Effects of Exogenous Salicylic Acid on Endogenous Polyamine Levels in Leaves of the Yali Pear

摘要

In this paper changes of endogenous polyamine levels and polyamine synthesis enzyme activity in leaves of the Yali Pear were studied. In order to reduce environmental effects on results, leaf disk tests were first used to confirm whether the salicylic acid affected the metabolism of polyamines. The results show that in the leaf disk experiment, exogenous salicylic acid changes the endogenous polyamine levels, and different SA concentrations have different effects. Puterescine concentration levels reach a peak in 2 hours; endogenous spermidine concentration levels reach a peak in 4 hours; and endogenous spermine concentration levels reach a peak in 10 hours. After SA treatments arginine decarboxylase and ornithine decarboxylase activities in the leaves are higher than that in the control, and ADC responds earlier than ODC. The field test results show that, salicylic acid significantly increases Put and Spd contents during the period of 26 May to 26 July, which is during the flower bud physiological differentiation period. However, salicylic acid has no significant effect on Spm content. SA has positive effects on the ADC activity, but has no significant effect on ODC activity.