Purify native antifungal peptides from bacteria, sequence peptides, and synthesize L-amino acid containing linear peptides based upon native peptide sequences with antifungal activity against Aspergillus flavus. Synthesize peptide genes coding for antifungal activities. Construct plant expression vectors for targeted expression of antifungal peptide genes in peanut and cotton fruit/seed tissues, and determine their antifungal effect.
Peptides from Bacillus subtilis using liquid chromotography and protein purification systems. Bioassays will be performed to determine the antifungal activity of purified peptides against Aspergillus spp. Peptides will be sequenced and synthetic L-amino acid containing linear peptides will be synthesized based upon the native peptide sequences. Synthetic peptides (L-conformation) will be tested for antifungal activity. Genes encoding the most active peptides will be synthesized (with codon usage based upon plants) for insertion into plant transformation vectors. The plant expression vector will be constructed for constitutive expression of the cloned antifungal genes. Bacterial based genes will ultimately be expressed in cotton and peanut tissues.