T-DNA tagging lines

Abstract

Recent annotation of rice genome has identified nearly 40,000 genes (Feng et al. 2002; Goff et al. 2002; Sasaki et al. 2002; Yu et al. 2002). To facilitate discovery of their functional roles, several approaches have been developed. Current methods include antisense and RNAi technologies to decrease the expression of target genes, as well as insertional mutagenesis to knock out gene expression (Jeon et al. 2000). Random insertional mutagenesis has been achieved by transferred DNA (T-DNA) or transposons for large-scale analyses. This technique not only is efficient for identifying knockout mutants, but also can be employed for both promoter- and activation-tagging. The establishment of a large number of insertional mutants will accelerate these reverse-genetics approaches for studying rice gene function in this model monocot species. In addition, homologous recombination and viral-induced gene silencing are apparently effective techniques, although their popular usages are still awaited. The Targeting Induced Local Lesions in Genomes (TILLING) method has been adapted in rice in order to find point mutations in genes of interest (Henikoff et al. 2004). In this chapter we will review the progress in generation and characterization of T-DNA insertional lines and identification of gene function using the insertional element in rice.