Studies on expression of transciptional factor genes GmNAC092, GmNAC083 and GmNAC057 in response to drought stress of two soybean varieties Williams 82 and Mtd777-2 for enhancing drought tolerance by genetic engineering
Keywords:Drought stress, GmNAC057, GmNAC083, GmNAC092, soybean.
Soybean is a drought-sensitive crop, thus their productivity is significantly affected by this factor. Among two soybean varieties studied, based on the evaluation of root and shoot growth and architecture under drought treatment and normal condition, our results showed that MTD777-2 is more drought-resistant than the control Williams 82. The quantitative Realtime-PCR results of different tissue samples showed that there was an over expression of GmNAC092 in both shoot and root of MTD777-2 under drought condition compared to that under normal condition. Meanwhile, the expression increase of GmNAC092 in William 82 was significantly lower than that in MTD777-2. As a result, we conclude that GmNAC092 is a potential positive regulator for drought response in soybean. The expression of GmNAC057 in specific tissues of MTD777-2 was lower than that of Williams 82 under both conditions ; however, there was an up-regulation of GmNAC057 under water stress. This showed that negative regulating role of GmNAC057 was still unclear. Besides that, GmNAC083 showed a significant expression reduction in root tissue of MTD777-2 under drought treatment, as well as a lower expression in MTD777-2 than in Williams 82. Therefore, GmNAC083 might be a negative regulator in drought response of root tissue in soybean. These selected candidate genes can be used later for enhancing drought-tolerance of soybean via genetic engineering.