Epigenetic Involvement in Hormone Signaling Pathways and Phytohormone Crosstalk: an Emerging Regulatory Network

Phytohormone signaling underpins practically all facets of plant growth, development, and responses to environmental stressors. While the molecular foundation of hormone monitoring and subsequent signaling is well understood, it is evident that these pathways function within a wider epigenetic context that introduces flexibility, regulatory memory, and environmental responsiveness. The current review summarizes recent discoveries elucidating the impact of DNA methylation, histone modifications, chromatin remodeling, and small RNA pathways on hormone biosynthesis, trans port, perception, and transcriptional regulation across principal phytohormone classes, including the auxin, gibberellins, cytokinins, ethylene, abscisic acid, jasmonates, brassinosteroids, and salicylic acid. Epigenetic modification of chromatin architecture at hormone-responsive sites enables the plants to synchronize developmental processes with environmen tal stimuli, including high temperatures, water scarcity, and pathogen attacks. Dynamic and reversible chromatin states facilitate rapid hormonal reprogramming, regulate hormone interactions, and are integral to vital phenotypic processes like thermomorphogenesis, regulation of flowering intervals, fruit ripening, and immune signaling. Subsequent research further substantiates the involvement of hormone-associated epigenetic memory in heterosis and stress adaption across generations. Future advancements in single-cell epigenomics, spatio-temporal chromatin profiling, and targeted epigenome editing is essential for elucidating causal relationships between hormone signaling and chromatin dynamics, especially in agricultural settings. Bibliometrics inevitably illustrate the rapid growth in this area, pinpoint dominant research trends and gaps, and underscore prospective opportunities at the intersection of phytohormone regulation, epigenetic inheritance, crop improvement and protection.植物激素信号通路几乎支撑着植物生长、发育以及对环境胁迫的所有响应过程。尽管激素感知与后续信号转导的分子基础已得到充分阐释，但显而易见的是，这些通路在更广阔的表观遗传框架内发挥功能，该框架赋予通路灵活性、调控记忆性以及环境响应能力。本综述总结了近期研究进展，阐明了DNA甲基化（DNA methylation）、组蛋白修饰（histone modifications）、染色质重塑（chromatin remodeling）以及小RNA通路（small RNA pathways）对各类主要植物激素——包括生长素、赤霉素、细胞分裂素、乙烯、脱落酸、茉莉素、油菜素甾醇与水杨酸——的生物合成、转运、感知及转录调控的影响。在激素响应位点发生的染色质结构表观遗传修饰，可使植物将发育进程与高温、缺水以及病原体侵染等环境刺激同步协调。动态且可逆的染色质状态可促进快速的激素重编程、调控激素间的相互作用，并且是热形态建成、开花周期调控、果实成熟以及免疫信号传导等关键表型过程的核心组成部分。后续研究进一步证实，与激素相关的表观遗传记忆参与了跨世代的杂种优势与胁迫适应过程。未来，单细胞表观基因组学、时空染色质图谱分析以及靶向表观基因组编辑技术的发展，对于阐明激素信号通路与染色质动态变化之间的因果关系至关重要，尤其是在农业场景中。文献计量分析清晰展现了该领域的快速发展，明确了主流研究趋势与研究空白，并强调了植物激素调控、表观遗传继承、作物改良与保护交叉领域的潜在研究机遇。