ИСТИНА

Floral transition is an important process in the life cycle of a flowering plant to ensure its reproductive success. Some genes regulating this process are well studied, but the global changes in transcriptome in time when a vegetative meristem turns into an inflorescence are not characterized. Using high-throughput sequencing, we analyzed gene expression during Arabidopsis thaliana meristem development from day 7 to 16 after germination in one-day increments. Main flowering regulators have expression dynamics consistent with previous reports: the expression of negative regulator FLOWERING LOCUS C (FLC) decreased over the course of the time series while expression of positive regulator LEAFY (LFY) increased. We found a time point between 10 and 12 days after germination where FLC and LFY have parity in expression: first had already decreased but second had not yet increased. This time point is characterized by a peak in the number of differentially expressed genes. Gene Ontology (GO) enrichment analysis of these genes identified an overrepresentation of genes related to the cell cycle. Analysis of expression profiles of specific genes involved in cell cycling suggests that acceleration of rate of the divisions and partial cell cycling synchronization takes place at this point.