Monday, December 10, 2007 - 9:05 AM

Characterization of defense-related gene expression levels in chinch bug resistant buffalograsses

Luciana Toda, toda2@unl.edu1, Paul Twigg, twiggp@unk.edu2, Tiffany M. Heng-Moss, thengmoss2@unl.edu1, Robert Shearman, rshearman1@unl.edu3, and Frederick P. Baxendale, fbaxendale1@unl.edu1. (1) Department of Entomology, 202 Plant Industry, Department of Entomology, Lincoln, NE, (2) University of Nebraska - Kearney, Biology, BHS 211 C, Kearney, NE, (3) University of Nebraska - Lincoln, Agronomy and Horticulture, 279 PS, Lincoln, NE

Over the past decade, the western chinch bug Blissus occiduus (Hemiptera: Blissidae) has emerged as one of the most important insect pests of buffalograss in Nebraska and other regions where buffalograss is grown. Buffalograsses with resistance to B. occiduus have been identified, but the nature of this resistance remains poorly understood at the genomic level. Prior to this study, subtractive cDNA libraries for resistant (Prestige) and susceptible (378) buffalograsses were created. From these libraries, several putatively up-regulated defense-related transcripts were identified and three (GRAS transcription factors, glutathione-S-transferase (GST), and catalase) were selected for further study. In this study, qRT-PCR assays were developed to quantify transcript abundance in chinch bug-infested 378 and Prestige plants at 5, 8, and 11 days after chinch bug introduction. Results from these assays documented the up-regulation of the three transcription factors. These results also revealed several interesting trends that will enhance our understanding of the role these transcription factors play in the defense response of resistant and susceptible buffalograsses.

Species 1: Hemiptera Blissidae Blissus occiduus (western chinch bug)