Journal de pathologie végétale et de microbiologie

Abstrait

Interaction of Extracellular Proteinases of Phytophthora cinnamomi with Proteinase Inhibitors Produced by Avocado Root

Jonatan Encino-López, Elda Castro-Mercado, Gerardo Rangel-Sánchez and E. García-Pineda

The interaction avocado plant/Phytophtora cinnamomi has not been explored at the level of defense responses induced by this pathogen. Here, we show that the infection of avocado plants by Phytophthora cinnamomi induced proteinase inhibitor, which had inhibitor activity against extracellular proteases of P. cinnamomi. Extracellular proteinase activity was not increased with the addition of the avocado root cell wall to liquid culture but decreased in the presence of root of healthy avocado plants. The pretreatment of avocado roots with the avocado inhibitor before the infection by P. cinnamomi inhibited root colonization by the pathogen. Avocado inhibitor had no effect on in vitro growth of the oomycete, suggesting that the inhibition of root colonization could be due to its interaction with pathogen proteinases.