Résumé
Gene expression in individual cells can be surprisingly noisy. In unicellular organisms this noise can be functional; for example, by allowing a subfraction of the population to prepare for environmental stress. The role of gene expression noise in multicellular organisms has, however, remained unclear. In this review, we discuss how new techniques are revealing an unexpected level of variability in gene expression between and within genetically identical plants. We describe recent progress as well as speculate on the function of transcriptional noise as a mechanism for generating functional phenotypic diversity in plants.
Gene expression levels can be surprisingly noisy, both between individual cells and between individual plants, even in the absence of genetic and environmental variation.Arabidopsis thaliana is a promising system to study interindividual gene expression variability since it is an inbreeding species with extremely low heterozygosity.Noise in gene expression in plants is widespread, as revealed by studies that have begun to systematically quantify it at the between-cell and between-individual levels. This could be detrimental or, by contrast, used to drive developmental patterns or create phenotypic diversity without genetic diversity.The sources and roles of gene expression noise in plants are still not well understood. New experimental techniques now allow the analysis of plant-to-plant and cell-to-cell gene expression noise in plants.