Weak OsBRI1 allele in Zhonghua 11 as genetic tool for brassinosteroid signaling research in rice

Brassinosteroids (BRs) are essential phytohormones that shape rice architecture, grain development, and stress resilience by modulating leaf angle, stem elongation, tillering, and spikelet growth — all of which collectively influence light interception and yield formation. Although partial manipulation of BR signaling has gained attention as a strategy for ideotype breeding, the translation of BR biology into crop improvement remains hindered by an incomplete understanding of how BR responsiveness varies among elite japonica backgrounds.

To that end, a team of researchers from China developed a non-transgenic near-isogenic BR-insensitive line, d61-zh11, by introgressing the classical weak OsBRI1 allele (d61-1) from TC65 into the modern, genome-enabled ZH11 background. Their findings are published in the Journal of Integrative Agriculture.

“This line fulfills a critical need by offering a standardized genetic platform for validating BR signaling components, thereby enabling seamless integration with ZH11's expansive mutant resources for systematic investigations, while also enhancing experimental reproducibility through ZH11's stable environmental performance,” explains correspondence Yang Yu from Guangdong Academy of Agricultural Sciences.

Strong loss-of-function mutations in core BR-signaling genes often cause severe developmental defects, which may mask additional regulatory inputs and also limit their suitability for breeding applications. “By contrast, weak alleles such as d61-zh11 retain relatively normal agronomic performance while still exhibiting reduced BR responsiveness, so they offer a more favorable background for uncovering subtle BR regulatory factors and exploring breeding-compatible BR modulation,” adds Yu.

“As BR research advances toward dissecting complex, multi-gene regulatory networks, d61-zh11 will serve as a pivotal reference mutant for elucidating BR signaling hierarchies in rice.,” says co-correspondence Jiao Xue, “We are making this resource available to the research community to support broader collaborative efforts.”

Contact Authors:

Correspondence Jiao Xue, E-mail: xuejiao@gdaas.cn; Yang Yu, E-mail: yuyang@gdaas.cn

Funder:

This research was supported by the Special Funding for the Construction of the High-Level Academy of Agricultural Sciences, Guangdong Province, China (NYQS202606), the National Natural Science Foundation of China (32372066 and 32300454), the Guangdong Basic and Applied Basic Research Foundation, China (2023A1515012075 and 2024A1515013064), the Guangzhou Science and Technology Programme, China (2024B03J1363), and the Guangdong Academy of Agricultural Sciences, China (R2021YJ-QG005, R2021YJ-YB3011 and R2022PY-QY011)

Conflict of Interest:

The authors declare that they have no conflict of interest.

See the Article:

Feng Y Z et al. 2026. A weak OsBRI1 allele in Zhonghua 11 as a genetic tool for brassinosteroid signaling research in rice. Journal of Integrative Agriculture, 25(5): 2169-2173.

https://www.sciencedirect.com/science/article/pii/S2095311926000584