ARS | Publication request: Examining the molecular interaction between potato (Solanum tuberosum) and Colorado potato beetle Leptinotarsa decemlineata (Say)

Submitted to: Canadian Journal of Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2008
Publication Date: N/A

Interpretive Summary: Colorado potato beetle costs hundreds of millions of dollars for pesticide control and yield loss each year in the United States. To address this problem we are trying to understand the natural defenses of the plant to this insect pest. Here we have identified 297 genes in potato affected by Colorado potato beetle feeding. This is of interest to scientists so that they will know which genes should be manipulated to produce a plant that is better able to mount a defensive response to insect attack.

Technical Abstract: Colorado potato beetle (CPB) is a leading pest of solanaceous plants; however, little is known about its molecular interaction with the potato plant. Using the 11,421 EST array solanaceae microarray profiling services at TIGR, we have identified genes that are differentially expressed in potato leaves by Colorado potato beetle feeding. Applying a cutoff corresponding to an adjusted P value of < 0.01 and a fold change (FC) of >1.5 or <0.67, 297 genes were identified. Real time quantitative RT-PCR was used to validate microarray results of a subset of genes. In general, genes encoding proteins involved in secondary metabolism and stress were found to be induced by CPB feeding. Two of these induced genes - encoding S-adenosyl-L-methionine:salicylic acid carboxyl methyltransferase (SAMT) and aromatic amino acid decarboxylase - are responsible for synthesis of the volatiles methyl salicylic acid (MSA) and the precursor of 2-phenylethanol, respectively. This is significant because MSA is attractive to the CPB predator Podisus maculiventris while 2-phenylethanol is recognized by the CPB predator Perillus bioculatis, possibly invoking an indirect defense against CPB.