Spatiotemporal deposition of cell wall polysaccharides in oat endosperm during grain development

作者：Pavani P. Nadiminti, Sarah M Wilson, Allison van de Meene, Pengfei Hao, John Humphries, Julian Ratcliffe, Changyu Yi, Marta Peirats‐Llobet, Mathew G. Lewsey, James Whelan, Antony Bacic, Monika S. Doblin · 发表于：PLANT PHYSIOLOGY · 年份：2023 · DOI：10.1093/plphys/kiad566 · 被引用次数：8 · 研究领域：Polysaccharides and Plant Cell Walls、Food composition and properties、Polysaccharides Composition and Applications

Oat (Avena sativa) is a cereal crop whose grains are rich in (1,3;1,4)-β-D-glucan (mixed-linkage glucan or MLG), a soluble dietary fiber. In our study, we analyzed oat endosperm development in 2 Canadian varieties with differing MLG content and nutritional value. We confirmed that oat undergoes a nuclear type of endosperm development but with a shorter cellularization phase than barley (Hordeum vulgare). Callose and cellulose were the first polysaccharides to be detected in the early anticlinal cell walls at 11 days postemergence (DPE) of the panicle. Other polysaccharides such as heteromannan and homogalacturonan were deposited early in cellularization around 12 DPE after the first periclinal walls are laid down. In contrast to barley, heteroxylan deposition coincided with completion of cellularization and was detected from 14 DPE but was only detectable after demasking. Notably, MLG was the last polysaccharide to be laid down at 18 DPE within the differentiation phase, rather than during cellularization. In addition, differences in the spatiotemporal patterning of MLG were also observed between the 2 varieties. The lower MLG-containing cultivar AC Morgan (3.5% w/w groats) was marked by the presence of a discontinuous pattern of MLG labeling, while labeling in the same walls in CDC Morrison (5.6% w/w groats) was mostly even and continuous. RNA-sequencing analysis revealed higher transcript levels of multiple MLG biosynthetic cellulose synthase-like F (CSLF) and CSLH genes du...