The generation of reactive oxygen intermediates and expression of defense genes in transgenic hpa1_(Xoo) cotton

In this study,respective methods in detection of H2O2 and relative enzyme activity,DAB staining and quantitative real time PCR were used for confirming the reactive orygen intermediates(ROI)generation in T-34 compared with untransformed cotton Z35.The results showed that after T-34 leaves were inoculated by Verticillium dahliae conidia,compared with Z35 leaves,H2O2 content in T-34 leaf tissue exhibited two peak values during 0-8 h;PAL and POD activities were significantly enhanced,DAB staining revealed visual reddish-brown coloration spots,and expressions of ghAOX1 and hsr203J genes were significantly induced.These evidences indicated that HarpinXoo expressing cotton possessed the molecular basis for expression of some defense genes,and the expression of HarpinXoo was responsible for the generation of ROI and the expression of the related defense gene in transgenic hpa1Xoo plant,and conferred the resistance of transgenic hpa1Xoo cotton to Verticillium dahliae.