Methyl jasmonate is a potent elicitor of multiple defense responses in grapevine leaves and cell-suspension cultures

Treatment with methyl jasmonate (MeJA) stimulates a multicomponent defense response in leaves and suspension-cultured cells of grapevine (Vitis vinifera L. cv. Limberger). MeJA induces development of necrotic lesions, similar to that normally associated with resistance to avirulent pathogens. Sustained exposure of both leaves and cell-suspension cultures to 50 muM MeJA provoked hypersensitive cell death, stimulated medium alkalinization accompanied by massive callose deposition, but did not induce accumulation of hydrogen peroxide from the oxidative burst. Transcripts of genes encoding diverse families of the pathogenesis-related proteins accumulated rapidly after MeJA application, followed by salicylic acid production. After several days systemic accumulation of a large number of defense-associated proteins, including pathogenesis-related proteins, peroxidase, cell wall extensin and enzymes involved in the phenylpropanoid biosynthetic pathway was induced. These cumulative results suggest that grapevine cells that perceived MeJA generated a cascade of events acting at both local and long distances, and causing the sequential and coordinated expression of specific defense responses with a timing and magnitude similar to the typical hypersensitive response against pathogens.