Arabidopsis thaliana: a Model Plant for Studying the Molecular Basis of Morphogenesis

Morphogenesis in higher plants is likely to be controlled by the serial activation of genes. These genes could be identified if the structure which they normally control is specifically disrupted when they are in mutant form. By cloning and characterising the products of such genes we could gain an understanding of the genetic control of morphogenesis. This report makes a case for following this strategy using Arabidopsis thaliana as a model species. This species is easily grown, has a short, 6-week life cycle and convenient genetics. Mutations affecting embryogenesis, trichome structure, the inflorescence and floral organs are already known. Because Arabidopsis has a tiny genome (70 000 kbp), cloning of genes known only by mutant phenotype is practicable by chromosome walking and DNA tagging. The role of their products in cellular and developmental decisions could then be investigated. Genes controlling morphogenesis are likely to be conserved across higher plants. Once they have been cloned from a model species their isolation from other species by DNA hybridisation is relatively simple. Generalisations about the origin, action and evolution of such genes would then be possible. Also artificial manipulation of morphogenesis may be achievable.