Shewry Peter R, Wan Yongfang, Hawkesford Malcolm J, Tosi Paola
Plant Science Department, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK.
School of Agriculture, Policy and Development, University of Reading, Whiteknights Campus, Early Gate, RG6 6AR, Reading, UK.
J Cereal Sci. 2020 Jan;91:102869. doi: 10.1016/j.jcs.2019.102869.
The starchy endosperm of the mature wheat grain comprises three major cell types, namely sub-aleurone cells, prismatic cells and central cells, which differ in their contents of functional components: gluten proteins, starch, cell wall polysaccharides (dietary fibre) and lipids. Gradients are established during grain development but may be modified during grain maturation and are affected by plant nutrition, particularly nitrogen application, and environmental factors. Although the molecular controls of their formation are unknown, the high content of protein and low content of starch of sub-aleurone cells, compared to the other starchy endosperm cells types, may result from differences in developmental programming related to the cells having a separate origin (from anticlinal division of the aleurone cells). The gradients within the grain may be reflected in differences in the compositions of mill streams, particularly those streams enriched in the central and outer cells of the starchy endosperm, respectively, allowing the production of specialist flours for specific end uses.
成熟小麦籽粒的淀粉胚乳包含三种主要细胞类型，即亚糊粉层细胞、柱状细胞和中心细胞，它们在功能成分的含量上存在差异：面筋蛋白、淀粉、细胞壁多糖（膳食纤维）和脂质。这些梯度在籽粒发育过程中形成，但在籽粒成熟过程中可能会发生变化，并受到植物营养（特别是氮肥施用）和环境因素的影响。尽管它们形成的分子调控机制尚不清楚，但与其他淀粉胚乳细胞类型相比，亚糊粉层细胞中蛋白质含量高而淀粉含量低，这可能是由于与具有独立起源（来自糊粉层细胞的垂周分裂）的细胞相关的发育程序差异所致。籽粒内部的梯度可能反映在制粉流程成分的差异上，特别是那些分别富含淀粉胚乳中心细胞和外层细胞的流程，从而能够生产出用于特定最终用途的专用面粉。
