Beneficial effects of methyl jasmonate (MeJA) on plants under different abiotic conditions have long been demonstrated. This study aimed to figure out how exogenous MeJA mitigated high-Se toxicity in rice from plant physiology and gene express perspective to provide the theory and technique for safe production of Se-rich rice. The results showed that low concentrations of MeJA at 0.1–1.0 μM inhibited high-Se induced nonreversible toxicity by enhancing antioxidant-system and reducing H₂O₂ and MDA content in rice seedlings. In comparison with control, addition of low concentrations of MeJA at 0.1–1.0 μM reduced the Se content in the roots by 13.6–48.8% and in the shoots by 52.6–59.9%. Besides, lower concentrations of MeJA decreased the Se(IV) transformation to SeCys and SeMet, which hindered normal protein synthesis. The qRT-PCR analysis showed that application of low concentration of MeJA down-regulated the gene expression of OsNIP2;1, and OsPT2 in the roots and OsNIP2;1, OsPT2, OsSBP1, and OsCS in the shoots, which inhibited Se absorption. However, high concentrations of MeJA at 2.5–5.0 μM decreased the antioxidant capacity and increased the H₂O₂ and MDA content in rice seedlings. The results suggested that MeJA at 0.1–1.0 μM can be used to mitigate high-Se toxicity in rice production. This research augments the knowledge for future utilization of MeJA in down-regulating Se levels in crops.

茉莉酸甲酯（MeJA）在不同非生物条件下对植物的有益作用早已证明。本研究旨在从植物生理学和基因表达角度探讨外源MeJA如何减轻水稻中高硒的毒性，为富硒水稻的安全生产提供理论和技术。结果表明，低浓度的MeJA（0.1–1.0μM）通过增强抗氧化剂体系和减少H ₂ O ₂抑制高硒诱导的不可逆毒性。和水稻幼苗中的丙二醛含量。与对照相比，添加0.1–1.0μM的低浓度MeJA可使根部的硒含量降低13.6–48.8％，而芽中的硒含量降低52.6–59.9％。此外，较低浓度的MeJA降低了Se（IV）向SeCys和SeMet的转化，从而阻碍了正常蛋白质的合成。qRT-PCR分析表明，低浓度MeJA的施用会下调根中OsNIP2; 1和OsPT2的基因表达，并降低芽中OsNIP2; 1，OsPT2，OsSBP1和OsCS的基因表达，从而抑制了Se的吸收。但是，高浓度的MeJA在2.5–5.0μM下会降低抗氧化能力并增加H ₂水稻幼苗中的O ₂和MDA含量。结果表明，0.1–1.0μM的MeJA可用于减轻水稻生产中的高硒毒性。这项研究增加了MeJA在下调作物中硒水平方面的应用知识。