Xyloglucan Deficiency Disrupts Microtubule Stability and Cellulose Biosynthesis in Arabidopsis, Altering Cell Growth and Morphogenesis

Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis

“…xxt1 xxt2 mutants had smaller rosettes as well as smaller rosette leaves when grown in soil (Supplemental Fig. S12, B and C), as has been reported elsewhere (Cavalier et al, 2008;Park and Cosgrove, 2012a;Xiao et al, 2016). We found that, in contrast to cesa3 je5 mutants, xxt1 xxt2 plants have rosette leaf emergence patterns that are indistinguishable from wild-type controls (Supplemental Fig.…”

Diffuse Growth of Plant Cell Walls

“…These are remarkable facts that seem counterintuitive to expectations based on conventional models of cell walls (Carpita and Gibeaut, 1993). To illustrate the point in another way: Xyloglucan-deficient hypocotyl walls from the xxt1,xxt2 mutant of Arabidopsis are more compliant (more easily stretched) in tensile tests compared with wild-type walls, yet xxt1,xxt2 hypocotyls grow more slowly than the wild type (Xiao et al, 2016). Moreover, despite their greater mechanical compliance, the xxt1,xxt2 walls extend more slowly in creep tests, exhibit less stress relaxation, and are less responsive to a-expansins compared with wild-type walls (Park and Cosgrove, 2012a).…”

Update: Plant Cortical Microtubule Arrays

“…Disruption of normal microtubule organization also was observed in cases where mutations affected cellulose biosynthesis genes, including CESA1, CESA3, CESA6, CSI1, and KORRIGAN (Paredez et al, 2008;Panteris et al, 2013Panteris et al, , 2014. The notion of cell wall feedback is further supported by chemical and genetic perturbation of other cell wall components, including xyloglucans and arabinogalactans, that led to disorganization and reduced stability of cortical microtubules (Nguema-Ona et al, 2007;Driouich and Baskin, 2008;Xiao et al, 2016).…”