Zinc-finger protein GmZF351 improves both salt and drought stress tolerance in soybean

Abiotic stress is one of the most important factors reducing soybean yield. It is essential to identify regulatory factors contributing to stress responses.A previous study found that the tandem CCCH zincfinger protein Gm ZF351 is an oil level regulator. In this study, we discovered that the Gm ZF351 gene is induced by stress and that the overexpression of Gm ZF351 confers stress tolerance to transgenic soybean. Gm ZF351 directly regulates the expression of Gm CIPK9 and Gm SnRK, leading to stomata closing, by binding to their promoter regions, which carry two CT(G/C)(T/A)AA elements.Stress induction of Gm ZF351 is mediated through reduction in the H3K27me3 level at the Gm ZF351locus.TwoJMJ30-demethylase-likegenes,Gm JMJ30-1 and Gm JMJ30-2, are involved in this demethylationprocess.Overexpressionof Gm JMJ30-1/2 in transgenic hairy roots enhances Gm ZF351 expression mediated by histone demethylation and confers stress tolerance to soybean.Yield-related agronomic traits were evaluated in stable Gm ZF351-transgenic plants under mild drought stress conditions. Our study reveals a new mode of Gm JMJ30-Gm ZF351 action in stress tolerance, in addition to that of Gm ZF351 in oil accumulation. Manipulation of the components in this pathway is expected to improve soybean traits and adaptation under unfavorable environments.