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Unraveling the molecular and metabolic mechanisms of 6-benzylaminopurine-mediated dormancy release in Xianheng 01 apple rootstock

Zohaib Asghar1, Asad Shehzaib1, Muhammad Atal Shah1, Dantong Shao1, Le Du2, Xinyue He1, Muhammad Mobeen Tahir1, Namozov Ikhtiyor3, Hongjuan Ge4, Jin Lv5, 6, Rongxin Chen5, 6, Aimin Han5, Dong Zhang1, Juanjuan Ma1, Jiangping Mao1, Yawen Shen7#, Na An2# 

1 College of Horticulture, Northwest A&F University, Yangling 712100, China

2 College of Life Science, Northwest A&F University, Yangling 712100, China

3 Tashkent State Agrarian University, Tashkent 100140, Uzbekistan

4 Qingdao Academy of Agricultural Science, Qingdao 266000, China

5 Shaanxi Zhaojin Xianheng Agricultural Technology Co., Ltd, Tongchuan 727100, China

6 Yaozhou District Horticultural Workstation, Tongchuan 727100, China

7 College of Horticulture, Henan Agricultural University, Zhengzhou 450046, China

 Highlights 

· 6-BA induces bud dormancy release through modulation of cytokinin-ABA balance.

· A total of 7009 DEGs were identified in response to 6-BA, with A-ARR8 upregulated and ABA genes downregulated.

· A shift from phenylpropanoid/flavonoid pathways to ABC transporter-mediated processes supports bud break.

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摘要  

芽休眠是多年生植物为应对不利环境条件、确保自身存活而形成的一种关键适应性策略。然而,这一策略对园艺作物(尤其是苹果等果树)构成了难题:芽萌发的整齐一致性是稳定生长和产量的关键,但休眠会干扰这种整齐性。人工合成细胞分裂素——6-苄氨基嘌呤(6-BA)能够促进休眠解除,但其分子和代谢机制尚不明确。本研究以咸恒1苹果砧木苗为材料,对休眠芽施用6-BA,随后在30 d内进行植株形态指标和激素含量测定,并结合转录组和代谢组分析,探究6-BA处理对芽休眠解除的调控作用。研究结果表明,6-BA处理提高了咸恒1苹果砧木的株高和叶片萌发数,其机制在于提高了细胞分裂素类,如二氢玉米素核苷(DHZR)、异戊烯基腺苷(IPA)等内源激素水平,同时降低了脱落酸(ABA)水平。转录组分析共鉴定到7,009个响应6-BA处理的差异表达基因(DEGs)。细胞分裂素响应基因A-ARR8表现出独特的表达模式:在处理后136 d保持上调,而11 d转为下调。相比之下,ABA相关基因SnRK2a/bPP2CABF3在整个处理期间均持续下调。代谢组分析鉴定出2,053种代谢物,处理早期苯丙烷类和黄酮类代谢物占主导,后期转向以ABC转运蛋白介导的养分动员为主。联合分析揭示了次生代谢物生物合成与细胞分裂素信号转导之间存在着协同激活关系。以上结果表明6-BA诱导芽休眠解除,依赖于细胞分裂素与脱落酸的拮抗关系,以及代谢从胁迫保护向生长促进的分阶段重编程。本研究可为苹果栽培中休眠调控技术的优化提供系统的理论支撑,为优化苹果栽培中的休眠管理提供了系统的理论依据,同时证实6-BA是一种可有效促进温带水果生产的植物生长调节剂。



Abstract  

Bud dormancy is a key adaptive strategy in perennial plants, enabling them to survive in adverse environmental conditions. However, it generates challenges in crop cultivation, especially in fruit crops like apple, where synchronized bud break is crucial for consistent growth and yield. The synthetic cytokinin 6-benzylaminopurine (6-BA) promotes dormancy release, but its molecular and metabolic mechanisms remain poorly understood. This study investigates dormancy release in Xianheng 01 apple rootstock nursery plants through integrated transcriptomic, metabolomics, and hormonal analyses. Dormant buds were treated with 6-BA, followed by morphological, biochemical, and molecular profiling conducted over 30 days. 6-BA treatment increased plant height and leaf emergence by increasing the level of endogenous hormones such as cytokinins (DHZR/IPA) and decrease in level of abscisic acid (ABA). Transcriptomics analysis identified 7,009 differentially expressed genes (DEGs) in response to 6-BA treatment. The cytokinin-responsive gene A-ARR8 exhibited a distinct expression pattern, remained upregulated at 1, 3 and 6 d post-treatment but downregulated at 11 d. In contrast ABA related genes SnRK2a/b, PP2C and ABF3 were consistently downregulated throughout the treatment period. Metabolomics analysis identified 2,053 metabolites, showing early-phase dominance of phenylpropanoids and flavonoids, followed by a shift towards ABC transporter-mediated nutrient mobilization. Conjoint analysis highlighted coordinated activation of secondary metabolite biosynthesis and cytokinin signaling. These results demonstrate that 6-BA induces dormancy release through cytokinin-ABA antagonism and phased metabolic reprogramming from stress protection to growth promotion. Our findings provide a comprehensive framework for optimizing dormancy management in apple cultivation and highlight 6-BA as an effective agrochemical for enhancing temperate fruit production.

Keywords:  bud dormancy              6-benzylaminopurine              apple rootstock              cytokinin signaling              multi-omics analysis              temperate fruit production  
Online: 02 June 2026  
Fund: 

This work was financially supported by the National Natural Science Foundation of China (32372657, 32372675), Breeding of New Apple Rootstock Variety Xianheng 01, the national Key Research and Development project, China (2023YFD2301002), the Science and Technology Major Project of Xinjiang Production and Construction Corps, China (2023AB077), the Chinese Universities Scientific Fund (2452023005), the China Apple Research System (CARS-27), the Cyrus Tang Foundation, and the Fundamental Research Funds for the Central Universities, China. Shandong Provincial Natural Science Foundation, Youth and General Program (ZR2024MC117).

About author:  # Correspondence Yawen Shen, E-mail: yawen.shen@henau.edu.cn; Na An, E-mail: anna206@nwsuaf.edu.cn

Cite this article: 

Zohaib Asghar, Asad Shehzaib, Muhammad Atal Shah, Dantong Shao, Le Du, Xinyue He, Muhammad Mobeen Tahir, Namozov Ikhtiyor, Hongjuan Ge, Jin Lv, Rongxin Chen, Aimin Han, Dong Zhang, Juanjuan Ma, Jiangping Mao, Yawen Shen, Na An. 2026. Unraveling the molecular and metabolic mechanisms of 6-benzylaminopurine-mediated dormancy release in Xianheng 01 apple rootstock. Journal of Integrative Agriculture, Doi:10.1016/j.jia.2026.06.001

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