Salinity, waterlogging, and elevated [CO2] interact to induce complex responses in cultivated and wild tomato

The interaction of salinity and waterlogging with elevated [CO2] caused distinct phenotypes of cultivated and wild tomatoes, with elevated [CO2] alleviating the negative impact of the stresses on cultivated tomato. The effects of individual climatic factors on crops are well documented, whereas the interaction of such factors in combination has received less attention. The frequency of salinity and waterlogging stress is increasing with climate change, accompanied by elevated CO2 concentration (e[CO2]). This study explored how these three variables interacted and affected two tomato genotypes. Cultivated and wild tomato (Solanum lycopersicum and Solanum pimpinellifolium) were grown at ambient [CO2] and e[CO2], and subjected to salinity, waterlogging, and combined stress. Leaf photosynthesis, chlorophyll fluorescence, quenching analysis, pigment, and plant growth were analyzed. The response of tomatoes depended on both genotype and stress type. In cultivated tomato, photosynthesis was inhibited by salinity and combined stress, whereas in wild tomato, both salinity and waterlogging stress, alone and in combination, decreased photosynthesis. e[CO2] increased photosynthesis and biomass of cultivated tomato under salinity and combined stress compared with ambient [CO2]. Differences between tomato genotypes in response to individual and combined stress were observed in key photosynthetic and growth parameters. Hierarchical clustering and principal component analysis revealed genetic variations of tomatoes responding to the three climatic factors. Understanding the interacting effects of salinity and waterlogging with e[CO2] in tomato will facilitate improvement of crop resilience to climate change.

Automated summary

The interaction of salinity and waterlogging with elevated CO2 affects the phenotypes of tomatoes, with elevated CO2 alleviating the negative impact of stresses on cultivated tomato. The response of tomatoes depends on genotype and stress type, and elevated CO2 can increase photosynthesis and biomass of cultivated tomato under salinity and combined stress.