Salicylic acid, ethephon, and methyl jasmonate induce the expression of phospholipase D in mechanically-wounded cucumber

Abstract

SummaryPhospholipase Dα (PLDα) has been implicated in several responses to stress, including mechanical wounding. The effects of salicylic acid (SA), ethephon (ETH), or methyl jasmonate (MeJA) on the levels of wound-induced PLDα gene transcripts were studied in cucumber fruit. The relative levels of expression of the PLDα gene induced by wounding following SA, ETH, or MeJA pre-treatment were detected by quantitative real-time PCR analysis. Wounding increased the level of expression of the PLDα gene 4 h after stress. MeJA and ETH pre-treatments activated expression of the PLDα gene, but the stimulatory effect of MeJA was greater than that of ETH, with the highest level of expression observed 24 h after wounding, with a MeJA pre-treatment. SA did not have any significant effect on expression of the PLDα gene. The levels of PLDα gene expression were almost the same in intact and wounded cucumber fruit 4 h after wounding, with a SA pre-treatment. In conclusion, MeJA or ETH pre-treatment stimulated expression of the PLDα gene following mechanical wounding. We speculate that MeJA and ETH may be involved in the signalling pathway in response to mechanical wounding.