On November 5, 2025, the research group of Jiang Shuling from Institute of Pomology, Chinese Academy of Agricultural Sciences (IPCAAS), and the research group of Professor Li He from Shenyang Agricultural University jointly published a research paper titled "A novel R2R3-MYB transcription factor PpMYB5 assisting Ppbbx24-del positively regulates anthocyanin biosynthesis in 'Red Zaosu' pear" in the JCR Q1 journal Horticulture Research (2025IF=8.5), revealing the molecular mechanism by which a new R2R3 MYB transcription factor PpMYB5 assists Ppbbx24-del in positively regulating anthocyanin biosynthesis in 'Red Zaosu' pear.

PpMYB5 is involved in the transport process of Ppbbx24-del from the cell membrane to the cell nucleus

Red pears are highly favored by consumers due to their beautiful appearance and rich nutrition. Exploring the key genes and analyzing the formation mechanism of red trait are great significant for red pear breeding and cultivation regulation. Previously, the team identified a Ppbbx24-del gene (the coding region lacks 14 bp, and the protein sequence lacks the nuclear localization signal NLS) closely related to the red trait in the red sport of 'Zaosu' pear, and proved that this gene positively regulates the anthocyanin accumulation in 'Red Zaosu' pear due to frame shift mutations.

The dual luciferase reporter assay confirms the effects of PpMYB5, Ppbbx24-del, and PpBBX24 on the promoter activity of PpCHS and PpCHI

On the basis of previous research, this article further identified an R2R3-MYB transcription factor PpMYB5 that can interact with mutant Ppbbx24-del and wild-type PpBBX24. Its core function is to assist in the transport of Ppbbx24-del from the cytoplasm to the nucleus; After the formation of regulatory modules, it not only could significantly up-regulate the expression of key structural genes for anthocyanin synthesis such as PpCHS and PpCHI, but also could bind to the promoter of PpMYB5 and promote its own expression, thereby synergistically enhancing the accumulation of anthocyanins in Red Zaosu' pear peel. However, the interaction between PpMYB5 and PpBBX24 did not have this promoting effect. This study clarified the synergistic regulatory mode of PpMYB5 and Ppbbx24-del, providing a theoretical basis for understanding the mechanism of anthocyanin biosynthesis in plants and breeding red skinned pear varieties through gene editing

Synergistic regulation of anthocyanin biosynthesis in 'Zaosu' (left) and 'Red Zaosu' (right) pears by PpMYB5, PpBBX24, and Ppbbx24-del

Doctoral student Li Shuran jointly trained by Shenyang Agricultural University and IPCAAS is the first author of this article, while Researcher Ou Chunqing and Jiang Shuling from IPCAAS, and Professor Li He from Shenyang Agricultural University are the co-corresponding authors of this article. This study was supported by the National Natural Science Foundation of China (32072531), China Agriculture Research System - Pear (CARS-28), and the Science and Technology Innovation Project of the CAAS (CAAS-ASTIP-2016-RIP).

Link: https://doi.org/10.1093/hr/uhaf300

By: Ou Chunqing

(ouchunqing@caas.cn)