卷丹百合LlARF12基因的克隆、表达及功能分析OA北大核心CSTPCD

[Objective]In order to explore the internal mechanism of bulbil formation in Lilium lancifolium,the cellular and histological changes before bulbil formation were discussed.The auxin response factor LlARF12 was cloned to provide a theoretical reference for analyzing the mechanism of LlARF12 gene in the process of bulbil formation of lily.[Method]Histological observation of leaf axilla before the formation of axillary organs was made by paraffin section.The key gene LlARF12 was screened from the transcriptome of the process of bulbil formation,and its coding region sequence(CDS)was cloned.Bioinformatics software was used to analyze and predict the gene characteristics.The LlARF12 gene expression pattern in lily tissues of different periods and different species or varieties was analyzed by qRT-PCR,and the LlARF12 gene was silenced by VIGS technique to verify its gene function.[Result]The length of LlARF12 gene was 2346 bp,encoding 781 amino acids.The results of qRT-PCR showed that the expression level of LlARF12 was significantly lower in the white spot stage of bulbil occurrence than in the non-bulbil occurrence stage.The expression level in the upper part of the stem of the plant in S1 stage was significantly lower than that in the lower part of the plant,and the expression level in the lily varieties with natural bulbil occurrence was significantly lower than that in other lily varieties.The silencing of LlARF12 gene resulted in the advance of the bulbil occurrence time and the number of bulbil increased significantly.[Conclusion]Prior to the S1 stage,axillary meristem has begun to activate,where parenchyma cell layers near the epidermis increase,nuclei accumulate,and mature vascular tissue is gradually produced.The expression level of LlARF12 was generally higher in the tissues and periods where and when the bulbil formation was not possible,suggesting that LlARF12 might play a transcriptional inhibitory role in the process of bulbil formation.Gene function verification by VIGS technology proved that LlARF12 inhibited the bulbil formation.