Combined physicochemical and transcriptomic analyses reveal the effect of the OsGA20ox1 gene on the starch properties of germinated brown rice

• Published in: International journal of biological macromolecules 2024-10, Vol.278 (Pt 4), p.134849, Article 134849
• Main Authors: Zhang, Guangchen, Hua, Dong, Wang, Yiqiao, Xu, Jiaxin, He, Yutang, Liu, Youhong, Tang, Ao, Liu, He, Sun, Jian
• Format: Article
• Language: English
• Subjects: Chemical Phenomena; Gene Expression Profiling; Gene Expression Regulation, Plant; Germinated brown rice; Germination - genetics; Germination genes; Oryza - genetics; Oryza - growth & development; Oryza - metabolism; OsGA20ox1; Physicochemical and transcriptomic; Plant Proteins - genetics; Plant Proteins - metabolism; Seeds - genetics; Seeds - metabolism; Starch - chemistry; Starch - metabolism; Starch properties; Transcriptome; Viscosity
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.134849

Genes play a pivotal role in regulating the germination of cereal grains; however, there is limited research on the impact of germination genes on the physicochemical properties of germinated cereal starch. We investigated the effects of the OsGA20ox1 gene on the multiscale structural features and adhesion behavior of germinated brown rice starch. Compared to the knockout lines group, the wild type exhibited a decrease in double-helix content (62.74 %), relative crystallinity (47.39 %), and short-range molecular ordering (2.47 %), accompanied by enhanced erosion on the surface of starch granules. The damage to glycosidic bonds at the double-helix level and the heightened structural amorphization (90.95 %) led to reduced entanglement and interaction among starch molecules, ultimately resulting in reduced characteristic viscosity. Further transcriptomic analysis revealed that OsGA20ox1 could regulate the expression of starch-related enzyme genes in the starch metabolism pathway during germination of brown rice. This study contributes to understanding the role of germination genes in promoting the physicochemical properties of starch in germinated grains, thereby opening up new avenues for the improvement of plant-based starch, and paving the way for further research in this field. [Display omitted] •OsGA20ox1 affects the uniformity and integrity of germinated brown rice (GBR) starch.•OsGA20ox1 promotes the augmentation of amorphous regions in GBR starch.•Improved GBR quality shown in viscosity changes, driven by OsGA20ox1.•Starch and sucrose metabolism are key pathways in response to OsGA20ox1.