Abstract
Starch is the most important food energy source in cereals. Many of the known enzymes involved in starch biosynthesis are partially or entirely granule-associated in the endosperm. Studying the proteome of rice starch granules is critical for us to further understand the mechanisms underlying starch biosynthesis and packaging of starch granules in rice amyloplasts, consequently for the improvement of rice grain quality. In this article, we developed a protocol to purify starch granules from mature rice endosperm and verified the quality of purified starch granules by microscopy observations, I2 staining, and Western blot analyses. In addition, we found the phenol extraction method was superior to Tris-HCl buffer extraction method with respect to the efficiency in recovery of starch granule associated proteins. LC-MS/MS analysis showed identification of already known starch granule associated proteins with high confidence. Several proteins reported to be involved in starch synthesis in prior genetic studies in plants were also shown to be enriched with starch granules, either directly or indirectly, in our studies. In addition, our results suggested that a few additional candidate proteins may also be involved in starch synthesis. Furthermore, our results indicated that some starch synthesis pathway proteins are subject to protein acetylation modification. GO analysis and KEGG pathway enrichment analysis showed that the identified proteins were mainly located in plastids and involved in carbohydrate metabolism. This study substantially advances the understanding of the starch granule associated proteome in rice and post translational regulation of some starch granule associated proteins.
Highlights
Rice (Oryza sativa L.) is one of the most vital crops in the world, which serves as the staple food for over half of the world’s population [1]
To better understand all the proteins associated with the starch granule and the packaging of starch granule components, we developed a protocol for rice starch granule purification from mature endosperm, examined the starch granule proteome using LC-MS/MS, and compared the proteomes extracted by two different protein extraction methods
The blue color indicated that the purified particles could be stained by I2 and the estimated size of the purified particles was about 10 μm in diameter, which is consistent with the reported starch granule size [41]
Summary
Rice (Oryza sativa L.) is one of the most vital crops in the world, which serves as the staple food for over half of the world’s population [1]. Rice endosperm is mainly composed of starch, a good source of carbohydrates [2]. The eating and cooking quality of rice-grain is directly connected to the starch composition in rice endosperm [3, 4]. There are two major types of starch in rice grains, highly structurally organized branched amylopectin and relatively.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
