Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2005
Publication Date: 1/15/2006
Citation: Saltzmann, K.D., Giovanini, M.P., Marshall, A.J., Rhodes, D., Williams, C.E. 2006. Evaluation of free amino acids in wheat infested by virulent and avirulent Hessian fly larvae (Diptera: Cecidomyiidae) [abstract]. Plant and Animal Genome Conference. http://www.intl-pag.org. Interpretive Summary:
Technical Abstract: The Hessian fly, Mayetiola destructor (Say), is a serious pest of wheat, Triticum aestivum (L.), throughout many of the world’s wheat growing regions. Wheat-Hessian fly interactions are characterized as compatible when virulent Hessian fly larvae establish feeding sites and survive on wheat seedlings and incompatible when avirulent larvae fail to establish feedling sites and do not survive. Similar to other gall-forming cecidomyiid midges, Hessian fly larvae are thought to induce formation of nutritive tissue (compatible interaction) that serves as a nutrient sink and helps support the rapid growth of first- and second-instar larvae. In order to test the hypothesis that plants in a compatible interaction will contain higher concentrations of free amino acids than plants in an incompatible interaction, levels of free amino acids in wheat seedlings were examined at one, three and six days after initiation of larval attack. Amino acid identities and concentrations were determined by GC/MS. At three and six days after larval attack began, increased proline was observed in wheat seedlings in the compatible interaction. The accumulation of proline in plants subjected to water deficit is well known, but increased proline has also been documented in tomato plants following infection by root knot nematodes and was hypothesized to serve as a ready source of energy. We propose that proline accumulation supports rapid Hessian fly larval growth by 1) serving as a direct energy source (ingested by larvae), or 2) by serving as an energy source used by the plant to support development of nutritive tissue.