Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education, Heilongjiang University, Harbin 150080, China.
National Sugar Crop Improvement Centre, College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin 150080, China.
Int J Mol Sci. 2021 Apr 1;22(7):3669. doi: 10.3390/ijms22073669.
The basic/helix-loop-helix (bHLH) transcription factor (TF) plays an important role for plant growth, development, and stress responses. Previously, proteomics of NaCl treated sugar beet leaves revealed that a bHLH TF, , was significantly increased under salt stress. The BvbHLH93 protein localized in the nucleus and exhibited activation activity. The expression of was significantly up-regulated in roots and leaves by salt stress, and the highest expression level in roots and leaves was 24 and 48 h after salt stress, respectively. Furthermore, constitutive expression of conferred enhanced salt tolerance in as indicated by longer roots and higher content of chlorophyll than wild type. Additionally, the ectopic expression lines accumulated less Na and MDA, but more K than the WT. Overexpression of the enhanced the activities of antioxidant enzymes by positively regulating the expression of antioxidant genes and . Compared to WT, the overexpression plants also had low expression levels of and , which are involved in reactive oxygen species (ROS) production. These results suggest that plays a key role in enhancing salt stress tolerance by enhancing antioxidant enzymes and decreasing ROS generation.
该 bHLH 转录因子（TF）在植物生长、发育和应激反应中起着重要作用。先前，盐处理甜菜叶片的蛋白质组学研究表明，bHLH TF 显著增加了盐胁迫下的表达。BvbHLH93 蛋白定位于细胞核并表现出激活活性。盐胁迫下， 的表达在根和叶中显著上调，盐胁迫后 24 和 48 小时，根和叶中的表达水平最高。此外，组成型表达 赋予了 增强的耐盐性，表现在根更长，叶绿素含量更高。此外，异位表达系积累的 Na 和 MDA 比 WT 少，但 K 更多。过表达 通过正向调控抗氧化基因 和 的表达来增强抗氧化酶的活性。与 WT 相比，过表达植物的 和 ，参与活性氧（ROS）产生的基因表达水平也较低。这些结果表明， 通过增强抗氧化酶和减少 ROS 生成，在增强盐胁迫耐受性方面发挥着关键作用。
