OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm

Huang, Kunyong; Chen, Long; Jiao, Guiai; Ruan, Zheyan; Li, Xinwei; Tang, Shaoqing; Hu, Peisong; Wei, Xiangjin

doi:10.3390/life15060962

Open AccessEditor’s ChoiceArticle

OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm

by

Kunyong Huang

^1,†

,

Long Chen

^1,2,†,

Guiai Jiao

¹,

Zheyan Ruan

¹,

Xinwei Li

¹,

Shaoqing Tang

¹,

Peisong Hu

^1,*

and

Xiangjin Wei

^1,*

¹

State Key Laboratory of Rice Biology and Breeding, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou 310006, China

²

Environment-Friendly Crop Germplasm Innovational and Genetic Improvement Key Laboratory of Sichuan Province, Chengdu 610066, China

^*

Authors to whom correspondence should be addressed.

^†

These authors contributed equally to this work.

Life 2025, 15(6), 962; https://doi.org/10.3390/life15060962

Submission received: 19 April 2025 / Revised: 8 June 2025 / Accepted: 12 June 2025 / Published: 16 June 2025

(This article belongs to the Special Issue Recent Advances in Crop Genetics and Breeding)

Download

Browse Figures

Versions Notes

Abstract

Starch is the primary component of the endosperm and plays a crucial role in rice quality. Although the enzymes involved in starch synthesis have been extensively studied, the transcription factors that regulate these enzymes remain largely unknown. Here, we identified a MYB family transcription factor, OsMYBR1, that regulates starch biosynthesis in rice. OsMYBR1 is highly expressed during endosperm development. Mutations of OsMYBR1 result in reduced grain thickness and a decrease in 1000-grain weight. The endosperm of osmybr1 mutants exhibit rounded and loosely packed starch granules, decreased amylose content, altered fine structure of amylopectin, and modified physicochemical properties. The analysis of RT-qPCR showed that the expression of several starch-synthesis enzyme-coding genes (SSEGs), including OsGBSSⅠ, OsAGPL1, OsAGPL2, OsBEⅡb, OsISA1, PHOL, and OsSSⅢa, is altered in osmybr1 mutants. Further experiments indicated that OsMYBR1 directly binds to the promoters of OsGBSSⅠ, OsAGPL1, OsAGPL2, OsISA1, OsBEⅡb, and PHOL, resulting in an increase in the expression of OsGBSSⅠ but a decrease in the expression of OsAGPL2, OsISA1, and OsSSⅢa. In contrast, OsMYBR1-overexpressing endosperm appears normal, with starch granule morphology, increased amylopectin content, and improved alkali spreading value, indicating enhanced rice eating and cooking quality (ECQ). These findings suggest that the overexpression of OsMYBR1 could be a promising strategy for improving rice ECQ.

Keywords: rice; starch synthesis; amylose content; OsMYBR1; rice quality

Share and Cite

MDPI and ACS Style

Huang, K.; Chen, L.; Jiao, G.; Ruan, Z.; Li, X.; Tang, S.; Hu, P.; Wei, X. OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm. Life 2025, 15, 962. https://doi.org/10.3390/life15060962

AMA Style

Huang K, Chen L, Jiao G, Ruan Z, Li X, Tang S, Hu P, Wei X. OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm. Life. 2025; 15(6):962. https://doi.org/10.3390/life15060962

Chicago/Turabian Style

Huang, Kunyong, Long Chen, Guiai Jiao, Zheyan Ruan, Xinwei Li, Shaoqing Tang, Peisong Hu, and Xiangjin Wei. 2025. "OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm" Life 15, no. 6: 962. https://doi.org/10.3390/life15060962

APA Style

Huang, K., Chen, L., Jiao, G., Ruan, Z., Li, X., Tang, S., Hu, P., & Wei, X. (2025). OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm. Life, 15(6), 962. https://doi.org/10.3390/life15060962

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Menu

OsMYBR1, a 1R-MYB Family Transcription Factor Regulates Starch Biosynthesis in Rice Endosperm

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Further Information

Guidelines

MDPI Initiatives

Follow MDPI