Expression and localization of nitrilase during symptom development of the XXXX in @entity958 .

@entity73076 @entity66 @entity958 @entity3260 @entity73077 @entity9634
The expression of nitrilase in @entity958 during the development of the @entity66 caused by the obligate biotroph Plasmodiophora brassicae was investigated. A time course study showed that only during the exponential growth phase of the clubs was nitrilase prominently enhanced in infected roots compared with controls. @entity73076 and @entity73077 are the nitrilase isoforms predominantly expressed in clubroot tissue, as shown by investigating promoter-beta-glucuronidase fusions of each. Two peaks of beta-glucuronidase activity were visible: an earlier peak (21 d post inoculation) consisting only of the expression of @entity73076 , and a second peak at about 32 d post inoculation, which predominantly consisted of @entity73077 expression. Using a polyclonal antibody against nitrilase, it was shown that the protein was mainly found in infected cells containing sporulating plasmodia, whereas in cells of healthy roots and in uninfected cells of inoculated roots only a few immunosignals were detected. To determine which effect a missing nitrilase isoform might have on symptom development, the P. brassicae infection in a nitrilase mutant ( @entity73076 -3) of @entity958 was investigated. As a comparison, transgenic plants overexpressing @entity73077 under the control of the @entity3260 35S promoter were studied. Root galls were smaller in @entity73076 -3 plants compared with the wild type. The phenotype of smaller clubs in the mutant was correlated with a lower free @entity9634 content in the clubs compared with the wild type. Overexpression of nitrilase did not result in larger clubs compared with the wild type. The putative role of nitrilase and auxins during symptom development is discussed.
