Zephyranthes candida is a frequently cultivated ornamental plant containing several secondary metabolites, including alkaloids, flavonoids, and volatile organic compounds (VOCs). However, extensive research has been conducted only on non-VOCs found in the plant, whereas the production of VOCs and the molecular mechanisms underlying the biosynthesis of terpenes remain poorly understood. In this study, 17 volatile compounds were identified from Z. candida flowers using gas chromatography–mass spectrometry (GC-MS), with 16 of them being terpenoids. Transcriptome sequencing resulted in the identification of 17 terpene synthase (TPS) genes; two TPS genes, ZcTPS01 and ZcTPS02, had high expression levels. Biochemical characterization of two enzymes encoded by both genes revealed that ZcTPS02 can catalyze geranyl diphosphate (GPP) into diverse products, among which is β-ocimene, which is the second most abundant compound found in Z. candida flowers. These results suggest that ZcTPS02 plays a vital role in β-ocimene biosynthesis, providing valuable insights into terpene biosynthesis pathways in Z. candida. Furthermore, the expression of ZcTPS02 was upregulated after 2 h of methyl jasmonate (MeJA) treatment and downregulated after 4 h of the same treatment.
Vegetative propagation through stem cuttings represents the primary mode of reproduction in Rosa species. While numerous studies have reported physiological factors affecting cutting rooting, the genes regulating the formation of adventitious roots in roses have not yet been fully explored and studied. In this study, we demonstrate that Rosa rugosa ‘Feng Hua’ exhibits an indirect rooting pattern, requiring callus formation prior to root primordium differentiation. Phytohormone profiling revealed exceptionally high concentrations of auxin precursors, particularly tryptophan (Trp), in both callus and root tissues. Therefore, we identified and analyzed the members of the YUCCA family, which are the key rate-limiting enzymes in the tryptophan-dependent IAA biosynthesis pathway. A total of 11 RrYUCs family genes were identified, with RT-qPCR analysis showing that RrYUC10 was highly expressed in callus and root tissues. Functional studies confirmed its critical role in adventitious root formation: virus-induced gene silencing (VIGS) of RrYUC10 significantly inhibited AR development, whereas its overexpression enhanced rooting. Our findings have provided a molecular theoretical basis for the rooting of cuttings in roses.