Cell wall deposition and metabolism in wheat grain

Breeding maize for silage and biofuel production, an illustration of a step forward with the genome sequence

“…Candidate genes for xylan synthase have been identified as members of the GT43 (IRX9/14-like) and GT47 (IRX10-like) families, although the precise contribution of both protein families remains unclear [90,91]. Rice OsGT47A (also named OsIRX10) mutants had a reduced level of xylans and showed an increase in saccharification efficiency [92] .…”

“…Several members of the GT61 family (clade A) were shown to be xylan O-3-arabinosyltransferases in wheat and rice [90,95,96]. A mutation in a GT61 gene, involved in arabinoxylan substitution, was shown to improve saccharification in Brachypodium plants, without any significant alteration in plant growth or stem strength [97].…”

Does Illumination of Non-Mature Cereal Kernels During Drying Affect the Germination Ability?

“…It is interesting that evidently the winter wheat harvested in 2 nd term required one day more to get the constant weight than in 1 st term, independently from lighting as well as the spring wheat kernels harvested in 2 nd term dried in darkness shorter than under lighting. These small differences in the time required to obtain a constant weight by kernels the most likely could result from differences in sugars and proteins content and polymers composition, which affect the water holding capacity (Rybka, 1994;Rybka, et al, 1988;Saulnier, et al, 2012). The seed moisture content depended on the term of harvest.…”

Exploiting natural variation to improve the content and composition of dietary fibre in wheat grain: A review

“…The extent of feruloylation also varies between tissues, with the AX in the starchy endosperm having a low level of feruloylation (about 0.3% of the total AX), only traces of dehydrodiferulate and no triferulate (BArron et al, 2007;SAuLnier et al, 2012), while the aleurone cell walls contain about 3.2% ferulate, 0.45% dehydrodiferulate (SAuLnier et al, 2012), and also p-coumaric acid (0.2-0.3 mg g -1 tissue) (BArron et al, 2007). The AX in the outer layers is generally more highly substituted than in the endosperm tissues, (with galactose and glucuronic acid substitutions) and is often termed glucuronoarabinoxylan.…”

“…These cell types differ in their composition, with the sub-aleurone cells being particularly rich in protein and the prismatic and central cells being rich in starch. FT-IR microspectroscopy and micro-scale enzyme fingerprinting have shown that differences in cell wall composition also occur across the grain, including the ratio of AX:β-glucan and the degree of substitution of the AX 2011a, b;2012;SAuLnier et al, 2012). Grain development is associated with an increase in the ratio of monosubstituted to disubstituted AX, with this transition being initiated in the outer part of the starchy endosperm and being accelerated under hot and dry growing conditions .…”