Altering FVE/MSI4 results in a substantial increase of biomass in Arabidopsis-the functional analysis of an ontogenesis accelerator

FVE/MSI4, a highly conserved gene through evolution, is considered a classical flowering time gene from the autonomous pathway in Arabidopsis thaliana. Our work provides complementary, yet distinct, evidence that mutations in FVE/MSI4 have highly pleiotropic effects on plant architecture and organ production and growth, indicating an overall role in reprogramming the genome. First, this is illustrated by the fact that fve mutants and transgenic versions of the gene show no morphological aberrations while living, on average, twice as long and producing more biomass and seeds than the wild type. For example, depending on the photoperiod, the vegetative biomass in the mutants is increased three- to eightfold. FVE/MSI4 can therefore be considered a multifactor component of biomass and yield. Second, the gene functions primarily at the shoot apical meristem, acting to calibrate its overall cell proliferation activity and organ initiation. At the same time, FVE/MSI4 regulates cell growth during organ formation mainly by modulating the timing of proliferation-differentiation transition and that of endoreduplication. FVE/MSI4 is an accelerator of ontogenesis. The function of the gene is to scale-down meristem activities, while accelerating developmental transitions and cellular differentiation. Genes of the kind are ideal tools in biotech for engineering biomass and yield according to geographical or climate constraints. The results enhance our understanding on the role epigenetic components of the genome, such as FVE/MSI4, play in adaptation and biomass calibration. They also illustrate the kind of functional characterization biotech applications might require during the first steps of product development.