Response of photosynthesis of Pisum sativum to salt stress as affected by methyl jasmonate

10(-5) M methyl jasmonate (JA-Me) treatment itself did not considerably change the (CO2)-C-14 fixation, parameters of room temperature chlorophyll fluorescence induction, proline content, and Naf as well as Cf accumulation. Salt stress (30 mM NaCl) lead to a decrease of both (CO2)-C-14 fixation and relative water content, and to an increase of proline content. Immediate nonvariable fluorescence (F-0) also increased and the variable to maximal fluorescence ratio (F-v/F-m) decreased. Pretreatment with JA-Me for 3 d before salt treatment diminished the inhibitory effect of NaCl on the rate of (CO2)-C-14 fixation, protein content, and activity and content of ribulose-1,5-bisphosphate carboxylase/oxygenase. The Na+ and Cl- contents in leaves decreased in JA-Me pretreated plants. The JA-Me pretreatment prevented the increase of F-0 level and restored the values of F-v/F-m.