Arabidopsis thaliana, a small annual weed of central Eurasian origin, has become the organism of choice for the genetic analysis of plant biology. Arabidopsis has many advantages as an experimental system, including a complete genome sequence (The Arabidopsis Genome Initiative; 2000), that has improved the rate of gene discovery. (Azpiroz-Leehan and Feldmann; 1997)

Arabidopsis is ideally suited to laboratory studies for several reasons. It is small enough to allow 1000 seeds to be germinated on a single petri dish, it is self-fertilising, and it can produce over ten thousand seeds from an individual plant. The five-week life-cycle of Arabidopsis is extremely short for any laboratory plant, thus mutant identification and genetic analysis can be completed much sooner. In perspective of molecular genetics, Arabidopsis has a very small genome size (of about 125 megabases (The Arabidopsis Genome Initiative; 2000)) and the scarcity of repeated regions make it a very convenient genome to work with. (Azpiroz-Leehan and Feldmann; 1997)

As less than 10% of the 25498 genes of the Arabidopsis genome have an experimentally determined function, systematic strategies to try to determine the gene function have been initiated (the Arabidopsis 2010 Functional Genome Project) in 2001. These approaches utilise either maize transposable elements or Agrobacterium tumefaciens T-DNA as mutagens. Inserted DNA can have the effect of disrupting the expression of the particular gene into which it is inserted. It can also be used as a marker gene for subsequent identification of the mutation. Insertions are a vital aspect of molecular genetics because they can reveal the gene function by either gene knock-out or gene knock-up (overexpression or misexpression) technology or by expression patterns that are exposed by modified insertion elements. (Pan et. al.; 2003)

Recently, its has been demonstrated that transposable elements and T-DNA can and have been used to generate libraries of Arabidopsis lines in which each individual line carries a single, tagged gene disruption through the publishing of several reports. Several large scale T-DNA and transposon insertional mutagenesis projects using these reported strategies are underway to support projects that are aimed at gene discovery. Modifications to transposable elements and T-DNAs have been made to create systems such as gene traps (GTs) and enhancer traps (ETs), activation tagging (AT) and promoter traps, which can be used to provide information on promoter and enhancer activity and function and gene expression patterns. Transposon and T-DNA mutagenesis has created the opportunity to rapidly identify gene disruption mutants through the Arabidopsis genome by amplifying and sequencing the genomic DNA flanking the insertion sites. (Pan et. al.; 2003)

The precise location of the sequenced insertion sites supplies information about both the likely effect of insertion on the genes function and a unique tag for database searches. T-DNA and transposon insertion sites in the Arabidopsis genome are being sequenced in several large scale projects all over the world and these are being integrated with genome databases. Users can then access this information through a variety of databases which vary in utility. (Pan et. al.; 2003)