Identificatioan and investigation of DRO1 gene in rice cultivar Hashemi and its simultaneous transfer with OsCKX4 gene to improve root structure

Improvement of the root architecture lead to higher grain yield and seed quality. This is achieved via improvement of the plant growth, better establishment in soil, higher absorption of water and nutrition resulting in the biosynthesis of the essential amino acids and hormones. It increases the efficiency of the nutrition usage and the stress tolerance. Drought conditions are a serious challenge in Iran; therefore, improving crop tolerance has a major importance. In this study, we investigate the presence of DRO1 gene, which is involved in the modification of the root growth angle, in rice cultivar Hashemi and compared to the Kinandang Patong cultivar. We further analyze the simultaneous presence of DRO1 and a second gene, OsCKX4, which is involved in the improvement of root structure. DRO1 and OsCKX4 are cloned together in a single construct under the control of the ubiquitin and the root specific promoters, respectively. The resulting construct, pUhrCkDro is transformed into the Agrobacterium tumefactions strain EHA105 and used for the gene transformation into Hashemi cultivar. Putative transgenic plants, survived on 50 mg. L−1 Hygromycin during tissue culture steps, are transplanted into the Yoshida solution and then into the pots until they set seeds. Construct specific and gene specific PCR analysis are used to confirm the transgenic plants. Transgenic plants show stronger root structure compared to the non-transgenic ones. Molecular analysis in the T1 and T2 generations leads to the homozygous events. The multi-genic construct used in this study, can be introduced into other crops for the aim of root structure improvement and drought tolerance. It is hoped that the production of transgenic rice with enhanced root structure results in improving drought tolerance, reducing water consumption and enhancing yield under drought stress conditions.