Identification and Characterization of a Stress-Inducible Gene OsNLI-IF Enhancing Drought Tolerance in Transgenic Tobacco

Plants respond to the adverse environment by activat-ing a series of stress-inducible genes, including genes encoding transcription factors. The expression of these genes is regulated by a core DNA sequence con-tained in their promoter region called cis-acting element. The promoter region of several stress-responsive genes contains several stress-regulated cis-acting elements such as dehydration-responsive element, C-repeat, low-temperature-responsive element, NAC recognition sequence and ZFHD recognition sequence. In this study we isolated a cDNA for a transcription factor named nuclear LIM interactor-interacting fac-tor from rice cDNA library by yeast one-hybrid screening using two target sequences of 50 nucleotides derived from two stress-inducible promoters, JRC0528 and JRC0332, of cold-inducible genes OsZF1 and OsNAC6 respectively, as baits. The NLI-IF protein showed both DNA-binding and transcriptional activities in yeast experiments. Expression of OsNLI-IF was found to be induced by cold, heat, salt and drought stresses. The OsNLI-IF gene overexpressing transgenic tobacco plants showed improvement in drought tolerance. The present study emphasizes that OsNLI-IF could be useful for development of drought-tolerant transgenic crop plants.