Cell-Tissue Specific Functional Genomics by Sense-RNAi
This work is led by project PI and collaborator Dr. Rich Jorgensen, U
Arizona, and is funded by the NSF Plant Genome Program. The goal of this project is to develop a new tool for functional genomics based on the gene silencing phenomenon known as RNA interference (RNAi). A particular form of RNAi, known as Sense-RNAi, will be optimized for use as a focused genomics tool with special application in crop plants. The method will produce a series of individual plants, in each of which a single gene has been silenced. By screening a population of Sense-RNAi silenced plants, investigators will be able to identify genes that contribute to valuable traits of particular interest to the investigator. The technique of laser microdissection will be used to collect RNA from specific tissues (mesophyll, and developing trichome cells), for use in generating libraries of Sense-RNAi mutagenesis constructs that will target these specific cells. By using Sense-RNAi rather than standard RNAi approaches, we expect to be able to produce silencing transgene constructs very efficiently. This will allow us to focus silencing on a select subset of the genes in a crop plant, increasing dramatically the overall efficiency of identifying genes that affect a given trait. This new technology will be developed, tested and optimized in a model plant species and then applied to crop plants, beginning with tomato. We will focus our gene silencing method on genes expressed in trichomes, tiny hairs on the surface of a leaf that help protect the plant from insects and microbes. The expected outcome of the funded project is primarily the optimized method for silencing of a focused set of genes, including the necessary plant transformation vectors and experimental protocols for successful application of this method to crop plants.