Meeting Abstract
S6.11 Monday, Jan. 5 Chemicogenomics of plants FOLEY, William J.*; MORAN, Gavin F.; KESZEI, Andras; KULHEIM, Carsten; Australian National University; Australian National University; Australian National University; Australian National University william.foley@anu.edu.au
Many studies have documented variation in the profile and concentration of plant secondary metabolites (PSMs). Ecologists assume that much of this variation is environmentally determined and best described by carbon-nutrient balance hypotheses. Genetic influences can be estimated through detection of family level variance in traits in common garden experiments. Although concentrations of many PSMs with defined effects on herbivores have been shown to be strongly heritable, there has been little attempt to identify specific gene variants and quantify the degree to which they are under selective pressure. Careful analysis of phenotypes can provide information on the nature of the genetic structure of PSMs. Particular care must be taken in the measurement of chemical phenotypes and this is more difficult than anticipated. Large numbers of phenotypes from the whole range of the population need to be measured using techniques such as near-infrared spectroscopy. Candidate genes for PSMs can be identified by homology from better-characterized systems such as Arabidopsis and Populus. Common variants (most usually single nucleotide polymorphisms (SNPs)) must be identified and characterized. This can be done by functional expression and transformation of the plant or by association (linkage disequilibrium) mapping. Association mapping requires a specific population of unrelated individuals, many candidate genes, and SNP genotyping in addition to phenotyping. However, once a suitable population has been established, it can be re-used as more candidate genes and traits become available. The use of these approaches to identify important gene variants associated with herbivore defence in Eucalyptus will be discussed as will the more general problem of identifying the influence of gene variants in pharmacological studies with wild herbivores.
