Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/8/2006
Publication Date: 2/20/2007
Citation: Omprakash, M., Sardesai, N., Shukle, R.H. 2007. CDNA cloning and transcriptional expression of a peritorphin-like gene in the Hessian fly, Mayetiola destructor (say). Archives of Insect Biochemistry and Physiology. 64:19-29. Interpretive Summary: The Hessian fly is a destructive pest of wheat, and in the eastern soft-winter-wheat region of the United States it is the most important insect pest. Losses in Georgia due to the Hessian fly were estimated at $28 million in 1989, and nation-wide monetary losses due to the pest have approached $100 million in a single year. Resistant wheat is the most economical and environmentally sound method of control. However, the widespread use of resistant wheat has resulted in the selection of biotypes of Hessian fly that can survive on formerly resistant wheat. Recent work by USDA-ARS scientists has shown that a number of toxic proteins are produced by resistant wheat plants when attacked by Hessian fly larvae. One of the targets for these toxic proteins is the lining of the insect gut. This lining is essential to digestion and its disruption has deleterious effects on insect survival. We have cloned the gene for the protein making up the gut lining in Hessian fly and are testing what happens to this protein and the gut lining when Hessian fly larvae feed on resistant wheat. Results from this work can reveal one of the target sites in Hessian fly for resistance in wheat. Such knowledge will benefit scientists facing the challenge of devising more durable resistance in wheat to this pest through genetic engineering and other contemporary approaches. The agricultural community (crop producers and commodity groups) will benefit from improved pest control that increases yield and quality without increasing costs.
Technical Abstract: One of the well-studied components of the insect gut is the peritrophic matrix (PM). This biophysical structure, which is semipermeable, primarily functions in digestion, and protection against invasive microorganisms and mechanical damage. We report the cDNA cloning and transcription profiles of a peritrophin-A like gene (designated MdesPERI-A1) in the Hessian fly Mayetiola destructor. The predicted amino acid sequence of MdesPERI-A1 revealed a putative secretion signal peptide at its amino terminus, similarity to peritrophins from other insects including dipterans, and the presence of two chitin binding domains each containing six cysteine residues. Quantitative expression analysis of MdesPERI-A1 mRNA in different larval tissues revealed the transcript to be predominantly present in the midgut (597.9-fold) compared to other tissues assayed including salivary glands and fat bodies. Spatial expression patterns during development, showed a peak expression of MdesPERI-A1 in the feeding second –instars (146-fold) and a decline in expression in the pupal and adult stages. Transcription profiling of MdesPERI-A1 during compatible (larvae on susceptible plants) and incompatible (larvae on resistant plants) interactions with wheat revealed a greater level (1.7-fold) of MdesPERI-A1 transcript in larvae on resistant plants in the initial time point examined. However, MdesPERI-A1 expression declined in larvae on resistant plants at the later time points. Results provide knowledge into the expression of a Hessian fly peritrophin-A like gene during development and during larval interactions with wheat.