Electrical and photosynthetic response of Rosa chinensis under drought stress

Plants develop a series of mechanisms under drought stress, involving changes in chemical, physiological, and electrical signals. Measurement of these signal changes could reflect the growth status of plants under adversity stress. Aim of this study was to investigate the changes in water potential, photosynthetic parameters (i.e., net photosynthesis rate, transpiration rate, stomatal conductance, and the concentration of inter-cellular CO2), and electrical signals (peak-to-peak value, mean value, gravity frequency, power spectral entropy) of Rosa chinensis under drought stress. Analysing these parameters fills in the research need to have a comprehensive understanding of plants' responses to drought stress. The results show all parameters present an overall decreasing trend, except the concentration of inter-cellular CO2 and peak-to-peak value. There is a slight recovery at the end of the drought treatment, indicating that plants are adapted to the new level of drought status. Besides, most of the electrical signals (mean value, gravity frequency, power spectrum entropy) and water potential first showed significant differences (P < 0.05) from the control, followed by photosynthetic parameters, and transpiration. This result, combined with the results on the correlation between these parameters, indicates that changes in electrical signals can reflect physiological processes in plants. Therefore, this study reveals that electrical signals could serve as an early and accurate indicator to reflect the growth status of plants under drought stress, which provides a theoretical basis for the water management of Rosa chinensis.