of Agro-Environmental Remediation, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
Huan Jing Ke Xue. 2020 Jul 8;41(7):3441-3448. doi: 10.13227/j.hjkx.202001039.
Rice contaminated by Cd has aroused widespread public concern. It is of great importance to find effective ways to reduce Cd translocation from roots to shoots and alleviate Cd stress in rice to ensuring food quality and safety. In this study, 2,3-dimercaptosuccinic acid (DMSA) was sprayed onto the leaves of rice seedlings to evaluate the feasibility of DMSA reducing Cd translocation to rice shoots and alleviating Cd stress. Therefore, seedlings of Zhongzao 35, one of the main rice cultivars in southern China, were used to study the effects of different concentrations of DMSA on the uptake and transport of Cd in rice seedlings by hydroponics. The effects of DMSA on MDA and GSH content, and activities of antioxidant enzymes such as CAT and SOD in rice seedlings, were also investigated. The results showed that after four iterations of foliar application of DMSA at concentrations of 0.2, 0.4, and 1.0 mmol·L, the Cd concentration in the rice seedling shoots decreased significantly with increasing DMSA spraying concentration. Compared with the control, the Cd concentration in shoots decreased by 22.1%, 39.7%, and 43.5%, respectively, but had no significant effect on the root Cd concentration. There was no significant effect on the concentrations of K, Ca, Mg, Fe, Zn, or Mn in the shoot or root. The content of MDA and GSH in the shoots of rice seedlings decreased significantly after four spraying times of DMSA and the activity of CAT and SOD increased significantly, which shows that spraying DMSA alleviated the stress effect of Cd on rice seedlings. Foliar application of DMSA can significantly reduce the accumulation of Cd in rice shoots but has no significant effect on the content of six common mineral elements, and can effectively relieve the oxidative damage caused by Cd stress. DMSA has the potential to develop a foliar modulator for reducing rice grain Cd content.
镉污染的大米已引起公众广泛关注。寻找有效的方法来减少镉从根部向地上部的转运并缓解水稻中的镉胁迫对于确保粮食质量和安全至关重要。在本研究中，将2,3-二巯基丁二酸（DMSA）喷洒到水稻幼苗叶片上，以评估DMSA降低镉向水稻地上部转运并缓解镉胁迫的可行性。因此，选用中国南方主要水稻品种之一的中早35幼苗，通过水培研究不同浓度DMSA对水稻幼苗镉吸收和转运的影响。还研究了DMSA对水稻幼苗丙二醛（MDA）和谷胱甘肽（GSH）含量以及抗氧化酶如过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性的影响。结果表明，在0.2、0.4和1.0 mmol·L浓度下对DMSA进行四次叶面喷施后，水稻幼苗地上部的镉浓度随着DMSA喷施浓度的增加而显著降低。与对照相比，地上部的镉浓度分别降低了22.1%、39.7%和43.5%，但对根部镉浓度没有显著影响。对地上部或根部的钾、钙、镁、铁、锌或锰浓度没有显著影响。在对DMSA进行四次喷施后，水稻幼苗地上部的MDA和GSH含量显著降低，CAT和SOD活性显著增加，这表明喷施DMSA缓解了镉对水稻幼苗的胁迫效应。叶面喷施DMSA可显著降低水稻地上部镉的积累，但对六种常见矿质元素的含量没有显著影响，并可有效缓解镉胁迫引起的氧化损伤。DMSA有开发一种降低水稻籽粒镉含量的叶面调节剂的潜力。
