Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 30, 2003
Publication Date: August 15, 2003
Citation: Liang, X.Q., Guo, B.Z., Holbrook, C.C. 2003. Identification of peanut seed-storage proteins associated with resistance against Aspergillus flavus infection and aflatoxin production [abstract]. American Peanut Research and Education Society. Paper No. 102. Technical Abstract: Peanut germplasm has been evaluated in the laboratory and the field for resistance to Aspergillus flavus infection and aflatoxin production. Protein profiles of 4 genotypes, Georgia Green, A-100, GT-C20, and GT-C9, have been analyzed using 2-D gel electrophoresis. Laboratory bioassay shows that GT-C20, a genotype from China, has resistance to fungal colonization and sporulation in comparison with Georgia Green and A-100. In one year field test, GT-C20 had significant lower aflatoxin concentration than Georgia Green. Total seed protein was extracted from 4 genotypes (Georgia Green and A100, GT-C20, and GT-C9), which had different fungal growth/colonization and aflatoxin production in the laboratory and the field. Six protein spots were identified unique or up- or down-regulated in resistant genotypes. These 6 major protein spots are labeled as P-1 (35 kD, pI 4.7), P-2 (22.5 kD, pI 4.1), P-3 (22.5 kD, pI 8.2), P-4 (22.5 kD, pI 7.3), P-5 (23.8 kD, pI 5.9) and P-6 (23.5 kD, pI 7.0). GT-C20 has P-1 to P-5 with P-4 at a trace level, and misses P-6. The protein profiles are almost identical for Georgia Green and A-100, in which both have P-4 and P-6, and miss P-2, P-3 and P-5. GT-C9 has only P-3 with trace level and P-1 to P-5 could be induced in the seeds by imbibition of water or inoculation of A. flavus in the laboratory. The major qualitative differences are that protein P-2, P3, and P5 are unique in resistant genotypes and P-4 and P-6 are unique in susceptible genotypes. Protein spot P-4 is much higher in susceptible genotypes than in resistant genotypes. Further characterization of these proteins in association with resistance/susceptibility to A. flavus will be needed.