Phenotypic screening of Arabidopsis T-DNA insertion lines for cell wall mechanical properties revealed ANTHOCYANINLESS2, a cell wall-related gene

Abstract

We performed a phenotypic screening of confirmed homozygous T-DNA insertion lines in Arabidopsis for cell wall extensibility, in an attempt to identify genes involved in the regulation of cell wall mechanical properties. Seedlings of each line were cultivated and the cell wall extensibility of their hypocotyls was measured with a tensile tester. Hypocotyls of lines with known cell wall-related genes showed higher or lower extensibility than those of the wild-type at high frequency, indicating that the protocol used was effective. In the first round of screening of randomly selected T-DNA insertion lines, we identified ANTHOCYANINLESS2 (ANL2), a gene involved in the regulation of cell wall mechanical properties. In the anl2 mutant, the cell wall extensibility of hypocotyls was significantly lower than that of the wild-type. Levels of cell wall polysaccharides per hypocotyl, particularly cellulose, increased in anl2. Microarray analysis showed that in anl2, expression levels of the major peroxidase genes also increased. Moreover, the activity of ionically wall-bound peroxidases clearly increased in anl2. The activation of peroxidases as well as the accumulation of cell wall polysaccharides may be involved in decreased cell wall extensibility. The approach employed in the present study could contribute to our understanding of the mechanisms underlying the regulation of cell wall mechanical properties.

A tomato LATERAL ORGAN BOUNDARIES transcription factor, SlLOB1 , predominantly regulates cell wall and softening components of ripening

“…S7 A ). SlANL2b (Solyc06g035940.2) is paralogous to CD2 ( CUTIN DEFICIENT 2 ), a regulator of epidermal cell cuticle deposition ( 38 ) whose orthologous A. thaliana loss-of-function mutant increased cell wall polysaccharide content ( 39 ). Solyc03g120910.2 is orthologous to an A. thaliana gene involved in vascular development and parenchyma pith cell primary wall retention ( 40 ).…”

CROWN ROOTLESS1 binds DNA with a relaxed specificity and activates OsROP and OsbHLH044 genes involved in crown root formation in rice

“…Moreover, it was shown that ROC4 is involved in the regulation of genes involved in cell wall precursor metabolism and by consequence in the specification of outer cell layers such as epidermis, exodermis, and sclerenchyma (Huang et al., 2012; Ito et al., 2003). Its closest homologs in Arabidopsis, HOMEODOMAIN GLABROUS1 ( HDG1 , At3g61150 ) and ANTHOCYANINLESS2 ( ANL2 , At4g00730 ), are involved in lateral root development and in meristem cell proliferation and root radial patterning (Horstman et al., 2015; Kubo et al., 1999; Kubo & Hayashi, 2011; Mabuchi et al., 2016; Nakamura et al., 2006). Altogether, the data suggest that ROC4 is likely involved in crown root primordia formation downstream of CRL1.…”

Silencing against the conserved NAC domain of the potato StNAC103 reveals new NAC candidates to repress the suberin associated waxes in phellem

“…As explained above, the gene CD2/ANL2 was strongly upregulated in both StNAC103 transgenic lines in agreement with the increase of suberin and wax compounds. It has been reported that CD2/ANL2 is a class IV homeodomain Leucine zipper (HD-ZIP IV) whose mutation in addition to the effects in cutin and waxes, gives rise to an increase in cuticle water permeability [51,57] and also lower cell wall extensibility [58]. ALCATRAZ is a basic helix loop helix (bHLH) transcription factor involved in fruit dehiscence by promoting cell differentiation [59] and was also upregulated in both NAC silencing lines.…”