Premium
TRM 4 is essential for cellulose deposition in Arabidopsis seed mucilage by maintaining cortical microtubule organization and interacting with CESA 3
Author(s) -
Yang Bo,
Voiniciuc Cătălin,
Fu Lanbao,
Dieluweit Sabine,
Klose Holger,
Usadel Björn
Publication year - 2019
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15442
Subject(s) - mucilage , microtubule , arabidopsis , cellulose , cell wall , microbiology and biotechnology , secondary cell wall , cellulosic ethanol , biology , arabidopsis thaliana , biophysics , botany , chemistry , biochemistry , gene , mutant
Summary The differentiation of the seed coat epidermal ( SCE ) cells in Arabidopsis thaliana leads to the production of a large amount of pectin‐rich mucilage and a thick cellulosic secondary cell wall. The mechanisms by which cortical microtubules are involved in the formation of these pectinaceous and cellulosic cell walls are still largely unknown. Using a reverse genetic approach, we found that TONNEAU 1 ( TON 1) recruiting motif 4 ( TRM 4 ) is implicated in cortical microtubule organization in SCE cells, and functions as a novel player in the establishment of mucilage structure. TRM 4 is preferentially accumulated in the SCE cells at the stage of mucilage biosynthesis. The loss of TRM 4 results in compact seed mucilage capsules, aberrant mucilage cellulosic structure, short cellulosic rays and disorganized cellulose microfibrils in mucilage. The defects could be rescued by transgene complementation of trm4 alleles. Probably, this is a consequence of a disrupted organization of cortical microtubules, observed using fluorescently tagged tubulin proteins in trm4 SCE cells. Furthermore, TRM 4 proteins co‐aligned with microtubules and interacted directly with CELLULOSE SYNTHASE 3 in two independent assays. Together, the results indicate that TRM 4 is essential for microtubule array organization and therefore correct cellulose orientation in the SCE cells, as well as the establishment of the subsequent mucilage architecture.