Overexpression of PavbHLH28 from Prunus avium enhances tolerance to cold stress in transgenic Arabidopsis
Xuejiao Cao, Zhuang Wen, Tianjiao Shen, Xiaowei Cai, Qiandong Hou, Chunqiong Shang, Guang Qiao
Abstract
BACKGROUND: The basic helix-loop-helix (bHLH) gene family is one of plants' largest transcription factor families. It plays an important role in regulating plant growth and abiotic stress response. RESULTS: , the transcript level of PavbHLH28 was affected. At low temperature, overexpression of the PavbHLH28 gene enhanced the cold resistance of plants with higher proline content, lower electrolyte leakage (EL) and malondialdehyde (MDA) content. Compared with the WT plants, the transgenic plants accumulated fewer reactive oxygen species (ROS), and the activity and expression levels of antioxidant enzymes were significantly increased. The expression of proline synthesis enzyme genes was up-regulated, and the transcripts levels of degradation genes were significantly down-regulated. The transcripts abundance of the cold stressed-related genes in the C-repeat binding factor (CBF) pathway was not significantly different between WT plants and transgenic plants after cold stress. Moreover, the PavbHLH28 could directly bind to the POD2 gene promoter and promote its gene expression. CONCLUSIONS: Overall, PavbHLH28 enhanced the cold resistance of transgenic plants through a CBF-independent pathway, which may be partly related to ROS scavenging.