State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, No.3, Taicheng Road, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Vegetables, No. 3, Taicheng Road, Yangling, Shaanxi, 712100, China.
Plant Sci. 2021 Feb;303:110753. doi: 10.1016/j.plantsci.2020.110753. Epub 2020 Nov 18.
Dynein light chain (DLC) proteins are an important component of dynein complexes, which are widely distributed in plants and animals and involved in a variety of cellular processes. The functions of DLC genes in plant chilling stress remain unclear. In this study, we isolated a DLC gene from tomato, designated SlLC6D. Promoter analysis revealed many cis-elements involved in abiotic stress in the SlLC6D promoter. Expression of SlLC6D was induced by heat and salt stress, and inhibited by polyethylene glycol and chilling stress. Knockdown of SlLC6D in tomato exhibited low relative electrolyte leakage, malondialdehyde content, and reactive oxygen species (ROS) accumulation under chilling stress. The content of proline and activities of superoxide dismutase and peroxidase in knockdown lines were higher than in the wild type and overexpression lines during chilling stress. The high transcript abundances of three cold-responsive genes were detected in knockdown lines in response to chilling stress. Seedling growth of knockdown lines was significantly higher than that of the wild type and overexpression lines under chilling stress. These results suggest that SlLC6D is a negative regulator of chilling stress tolerance, possibly by regulating ROS contents and the ICE1-CBF-COR pathway.
动力蛋白轻链 (DLC) 蛋白是动力蛋白复合物的重要组成部分，广泛分布于动植物中，参与多种细胞过程。DLC 基因在植物冷胁迫中的功能尚不清楚。本研究从番茄中分离到一个 DLC 基因，命名为 SlLC6D。启动子分析表明 SlLC6D 启动子中存在许多参与非生物胁迫的顺式元件。SlLC6D 的表达受热和盐胁迫诱导，受聚乙二醇和冷胁迫抑制。番茄中 SlLC6D 的敲低导致相对电解质渗漏率、丙二醛含量和活性氧 (ROS) 积累降低，在冷胁迫下脯氨酸含量和超氧化物歧化酶和过氧化物酶的活性均高于野生型和过表达系。在冷胁迫下，三个冷响应基因的转录丰度在敲低系中明显上调。在冷胁迫下，敲低系的幼苗生长明显高于野生型和过表达系。这些结果表明 SlLC6D 是冷胁迫耐受性的负调控因子，可能通过调节 ROS 含量和 ICE1-CBF-COR 途径。
