As a main source of vegetable protein and oil, soybean growth is restrained by multiple abiotic stresses. Therefore, it is urgent to unravel the molecular mechanism of stress response for improving the stress tolerance of soybean cultivars.

The research groups led by Prof. ZHANG Jinsong and Prof. CHEN Shouyi from the Institute of Genetics and Developmental Biology (IGDB) of Chinese Academy of Sciences found that soybean miR172a improves salt tolerance and can function as a long distance signal.

Figure: Model of miR172a function in plant response to salt stress. (Image by IGDB)

 

Among their previously identified miRNAs from soybean, the gma-miR172a can be induced by salt stress and so was selected for further investigation of its role in plant response to salt stress. A series of experiments unraveled that soybean miR172a improves salt tolerance by cleaving its target gene SSAC1, an AP2-type transcription repressor gene, and relieving the SSAC1 inhibition on the thiamin biosynthesis-related gene THI1.
 

Interestingly, soybean miR172a was found to be transportable from transgenic hairy root to shoot and can function as a long distance signal in plant response to salt stress. Further manipulation of these genes may enhance stress tolerance and improve agronomic traits in soybean.
 

This work entitled “Soybean miR172a improves salt tolerance and can function as a long distance signal” has been published online in Molecular Plant.

This study was supported by the National Key Basic Research Projects, the National Transgenic Research Projects, National Natural Science Foundation of China and State Key Lab of Plant Genomics.