Silica Biomineralization with Lignin Involves Si-O-C Bonds That Stabilize Radicals.

Plants undergo substantial biomineralization of silicon, which is deposited primarily in cell walls as amorphous silica. The mineral formation could be moderated by the structure and chemistry of lignin, a polyphenol polymer that is a major constituent of the secondary cell wall. However, the reactions between lignin and silica have not yet been well elucidated.

Deposition of silica in sorghum root endodermis modifies the chemistry of associated lignin.

Silica aggregates at the endodermis of sorghum roots. Aggregation follows a spotted pattern of locally deposited lignin at the inner tangential cell walls. Autofluorescence microscopy suggests that non-silicified (-Si) lignin spots are composed of two distinct concentric regions of varied composition.

Raman developmental markers in root cell walls are associated with lodging tendency in tef.

Using Raman micro-spectroscopy on tef roots, we could monitor cell wall maturation in lines with varied genetic lodging tendency. We describe the developing cell wall composition in root endodermis and cylinder tissue. Tef [Eragrostis tef (Zucc.

Silicon-mediated herbivore defence in a pasture grass under reduced and Anthropocene levels of CO.

The uptake and accumulation of silicon (Si) in grass plants play a crucial role in alleviating both biotic and abiotic stresses. Si supplementation has been reported to increase activity of defence-related antioxidant enzyme, which helps to reduce oxidative stress caused by reactive oxygen species (ROS) following herbivore attack. Atmospheric CO levels are known to affect Si accumulation in grasses; reduced CO concentrations increase Si accumulation whereas elevated CO concentrations often decrease Si accumulation.

Siliplant1 B-domain precipitates silica spheres, aggregates, or gel, depending on Si-precursor to peptide ratios.

Silica is extensively deposited by plants, however, only little is known about the molecular control over this process. Siliplant1 is the only known plant protein to precipitate biosilica. The protein contains seven repeats made of three domains.