Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2004
Publication Date: 10/1/2004
Citation: Brown, R.L., Chen, Z., Cleveland, T.E. 2004. The role of kernel water relations in resistance to aflatoxin production in corn. Phytopathology. 94:S11.
Technical Abstract: Corn genotypes resistant to aflatoxin production have been identified, and several investigations are now focused on the identification of resistance traits in these genotypes. Enhanced knowledge pertaining to the mode of operation of resistance mechanisms would lay a solid foundation for successful deployment of resistance genes into desired germplasm. Preliminary studies have indicated a potential link between resistance and kernel ability to both imbibe water and germinate in a relatively shorter time. In previous studies, aflatoxin-susceptible genotypes accumulated significantly and drastically less aflatoxin when allowed to imbibe water prior to inoculation with Aspergillus flavus. This was demonstrated even when imbibition was facilitated at 0 degrees C. To determine an association between kernel water relations and resistance, further investigations of kernel imbibing and germinating ability were conducted. Kernel hormone levels under constitutive, imbibed and infected conditions were also determined. Previous studies have demonstrated the induction of specific antifungal proteins during imbibition. A recent comparative proteome analysis of kernels revealed 5-fold higher constitutive levels of stress-related proteins in resistant over susceptible genotypes. Therefore, proteomics was also performed to assess the effect of imbibition/infection on constitutive levels of kernel antifungal and stress-related proteins. Results of these investigations will be discussed.