The Defferent Respone of P. euphratica to Peg and NaCL

P. euphratica was treated respectively with NaCl and PEG solutions with isomotic potential Under isomotic potential,ABA and Polyamine contents increased earlier under NaCl treatments than that under PEG treatment,and increments were higher under NaCl treatments than that under PEG treatment,indicating that P. euphratica was more sensitive to specific ion toxicity than to non-specific osmotic stress Thus it can be postulated that salt stress signal is a complex signal composed by non-specific osmotic stress signal and specific ion toxicity signal,and those two signals are additive. Therefore,under isomotic potential,stress intensity caused by NaCl was higher than that caused by PEG. In the processes of stress communication,ABA is a signal substance Difference of stress intensity induces difference in ABA contents which will further induce the difference in metabolic adjustment and growth adjustment.