The genetics behind drought resistance in plants
Arabidopsis thaliana, a small flowering plant belonging to the mustard family, is a model organism that has facilitated important research in plant genetics. Yet mustard bears little resemblance to wheat, rice and the other cereal crops upon which the world relies for sustenance. Recently, the temperate grass Brachypodium distachyon has been proposed as a suitable candidate for a role in research. The EU is supporting fundamental research in this area through a project entitled 'Natural variation for drought tolerance in the grass Brachypodium distachyon, a new model species for ecological genomics' (Vargendroutolbrachy). The goal is to improve our understanding of how plants deal with stresses such as drought. Genetic screening of samples of B. distachyon found throughout the arid region of the Iberian Peninsula in Spain has been carried out. Data concerning the plants' capacity to deal with water stress, namely water use efficiency (WUE) and flowering time, have also been collected. A considerable degree of variation was discovered, although it was not randomly distributed. A distinct pattern was established - the more arid the region, the greater the WUE and the earlier the flowering time. Interestingly, a strong correlation was detected between these traits and the number of chromosomes in the plants, known as its ploidy level. The researchers' next step involves determining which segments of the plants' genetic code are responsible for these characteristics, using quantitative trait locus analysis. The results will not only shed light on how this adaptation came about, but will open the door to encouraging drought resistance in closely related species such as cereal crops.
