Abiotic stresses like salinity and drought directly affect plant growth and water availability, resulting in lower yield in rice. Salinity and drought tolerance mechanisms are very complex and usually regulated by multiple genes. Moreover, along with stress tolerance, enhanced grain yield is also a major focus of rice breeding. Previous studies separately showed that mutations or loss in function of the drought and salt tolerance (DST) gene results in abiotic stress tolerance and enhanced yield in rice. So, in our study, we attempted to obtain the combination of simultaneous stress tolerance and improved grain yield in the commercial but salt sensitive, high-yielding rice variety BRRIdhan 28 (BR28) by downregulating DST using artificial microRNA (amiRNA). DST_amiRNA transformed plants at T0 generation showed vigorous growth with significantly higher yield, compared to the wild type (WT) BR28. Moreover, T1 transgenic plants also showed improvement in a number of physiological parameters and greater growth compared to WT after 14 days of 120 mM salt (NaCl) stress at seedling stage. So, results obtained from the studies at T0 and T1 generations are immensely promising and put a landmark in obtaining the combination of simultaneous stress tolerance as well as better yields in DST downregulated transgenic plants.
Article link: http://file.scirp.org/Html/16-2603305_78500.htm