Submitted to: International Society of Chemical Ecology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2005
Publication Date: 8/15/2005
Citation: Puthoff, D.P., Ivic-Haymes, S., Smigocki, A.C. 2005. Elucidation of resistance and disease mechanisms in roots using sugar beet and sugar beet root maggot as a model system. International Society of Chemical Ecology Meeting. p. 79.
Technical Abstract: U.S. sugar beet (Beta vulgaris L.) production is plagued by the sugar beet root maggot (SBRM, Tetanops myopaeformis Röder), the most devastating insect pest of sugar beet. To study the interactions between sugar beet roots and SBRM, we developed an in vitro bioassay using seedlings and hairy root cultures of susceptible (F1010) and moderately resistant (F1016) sugar beet germplasm. SBRM larvae aggregated and fed on F1010 roots but moved away from the F1016 tissues. Damage to F1010 roots included rasping, tunneling and severed roots and was similar to damage observed in SBRM-infested fields. We collected infested F1010 and F1016 root and hypocotyl tissues at 24 and 48 h to identify genes that are regulated by SBRM feeding. The Suppressive Subtractive Hybridization (SSH) method was used to compare infested and uninfested plants of the same genotype. Infested samples of the two genotypes were also compared in order to identify genes up-regulated in one genotype while down-regulated in the other. Over 1000 cDNA fragments were cloned and approximately half of them have been confirmed to be differentially expressed in response to SBRM infestation. Further characterization is ongoing and includes DNA sequence determination, functional annotation and expression profiling following various plant stresses. Functionality of genes with potential roles in resistance or susceptibility will be analyzed in vitro using sugar beet hairy root cultures. Given that root defense responses have not been well characterized, identification of the genes involved will yield a better understanding of root-insect interactions for devising effective insect control measures.