Медикаго трункатула: Геномдық зерттеулердегі бұршақ тұқымдас өсімдік моделі

Species of legume

Medicago truncatula, the barrelclover, strong spined medick, barrel medic, or barrel medick, is a small annual legume native to the Mediterranean region that is used in genomic research. It is a low growing, clover like plant tall with trifoliate leaves. Each leaflet is rounded, long, often with a dark spot in the center. The flowers are yellow, produced singly or in a small inflorescence of two to five together; the fruit is a small, spiny pod. This species is studied as a model organism for legume biology because it has a small diploid genome, is self fertile, has a rapid generation time and prolific seed production, is amenable to genetic transformation, and its genome has been sequenced. It forms symbioses with nitrogen fixing rhizobia (Sinorhizobium meliloti and Sinorhizobium medicae) and arbuscular mycorrhizal fungi including Rhizophagus irregularis (previously known as Glomus intraradices). The model plant Arabidopsis thaliana does not form either symbiosis, making M. truncatula an important tool for studying these processes. It is also an important forage crop species in Australia.

The draft sequence of the genome of M. truncatula cultivar A17 was published in the journal Nature in 2011. The assembly of the genome sequence in M. truncatula was based on bacterial artificial chromosomes (BACs). This is the same approach used to sequence the genomes of humans, the fruitfly, Drosophila melanogaster, and the model plant, Arabidopsis thaliana. In July 2013, version 4.0 of the genome was released. This version combined sequences gained from shotgun sequencing with the BAC based sequence assemblies, which has helped to fill in the gaps in the previously mapped sequences. A parallel group known as the International Medicago Gene Annotation Group (IMGAG) is responsible for identifying and describing putative gene sequences within the genome sequence.

Researcher Toby Kiers of VU University Amsterdam and associates used M. truncatula to study symbioses between plants and fungi – and to see whether the partners in the relationship could distinguish between good and bad traders/suppliers. By using labeled carbon to track the source of nutrient flowing through the arbuscular mycorrhizal system, the researchers have proven that the plants had indeed given more carbon to the more generous fungus species. By restricting the amount of carbon the plants gave to the fungus, the researchers also demonstrated that the fungi did pass along more of their phosphorus to the more generous plants.

Proteomic investigation by mass spectrometry has been performed by Wienkoop et al 2004 and Larrainzar et al 2007.