Xyloglucan Fucosylation Modulates Arabidopsis Cell Wall Hemicellulose Aluminium binding Capacity

Abstract

Although xyloglucan (XyG) is reported to bind Aluminium (Al), the influence of XyG fucosylation on the cell wall Al binding capacity and plant Al stress responses is unclear. We show that Arabidopsis T-DNA insertion mutants with reduced AXY3 (XYLOSIDASE1) function and consequent reduced levels of fucosylated XyG are more sensitive to Al than wild-type Col-0 (WT). In contrast, T-DNA insertion mutants with reduced AXY8 (FUC95A) function and consequent increased levels of fucosylated XyG are more Al resistant. AXY3 transcript levels are strongly down regulated in response to 30 min Al treatment, whilst AXY8 transcript levels also repressed until 6 h following treatment onset. Mutants lacking AXY3 or AXY8 function exhibit opposing effects on Al contents of root cell wall and cell wall hemicellulose components. However, there was no difference in the amount of Al retained in the pectin components between mutants and WT. Finally, whilst the total sugar content of the hemicellulose fraction did not change, the altered hemicellulose Al content of the mutants is shown to be a likely consequence of their different XyG fucosylation levels. We conclude that variation in XyG fucosylation levels influences the Al sensitivity of Arabidopsis by affecting the Al-binding capacity of hemicellulose.

The plant cell wall: Biosynthesis, construction, and functions

“…The glycosylphosphatidylinositol-anchored fasciclin-like arabinogalactan (FLA) protein Salt overly-sensivity5 (SOS5) and the nucleotide sugar conversion enzyme Murus4 help plants adapt to salt stress (Shi et al, 2003;Zhao et al, 2019). Several xyloglucan processing enzymes, such as XTH31, are required for root growth in plants under aluminum stress (Zhu et al, 2012(Zhu et al, , 2014Wan et al, 2018). Xylan O-acetyltransferase1 (XOAT1/Eskimo1) functions in freezing tolerance (Xin and Browse, 1998;Lunin et al, 2020).…”

“…The cell wall is not uniform, as it possesses plasmodesmata, Casparian strips, pitted and spiral patterns, and so on. During plant growth, the asymmetrical deposition of wall products must be tightly controlled to allow the cell wall to fulfill its many physiological functions, such as determining cell shape, seed dispersion, and nitrate uptake during nodule symbiosis (Feraru et al, 2011; Hofhuis et al, 2016; Wang et al, 2020). Considering the close‐knit contacts between the cell wall and PM, the cell wall–PM continuum might be crucial for directing the heterogeneous deposition of cell wall material and determining the behaviors of the cell wall in cell polarization and morphogenesis (Oda and Fukuda, 2012a; Bashline et al, 2014; Liu et al, 2015).…”

Al-induced proteomics changes in tomato plants over-expressing a glyoxalase I gene

“…Xyloglucan (XyG) is the principal hemicellulose in primary walls of dicots, where a O-acetylated XyG backbone is present in Solanaceae as well as in grass 70 . The acetylation of XyG affects its Al 3+ -binding capacity 71 , as lowering acetylation level makes plants more sensitive to Al treamtents 72 . Acetyl xylan esterase catalyzes the reaction of deacetylation of substituted xylans 73 .…”

Comparative study of response of four crop species exposed to carbon nanotube contamination in soil

“…Likewise, root binding capacity for trace metal ions is usually higher in dicots than in monocots and this difference is also attributed to a higher pectin content in the dicot cell walls (20e35% of the dry mass) than in monocot cell walls (5% of the dry mass) (Vogel 2008;Rabę da et al, 2015). Furthermore, hemicellulose acts as a heavy metal binding site, in particular xyloglucans and, according to Wan et al, the absence of fucose decreases the capacity of xyloglucans to sequester heavy metals and thus increases plant sensitivity (Wan et al, 2018). Concerning CNTs, they were negatively charged in soil suspension (Figure S1) but once in plants, diverse molecules may adsorb onto their surface leading to modifications of their overall surface charge.…”