Proteomic analysis of flax (Linum usitatissimum L.) phloem fibres and stem tissues.

摘要

To better understand the molecular mechanisms underlying cell wall development in flax (Linum usitatissimum L.) bast fibres, proteins from individually dissected phloem fibres (i.e. individual cells) at an early stage of secondary cell wall development, were extracted and compared with protein extracts from surrounding, non-fibre cells, using fluorescent (DiGE) labels and 2D-gel electrophoresis. Identities were assigned to some proteins by mass spectrometry. Phosphoprotein and glycoprotein specific staining were used to investigate post-translational modifications (PTMs). The abundance of many proteins in fibres was notably different from the surrounding non-fibre cells, with approximately 13% of the 1,850 detectable spots being significantly (>1.5 fold, p≤0.05) enriched in fibres. A K+ channel subunit, annexins, secretory pathway components, beta-galactosidase and pectin and galactan biosynthetic enzymes were observed to be among the most highly enriched proteins detected in developing flax fibres, with many of these proteins showing electrophoretic patterns consistent with PTMs.