Abstract:In order to understand the mechanism of the narcissus (Narcissus tazetta var. chinensis) floral induction, the differentially expressed metabolites and genes were screened from the outermost buds treated with exogenous ethylene by using metabolome and transcriptome sequencing techniques. The results showed that 12 differentially expressed metabolites (DEMs) were detected, including 7 up-regulated and 5 down-regulated DEMs. Among them, (±) 7-epigenJasmonic acid, dopamine and spermidine might be positively correlated with narcissus floral induction, while indole and its derivatives were negatively correlated. A total of 1 021 differentially expressed genes (DEGs) were identified in the transcriptome, including 615 up-regulated and 406 down-regulated DEGs. Forty-five differentially expressed genes related to ethylene signal transduction and flowering were identified in the DEGs. The changes of endogenous plant hormone (especially ethylene) signaling pathway in narcissus bulbs were activated firstly by exogenous ethylene, and the floral induction of narcissus via exogenous ethylene was closely related to the up-regulated expression of FPF1 and MADS15. Nine genes correlated with flowering were verified by qRT-PCR analysis and the expression profiles were consistent with the RNA-Seq results. Therefore, these DEMs and DEGs might have vital function on the narcissus floral induction, which might play an important role in the floral formation of narcissus induced exogenous ethylene.
