Genetic Engineering of Sugarcane for Drought and Salt Tolerant Transgenic Plants Expressing the BcZAT12 Gene

Abstract

Journal homepage: http://www.ijcmas.com Sugarcane (Saccharum officinarum L.) is one of the staple sources of sweetening in the world and is of substantial importance to the economy of several sugarcane producing countries. Sugarcane is a major cash crop cultivated in many parts of the world, especially in the tropics. Commercial sugarcane (Poaceae), mainly the complex aneuploidy, polyploidyinterspecific hybrids of Saccharum officinarum and S. spontaneum is a major field crop accounting for about 85 per cent of sugar production worldwide. Sugarcane crop frequently encounters abiotic stresses that adversely affect growth, development and productivity. Among the environmental stresses, Drought and Salinity affect the cane productivity and yield. Genetic engineering approach is a viable method to engineer Drought and Salt stress tolerance in crop plants. BcZAT12 gene isolated from Brassica carinata is used for sugarcane transformation in the present study. To confer abiotic stress tolerance, candidate gene pCAMBIA1300-BcZAT12was used to transform by agrobacterium mediated, the sugarcane cultivar, Co86032. Forty five independent transgenic lines of sugarcane transformed with BcZAT12 gene were generated. PCR analysis confirmed the integration of Drought and Salt stress tolerant gene BcZAT12and hygromycin (hpt) in all the 45 putative transgenic sugarcane plants found to be positive. By screening these 45 lines for the drought and salt tolerance, we identified 10 lines, which are highly tolerant to drought and salt. Out of 10 lines, 3 lines were randomly selected for morphological, physiological, biochemical and molecular analyses. These analyses revealed that growth and vigor, relative water content, photosynthetic rate, transpiration rate, stomatal conductance, chlorophyll content, proline and glycine betaine content were higher in the stress tolerant transgenic plants compared to control plants. Moreover, RT-PCR analysis revealed that highly tolerant lines exhibited a higher level of-BcZAT12‖ expression compared to less tolerant lines. In conclusion, this study has established that-BcZAT12‖ gene can confer drought and salt tolerance in sugarcane, indicating that this gene can be exploited in the improvement of other crops.