Differential induction of symptoms in XXXX by P6 of @entity3260 .

@entity16491 @entity24194 @entity958 @entity3260 @entity1109
The gene VI protein (P6) of @entity3260 ) functions as a virulence factor in crucifers by eliciting @entity1109 in infected plants. The ability to induce @entity24194 has been associated previously with P6 through gene-swapping experiments between strains and through the development of transgenic plants that express P6. The primary role that has been identified for P6 in the @entity3260 infection cycle is to modify the host translation machinery to facilitate the translation of the polycistronic @entity3260 35S RNA. This function for P6 has been designated as the translational transactivator ( @entity16491 ) function. In the present study, we have characterized an unusual variant of P6, derived from @entity3260 D4, that does not induce @entity24194 upon transformation into @entity958 . The level of D4 P6 produced in transgenic @entity958 line D4-2 was comparable to the amount found in transgenic plants homozygous for W260 and CM1841 P6, two versions of P6 that induce strong @entity1109 and stunting in @entity958 . A complementation assay proved that P6 expressed in the D4-2 line was functional, as it could support the systemic infection of a CM1841 mutant that contained a lethal frame-shift mutation within gene VI. This complementation assay allowed us to separately assess the contribution of CM1841 gene VI to symptom development versus the contribution of other CM1841 genes. Furthermore, a previous study had shown that the @entity16491 activity of D4 P6 was comparable to that of W260 P6. That comparative analysis of @entity16491 function, coupled with the characterization of the D4-2 transgenic line in the present paper, indicates that the @entity16491 function of P6 may play only a minor role in the development of @entity1109 .
