The expression of several cell wall-related genes in Arabidopsis roots is down-regulated under boron deficiency

Plant cell wall is a dynamic structure that is of fundamental importance in plant growth and development, as well as in the response to environmental stresses. There is direct evidence for a role of boron (B) in cross-linking of cell wall rhamnogalacturonan II (RG-II) and pectin assembly, which shows that B is essential for cell wall structure and function. The aim of the present work was to investigate the effects of B deficiency on the expression of cell wall-related genes in Arabidopsis roots. For this purpose, plants were grown hydroponically in a nutrient solution supplemented with 2 μM B and then transferred to a boron-free medium for 6 and 24 h. A transcriptome analysis was carried out and several cell wall-related genes were identified, whose expressions were down-regulated by B deficiency. These genes belong to arabinogalactan protein, xyloglucan endotransglycosylase/hydrolase, polygalacturonase, pectate lyase, pectin methylesterase, expansin, and cellulose synthase-like gene families. These results suggest that in addition to the essential role that B plays in the structural organization of the cell wall, it could directly or indirectly have an impact on the expression levels of genes related to the cell wall.