Genes controlling cell growth
Plant leaves use photosynthesis to convert sunlight into sugar, thereby directly or indirectly providing energy for much of life on Earth. Understanding the genes involved in leaf development is important for agriculture and breeding, and for revealing similarities and differences between plant and animal genetics. The EU-funded ‘Uncovering conserved proliferation pathways between plants and animals’ (ARABIGANS) project aimed to identify key growth pathways for biotechnological applications in both plants and animals. ARABIGANS used Arabidopsis thaliana, a model plant species that has been fully sequenced, to identify and characterise genes important for leaf size, shape and function. Researchers used a publically available collection of A. thaliana mutants containing hundreds of thousands of genetic changes that disrupt gene function. By looking at which genetic sequences have been disrupted and linking these to aberrant leaf growth, scientists can assign a function to the genes. ARABIGANS identified 608 genes in which these disruptions affected leaf traits, including increased or decreased leaf size, altered shape or altered colour pattern. To help identify gene functions, they developed a public web application named PhenoLeaf, which can be used to link specific gene sequences with associated leaf traits. Researchers also screened another set of A. thaliana mutants in which genes were upregulated to produce high levels of proteins. Using this approach, they identified two genes with previously unknown function that have a role in cell proliferation and patterns of leaf veins. Finally, ARABIGANS identified and fully characterised a gene they called deal, which has a role in cell proliferation-driven leaf expansion and development. In the future, potential plant growth modulators identified in this study will be tested in an animal model system (the roundworm Caenorhabditis elegans). If their function is common to plants and animals, they could have pharmacological or therapeutic application as universal regulators of cell proliferation.
Keywords
Cell growth, proliferation pathways, plants, animals, leaf development