The Role of Calcium in Mediating SlIAAs Expression in Tomato Pedicel Explants

In order to illuminate the effect of calcium on the IAA signal transduction,we studied the expression of eight SlIAA genes which were up-regulated by calcium during the abscission after short-term(1 h) and long-term(16 h) treatments with calcium,IAA and calcium inhibitors.The results indicated that calcium induced SlIAAs expression in 1 h at low concentration,EGTA affected little SlIAAs expression;it also increased IAA-induced transcript level of SlIAAs,TFP(named trifluoperazine) decreased most SlIAAs expression below the level of calcium combined with IAA-induced expression,except for SlIAA17.Long-term treatment of calcium or calcium inhibitors suppressed some SlIAAs expression,whereas TFP enhanced all SlIAAs expression.Interestingly,SlIAA29 was induced by most treatments excluding 16 h EGTA.