Function of the auxin-responsive gene TaSAUR75 under salt and drought stress

Small auxin-upregulated RNAs(SAURs) are genes regulated by auxin and environmental factors. In this study, we identified a SAUR gene in wheat, Ta SAUR75. Under salt stress,Ta SAUR75 is downregulated in wheat roots. Subcellular localization revealed that Ta SAUR75 was localized in both the cytoplasm and nucleus. Overexpression of Ta SAUR75 increased drought and salt tolerance in Arabidopsis. Transgenic lines showed higher root length and survival rate and higher expression of some stress-responsive genes than control plants under salt and drought stress. Less HOaccumulated in transgenic lines than in control plants under drought stress. Our findings reveal a positive regulatory role of the auxin-responsive gene Ta SAUR75 in plant responses to drought and salt stress and provide a candidate gene for improvement of abiotic stress tolerance in crop breeding.