Individual Effects of High Temperature and Tropospheric Ozone on Tomato: A Review

Abstract

Rising tropospheric ozone (O3) and temperature, the two most important stresses caused due to climate change. Both stresses have now become foremost concerns for production of tomato worldwide due to their role in immensely afflicting productivity. These stresses have been found to occur concomitantly, and tomato is very sensitive to both heat stress and elevated O3. This paper reviews the individual effects of high temperature and elevated O3 on the overall performance of tomato and the defense strategies responsible for varying sensitivities among the genotypes. High temperature influences photosynthesis directly, and Fv/Fm ratio was widely used in identifying the sensitivity of tomato cultivars. It also affects pollen viability and germination, which ultimately results in the decline of fruit set and yield. Phytohormones are crucial for reducing the negative impacts of high temperature on tomato. Besides, several heat-shock proteins and factors and stress-regulated genes were upregulated in tomato under heat stress. An increase in surface O3 level causes reductions in photosynthesis, biomass accumulation, pollen viability, fruit quality, and yield. Various molecular and physiological processes deployed during elevated O3 conditions are believed to be intervened by signaling molecules like ethylene and jasmonic acid. The review concludes that responses of tomato to both the stresses are somewhat similar, but their nature and effects may vary with intensity and duration of stresses, genotypes, and other environmental factors. Since these stresses occur simultaneously, their combined effects need to be understood to avoid the yield losses under future scenarios of climate change. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.