A Model Plant

Thale Cress, Arabidopsis thaliana

An inconspicuous weed of waste ground and walls throughout Ireland, and indeed much of the northern hemisphere, Arabidopsis thaliana (Thale Cress) doesn't look much. With tiny white flowers on a long stem arising from a neat rosette of leaves, the whole plant rarely grows over 40 cm high (1). Yet its small size belies its enormous stature as a model plant in genetics. Research on Arabidopsis has resulted in priceless information a variety of plant mechanisms such as how flowers develop and how plants control their circidarian rhythms (2). In terms of publication in the scientific literature, Arabidopsis is by far and away the most thoroughly studied plant in the world: in 2008, for example, 3500 papers were published on the plant (3).

Thale Cress, Arabidopsis thaliana

But why is it such an important plant? Economically it has no value, either as a food stuff or as a raw material. Crucially, Arabidopsis possess features that make it very suitable for genetic research, namely a short generation time, a small physical size that limits the need for growth facilities and prolific seed production through self pollination. It has a small genome, just 157 megabase pairs in length with just 5 chromosomes making it ideal for gene mapping (3).

Thale Cress, Arabidopsis thaliana

Such seemingly suitability is really only part of the story however when explaining its enduring  popularity as a model organism. Tireless work by a number of individuals in experimentation and analysis of Arabidopsis has also help elevate it to the plant par excellence in genetic research. The first research carried out on Arabidopsis was by Friedrich Laibach who determined the correct chromosome number during his PhD research in 1907 and published a compelling argument for its case as a model for genetic studies in 1943 (3). The Hungarian botanist George Rédei, working in the United States, continued to work on the plant in the 1950's and it was a review published by him in 1975 (4) that lead researchers such as Chris Somerville, Elliot Meyerowitz, Maarten Koornneef and David Meinke to realise its potential as a genetic model. Through collaboration and conferences they, among others, helped establish a vibrant network and a critical mass of information that lead to Arabidopsis' currently importance.

References:

1. Sterry, 2004. Collins Complete Guide to Irish Wildlife
2. Reeves and Coupland, 2000. Current Opinion in Plant Biology 3 pp 37–42
3. Koornneef and Meinke, 2010. The Plant Journal  61 pp. 909–921
4. Rédei, 1975. Annual Review of Genetics 9 pp 111-127