Location: Crop Bioprotection Research2012 Annual Report
1a. Objectives (from AD-416):
Make publicly available a predictive computer program for mycotoxin levels in Midwest corn and adapt as necessary for a wider range of human food use corn varieties. Use molecular biological approaches to discover, introduce, and evaluate new insect resistance genes (producing bioactive proteins and secondary metabolites), alone and in combination. Use molecular biological approaches to discover, introduce, and evaluate plant-derived selectable markers for transgnic plant production.
1b. Approach (from AD-416):
As part of the process of making the program publicly available, feedback on the present state of the program will be sought and utilized as appropriate. An economic module to assist in making control decisions will be developed and incorporated. The program will be tested for utility in food grade corn by comparing actual field collected data with predicted levels and correcting as necessary empirically. Genes identified in the prior project that are potentially useful in combination will be examined in model systems and further evaluated. New genes of potential use will be identified through functional targeting of cDNA, array-based technology. Molecular evolution of genes coding for resistance proteins will be utilized to further optimize efficacy against insects, while at the same time minimizing vertebrate effects. Gene product efficacy will be examined in model systems and in regenerated corn. Plant-derived genes involved in toxin resistance will be the ultimate focus of the investigation, although genes from other sources will initially be examined if appropriate plant-derived gene sequence information is not yet sufficient for cloning. Efficacy of target gene products as selectable markers and against insects, alone and in combination with insect-active genes, will be investigated.
3. Progress Report:
This report documents progress for the bridging Project 3620-42000-041-00D and continues research from Project 3620-42000-040-00D which terminated in October of 2010. Progress achieved during FY12 will benefit researchers in allied fields from academia, government, and industry and will facilitate the development of corn lines with reduced levels of insect damage and fungal toxins in kernels. ARS Researchers in Peoria, IL, discovered new insect resistance mechanisms that can be integrated into corn to control corn ear insect pests and associated fungi that produce toxins. As part of studies to determine which genes are involved in lowering mycotoxin levels in popcorn, ears were collected from popcorn fields, rated for insect and mold damage, and analyzed for mycotoxins. Damaged ears were stored for future use in gene expression analysis. As part of studies to determine which insect resistance genes may be added or lost when breeding for higher yields, leaves were collected from a second series of corn inbred parent and progeny and found to have different levels of insect resistance. The leaves are being evaluated for differential gene expression in order to determine which genes may be involved in increased insect resistance. In studies designed to discover novel chemicals that defend against insects, extracts from range plants, and extracts and pure compounds from novel fungi were found to be active against agriculturally important pest caterpillars. Characterization of these compounds is ongoing. This research addresses National Program 301, Component 2: Crop Informatics, Genomics, and Genetic Analysis, Problem Statement 2C: Genetic Analyses and Mapping of Important Traits.