Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops/Joint International Research Laboratory of Agriculture & Agri-Product Safety, Yangzhou University, Yangzhou 225009, China.
Int J Biol Macromol. 2020 Oct 1;160:328-339. doi: 10.1016/j.ijbiomac.2020.05.210. Epub 2020 May 28.
The quality of rice grain is characterized by the component, structure and physicochemical properties of starch accumulated in endosperm cell. Nitrogen uptake strongly affects rice growth and starch development. In this study, Nangeng 9108 was used to investigated the accumulation of starch in different positions of the endosperm and physical properties of starch under nitrogen treatment of panicle initiation (PI) stage. Compared with the control group (CG), nitrogen treatment group (NTG) featured a higher number of grains per panicle and 1000-grain weight. Nitrogen treatment significantly increased starch accumulation among different regions during endosperm development, which was expressed as central endosperm cells > sub-aleurone cells of abdominal endosperm > sub-aleurone cells of dorsal endosperm. The amyloplast increased by constricting and budding-type division, generated a bead-like structure and derived some vesicles. The particle size of the starch granules obtained from the NTG was smaller and the apparent amylose content was lower than those of the CG, resulting in higher relative crystallinity. Nitrogen treatment promoted double helical components and provided a higher degree of order at short-rang scale for the starch granules. This study indicated that nitrogen significantly affected the accumulation and physicochemical properties of starch in the endosperm.
稻米品质主要由胚乳细胞中积累的淀粉的成分、结构和物理化学性质来决定。氮素吸收强烈影响水稻的生长和淀粉的形成。本研究以籼稻品种南粳 9108 为材料，在颖花分化期（PI）进行氮肥处理，探讨了不同部位胚乳中淀粉的积累以及淀粉理化特性的变化。与对照（CG）相比，氮处理（NTG）组每穗粒数和千粒重均增加。氮处理显著增加了胚乳发育过程中不同区域的淀粉积累，表现为中部胚乳细胞＞腹部胚乳亚糊粉层细胞＞背部胚乳亚糊粉层细胞。淀粉体通过缢缩和出芽式分裂增加，形成串珠状结构，并衍生出一些小泡。NTG 获得的淀粉颗粒粒径较小，直链淀粉含量较低，相对结晶度较高。氮处理促进了双螺旋成分的形成，并为淀粉颗粒提供了更高的短程有序度。本研究表明，氮素显著影响了胚乳中淀粉的积累和理化特性。
