Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun 130024 China.
Laboratory of Plant Molecular Genetics & Crop Gene Editing, School of Life Sciences, Linyi University, Linyi 276000, China.
Gene. 2022 Dec 20;846:146846. doi: 10.1016/j.gene.2022.146846. Epub 2022 Aug 28.
Abiotic stresses such as salt and drought affect plants growth and development, whereas the plant hormone ABA is able to regulate plant responses to abiotic stresses by regulating downstream gene expression. Therefore characterization of unknown function ABA responsive genes is able to identify novel regulators of plant abiotic stress responses. We report here the characterization of AtS40-1, a Group I DUF584 protein in the regulation of ABA and salt responses in Arabidopsis. RT-PCR results show that the expression of AtS40-1 was dramatically induced by ABA, but only slightly increase, if any, was observed for other three Group I DUF584 genes including AtS40-1L, AtS40-2 and AtS40-3. Transfection assays in Arabidopsis protoplasts show that all the four Group I DUF584 proteins were predominately localized in nucleus and were able to repress the expression of the co-transfected reporter gene. The roles of AtS40-1 in regulating plant response to ABA and abiotic stress responses were analyzed, by using transgenic plants and inactivation mutants. The results show that the ABA responses were increased in the 35S:AtS40-1 transgenic plants, but decreased in the ats40-1 mutants. Similar to AtS40-1, the results indicate that AtS40-1L, the most closely related DUF584 protein to AtS40-1, positively regulates ABA responses in Arabidopsis. However, further decreased ABA responses were not observed in the ats40-1 ats40-1L double mutants. On the other hand, salt tolerance was increased in the transgenic plants overexpressing AtS40-1 or AtS40-1L, but decreased in the ats40-1 and ats40-1L mutants. Quantitative RT-PCR results show that the ABA induced expression of the ABA signaling regulator genes ABI3, ABI4 and ABA responsive gene RAB18 was decreased, where as ABA signaling gene ABI1 was increased in the ats40-1 mutants. These results suggest that AtS40-1 regulates ABA and salt responses in Arabidopsis, possibly by affecting ABA induced expression of some ABA signaling regulator genes.
非生物胁迫，如盐和干旱，会影响植物的生长和发育，而植物激素 ABA 能够通过调节下游基因的表达来调节植物对非生物胁迫的反应。因此，鉴定未知功能的 ABA 响应基因能够识别植物非生物胁迫反应的新调节剂。在这里，我们报告了 AtS40-1 的特征，它是拟南芥中 ABA 和盐响应的 I 组 DUF584 蛋白。RT-PCR 结果表明，ABA 诱导 AtS40-1 的表达明显增加，但其他三个 I 组 DUF584 基因（包括 AtS40-1L、AtS40-2 和 AtS40-3）的表达只有轻微增加。在拟南芥原生质体中的转染实验表明，所有四个 I 组 DUF584 蛋白都主要定位于细胞核内，并能够抑制共转染报告基因的表达。通过使用转基因植物和失活突变体，分析了 AtS40-1 在调节植物对 ABA 和非生物胁迫反应中的作用。结果表明，35S:AtS40-1 转基因植物中 ABA 反应增加，而 ats40-1 突变体中 ABA 反应减少。与 AtS40-1 相似，结果表明，与 AtS40-1 最密切相关的 DUF584 蛋白 AtS40-1L，正向调节拟南芥中的 ABA 反应。然而，在 ats40-1 ats40-1L 双突变体中没有观察到进一步降低的 ABA 反应。另一方面，过表达 AtS40-1 或 AtS40-1L 的转基因植物的耐盐性增加，而 ats40-1 和 ats40-1L 突变体的耐盐性降低。定量 RT-PCR 结果表明，ABA 诱导的 ABA 信号调节基因 ABI3、ABI4 和 ABA 响应基因 RAB18 的表达减少，而 ats40-1 突变体中的 ABA 信号基因 ABI1 增加。这些结果表明，AtS40-1 可能通过影响某些 ABA 信号调节基因的 ABA 诱导表达，调节拟南芥中的 ABA 和盐响应。
