College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China.
Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410008, China.
Curr Microbiol. 2023 Aug 16;80(10):320. doi: 10.1007/s00284-023-03434-6.
Paddy rice trends to accumulate more arsenic (As) from soils than other terrestrial crops. The toxicity and mobility of As mainly depend on its chemical species. Transformation of arsenite [As(III)] into arsenate [As(V)] would be a promising method to mitigate As toxicity. In the current study, As(III)-oxidizing strain SMS11 isolated from As-contaminated soils was employed for As remediation. Co-cultured with SMS11 alleviated As(III) stress to the rice plants by increasing the length and biomass of rice shoots up to 10% and 15%, respectively. Evaluation of oxidative stress indices showed that the activity of catalase in the rice shoots was weakened when exposed to As(III), increasing the risk of hydroxyl radical (OH) formation. When co-cultivated with the bacteria, OH formation was significantly inhibited in the rice shoots. The ionomes of the rice plants were impacted by the external conditions. As(III) stress significantly disturbed ionome homeostasis in the rice plants. Uptake of As simultaneously elevated the levels of macro and nutrient elements such as Mg, P, K, Ca, and Zn in the rice shoots. The ionomic variation in the rice plants under As(III) stress was mitigated by inoculated with SMS11. The results represented that the As(III)-oxidizing bacteria alleviated external As(III) stress to the rice plants through elevating antioxidative activities and modulating ionome homeostasis.
水稻从土壤中积累的砷（As）比其他陆生作物更多。As 的毒性和迁移性主要取决于其化学形态。将亚砷酸盐[As(III)]转化为砷酸盐[As(V)]是减轻 As 毒性的一种很有前途的方法。在本研究中，从砷污染土壤中分离出的砷（III）氧化菌 SMS11 被用于 As 修复。与 SMS11 共培养通过将水稻苗的长度和生物量分别增加 10%和 15%，减轻了 As(III)对水稻的胁迫。氧化应激指标的评估表明，当暴露于 As(III)时，水稻苗中的过氧化氢酶活性减弱，增加了羟基自由基（OH）形成的风险。当与细菌共培养时，水稻苗中的 OH 形成明显受到抑制。植物的离子组受外部条件的影响。As(III)胁迫显著干扰了水稻植株的离子组稳态。As 的摄取同时提高了水稻苗中 Mg、P、K、Ca 和 Zn 等大量和营养元素的水平。接种 SMS11 减轻了水稻植株在 As(III)胁迫下的离子组变化。结果表明，As(III)氧化细菌通过提高抗氧化活性和调节离子组稳态来减轻水稻植株的外部 As(III)胁迫。
