LAUSR

Temperature and humidity play an important role in plant-pathogen interactions. However, regulating the temperature and humidity specifically to inhibit the development of plant diseases remains unclear. In this study, we explored the influence of intermittent temperature and humidity variation on tomato gray mold. Intermittent regulation of temperature and humidity (increasing temperature with decreasing humidity for different periods within 24 h) inhibited the disease severity of plants and the infection process of Botrytis cinerea. The 4h treatment (increasing temperature accompanied by decreasing humidity for 4 h and recovering for 4 h, and so on) effectively inhibited the development of tomato gray mold, reduced the biomass of B. cinerea, delayed the differentiation time of mycelia, and inhibited the accumulation of H2O2 in tomato leaves at the later stage of infection. The increased expressions of HSP20, HSP70, HSP90, BAG6, and BAG7 in tomatoes were mainly caused by environmental changes and environment-plant-pathogen interactions, and the increased expression of the latter was greater than that of the former in the 2h (increasing temperature accompanied by decreasing humidity for 2 h and recovering for 2 h, and so on) and 4h treatments. Pathogen infection induced the expression of defense-related genes in tomatoes, and the increase in the expressions of FLS2, FEI1, PI2, Pti5, and WRKY75 induced by B. cinerea in the 4h treatment was greater than that under unregulated temperature and humidity conditions. In general, intermittent temperature and humidity variation can effectively inhibit the development of tomato gray mold, and the 4h treatment had the best inhibitory effect.