MULTIFACETED MOLECULAR APPROACH FOR CONTROL OF THE SUGAR BEET ROOT MAGGOT (TETANOPS MYOPAEFORMIS RODER)

Authors: Smigocki, Anna

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/2003
Publication Date: 1/10/2004
Citation: Smigocki, A.C. 2004. Multifaceted molecular approach for control of the sugar beet root maggot (tetanops myopaeformis roder). Plant and Animal Genome Abstracts. page 68.

Interpretive Summary:

Technical Abstract: The sugar beet root maggot (SBRM), Tetanops myopaeformis Roder, is considered a major pest of sugar beet in the United States and Canada. We are developing strategies for SBRM control that include the identification of beneficial genes that can be used to increase disease and insect resistance in sugar beet. One class of genes targets the activity of the insect's digestive enzymes to prevent the assimilation of nutrients from ingested foods. We determined that two predominant classes of proteases are responsible for digestion in SBRM. Pepstatin A and squash aspartyl proteinase inhibitor reduced the aspartyl protease activity by more than 90%. PMSF and soybean trypsin-chymotrypsin inhibitor reduced serine protease activity by 50 and 90%, respectively. E-64 and rice oryzacystatin I had a minor inhibitory effect on cysteine protease activity (7 and 20%, respectively). The manipulation of plant biosynthetic pathways that produce insecticidal compounds is being explored as an approach for enhancing disease resistance in sugar beet. We demonstrated that over 90% of SBRM were killed by secondary metabolites extracted from cytokinin-overproducing transgenic tobacco. We also initiated studies to identify the mechanisms that are responsible for insect tolerance in sugar beet cultivars that are moderately resistant to SBRM. We developed an in vitro SBRM bioassay using resistant and susceptible parental lines to generate infested tissues for preparation of cDNA libraries enriched for resistance genes. Profiling of genes associated with plant defense responses will provide useful information for developing new control strategies for SBRM and other pests.