Phytohormone-microbial nexus targeting-next-generation strategy for fruit growth and postharvest resilience

Hormonal networks comprising auxins, gibberellins, cytokinins, abscisic acid, ethylene, salicylic acid, and jasmonates regulate fruit growth, ripening, and post-harvest behavior. Increasing evidence indicates that plant-associated microbiomes, including rhizospheric, phyllospheric, and endophytic communities, significantly influence these networks by synthesizing phytohormones, regulating enzymes, and producing volatile compounds. The microbial synthesis of indole-3-acetic acid (IAA) facilitates fruit development, whereas 1-aminocyclopropane-1-carboxylate (ACC) deaminase reduces stress-induced ethylene accumulation, therefore delaying senescence and extending shelf life. Comparative analyses of climacteric and non-climacteric fruits reveal that microbial manipulation of ethylene can provide effects similar to pharmacological inhibitors such as 1-methylcyclopropene (1-MCP) or controlled storage methods. Besides imitating hormones, microbial volatile organic compounds (VOCs) enhance systemic resistance, maintain antioxidant reserves, and safeguard crops post-harvest without leaving residues. Recent advancements in multi-omics have elucidated the influence of microbial metabolites on hormone-responsive transcription, metabolism, and signaling throughout critical developmental stages. These mechanistic insights facilitate the rational development of SynComs that integrate hormone-modulating characteristics with VOCs synthesis. This article addressed the particular methods for enhancing fruit yield, nutritional quality, and stress resilience through the utilization of microbe-hormone interactions. It analyses crucial microbial intervention sites in hormonal processes, compares them to traditional approaches, and suggests climate-smart horticulture-aligned translational solutions.