Response of photosynthetic efficiency to short-term fluctuating light and cold in tomato

Climate-resilient crops are crucial for meeting global food demand and increasing crop productivity. Photosynthesis, a crucial process, is impacted by environmental changes such as temperature and irradiance. Photosynthesis and stomatal opening often lag behind these changes, resulting in a loss in Light Use Efficiency (LUE). Temperature variations also affect photosynthesis, with a decrease below the optimal threshold resulting in a decrease in photosynthetic efficiency. To enhance photosynthetic LUE, understanding plant responses to environmental changes is essential. This study examines the short-term responses of four tomato genotypes to irradiance fluctuations using chlorophyll fluorescence and the effects of transient cold stress. The results show genotype-to-genotype variation in the maximum quantum efficiency of PSII, the kinetics of the quantum efficiency of PSIIs response to step changes in irradiance, and steady-state values of {Phi}PSII, which is used as a stand-in for photosynthetic efficiency. The control conditions were measured at 24{degrees}C and the cold stress conditions at 14{degrees}C. The fact that {Phi}PSII responds dynamically to step decrease and increase in irradiance and how cold impacts these responses illustrates the way tomato genotypes are impacted by cold stress. It also reveals how the genotypes adapt to cold exposure and recover once the cold stress is reversed. HighlightThis study investigates the adaptation and recovery of four tomato genotypes to irradiance fluctuations and transient cold stress, highlighting the importance of climate-resilient crops for food demand.