Submitted to: Molecular Genetics of Plant-Microbe Interactions Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/2001
Publication Date: N/A
Technical Abstract: Cacao, the source of chocolate, is grown in tropical areas of South and Central America, Africa, and Southeast Asia. Traditionally grown as an under story tree in mixed forest, cacao is sometimes grown in monoculture. The crop, depending upon location, is continually exposed to various stresses, which included diseases, insects, drought, and sun scald among others. We are using differential display to identify genes that are differentially expressed in response to stress. The stresses presently being studied, include induced resistance, the phytotoxic protein Nep1, sun scald, plant hormones and their analogs, drought, and fungal infection. Although the identification of genes remains tentative based on homologies to published sequences, the list of genes showing differential expression in cacao in response to stresses includes genes involved in photosynthesis, nuclear organization, and respiration, in addition to genes regulated by nodulin formation, flavanoids, and drought in other plant species. Approximately 50 percent of the genes fail to show homology to published sequences from other species. The array of putative stress response genes in cacao will be presented along with analysis of their expression in the greenhouse grown plants. Genes of interest based on results in the greenhouse will be further studied in the field.