Expression of Cellulose Synthase Genes During the Gravistimulation of Flax (Linum usitatissimum) and Poplar (Populus alba x tremula) Plants

摘要

Plant cellulose is synthesized on the plasma membrane by the cellulose synthase complex and a number of coenzymes. Different cellulose synthases are thought to be involved in the primary and secondary cell wall biosynthesis. Plant fibers, such as flax phloem fibers and xylem fibers of poplar tension wood, produce a tertiary cell wall with increased cellulose content and a lack of xylan and lignin. The composition and types of cellulose synthase complexes involved in the tertiary cell wall biosynthesis have not yet been established. Based on transcriptome data for flax (Linum usitatissimum) and poplar (Populus alba x tremula) plants, we evaluated the expression of genes encoding cellulose synthases during the development of a gravitropic response with the participation of the phloem and/or xylem fibers producing the tertiary cell wall. Changes in the expression of cellulose synthase genes characteristic of both primary and secondary cell walls in various model systems indicate the mobility of an ensemble of different cellulose synthases during the gravistimulation, which can affect both an individual cell type and a set of tissues with different types of cell walls. For the isolated flax phloem fibers, the involvement of both types of cellulose synthases in the formation of the tertiary cell wall at all stages of graviresponse was demonstrated.