What is Arabidopsis thaliana?

Arabidopsis thaliana is a model plant used in research to study many aspects of plant biology.  Originating in Europe and Central Asia, it is a dicot, as are many important and culturally significant staple crops, such as potato;  commercially important food crops, such as soybean; and fiber crops, such as cotton and hardwood trees.  Unlike many other members of the family Brassicaceae (the same family contains canola, broccoli, cabbage, mustard and other food and oilseed crop species), Arabidopsis thaliana is not grown for food or oil production, and is not agronomically important in itself.  Plants are quite small (see Figure 1 below).

Although in the genus Arabidopsis there are approximately 9 species and 8 sub-species (see the entry for Arabidopsis in Wikipedia), it is not uncommon for plant biology researchers to use “Arabidopsis” to mean Arabidopsis thaliana, the convention used in this landscape.

Figure 1: Arabidopsis thaliana seedlings growing in tissue culture (seedling ~10mm in width)

The popularity of  as a model for all plant processes has given rise to numerous methods and protocols for its use in research. Because germination through to senescence is only approximately 50 days (The Arabidopsis Information Resource (TAIR)), Arabidopsis offers a fast system in which to study processes that may take months or years in other flowering plants. The availability of large numbers of mutants and T-DNA insertion lines (e.g. The European Arabidopsis Stock Centre, NASC) has made it useful in understanding the role of many plant genes, particularly those involved in development, metabolism, and disease resistance.

Arabidopsis was chosen as the first plant species for a public whole genome sequencing effort because of its small genome size. The table below shows the genome sizes of some commonly-studied organisms, including Arabidopsis.

Organism Common Name Genome Size
Escherichia coli K12 E.coli

        4.64 Mb

Saccharomyces cerevisiae YJM789 baker’s yeast       16 Mb
Arabidopsis thaliana thale cress     120 Mb
Oryza sativa rice     430 Mb
Lycopersicon esculentum
tomato     950 Mb
Zea mays maize   2365 Mb
Homo sapiens man   3038 Mb
Triticum aestivum wheat 17000 Mb

(Genome sizes were taken from the NCBI’s Genomic Biology web pages.)

The future of Arabidopsis thaliana research?

The availability of sequence data for the Arabidopsis genome and EST projects has ensured that Arabidopsis is now more widely used than ever as a model for the study of flowering plants, and new or improved enabling technologies are being applied to it as they become available for research.  For example, with the availability of genomic sequence and EST data, gene silencing or RNAi technology is being used as a research method to determine the function of Arabidopsis genes.  The Arabidopsis Genomic RNAi Knock-out Line Analysis (AGRICOLA) project was started in 2002 with the goal of providing the scientific community with research tools (specific vectors and cloned Arabidopsis DNA) necessary to study gene function via gene silencing.

Understanding the patent landscape surrounding Arabidopsis is important in planning research that aims for application in products, because of the continued importance of Arabidopsis as a research tool to many thousands of scientists. Furthermore, use of the genomic information of Arabidopsis in patents and patent applications has resulted in broad claims for patent coverage of genes in other flowering plants.

Khush GS (1997) Origin, dispersal, cultivation and variation of rice. Plant molecular biology 35 (1-2), 25-34 (Sep 1997)