New progress has been made in the study of stress tolerance of soybean

Zhang Jinsong Research Group and Chen Yiyi Research Group of Institute of Genetics and Developmental Biology of Chinese Academy of Sciences identified a series of soybean miRNA in previous studies. This study found that the expression of miR172a in these miRNA was induced by salt stress. The function of miR172a was deeply studied by using soybean hairy root transformation system.

The results showed that the salt tolerance of soybean was significantly enhanced after overexpression in hairy roots. A series of experiments have found that miR172a cleaves and degrades the target gene SSAC1, relieving the inhibition of its protein on the promoter of thiamine (vitamin B) precursor synthase gene THI1, thus promoting THI1 expression, thiamine synthesis and salt tolerance of soybean. In addition, through the grafting experiment, it was found that miR172a could be transported as a long-distance signal molecule from soybean transgenic hairy root to aboveground and regulate the expression of target genes and downstream genes.

This study provides an important theoretical basis for revealing the stress tolerance mechanism of soybean and improving the stress tolerance of soybean.