GsTIFY10, a novel positive regulator of plant tolerance to bicarbonate stress and a repressor of jasmonate signaling.

Recent discoveries show that TIFY family genes are plant-specific genes involved in the response to several abiotic stresses, also acting as key regulators of jasmonate signaling in Arabidopsis thaliana. However, there is limited information about this gene family in wild soybean, nor is its role in plant bicarbonate stress adaptation completely understood. Here, we isolated and characterized a novel TIFY family gene, GsTIFY10, from Glycine soja. GsTIFY10 could be induced by bicarbonate, salinity stress and the phytohormone JA, both in the leaves and roots of wild soybean. Over-expression of GsTIFY10 in Arabidopsis resulted in enhanced plant tolerance to bicarbonate stress during seed germination, early seedling and adult seedling developmental stages, and the expression levels of some bicarbonate stress response and stress-inducible marker genes were significantly higher in the GsTIFY10 overexpression lines than in wild-type plants. It was also found that GsTIFY10 could repress JA signal transduction. The roots of plants overexpressing GsTIFY10 grew longer than wild-type in the presence of MeJA, and some JA response and JA biosynthesis marker genes were suppressed in the GsTIFY10 overexpression lines. Subcellular localization studies using a GFP fusion protein showed that GsTIFY10 is localized to the nucleus. These results suggest that the newly isolated wild soybean GsTIFY10 is a positive regulator of plant bicarbonate stress tolerance and is also a repressor of jasmonate signaling, from hormone perception to transcriptional activity.