三七主根多糖合成相关且应答"拔鸡腿"基因的挖掘OA

[Objective]The genes related to polysaccharide synthesis and response to drumstick-forming in Panax notoginseng taproots were investigated to lay the foundation for studying the molecular mechanism of high polysaccharide content in P.notoginseng taproots with drumstick-forming characteristics and breeding of P.notoginseng varieties with drumstick-formed characteristics.[Method]The polysaccharide and soluble sugar content in taproots of non-drumstick-formed and drumstick-formed P.notoginseng plants with 2 years and 3 years old were determined by 3,5-dinitrosalicylic acid method and sulfuric acid-anthrone method,respectively.The structural genes and transcription factor genes related to polysaccharide synthesis and response to drumstick-formed in taproots of P.notoginseng were identified based on transcriptome sequencing,quantitative real-time PCR and Pearson correlation analysis.[Result]The polysaccharide content in taproots of drumstick-forming P.notoginseng plants with 2 years and 3 years old was 33.04 mg/g and 55.53 mg/g,75.37%and 92.82%significantly higher than that of non-drumstick-formed P.notoginseng plants with 2 years and 3 years old respectively.The soluble sugar content in taproots of drumstick-formed P.notoginseng plants with 2 years and 3 years old was 204.59 mg/g and 210.30 mg/g,14.08%and 22.19%higher than that of non-drumstick-formed P.notoginseng plants with 2 years and 3 years old respectively.The correlation coefficients between polysaccharide content in taproots of drumstick-formed P.notoginseng plants and the transcriptional level of the UDP-D-glucuronate-4-epimerase gene 1(GAE1),glucose-6-phosphate isomerase gene 2(GPI2),sucrose synthase gene 1(SUS1),phosphoglucomutase gene 2(PGM2)and phosphoglucomutase gene 1(PGM1)was 0.500,0.314,0.293,0.172 and 0.044,respectively.The correlation coefficients between polysaccharide content in taproots of drumstick-formed P.notoginseng plants and transcriptional level of AP2/ethylene responsive factor gene 1(AP2/ERF-1)and AP2/ERF-2 was 0.063 and-0.014,respectively.[Conclusion]The polysaccharide content in taproots of drumstick-formed P.notoginseng is higher than that of non-drumstick-formed P.notoginseng very significantly.The structural genes related to polysaccharide synthesis and response to drumstick-forming in P.notoginseng taproots are SUS1,SUS2,PGM1,PGM2,GPI2 and GAE1,and the transcription factor genes are AP2/ERF-1 and AP2/ERF-2.