Reverse genetics techniques: engineering loss and gain of gene function in plants.

Genetic analysis represents a powerful tool that establishes a direct link between the biochemical function of a gene product and its role in vivo. Genome sequencing projects have identified large numbers of plant genes for which no role has yet been defined. To address this problem a number of techniques have been developed, over the last 15 years, to enable researchers to identify plants with mutations in genes of known sequence. These reverse genetic approaches include RNAi and related technologies and screening of populations mutagenised by insertion (PCR), deletion (PCR) and point mutation (TILLING), each with its own strengths and weaknesses. The development of next-generation sequencing techniques now allows such screening to be done by sequencing. In the future, it is likely that the genomes of thousands of plants from mutagenised populations will be sequenced allowing for the identification of plants with mutations in specific genes to be done in silico.