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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 4/9/2006 Publication Date: 4/9/2006 Citation: Chen, M. 2006. Transcriptomic analysis of the hessian fly (mayetiola destructor) salivary gland secretome revealed diverse, elicitor-like genes. Meeting Abstract. Interpretive Summary: Technical Abstract: The Hessian fly [Mayetiola destructor (Say)] is a parasitic insect with sucking mouth. The ability of a single larva to stunt a wheat plant permanently indicates that Hessian fly larvae inject substances into host plants through the salivary glands during feeding. To identify proteins that are potentially injected into host plants, we conducted transcriptomic analysis of cDNAs derived from dissected salivary glands. From an analysis of 10,000 clones that were randomly selected, we found that 46% of the cDNA clones encoded proteins with a typical secretion signal. For comparison, we also analyzed 2,000 clones from gut cDNA libraries and 5,000 clones from cDNA libraries derived from whole insects. There were only 15% and 7% of clones encoding proteins with a secretion signal from the gut and whole body libraries, respectively. The high percentage of expressed genes encoding secreted proteins indicated that the salivary glands of Hessian fly larvae are specialized in producing proteins for secretion. Sequence comparison revealed that composition of secreted proteins from salivary glands is very different from those of secreted proteins derived from gut and whole body libraries. The secreted proteins from salivary glands are small proteins with no or very little sequence similarity with known proteins in the database while the secreted proteins from the gut are digestive enzymes, detoxification enzymes, and enzyme inhibitors, and the secreted proteins from whole body libraries are mainly cuticle proteins, metabolic enzymes, and chaperones. Analysis of genes encoding secreted proteins from the salivary glands of Hessian fly larvae revealed several unique features: including clustered organization of multiple members within short chromosomal regions, rapid diversification, and exclusive larval expression. These unique features suggest that these genes encode elicitor proteins that are likely the determinants of virulent/avirulent phenotypes associated with different Hessian fly biotypes. |
