Exogenous salicylic acid increases the heat tolerance in Tomato (Solanum lycopersicum L) by enhancing photosynthesis efficiency and improving antioxidant defense system through scavenging of reactive oxygen species

Heat stress seriously inhibits plant growth and development through damage the photosynthetic components and antioxidant enzymes functions. Salicylic acid (SA) is an important growth hormone regulator for combating heat stress, but its roles in response to high temperature in tomato are largely unknown. The present study was undertaken with a view to investigate the functional along with the potentiality of SA and how to nullify the adverse effects of heat stress (42 °C) in tomato seedlings. Our findings revealed that supplementation of 1 mM SA enhanced the gas exchange parameters (Pn, Gs, Ci, Tr, Ls), maximum quantum yield of photosystem II (Fv/Fm), water use efficiency, reduced electrolyte leakage and increased the antioxidant enzymes (SOD, POD, CAT, and APX) activity that…