Resumo

SILVA, Harllen S.A. et al. Endophytic bacteria inducing enzymes correlated to the control of coffee leaf rust (Hemileia vastatrix). Trop. plant pathol. [online]. 2008, vol.33, n.1, pp. 49-54. ISSN 1982-5676.  http://dx.doi.org/10.1590/S1982-56762008000100008.

Four endophytic bacteria strains (3F - Brevibacillus choshinensis, 109G - Bacillus megaterium, 115G - Microbacterium testaceum, and 119G - Cedecea davisae), isolated from healthy coffee plants, and screened previously as biocontrol agents of coffee leaf rust, were assessed for their ability in producing enzymes correlated to the control of the causal agent Hemileia vastatrix. Cell suspensions of these strains were sprayed on leaves three days before the inoculation of the pathogen. The enzymatic activities and the number of lesion per leaf were evaluated after seven and 18 days, respectively, after inoculation. The results showed that the peroxidase activity was increased in plants treated with B. choshinensis and C. davisae strains. On the other hand, no increase in phenylalanine ammonia-liase and lipoxygenase activities was detected. The strains C. davisae reduced the numbers of lesions per leaf, suggesting in this case, that beside resistance induction, others mechanisms of action probably is involved in the process. The detection of peroxidase in leaves free of the pathogen and endophytes, as well as, the spatial separations between them, furnish strong evidence of systemic resistance induction.

Palavras-chave : biological control; induced systemic resistance; Coffea.