Multi-omics analysis unveils the mechanisms underlying senescence-color-fragrance changes in cut roses (Rosa hybrida cv. Tineke) under short-term high-temperature treatment

Roses, as one of the world's four major cut flowers, hold significant commercial value. Most existing research focuses on postharvest preservation to extend the shelf life, with little attention to balancing senescence, color, and fragrance. The effects of different temperatures (5 °C, 15 °C, and 30 °C) and durations (12 h and 24 h) treatments on the senescence, color, and fragrance of Rosa hybrida cultivar Tineke were investigated through metabolome, transcriptome, and double-stranded RNA (dsRNA)-mediated gene silencing strategy. After 12 h of exposure, the 30 °C treatment markedly improved the fragrance of cut roses, with no significant impacts on their shelf life or color, in contrast to the 5 °C and 15 °C treatments. Conversely, prolonged treatment at 30 °C for 24 h exerted adverse effects on both fragrance quality and shelf life. Additionally, short-term high-temperature treatment did not affect the petal color. Overall, short-term high-temperature treatment most effectively enhances cut rose quality. Treatment at 30 °C for 12 h induced the highest accumulation of the crucial floral fragrance compound 2-phenylethanol (2PE), which was mediated by alternative splicing (AS)-driven changes in the expression of full-length transcripts and AS transcripts. A high RhAAAT2 expression may be a critical factor in promoting increased 2PE accumulation in cut roses. This study revealed a novel mechanism of temperature-triggered AS regulating fragrance synthesis in cut flowers. It provides a promising physical strategy for balancing the preservation of cut flowers with improving their quality, showcasing significant potential for practical application.