ABSTRACT: Plant hormones, or phytohormones, are essential chemical messengers that regulate the intricate processes of plant growth, development, and environmental adaptation. These signaling molecules, including auxins, gibberellins, cytokinins, abscisic acid (ABA), and ethylene, orchestrate critical stages from seed germination to fruit ripening, ensuring plants thrive under diverse conditions. This research article explores the multifaceted roles of plant hormones, their interactions, and their transformative applications in modern agriculture, while addressing challenges and future directions for sustainable innovation. Auxins drive cell elongation, root development, and apical dominance, with synthetic analogs like 2, 4-dichlorophenoxyacetic acid (2, 4-D) enhancing tissue culture and rooting in crop propagation. Gibberellins promote stem elongation, seed germination, and flowering, widely used to increase fruit size in crops like grapes and citrus and to break seed dormancy in cereals. Cytokinins stimulate cell division, organogenesis, and delay senescence, improving crop yields and extending post-harvest shelf life in leafy greens and tomatoes. ABA governs stress responses, seed dormancy, and stomatal regulation, with applications in developing drought-resistant crops and mitigating abiotic stresses. Ethylene, a gaseous hormone, regulates fruit ripening, leaf abscission, and stress adaptation, with ethylene-releasing compounds like ethephon synchronizing ripening and inhibitors like 1-methylcyclopropene (1-MCP) prolonging storage life. Hormonal crosstalk, such as the interplay between auxins and cytokinins in shoot-root balance or gibberellins and ABA in germination, ensures precise developmental control, offering opportunities for targeted agricultural interventions. In agriculture, synthetic hormones and biotechnological advances, including CRISPR-Cas9 gene editing, have revolutionized crop improvement by enhancing yields, stress tolerance, and fruit quality. For instance, ABA-based treatments improve drought resistance in wheat and maize, while gibberellin and cytokinin applications boost fruit set in horticultural crops. However, challenges persist, including the environmental risks of synthetic hormone overuse, such as herbicide runoff and soil microbial disruption, and the need for precise application to avoid growth abnormalities. Future research should prioritize precision hormone engineering, leveraging synthetic biology, nanotechnology, and digital agriculture to develop eco-friendly hormone analogs and optimize delivery systems. These innovations promise to minimize off-target effects and enhance sustainability. By integrating hormone regulation with climate-resilient crop varieties, agriculture can address global food security amidst challenges like climate change and population growth. This article underscores the pivotal role of plant hormones in driving agricultural productivity and resilience, highlighting the need for continued research to unlock their full potential. Sustainable hormone-based strategies will be crucial for transforming agriculture, ensuring robust crop performance from seed to harvest while safeguarding environmental health for future generations.
Keywords: Plant hormones, agriculture, growth, innovation, sustainability.