Enhancement of salt tolerance in soybean with NaCl pretreatment

Abstract

Acclimation response to salt stress in soybean ( Glycine max [L.] Merr. cv. Lee) was found in this study. Soybean seedlings were exposed to 0, 34 and 68 m M NaCl for 23 days (pretreatment), thereafter plants were exposed to 0, 68 and 137 m M NaCl until maturity (main treatment). There was no effect of pretreatment on growth, but at 137 m M NaCl, Na + concentration in leaves of the plants pretreated with 34 m M NaCl was lower than that of plants pretreated with 0 and 68 m M NaCl. Furthermore, the survival rate under 137 m M NaCl improved with the 34 m M NaCl pretreatment. Therefore, it is possible that soybean can acclimate to salt stress by its increased survival rate, without showing any improvement in growth. The regulation of Na + or Cl − concentration in leaves could be one of the possible factors involved in salt acclimation of soybean.