Photosynthetic processes in winter triticale under conditions of sodium chloride salinity

Abstract

Study of the functional state of the photosynthetic apparatus in winter triticale under conditions of salinity (120 mM NaCl) has been carried out. It is shown that the initial stress response (up to 24–48 hours) is characterized by a 35% reduction in stomatal conductance, an increase in the RuBisCo activity (up to 37 μmol NADH/min g), and a high rate of electron transport (up to 502 μmol DCPIP/mg Chl h). The response of plants after 48 hours of salinity is associated with a significant increase in stomatal conductance (up to 68.3 nmol/m2 s), as well as the decline in rate of electron transport (up to 222 μmol DCPIP/mg Chl h), the RuBisCo activity (up to 22 μmol NADH/min g), and the rate of photosynthesis (up to 10.96 μmol CO2/m2 s). In addition, plants preserve their functional photosynthetic apparatus under conditions of continuous salinity (lasting for more than 48 h) reducing the efficiency of photosynthesis.