The role of the small GTPases and the phytocyanins during secondary cell wall synthesis in Arabidopsis thaliana

The secondary cell wall of plants is a structure formed outside the cell during xylem development that comprises the largest amount of biomass available on earth. Currently the use of plant biomass has awakened large interest as a feedstock for the production of second generation biofuels. Nevertheless, there are still important aspects of the secondary cell wall synthesis and the xylem formation that need to be understood in order to make an efficient use of the available biomass. One of these aspects is the relationship between the plant cytoskeleton and the cell wall orientation. This study provided evidence about the involvement of ROP7 together with RIC2 and RIC4 interactors in the patterning of the cell wall during xylem development. Another aspect is the trafficking of the CESA proteins and the cell wall components from their places of synthesis to the plasma membrane. This study also suggests that RABA6A might be involved in the trafficking or recycling of some of these components required during cell wall assembly. Finally, it is necessary to properly deconstruct the tight linkage of lignin with the other components that confers recalcitrance to the biomass. In this study, it is suggested that members of the phytocyanin family might be involved in lignin assembly and that their manipulation could potentially change the characteristics of that linkage. The findings of this research could provide new insight into the process of secondary cell wall synthesis and xylem development.