MicroRNA-Mediated Hormonal Control of Fruit Morphology

Fruit morphogenesis represents a complex biological process resulting from the interactions among transcriptional regulation, hormone signaling, and environmental factors. MicroRNA (miRNAs) have been recognized recently as key genetic and epigenetic regulators in various plants, and they play critical roles in the regulation of diverse processes in response to endogenous developmental signals and external environmental cues, respectively. Recently, miRNA-mediated regulation mechanisms have also been extensively in horticulture plants, many novel mechanisms unveiled. Compared with model plants and field crops, miRNAs exhibit greater complexity and unique regulatory characteristics in governing fruit development in horticultural crops. Integrating the latest research, this review explores the roles of conserved miRNAs across multiple horticulture crops and synthesizes their regulatory networks in conjunction with phytohormones and transcription factors in governing fruit development, morphogenesis, and stress responses. It highlights the dual role of plant miRNAs under temperature stress, coordinating temperature adaptation, and fruit developmental plasticity through hormones and transcription factor networks. This review discusses the challenges and future prospects of utilizing this complex but promising epigenetic mechanism for crop improvement to cope with climate change.