M. Teresa Melillo,2
María Fe Andrés,3 and
1Departamento de Biotecnología, ETS Ing. Agrónomos, UPM, Madrid, E-28040, Spain; 2Istituto per la Protezione delle Piante, IPP, CNR, 70126 Bari, Italy; 3Instituto de Ciencias Agrarias, CCMA, CSIC, Serrano115 dpdo, Madrid, E-28006, Spain
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Accepted 8 May 2009.
The response of resistant wheat--Aegilops ventricosa introgression line H-93-8 and its susceptible parent, Triticum aestivum H-10-15, to Ha71 Spanish population of Heterodera avenae was studied to determine the changes in peroxidase gene expression during incompatible and compatible wheat--nematode interactions. Twenty peroxidase genes were characterized from both 211 expressed sequence tags and 259 genomic DNA clones. Alignment of deduced amino acid sequences and phylogenetic clustering with peroxidases from other plant species showed that these enzymes fall into seven different groups (designated TaPrx108 to TaPrx114) which represent peroxidases secreted to the apoplast by a putative N-terminal peptide signal. TaPrx111, TaPrx112, and TaPrx113 were induced by nematode infection in both genotypes but with differing magnitude and timing. TaPrx112 and TaPrx113 groups increased more in resistant than in susceptible infected lines. In addition, in situ hybridization analyses of genes belonging to TaPrx111, TaPrx112, and TaPrx113 groups revealed a more intense signal in cells close to the vascular cylinder and parenchyma vascular cells of resistant than susceptible wheat when challenged by nematodes. These data seem to suggest that wheat apoplastic peroxidases, because of their different expression in quantity and timing, play different roles in the plant response to nematode infection.
© 2009 The American Phytopathological Society