Arabidopsis Genetics and Functional Genomics in the Post-genome Era

Expressed-sequence tag and genome sequencing projects for Arabidopsis and other plants have yielded unprecedented amounts of new information about plant genes. The pending completion of the genome sequences for Arabidopsis and rice will provide comprehensive knowledge of the coding capacity of higher plant genomes. It is now possible to envision assigning the specific biological functions to all genes in an angiosperm. A variety of new experimental approaches, which are enabled by large amounts of sequence information, will be used to this effect. In particular, positional cloning of Arabidopsis genes corresponding to mutations has become a standard technique. In addition, highly efficient transformation protocols for Arabidopsis make it possible to generate very large transposon and T-DNA insertion collections. Mutants for any gene can be found in these collections with minimal effort using powerful polymerase chian reaction (PCR) screening procedures or by database searches of sequenced insertion sites. New or improved methods for targeted gene disruption and large-scale gene-silencing will also be useful, particularly for understanding the function of redundant genes. Large-scale surveys of transcript, protein and metabolite levels, and collection of the results in public databases will greatly extend our knowledge of gene-expression, gene-function and regulatory networks, and will facilitate the formulation of an integrated view of the information content and processing that regulates all aspects of plant growth and development.