title: Distribution, structure and biosynthetic gene families of (1,3;1,4)-β-glucan in Sorghum bicolor.
abstract: In cereals, the presence of soluble polysaccharides including (1,3;1,4)-β-glucan has downstream implications for human health, animal feed and biofuel applications. Sorghum bicolor (L.) Moench is a versatile crop, but there are limited reports regarding the content of such soluble polysaccharides. Here, the amount of (1,3;1,4)-β-glucan present in sorghum tissues was measured using a Megazyme assay. Very low amounts were present in the grain, ranging from 0.16%-0.27% (w/w), while there was a greater quantity in vegetative tissues at 0.12-1.71% (w/w). The fine structure of (1,3;1,4)-β-glucan, as denoted by the ratio of cellotriosyl and cellotetraosyl residues, was assessed by high performance liquid chromatography (HPLC) and ranged from 2.6-3:1 in the grain, while ratios in vegetative tissues were lower at 2.1-2.6:1. The distribution of (1,3;1,4)-β-glucan was examined using a specific antibody and observed with fluorescence and transmission electron microscopy. Micrographs showed a variable distribution of (1,3;1,4)-β-glucan influenced by temporal and spatial factors. The sorghum orthologs of genes implicated in the synthesis of (1,3;1,4)-β-glucan in other cereals, such as the Cellulose synthase-like (Csl) F and H gene families were defined. Transcript profiling of these genes across sorghum tissues was carried out using real-time quantitative polymerase chain reaction, indicating that, as in other cereals, CslF6 transcripts dominated.
authors: Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Glen Osmond, SA, 5064, Australia.
authors: Riksfardini A
authors: RA
authors: Ermawar
authors: Helen M
authors: HM
authors: Collins
authors: Caitlin S
authors: CS
authors: Byrt
authors: Natalie S
authors: NS
authors: Betts
authors: Marilyn
authors: M
authors: Henderson
authors: Neil J
authors: NJ
authors: Shirley
authors: Julian
authors: J
authors: Schwerdt
authors: Jelle
authors: J
authors: Lahnstein
authors: Geoffrey B
authors: GB
authors: Fincher
authors: Rachel A
authors: RA
authors: Burton
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D018515:Plant Leaves / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000378:metabolism / Q000648:ultrastructure; D045868:Sorghum / Q000166:cytology / Q000235:genetics*; D047071:beta-Glucans / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D047071:beta-Glucans; D005964:Glucosyltransferases; C478648:cellulose synthase
keywords: Cellulose  synthase-like  genes; cell wall composition; grain; mixed-linkage glucan; sorghum