摘要：AbstractThe speed of flower opening is closely related to their ornamental period. Ethylene functions as a negative regulator involved in the regulation of the petal expansion process. In this study, we isolated a NF-YC transcription factor gene,RhNF-YC9, from rose petals.RhNF-YC9expression was induced at the early stages of flower opening but was inhibited by ethylene treatment. SilencingRhNF-YC9decreased the speed of petal expansion from stage 2 to stage 5. The expressions of 11 cell expansion-related genes involved in cell wall loosening, cell turgor modulation, and cytoskeleton remodeling were significantly down-regulated inRhNF-YC9-silenced petals. We also found that silencingRhNF-YC9decreased the expression of gibberellin acid (GA) biosynthetic geneRhGA20oxwhile significantly increasing the transcripts of GA catabolic geneRhGA2ox, reducing the accumulation of GA4and GA7. The influence of ethylene treatment on the expression ofRhGA20oxandRhGA2oxshowed the same trend. These results together suggested that RhNF-YC9 positively regulated the speed of petal expansion and mediated the crosstalk between ethylene and GA. Our findings revealed a new insight into the function of NF-YC transcription factors involved in ethylene-regulated petal expansion.
