Artigo
Effect of acibenzolar-S-methyl and Saccharomyces cerevisiae on the activation of Eucalyptus defences against rust
Fecha
2009-01-01Registro en:
Australasian Plant Pathology. Collingwood: Csiro Publishing, v. 38, n. 6, p. 594-602, 2009.
0815-3191
10.1071/AP09045
WOS:000270866400006
3845989485833395
0000-0002-6924-835X
Autor
Universidade Estadual Paulista (Unesp)
Universidade Federal do Pampa (UNIPAMPA)
Universidade de São Paulo (USP)
Universidade Federal de Santa Catarina (UFSC)
Resumen
Tree defence mechanisms against the fungus Puccinia psidii were examined by comparing the activities of defence-related enzymes (chitinase, peroxidase and phenylalanine ammonia-lyase) of two Eucalyptus grandis x E. urophylla (urograndis) hybrids, previously classified as either susceptible to rust (VR hybrid) or moderately resistant to rust (C0 hybrid). Furthermore, the potential of disease control by artificial activation of host defences using either acibenzolar-S-methyl (ASM) or Saccharomyces cerevisiae extract was also investigated. Greenhouse inoculation trials revealed that the C0 hybrid had lower disease severity than the VR hybrid but following foliar applications of either ASM or S. cerevisiae extract treatment, disease severity (evaluated at 15 days after inoculation) was reduced in both hybrids. This enhanced resistance was associated with the induction of a hypersensitive reaction which appeared to be effective in controlling rust in both clones. The activity of all enzymes differed between clones and inducer treatment. The role of the defence-related enzymes in imparting resistance to eucalypt hybrids against rust is discussed.