Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, 510650, China.
Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of the People's Republic of China, Nanjing, 210042, China.
Plant Physiol Biochem. 2021 Nov;168:373-380. doi: 10.1016/j.plaphy.2021.10.030. Epub 2021 Oct 22.
Osmotic stress substantially affects plant growth and development. Study of plant transcription factors involved in osmotic stress can enhance our understanding of the mechanisms of plant osmotic stress tolerance and how the tolerance of plants to osmotic stress can be improved. Here, we identified the specific function of Arabidopsis thaliana BARLEY B RECOMBINANT/BASIC PENTACYSTEINE transcription factor, BPC2, in the osmotic stress response. Phenotypic analysis showed that loss-of-function of BPC2 led to an increase in osmotic stress tolerance in the seedling growth stage. Physiological analysis showed that mutation of BPC2 in Arabidopsis alleviated osmotic-induced increases in HO accumulation, the malondialdehyde (MDA) content, and percent electrolyte leakage. BPC2 was localized in the nucleus. RNA-seq and qRT-PCR analysis showed that BPC2 could negatively regulate the expression of late embryogenesis abundant (LEA) genes (LEA3, LEA4-2, and LEA4-5). Further analysis showed that BPC2 could directly bind to the promoter of LEA4-5 in vitro and in vivo. Overexpression of BPC2 enhanced hypersensitivity to osmotic stress in the seedling growth stage. Overexpression of BPC2 led to decreases in LEA4-5 expression and aggravated osmotic-induced increases in HO accumulation, the MDA content, and percent electrolyte leakage. Overall, our results indicate that BPC2 negatively regulates LEA4-5 expression to modulate osmotic-induced HO accumulation, the MDA content, and percent electrolyte leakage, all of which affect the osmotic stress response in Arabidopsis thaliana.
渗透胁迫显著影响植物的生长和发育。研究参与渗透胁迫的植物转录因子可以增强我们对植物渗透胁迫耐受机制的理解，以及如何提高植物对渗透胁迫的耐受能力。在这里，我们鉴定了拟南芥 barley B 重组/碱性五肽氨酸转录因子 BPC2 在渗透胁迫反应中的特定功能。表型分析表明，BPC2 功能丧失导致幼苗生长阶段对渗透胁迫的耐受性增加。生理分析表明，拟南芥中 BPC2 的突变减轻了渗透诱导的 HO 积累、丙二醛 (MDA) 含量和电解质渗透率的增加。BPC2 定位于细胞核。RNA-seq 和 qRT-PCR 分析表明，BPC2 可以负调控晚期胚胎丰富 (LEA) 基因（LEA3、LEA4-2 和 LEA4-5）的表达。进一步分析表明，BPC2 可以在体外和体内直接结合 LEA4-5 的启动子。BPC2 的过表达增强了幼苗生长阶段对渗透胁迫的敏感性。BPC2 的过表达导致 LEA4-5 表达下降，并加重渗透诱导的 HO 积累、MDA 含量和电解质渗透率的增加。总的来说，我们的结果表明，BPC2 负调控 LEA4-5 的表达来调节渗透诱导的 HO 积累、MDA 含量和电解质渗透率，这些都影响拟南芥的渗透胁迫反应。
