Integrative Role of Ethylene, Abscisic Acid, and Salicylic Acid in Tomato under Salt Stress

Salt stress is a serious limitation to tomato productivity affecting ion homeostasis, causing oxidative damage, and hampering growth at the seedling and reproductive stage. Over the past few years, however, it has been demonstrated that phytohormones have a significant role in the control of the salinity tolerance in tomato and thus their integrative mechanism has not been completely established. This review summarizes the current information about the unique and interactive action of ethylene (ET), abscisic acid (ABA) and salicylic acid (SA) in the process of salinity-induced tomato responses. The effects of ethylene are ionic transport control, root structure and expression of stress sensitive gene and the dominant role of ABA in osmotic regulation and stomatal control and antioxidant defense. Salicylic acid participates in the support of redox balance, preservation of mitochondria and generalized acquired tolerance. Notably, we also show the complexity of crosstalk between the ET, ABA and SA signaling network; however, all of which refine tomato resilience in a quality product of constructive interaction and antagonism. However, much remains to be explored as to the threshold hormone specific and spatiotemporal control and the responses are genotype specific. It is extremely important to be able to fill in these gaps to make use of the response provided by hormones in the process of enhancing tolerability of salts in tomato breeding and controlling the crop.