Transgenic Approaches of Improving Tomato (Solanum lycopersicum) to Salt Stress Tolerance

Environmental stresses mainly drought and salinity are now becoming potential threats for global agricultural production. Being a tropical crop, tomato is produced in warm and dry regions of the world, where salt stress is limiting the yield potential of the crop. Plant defense response to salt tolerance is very complex in which many morphological, physiological, and molecular modifications are enhanced. Although considerable effort has been made in developing salt tolerant tomato cultivars through conventional breeding, it has met with limited success due to the complex, multigenic nature of the trait and developmental stage regulated phenomenon of the salt tolerance response. Genetic engineering is an alternative approach to understand the mechanisms of salinity tolerance and apply the knowledge obtained to generate salt tolerant tomatoes. This review aims to highlight the latest developments in biotechnological techniques of improving tomato tolerance to salt stress. Recently, there have been many attempts to enhance tomato tolerance to salt stress including introduction and/or modifications of various genes involved in regulatory, signaling pathways, detoxifying enzymes and genes encoding functional and structural proteins. Plasma membrane Na+/H+ antiporters (SOS) and vacuolar Na+/H+ antiporters (NHXn), Dehydrin (DHN), Choline Oxidase (codA), and ROS scavengers have been the major genes targeted in many studies for developing salt stress tolerant transgenic tomato. Moreover, promising results have reported on the identification and use of various abiotic stress responsive elements and/or transcription factors such as SlDREB2, SL-ZH13, Sl-ERF.B.3, AREB, NAC-Type and WRKY TFs, which positively regulate the expression of the downstream genes in transgenic tomato with response to salt stress.Keywords׃ Salt Stress, Tomato, Transgenic, Transcription FactorDOI: 10.7176/JBAH/10-14-01Publication date:July 31st 202