AtFLL2, a member of theFLO2gene family, affects the enlargement of leaves at the vegetative stage and facilitates the regulation of carbon metabolism and flow

Arabidopsis thaliana FLL2, a member of theFLO2gene family, is expressed specifically in green leaves. Thefll2mutant showed significantly large rosette leaves and reduced the chlorophyll content. The sucrose content was significantly reduced. The glucose content was higher during the vegetative growth stage but decreased during the early reproductive growth stage. The amount of assimilated starch was lower than that in the wild type plant. The expression levels of genes involved in biosynthesis of sucrose and starch were largely altered. These results suggest that, in thefll2mutant, a small amount of photosynthetic products was used for the biosynthesis of starch, and the products were supplied to promote intracellular growth of the source organs or for transport to the sink organs. These findings suggest that FLL2 is a factor affecting the expression level of genes involved in sugar metabolism, whose mutation caused a change in the assimilated products.