A novel gene that increases cellulose synthesis

August 11, 2017

The National Institute of Genetics and RIKEN CSRS and the University of Tokyo worked collaboratively in a search for the genes that control the amounts and arrangements of microtubules, which act as a scaffold for cellulose synthase in plant cells. They focused their attention on vessels, which act as pipes for water transport. In order to withstand water pressure during transport, the cells that create these vessels synthesize strong cell walls.

When researchers investigated the genes active in creating these strong cell walls, they identified the IQD13 gene. The protein generated by IQD13 was found to bind tightly to microtubules to make them less fragile. Moreover, the IQD13 protein also binds to the cell membrane to effectively link microtubules to the cell membrane. Overproduction of IQD13 resulted in an increase of microtubules, up to triple the density.

There are proteins that inhibit cell wall synthesis in order for vessels to create cell-wall pits to pass water laterally. The researchers found that IQD13 associates with microtubules and the cell membrane but its distribution is restricted, resulting in an increase in the area of cell wall synthesis, which takes place at the cell's surface.

Artificially manipulating the function of the IQD13 gene to control cell wall synthesis could lead to the production of plants that are easy to use for cellulose production.

Original article
Current Biology doi:10.1016/j.cub.2017.06.059
Y. Sugiyama, M. Wakazaki, K. Toyooka, H. Fukuda, Y. Oda,
"A novel plasma membrane-anchored protein regulates xylem cell-wall deposition through microtubule-dependent lateral inhibition of Rho GTPase domains".
Kiminori Toyooka
Senior Research Scientist
Mass Spectrometry and Microscopy Unit