Drought-induced aesthetic decline and ecological impacts on ornamentals: mechanisms of damage and innovative strategies for mitigation.

Abstract

Drought stress poses a critical challenge to ornamental horticulture, significantly affecting the aesthetic, economic, and ecological value of these plants in landscapes and urban environments. As climate change exacerbates water scarcity, ornamental plants, prized for their vibrant foliage, abundant flowering, and overall vitality, are increasingly vulnerable to water deficits. Unlike many crop plants, which adapt to drought through structural and physiological modifications, such as reduced leaf size or altered metabolic processes, these adaptive changes often compromise the aesthetic appeal that defines ornamentals' value. Drought-induced effects, including reduced flowering, distorted foliage, and reduced fragrance, undermine both their marketability and ecological functions. This review delves into the intricate biochemical, molecular, and physiological mechanisms underlying the drought responses in ornamental plants, emphasizing hormone regulation, antioxidant defence, and gene expression changes. It highlights the unique dual challenge of ensuring drought tolerance while preserving aesthetic traits, which sets ornamentals apart from other plant types. Furthermore, it explores innovative management strategies, such as genetic engineering (e.g., CRISPR-Cas9), transcription factor manipulation, and exogenous applications of hormones and biostimulants to enhance resilience. The emerging approaches, including epigenetic priming, nanotechnology, and smart irrigation systems, are presented as sustainable solutions to mitigate drought-induced damage. Despite recent advances, significant gaps remain in understanding the trade-offs between stress resilience and ornamental traits, such as flowering patterns, pigment composition, and leaf morphology. This review underscores the urgent need for integrated molecular, physiological, and horticultural strategies to balance these demands, offering a roadmap to sustain the aesthetic and ecological contributions of ornamentals in an era of increasing climate variability.