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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #171828
Title: FIELD EVALUATION AND GENE EXPRESSION ANALYSIS OF CORN GENOTYPES FOR RESISTANCE TO PREHARVEST AFLATOXIN CONTAMINATION AND DROUGHT STRESS

Author
item Guo, Baozhu
item LUO, M - UNIVERSITY OF GEORGIA
item COY, A - UNIVERSITY OF GEORGIA
item LEE, R - UNIVERSITY OF GEORGIA

Submitted to: Multicrop Aflatoxin and Fumonisin Elimination and Fungal Genomics Workshop-The Peanut Foundation
Publication Type: Abstract Only
Publication Acceptance Date: 9/10/2004
Publication Date: 10/1/2004
Citation: Guo, B., Luo, M., Coy, A. E., Lee, R. D. 2004. Field evaluation and gene expression analysis of corn genotypes for resistance to preharvest aflatoxin contamination and drought stress [abstract]. In: Proceedings of the 17th Aflatoxin Elimination Workshop, October 25-28, 2004, Sacramento, California.

Interpretive Summary:

Technical Abstract: The development of 'southern hybrid-type' corn with resistance to ear-feeding insects, tolerance to drought, and resistance to Aspergillus infection or aflatoxin formation, and with acceptable yield will help southern corn growers produce a quality, profitable crop. The objectives of this program are to evaluate germplasm, hybrid combination of the selected inbreds for aflatoxin contamination and yield performance, and study gene expression in response to different factors using microarray gene expression analysis. We have conducted the field and laboratory screening of inbreds for resistance and susceptibility to A. flavus and aflatoxin production. Few lines, P56, P2, GT-A1-1, GT-A638, have similar aflatoxin levels as Tex6 and MP714, averaged from 44 ppb (GT-A638) to 19 ppb (P56). MP714 averaged 20 ppb of total aflatoxin. Selected single-cross hybrids were tested in the Georgia State Performance Test and SERAT (southeastern region aflatoxin test) in 2004. In comparison with the commercial hybrids, field tests in Georgia and Texas have shown that several crosses have good yield potential for the Southeastern region in comparison with local commercial hybrids in the irrigation and non-irrigation condition. We also used microarray analysis of gene expression to study the effects of drought stress, A. flavus infection, SA induction on gene expression in developing corn ear/kernels in 2003 and 2004. Three corn inbred lines, B73, GT-A1-1, and A638, have been used in the gene expression study. The laboratory bioassay of the seeds harvested from the rain-out shelters has showed that the pre-formed biochemical compounds were accumulated by the treatments used for gene expression study. The lower aflatoxin concentration from the lab assay will be correlated with the gene expression profiles induced by different treatment. Genomic research of gene expression analyses in the developing ears/kernels will help identify and understand the function of genes that control significant biological processes and agronomic performance under stress of drought and fungal infection, which are crucial in the development of genetic approaches for control of preharvest aflatoxin contamination.