Zhu Fengjin, Wang Kai, Li Danni, Liu Ziang, Li Minghui, Wang Zhenyu, Li Xiufeng, Lan Xingguo, Guan Qingjie
Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China.
College of Forestry, Northeast Forestry University, Harbin, 150040, China.
Rice (N Y). 2022 Dec 27;15(1):69. doi: 10.1186/s12284-022-00616-x.
Soil salinization is a worldwide environmental problem, especially in the arid and semiarid regions of northeastern China, which are heavily affected by soda saline-alkaline stress. At present, there is an urgent need to improve the soda saline-alkaline stress tolerance of rice.
Stress-associated proteins are involved in regulating the abiotic stresses in plants. There are 18 members of the rice stress-associated protein (OsSAP) gene family. In this study, the expression levels of OsSAP6 in leaves and roots were upregulated with increasing NaHCO stress duration. OsSAP6 was located in nucleus and cytoplasm. The bud length and total root length of OsSAP6 overexpression rice were significantly longer than those of Lj11 (Oryza sativa longjing11) during germination stage, and the survival rates, plant height and malondialdehyde content at the seedling stage showed tolerance growth of saline-alkaline stress. The expression of OsCu/Zn-SOD, OsAPX2, and OsCAT1 in transgenic lines was increased significantly under SAE (soda saline-alkali soil eluent) stress. OsSAP6 interacts with OsPK5 according to yeast two-hybrid screening and luciferase complementation experiments. The expression of OsPK5 increased under NaHCO and HO stress, and the overexpression of OsPK5 in rice improved soda saline-alkaline tolerance.
Overexpression of OsSAP6 in rice significantly enhanced saline-alkaline tolerance compared with the wild type. It is speculated that OsSAP6 responds to soda salinity stress and interacts with OsPK5 to positively regulate soda saline-alkaline tolerance through ROS homeostasis. This study revealed the features of OsSAP6 involved in response to soda saline-alkaline stress and the interaction with OsPK5, which provided resources for breeding aimed at improving the soda saline-alkaline stress tolerance of rice.
土壤盐渍化是一个全球性的环境问题，在中国东北干旱和半干旱地区尤为严重，这些地区受到苏打盐碱胁迫的严重影响。目前，迫切需要提高水稻对苏打盐碱胁迫的耐受性。
胁迫相关蛋白参与调节植物的非生物胁迫。水稻胁迫相关蛋白（OsSAP）基因家族有18个成员。在本研究中，随着NaHCO胁迫时间的延长，叶片和根中OsSAP6的表达水平上调。OsSAP6定位于细胞核和细胞质中。在萌发阶段，OsSAP6过表达水稻的芽长和总根长显著长于龙粳11（Oryza sativa longjing11），在幼苗期的存活率、株高和丙二醛含量显示出对盐碱胁迫的耐受性生长。在苏打盐碱土洗脱液（SAE）胁迫下，转基因株系中OsCu/Zn-SOD、OsAPX2和OsCAT1的表达显著增加。通过酵母双杂交筛选和荧光素酶互补实验，OsSAP6与OsPK5相互作用。在NaHCO和HO胁迫下，OsPK5的表达增加，水稻中OsPK5的过表达提高了对苏打盐碱的耐受性。
与野生型相比，水稻中OsSAP6的过表达显著增强了盐碱耐受性。推测OsSAP6响应苏打盐碱胁迫并与OsPK5相互作用，通过活性氧稳态正向调节苏打盐碱耐受性。本研究揭示了OsSAP6参与响应苏打盐碱胁迫的特征及其与OsPK5的相互作用，为旨在提高水稻苏打盐碱胁迫耐受性的育种提供了资源。
