SlWHY2 interacts with SlRECA2 to maintain mitochondrial function under drought stress in tomato
SlWHY2 interacts with SlRECA2 to maintain mitochondrial function under drought stress in tomato
复制标题
SlWHY2 与 SlRECA2 相互作用以维持番茄干旱胁迫下的线粒体功能
DOI：
10.1016/j.plantsci.2020.110674
复制
发表时间：
2020-12-01
期刊：
影响因子：
5.2
通讯作者：
Lv, Wei
中科院分区：
文献类型：
--
作者：
Meng, Chen;Yang, Minmin;Lv, Wei
植物中的干旱胁迫导致光合作用和呼吸作用受抑制、活性氧物质（ROS）积累以及基因表达重编程。在此，我们确定番茄（Solanum lycopersicum）的WHIRLY2（SlWHY2）基因（其编码一种线粒体单链DNA结合蛋白）受到干旱胁迫的显著诱导。在干旱条件下，SlWHY2 RNA干扰植株比野生型（WT）表现出更严重的萎蔫以及更低的鲜重、叶绿素含量、光系统I的量子产率（PSI；YI）和光系统II的最大光化学效率（Fv/Fm）。干旱处理还使得SlWHY2 RNA干扰株系比野生型积累更多的ROS，并且沉默株系具有更低的交替氧化酶（AOX）活性。正如预期的那样，SlWHY2 RNA干扰株系的线粒体膜电位（MMP）稳定性更差。在干旱胁迫下，线粒体基因组中的七个基因（SYCF15、NAD7、NAD4、COS2、COX1、COX2和COX3）在SlWHY2 RNA干扰株系中的表达水平比在野生型中下降得更多。SlWHY2在体内和体外都与SlRECA2直接相互作用，SlRECA2是一种对线粒体DNA重组和修复很重要的线粒体重组酶A。这些结果表明，SlWHY2在维持番茄线粒体功能和增强其耐旱性方面起着至关重要的作用。
Drought stress in plants leads to inhibition of photosynthesis and respiration, accumulation of reactive oxygen species (ROS), and reprogramming of gene expression. Here, we established that the tomato (Solanum lyco-persicum) WHIRLY2 (SlWHY2) gene, which encodes a mitochondrial single-stranded DNA-binding protein, was significantly induced by drought stress. Under drought conditions, SlWHY2 RNAi plants showed more wilting and lower fresh weight, chlorophyll content, quantum yield of photosystem I (PSI; YI), and maximal photochemical efficiency of PSII (Fv/Fm) than the wild type (WT). Drought treatment also caused the SlWHY2 RNAi lines to accumulate more ROS than the WT, and the silenced lines had lower AOX (alternative oxidase) activity. As expected, the mitochondrial membrane potential (MMP) was less stable in the SlWHY2 RNAi lines. The expression levels of seven genes in the mitochondrial genome (SYCF15, NAD7, NAD4, COS2, COX1, COX2, and COX3) were decreased even more in the SlWHY2 RNAi lines than they were in the WT under drought stress. SlWHY2 interacted directly in vivo and in vitro with SlRECA2, a mitochondrial recombinase A that is important for mitochondrial DNA recombination and repair. These results suggest that SlWHY2 plays an essential role in maintaining mitochondrial function and enhancing drought tolerance in tomato.