Nie Shengsong, Huang Weiting, He Chongchong, Wu Bowen, Duan Honglang, Ruan Jingjun, Zhao Quanzhi, Fang Zhongming
Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions, Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province, Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Agricultural Sciences, Institute of Rice Industry Technology Research, Guizhou University, Guiyang 550025, China.
Institute for Forest Resources and Environment of Guizhou, College of Forestry, Guizhou University, Guiyang 550025, China.
Plant Physiol. 2025 Feb 7;197(2). doi: 10.1093/plphys/kiae559.
Amino acid transporters (AATs) play important roles in plant growth and stress tolerance; however, whether the abscisic acid signaling pathway regulates their transcription in rice (Oryza sativa) under salt stress remains unclear. In this study, we report that the transcription factor OsMYB2 (MYB transcription factor 2) of the abscisic acid signaling pathway mediates the expression of the gene encoding the AAT aromatic and neutral AAT 1 (OsANT1), which positively regulates growth and salt tolerance in rice. OsANT1 was mainly expressed in the leaf blade and panicle under normal conditions and transports leucine, phenylalanine, tyrosine, and proline (Pro), positively regulating tillering and yield in rice. Nevertheless, salt stress induced the accumulation of abscisic acid and strongly increased the expression level of OsANT1 in the root, resulting in enhanced salt tolerance of rice seedlings, as evidenced by higher Pro concentration and antioxidant-like enzyme activities and lower malondialdehyde and hydrogen peroxide concentrations. Moreover, we showed that OsMYB2 interacts with the promoter of OsANT1 and promotes its expression. Overexpression of OsMYB2 also improved tillering, yield, and salt tolerance in rice. In conclusion, our results suggest that the transcription factor OsMYB2 triggers OsANT1 expression and regulates growth and salt tolerance in rice, providing insights into the role of the abscisic acid signaling pathway in the regulatory mechanism of AATs in response to salt stress.
氨基酸转运体（AATs）在植物生长和胁迫耐受性中发挥着重要作用；然而，脱落酸信号通路是否在盐胁迫下调节水稻（Oryza sativa）中它们的转录仍不清楚。在本研究中，我们报道脱落酸信号通路的转录因子OsMYB2（MYB转录因子2）介导编码AAT芳香族和中性AAT 1（OsANT1）的基因的表达，OsANT1正向调节水稻的生长和耐盐性。在正常条件下，OsANT1主要在叶片和穗中表达，并转运亮氨酸、苯丙氨酸、酪氨酸和脯氨酸（Pro），正向调节水稻的分蘖和产量。然而，盐胁迫诱导了脱落酸的积累，并强烈增加了OsANT1在根中的表达水平，导致水稻幼苗耐盐性增强，这表现为脯氨酸浓度和抗氧化酶活性较高，丙二醛和过氧化氢浓度较低。此外，我们表明OsMYB2与OsANT1的启动子相互作用并促进其表达。过表达OsMYB2也提高了水稻的分蘖、产量和耐盐性。总之，我们的结果表明转录因子OsMYB2触发OsANT1的表达并调节水稻的生长和耐盐性，为脱落酸信号通路在AATs响应盐胁迫的调控机制中的作用提供了见解。
