Horticulture Research

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Article|30 Jan 2026|OPEN

PpMYB123-mediated proanthocyanidin accumulation alleviates bacterial spot disease in peach

Lei Zhao¹ ^,† , Di Ai² ^,† , Zhaoyang Li² , Miaoyi Li² , Chaoxi Luo³ , Qian Peng⁴ , Yuepeng Han¹ ^, and Jian-Ping An,¹ ^,

¹State Key Laboratory of Plant Diversity and Specialty Crops, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
²University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
³Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
⁴Hubei Key Laboratory of Economic Forest Germplasm Improvement and ResourcesComprehensive Utilization, Huanggang Normal University, Huanggang 438000, China
*Corresponding author. E-mail: yphan@wbgcas.cn,anjianping@wbgcas.cn
^†Both authors contributed equally to the study.

Horticulture Research 13,
Article number: uhag032 (2026)
doi: https://doi.org/10.1093/hr/uhag032
Views: 88

Received: 06 May 2025
Accepted: 21 Jan 2025
Published online: 30 Jan 2026

Abstract

Bacterial spot (BS) disease significantly impairs vigor, fruit quality, and yield in peach trees. However, research on this disease remains limited. In this study, peach leaves and fruits were inoculated with the pathogen isolated from infected leaves, triggering a robust accumulation of proanthocyanidins (PA) in both tissues. Further investigation revealed that pathogen inoculation promoted PA accumulation by upregulating PpMYB123, which transactivated the core PA biosynthetic genes PpANR and PpLAR. Notably, the E3 ubiquitin ligase PpPUB23 negatively regulated PpMYB123. However, its transcript levels were significantly suppressed following inoculation, thereby stabilizing PpMYB123 and enhancing PA production. PA conferred dual protection by scavenging excess reactive oxygen species (ROS) and suppressing pathogen growth. Our findings provide molecular evidence for PA-mediated defense against BS disease in peach.