Effects of Exogenous Ethylene and 1-Methylcyclopropene on of DpXTH Gene Expression in Dahlia （ Dahlia pinnata Cav.） Flowers

摘要

[Objectives] This study was conducted to investigate the regulatory mechanism of ethylene on Dp XTH gene expression in dahlia( Dahlia pinnata Cav.)flower petals. [Methods] Dahlia flower petals were treated with ethephon( ETH) and 1-methylcyclopropene( 1-MCP) at different flower development stages and for different durations in vivo. Then,the relative expression of Dp XTH1 and Dp XTH2 in flower samples in different treatments was quantified with real-time PCR,using β-actin as a reference gene. [Results] The expression of Dp XTH1 and Dp XTH2 in ETH-or 1-MCP-treated dahlia flower petals increased at first,and decreased subsequently with increasing duration of treatment. The relative expression of both Dp XTH1 and Dp XTH2 in ETH-treated samples reached the maximum level at 12 h. Moreover,the relative expression of both Dp XTH1 and Dp XTH2 in dahlia flower petals treated with ETH at early stage of flowering was higher than that of the samples treated at other flowering stages; in 1-MCP-treated samples,it was higher at full-flowering stage than at other stages. The maximum relative expression levels of Dp XTH1 and Dp XTH2 in ETH-and 1-MCP-treated samples were all higher than those of control. [Conclusions] Exogenous ethylene can accelerate the opening of dahlia flowers,and 1-MCP can inhibit this process,so they can be used to regulate development of dahlia flowers.