Abstract: In order to determine the mechanism underlying the MeJA（methyl jasmonate）-induced defense response in grapes，the grape cell suspensions from Vitis vinifera L. × V. labrusca L.‘Kyoho’berries with being subcultured once were served as materials. The grape cells were shaking-cultured in the 100 mL B5 liquid medium，in which the MeJA were supplied to obtain the final concentration of 10 μmol ? L-1. Then the cell cultures in half of shake flasks were supplemented with 5 mL of 100 nmol ? L-1 cryptogein solution for simulating pathogenic inoculation process and then incubated for 15 days. The cell growth，intracellular H2O2 burst，expression levels of defense-related genes such as VvNPR1.1，PR1 and PR2 as well as contents of individual stilbene phytoalexins were measured at 3-day intervals. These results showed that treatment with 10 μmol ? L-1 MeJA alone could not activate the defense response in grape cells throughout the whole incubation. In contrast，the cryptogein treatment alone remarkably induced H2O2burst and promoted the expressions of PR genes and contents of individual phytoalexins. Upon challenged with the cryptogein，the 10 μmol ? L-1 MeJA-treated cells displayed a series of more significant augmented defense responses including stronger H2O2 burst，more enhanced transcript levels of defense-related genes and phytoalexins biosynthesis compared with the reaction in cryptogein elicitation alone. Since the MeJA-treated cells only showed an enhanced capacity to augment systemic resistance with the present of pathogenic elicitor，it is thus clear that 10 μmol ? L-1 MeJA triggers a defense response that can be attributed to obvious Priming mechanism in grape cell suspensions，rather than direct inducible resistance. In addition，the MeJA-induced Priming defense did not exhibit the significant influence on the growth of grape cell suspensions during the whole incubation，indicating that Priming mechanism had no negative effect on cell growth and accumulation of intercellular compounds.

Key words: grape cell suspensions, methyl jasmonate, defense response, Priming