Biotechnological Approaches to Modify Flower Color, Fragrance and Vase Life in Ornamental Plants

Ornamental plants are of immense economic and aesthetic significance worldwide, with global trade valued at hundreds of billions of dollars annually. Key quality attributes — flower color, fragrance, and postharvest vase life — are primary determinants of market value and consumer preference. Classical breeding approaches have been largely effective but are constrained by sexual incompatibility barriers, long generation times, and genetic complexity. Over the past three decades, biotechnological and molecular biological tools have emerged as powerful alternatives to precisely engineer these traits. This review comprehensively examines the current status and future prospects of biotechnological interventions targeting the three principal ornamental quality traits. In the realm of flower color, we discuss the manipulation of flavonoid and carotenoid biosynthetic pathways, transcription factor engineering, and the revolutionary application of CRISPR/Cas9-based gene editing. For fragrance modification, we explore the biosynthesis of volatile organic compounds (VOCs) including terpenoids, benzenoids, and fatty acid derivatives, alongside metabolic engineering strategies. Regarding vase life extension, we analyze ethylene signaling, senescence gene suppression, water transport optimization, and pathogen resistance enhancement. The review further highlights successful commercial cases, biosafety considerations, regulatory frameworks, and emerging genomic tools such as multi-omics integration and synthetic biology. We identify major research gaps and propose future research directions to accelerate translational applications in the ornamental plant industry.