| Autor: |
Dos Santos IB; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Lopes MDS; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Bini AP; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Tschoeke BAP; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Verssani BAW; Departament of Exact Sciences, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Figueredo EF; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Cataldi TR; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Marques JPR; Departament of Phytopathology, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Silva LD; Departament of Forest Science, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Labate CA; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil., Quecine MC; Departament of Genetics, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil. |
| Abstrakt: |
Austropuccinia psidii , the causal agent of myrtle rust, is a biotrophic pathogen whose growth and development depends on the host tissues. The uredospores of A. psidii infect Eucalyptus by engaging in close contact with the host surface and interacting with the leaf cuticle that provides important chemical and physical signals to trigger the infection process. In this study, the cuticular waxes of Eucalyptus spp. were analyzed to determine their composition or structure and correlation with susceptibility/resistance to A. psidii . Twenty-one Eucalyptus spp. in the field were classified as resistant or susceptible. The resistance/susceptibility level of six Eucalyptus spp. were validated in controlled conditions using qPCR, revealing that the pathogen can germinate on the eucalyptus surface of some species without multiplying in the host. CG-TOF-MS analysis detected 26 compounds in the Eucalyptus spp. cuticle and led to the discovery of the role of hexadecanoic acid in the susceptibility of Eucalyptus grandis and Eucalyptus phaeotricha to A. psidii . We characterized the epicuticular wax morphology of the six previously selected Eucalyptus spp. using scanning electron microscopy and observed different behavior in A. psidii germination during host infection. It was found a correlation of epicuticular morphology on the resistance to A. psidii . However, in this study, we provide the first report of considerable interspecific variation in Eucalyptus spp. on the susceptibility to A. psidii and its correlation with cuticular waxes chemical compounds that seem to play a synergistic role as a preformed defense mechanism. |
