Effects of transgenerational exposure to elevated atmospheric CO2 concentration on the growth and photosynthesis of Ricinus communis under salt stress

The elevated CO2 concentration (e[CO2]) and soil salinisation are critical global challenges. This study used castor (Ricinus communis) as the research material to investigate the modifications caused by salt stress on the growth, photosynthesis, chlorophyll fluorescence, and photosynthetic pigments of castor plants after two consecutive generations grown under either ambient CO2 concentration (a[CO2]) or e[CO2] conditions. The results revealed that salt stress significantly reduced biomass, photosynthetic parameters, chlorophyll fluorescence, and photosynthetic pigments in both a[CO2] and e[CO2] plants. Notably, increasing salt concentrations enhanced NPQ and WUE in both groups, particularly in the e[CO2] plants, demonstrating that transgenerational e[CO2] exposure intensified salt stress impacts.