Approaches to improving salt tolerance in maize

Abstract

Maize is a salt-sensitive crop and is affected even by low concentrations of salt, leading to loss in crop production Changing climate conditions (environmental stress) have forced plant biologists to explore alternate strategies to make maize plants salt tolerant. Breeding for salt resistance is difficult because it is a multigenic trait. When conventional breeding fails to meet the challenges imposed by these stresses, plant scientists shifted to marker-assisted selection and transgenic approaches. Genetic transformation have been proven to be successful. It has shown that over-expression of tonoplast Na+/H+ antiporters in plants resulted in improved salt resistance in plants. Currently, a vast number of gene regulatory elements, including si- and mi-RNA have been identified either leading to salt tolerance or resulting from salinity stress. Engaging the right elements on a case-by-case basis may provide answers to this long-standing problem. As with most complex systems, a combination of conventional breeding, exploiting physiological knowledge, transgenic approaches and field based testing is perhaps the way forward to address salinity problem in maize.