关键词: 菜薹, 乙烯, 木质化, ERF, POD, 马铃薯, 植原体病害, 分类, 功能基因, 抗病育种

Abstract: The purpose of this study was to investigate the effects of ethephon on the stem lignification of postharvest flowering Chinese cabbage（FCC，Bcassica campestris L. ssp. chinensis var. utilis Tsen et Lee）stored at low temperature. The postharvest FCC were treated with different concentrations of ethephon（100，200 and 500 μL · L-1），placed in an incubator at 1 ℃. The control was treated with distilled water. The content of lignin and activity of enzymes（4-coumaric acid coenzyme A ligase，4-CL；peroxidase，POD；cinnamate dehydrogenase，CAD）related to lignification were detected by spectrophotometer. The gene expression levels of BcERF2，BcERF1B，BcPOD67 and BcPOD69 were evaluated by real-time PCR. The results showed that the content of lignin in the treated FCC stems significantly increased and the activities of POD and 4-CL also showed a rising trend during storage. With the increase of ethephon concentration，the content of lignin and activities of POD and 4-CL gradually increased. The expression levels of BcERF2，BcERF1B，BcPOD67 and BcPOD69 were higher than the control，which were consistent with the lignin change in treated FCC with ethylene（200 μL · L-1）during storage. In summary，the ethephon treatment accelerated the lignification process of postharvest FCC at low temperature. The ethephon was involved in lignin biosynthesis，which may through the regulation BcPOD67 and BcPOD69 by transcription factors BcERF2 and BcERF1B.

Key words: flowering Chinese cabbage, ethylene, lignification, ERF, POD, potato, phytoplasma disease, taxonomy, function genes, disease resistant breeding