|Subramanyam, Subhashree - PURDUE UNIV.|
Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2006
Publication Date: November 15, 2006
Citation: Subramanyam, S., Williams, C.E. 2006. Molecular characterization of a set of genes regulated in wheat during Hessian fly infestation. [abstract] Plant and Animal Genome VX Conference Abstracts. Technical Abstract: Defense response genes are elicited in plants during interactions with pests or pathogens. We have identified several wheat genes that are responsive to Hessian fly, a major insect pest causing vast economic damage. Wheat interacts with Hessian fly in a gene-for-gene manner resulting in either a compatible (plants susceptible to the insect) or an incompatible (plants resistant to the insect) interaction. Here we present a case study of a lectin-encoding gene, Hfr-1, which is up-regulated in wheat during incompatible interactions, and a set of genes encoding S-adenosyl methionine decarboxylase (SAMDC) and aminopropyl transferase, key enzymes involved in the polyamine biosynthetic pathway, that are up-regulated during compatible interactions. The Hfr-1 protein includes a dirigent (disease-responsive) and jacalin-like lectin domain. Regulation of Hfr-1 was highly specific to Hessian fly larval feeding and operated through the salicylic acid signaling pathway. Immunoblot analysis of total soluble proteins from resistant and susceptible plants as well as the virulent and avirulent larvae with a polyclonal affinity-purified Hfr-1 antibody revealed a positive correlation between Hfr-1 transcript and protein levels. Hfr-1 and its proteolytic products were present in virulent larvae but conspicuously absent from avirulent larvae. Analyses of SAMDC activity in wheat and polyamine levels in wheat and larvae revealed positive correlations between transcript and product levels in the compatible interactions. Possible roles of these genes in wheat-Hessian fly interactions will be discussed to elucidate some of the mechanisms involved in resistance and susceptibility of wheat to Hessian fly.