Various physiological characteristics of Cj and C4 plants (14 species) grown along a salinity gradient were studied. The majority of plants occupying salt-marshes were succulent chenopods, mainly C4 annuals. The ash content of assimilating organs of plants was higher and osmotic potential lower in species grown under increasing soil salinity. The plants of the NADP-ME group accumulated more K than Na. Large amounts of Na"^ and CT characterized the NAD-ME plants and perennial C3 plants from sites with high soil salinity, Net photosynthetic rate (P^) and chlorophyll content were decreased in species grown under high salinity. Dark respiration was depressed by salinity to a lesser extent than P^.
10-5 M methyl jasmonate (JA-Me) treatment itself did not considerably change the 14CO2 fixation, parameters of room temperature chlorophyll fluorescence induction, proline content, and Na+ as well as Cl- accumulation. Salt stress (30 mM NaCl) lead to a decrease of both 14CO2 fixation and relative water content, and to an increase of proline content. Immediate nonvariable fluorescence (F0) also increased and the variable to maximal fluorescence ratio (Fv/Fm) decreased. Pretreatment with JA-Me for 3 d before salt treatment diminished the inhibitory effect of NaCl on the rate of 14CO2 fixation, protein content, and activity and content of ribulose-1,5-bisophosphate carboxylase/oxygenase. The Na+ and Cl- contents in leaves decreased in JA-Me pretreated plants. The JA-Me pretreatment prevented the increase of F0 level and restored the values of Fv/Fm. and M. Velitchkova, I. Fedina.