The article "Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell" by M. M. Chaves, J. Flexas, and C. Pinheiro reviews the complex responses of plants to drought and salt stresses. These stresses can affect photosynthesis directly through diffusion limitations through stomata and mesophyll, alterations in photosynthetic metabolism, and indirectly through oxidative stress. The authors highlight the importance of understanding these responses for stabilizing crop performance and protecting natural vegetation under water and saline conditions. Key points include: - Plants often face soil and atmospheric water deficits and high soil salinity, which can be exacerbated by climate change. - Photosynthesis and cell growth are primary processes affected by these stresses. - The effects of drought and salt stresses are both direct and secondary, with the latter often arising from multiple stress interactions. - Plants respond quickly to these stresses by altering gene expression, even under mild conditions. - Salt stress affects more genes and more intensely than drought stress, reflecting the combined effects of dehydration and osmotic stress. - Stomatal and mesophyll conductance to CO2 are crucial for photosynthesis, and their changes under stress are regulated biochemically. - Biochemical and photochemical limitations to photosynthesis, such as de-activation of Rubisco and changes in enzyme activities, are also significant. - Signal transduction pathways, including hormones (e.g., ABA, ethylene), reactive oxygen species (ROS), and intracellular messengers, play crucial roles in stress responses. - Gene expression, proteomics, and metabolomics studies have provided insights into the dynamic changes in plant metabolism under stress. - Recovery from stress is influenced by the velocity and extent of photosynthetic recovery, which can be limited by factors such as sustained stomatal closure and impaired photosynthetic biochemistry. The authors emphasize the need for further research to understand the physiological limitations to photosynthetic recovery and to develop strategies for improving plant stress tolerance.The article "Photosynthesis under drought and salt stress: regulation mechanisms from whole plant to cell" by M. M. Chaves, J. Flexas, and C. Pinheiro reviews the complex responses of plants to drought and salt stresses. These stresses can affect photosynthesis directly through diffusion limitations through stomata and mesophyll, alterations in photosynthetic metabolism, and indirectly through oxidative stress. The authors highlight the importance of understanding these responses for stabilizing crop performance and protecting natural vegetation under water and saline conditions. Key points include: - Plants often face soil and atmospheric water deficits and high soil salinity, which can be exacerbated by climate change. - Photosynthesis and cell growth are primary processes affected by these stresses. - The effects of drought and salt stresses are both direct and secondary, with the latter often arising from multiple stress interactions. - Plants respond quickly to these stresses by altering gene expression, even under mild conditions. - Salt stress affects more genes and more intensely than drought stress, reflecting the combined effects of dehydration and osmotic stress. - Stomatal and mesophyll conductance to CO2 are crucial for photosynthesis, and their changes under stress are regulated biochemically. - Biochemical and photochemical limitations to photosynthesis, such as de-activation of Rubisco and changes in enzyme activities, are also significant. - Signal transduction pathways, including hormones (e.g., ABA, ethylene), reactive oxygen species (ROS), and intracellular messengers, play crucial roles in stress responses. - Gene expression, proteomics, and metabolomics studies have provided insights into the dynamic changes in plant metabolism under stress. - Recovery from stress is influenced by the velocity and extent of photosynthetic recovery, which can be limited by factors such as sustained stomatal closure and impaired photosynthetic biochemistry. The authors emphasize the need for further research to understand the physiological limitations to photosynthetic recovery and to develop strategies for improving plant stress tolerance.