Effects of Exogenous Spermdine on Soluble Protein Expression in Cucumber Seedlings under Different Saline Concentrations

Effects of exogenous spermdine application on soluble protein expression in seedlings of cv.‘Jinchun No.2’ cucumber(Cucumis sativus L.) were conducted under different salinity treatments by hydroponic culture.The results showed that the soluble protein content both leaves and roots significantly increased under 50 mmol·L^-1,but decreased under 75 mmol·L^-1 and 100 mmol·L^-1 salt treatments.Exogenous 1 mmol·L^-1 spermdine spray applied increased the soluble protein content in leaves,but no significant changes in roots.By SDSPAGE electrophoresis analysis,61.5 kD,50 kD and 47 kD protein bands were increasing expressed in roots under 50 mmol·L^-1 and 75 mmol·L^-1 salt concentration,but not obviously expressed under 100 mmol·L^-1 salt concentration.However,when 1 mmol·L^-1 spermdine was applied,61.5 kD and 47 kD protein bands slimly expressed,interestingly,50 kD protein band disappeared even under 50 mmol·L^-1 and 75 mmol·L^-1 salt treatments,but increasing salt concentration to 100 mmol·L^-1,61.5 kD and 47 kD protein bands had not obvious changes,then 50 kD protein band expressed obviously.