Co-expression of AtNHX1 and Bar Genes Improves Both Salinity and Herbicide Tolerances in Mungbean

Mungbean (Vigna radiata) is a crop extensively cultivated in Southeast Asia for supply of easily digestible protein. However, salinity severely limits the growth and productivity of mungbean, while weeding poses nutritional and disease constraints to mungbean cultivation. To pyramid both salt tolerance and protection against herbicide in mungbean, Sanjeev Kumar from Indian Institute of Technology Guwahati co-expressed the AtNHX1 gene, encoding tonoplast Na+/H+ antiporter from Arabidopsis, and the bar gene, associated with herbicide resistance, in mungbean through Agrobacterium-mediated transformation.

Stress inducible expression of AtNHX1 significantly improved the tolerance to salt stress of transgenic mungbean plants compared to the wild type (WT) plants. Meanwhile, expression of bar provided resistance to herbicide. Compared to WT, transgenic mungbean plants grew better under high salt stress in the greenhouse. Transgenic plants also showed better intracellular ion homeostasis, osmoregulation, reduced cell membrane damage, improved photosynthetic capacity, and transpiration rate as compared to WT under salt stress.

This study presents a good foundation for improving mungbean yield in saline lands in Southeast Asia.

For more on this study, read the article in Frontiers in Plant Science.