Poster Session: Molecular/Cellular/Plant-Microbe Interactions - Plant Defense Responses

600-P

Defense responses induced by acibenzolar-S-methyl in cape gooseberry (Physalis peruviana) against Fusarium oxysporum.
I. M. Ramos-Peña (1), C. E. Carvajal-Arias (1), J. S. Montaña-Lara (1), P. Jiménez (2), S. Restrepo (3), M. X. RODRÍGUEZ-BOCANEGRA (1)
(1) Pontificia Universidad Javeriana, Bogotá, Colombia; (2) Universidad Militar Nueva Granada, Bogotá, Colombia; (3) Universidad de los Andes, Bogotá, Colombia

The phytoactivator acibenzolar-S-methyl (ASM) was evaluated on cape gooseberry plants for its potential to induce resistance to Fusarium oxysporum, causal agent of vascular wilt, which is currently considered the main constraint in this crop production. Cape gooseberry plants were treated with ASM (15mg/L, foliar application) at 0, 0-7, 0-7-14, 0-14 and 0-14-28 days and infected with a conidial suspension 4 days after first ASM application. Treated plants progressively reduced the severity of vascular wilt (up to 79.1%) with ASM applications at 0-14-28 days), as well as vascular browning and fungal colonization. Parallely, the accumulation of signal molecules and defense related enzymes was evaluated in plants sprayed with ASM at 0 and 7 days; salicylic and jasmonic acid were quantified by HPLC and chitinase (CHI), carbonic anhydrase (CA) and phenylalanine ammonia lyase (PAL) expression were determined by qRT-PCR. Salicylic acid accumulated at 0, 1, 7 and 8 days, while no signal for jasmonic acid was detected; confirming SAR signaling induction by ASM. CHI and PAL significatively increased their expression after the second ASM application (8-9 and 9-10 days, respectively). Therefore, ASM has the ability to control vascular wilt in cape gooseberry by induction of defense genes, related to fungal cell wall hydrolysis and phenolic compounds synthesis. Consequently, the application of ASM might be established as an effective alternative for preventive disease control.