Overexpressing a NAM, ATAF, and CUC (NAC) transcription factor enhances drought resistance...
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Overexpressing a NAM, ATAF, and CUC (NAC) transcription factor enhances drought resistance and salt tolerance in rice ( Oryza sativa | abscisic acid | stomata | dehydration ) Honghong Hu *, Mingqiu Dai *, Jialing Yao , Benze Xiao *, Xianghua Li *, Qifa Zhang *, and Lizhong Xiong * *National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan) and College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China Communicated by Deborah P. Delmer, The Rockefeller Foundation, New York, NY, June 11, 2006 (received for review April 7, 2006) Drought and salinity are major abiotic stresses to crop production. Here, we show that overexpression of stress responsive gene SNAC1 (STRESS-RESPONSIVE NAC 1) significantly enhances drought resistance in transgenic rice (22-34% higher seed setting than control) in the field under severe drought stress conditions at the reproductive stage while showing no phenotypic changes or yield penalty. The transgenic rice also shows significantly improved drought resistance and salt tolerance at the vegetative stage. Compared with WT, the transgenic rice are more sensitive to abscisic acid and lose water more slowly by closing more stomatal pores, yet display no significant difference in the rate of photosynthesis. SNAC1 is induced predominantly in guard cells by drought and encodes a NAM, ATAF, and CUC (NAC) transcription factor with transactivation activity. DNA chip analysis revealed that a large number of stress-related genes were up-regulated in the SNAC1-overexpressing rice plants. Our data suggest that SNAC1 holds promising utility in improving drought and salinity tolerance in rice.