Overexpression of OsTZF8, a CCCH-Tandem Zinc finger, increases drought tolerance in rice

Abstract

Tandem CCCH zinc finger proteins (TZFs), members of the zinc finger protein family, have been known to participate as post-transcriptional regulators of gene expression in eukaryotes. However, the function of TZF as a drought stress-related gene remains unclear. Here, we show that the OsTZF8, a rice gene for tandem CCCH zinc finger protein, is induced by abiotic stress and its transgenic rice plants overexpressing OsTZF8 increases drought tolerance. Gene expression analysis revealed that OsTZF8 is specifically expressed in embryo, but not in vegetative organs. In field evaluation, grain yield and seed size were higher in the transgenic plants with constitutive overexpression than non-transgenic plants under drought conditions. OsTZF8 not only localizes in the nucleus, but also co-localizes with both processing bodies and stress granules, two messenger ribo-nucleoprotein complexes which are known to activate by forming cytoplasmic foci under stress conditions. Taken together, these results suggest that OsTZF8 participates in RNA turnover in processing bodies and stress granules regulating drought stress in rice.