Accumulation of chloroplast-targeted lipoxygenase in passion fruit leaves in response to methyl jasmonate.
Wounding caused local and systemic induction of lipoxygenase (LOX) activity in passion fruit (Passiflora edulis f. flavicarpa) leaves, while exposing intact plants to methyl jasmonate (MJ) vapor provoked a much stronger response. Western blot analysis of these leaf protein extracts using polyclonal antibodies against cucumber LOX, revealed an accumulation of a 90 kDa protein, consistent with LOX enzymatic assays. The inducible LOX was purified to apparent homogeneity, and in vitro analysis of LOXactivity using linoleic acid as substrate showed that it possesses C-13 specificity. Immunocytochemical localization studies using leaf tissue from MJ-treated plants demonstrated that the inducible LOX was compartmented in large quantities in the chloroplasts of mesophyll cells, associated with the stroma. The results suggest that the wound response in passion fruit plants may be mediated by a chloroplast 13-LOX, a key enzyme of the octadecanoid defense-signaling pathway.
Laboratório de Biotecnologia, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, 28015-620 Campos dos Goytacazes, Rio de Janeiro, Brazil.
Mariana
M
Rangel
Olga L T
OL
Machado
Maura
M
da Cunha
Tânia
T
Jacinto
D000085:Acetates / Q000494:pharmacology*; D000941:Antigens / Q000276:immunology; D002736:Chloroplasts / Q000201:enzymology; D018553:Cucumis sativus / Q000201:enzymology / Q000276:immunology; D003517:Cyclopentanes / Q000494:pharmacology*; D004790:Enzyme Induction; D008084:Lipoxygenase / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D054883:Oxylipins; D029598:Passiflora / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D014947:Wounds and Injuries / Q000378:metabolism*
D000085:Acetates; D000941:Antigens; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C072239:methyl jasmonate; D008084:Lipoxygenase