Plants that use resources to defend themselves in the absence of pests or pathogens will pay off with energy costs that can reflect in the productivity. Thus, the objective of this work was to evaluate the fitness costs of the resistance induced in bean plants, before the presence of the pathogen, by using biotic (Bacillus cereus) and abiotic (acibenzolar-S-methyl, ASM) inducers, applied 2, 3 or 4 times during the cycle of the culture. The protecting effect was evaluated against the bacterium Xanthomonas axonopodis pv. Keywords: Chitinase β-1,3-glucanase; peroxidase; Phaseolus vulgaris; metabolism; yield.
Palavras-chave adicionais:Quitinase; β-1,3-glucanase; peroxidase; Phaseolus vulgaris; metabolismo; produtividade.
RESUMOPlantas que utilizam recursos para defesa na ausência de pragas ou patógenos, arcarão com custos energéticos que podem refletir na sua produtividade. Assim, teve-se por objetivo avaliar os custos adaptativos da indução de resistência, antes da chegada do patógeno, em feijoeiro induzido por um indutor biótico (Bacillus cereus) e um abiótico (acibenzolar-S-metil, ASM), em 2, 3 ou 4 aplicações distribuídas ao longo do ciclo da cultura. Avaliou-se o efeito protetor contra a bactéria Xan thomonas axono podi s pv. ph ase oli , além d a at ivid ade de peroxidase, quitinase, β-1,3-glucanase, síntese de lignina, fenóis e crescimento com base na matéria seca. Observou-se que os indutores Kuhn, O.J. & Pascholati, S.F.. Custo adaptativo da indução de resistência em feijoeiro mediada pela rizobactéria Bacillus cereus ou acibenzolar-S-metil: atividade de enzimas, síntese de fenóis e lignina e biomassa. Summa Phytopathologica, v.36, n.2, p.107-114, 2010. synthesis and plant growth were evaluated too. It was observed that the inducers protected the bean plants against X. axonopodis pv. phaseoli. The ASM increased the activity of peroxidase, chitinase and β-1,3-glucanase, while B. cereus only increased peroxidase activity. Unlike B. cereus, the ASM increased lignin synthesis and decreased ph enolic c ompound cont ent and pla nt growt h . Th erefore, t he resistance induced by ASM represents high fitness costs for bean plants, while the resistance induced by B. cereus represents low cost and its potential use can be explored.