Defects in Cell Wall Differentiation of the Arabidopsis Mutant rol1-2 Is Dependent on Cyclin-Dependent Kinase CDK8

Abstract

Plant cells are encapsulated by cell walls whose properties largely determine cell growth. We have previously identified the rol1-2 mutant, which shows defects in seedling root and shoot development. rol1-2 is affected in the Rhamnose synthase 1 (RHM1) and shows alterations in the structures of Rhamnogalacturonan I (RG I) and RG II, two rhamnose-containing pectins. The data presented here shows that root tissue of the rol1-2 mutant fails to properly differentiate the cell wall in cell corners and accumulates excessive amounts of callose, both of which likely alter the physical properties of cells. A surr (suppressor of the rol1-2 root developmental defect) mutant was identified that alleviates the cell growth defects in rol1-2. The cell wall differentiation defect is re-established in the rol1-2 surr mutant and callose accumulation is reduced compared to rol1-2. The surr mutation is an allele of the cyclin-dependent kinase 8 (CDK8), which encodes a component of the mediator complex that influences processes central to plant growth and development. Together, the identification of the surr mutant suggests that changes in cell wall composition and turnover in the rol1-2 mutant have a significant impact on cell growth and reveals a function of CDK8 in cell wall architecture and composition.

Intra‐ and inter‐specific variation in root mechanical traits for twelve herbaceous plants and their link with the root economics space

“…Additionally, including thicker (2–8 mm) and highly lignified roots (Genet et al 2005, de Baets et al 2008) can also bias results, as root mechanical integrity is compromised due to the presence of material defects in cell wall microstructure. Material defects can non‐linearly deteriorate the mechanical quality of a material (Timoshenko 1956) and are the result of anomalies in cell wall differentiation, imperfections in cell adhesion or damage caused as, for example, a root grows through soil with its multitude of diverse physical properties and root herbivores (Williamson and Gleason 2003, Schumacher et al 2021).…”

Characterization of almond scion/rootstock communication in cultivar and rootstock tissues through a RNA-Seq approach

“…These modi cations are crucial to ensure xylan integrity and cell wall strength. Knockout mutants of ROL1 (Prudul26A014014) produce aberrant pectin structure which leads to reduced elongation growth, highlighting a role for ROL1 in cell wall reorganization [90,91]. Nevertheless, some genes associated also to cell wall formation were found to be upregulated when 'Isabelona' was the scion (Table 3).…”