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香叶基焦磷酸(GPP)是香味成分单萜的前体物质,而香味是芒果重要的品质性状。本研究克隆了芒果中GPP合成关键酶基因,即香叶基香叶基焦磷酸合成酶小亚基基因(MinGGPPSssu),并开展了系统进化分析和表达分析。从芒果栽培品种贵妃芒的新鲜叶片中提取DNA和RNA,根据转录组测序拼接结果设计引物扩增得到Min GGPPSssu全长约1 kb的c DNA序列。通过测序、多重比对和聚类分析,证实该片段属于GGPPSssu的全长基因,且为最大的ORF。与近缘物种苦楝GGPPS1(KM108317)氨基酸序列同源性为83%。蛋白质序列分析表明该序列含有1个DDx_(2-4)D保守基元和一个Cxxx C基元。我们选取了拟南芥中12个GGPPS基因、2个FPPS基因、2个SPPS基因、一个GPS基因及其他物种的相关基因,通过聚类分析,将Min GGPPSssu聚类到香叶基香叶基焦磷酸合成酶小亚基所属的枝。表达分析表明,该基因在叶片中表达量最高,茎部表达量较低。果皮和果肉在芒果成熟前后表达量相似,但是在果皮中的表达量约为果肉表达量的3倍,推测其与果皮及叶片香味调控相关。
Geranyl pyrophosphate (GPP) is a monoterpene flavor precursor material, and the flavor is an important quality traits Mango. In this study, we cloned the key gene of GPP synthesis in mango, namely, the small subunit gene of geranylgeranyl pyrophosphate synthase (MinGGPPSssu), and carried out phylogenetic analysis and expression analysis. DNA and RNA were extracted from the fresh leaves of mango cultivated M. dahurica. Based on the results of the transcriptome sequencing, primers were designed and amplified to obtain a cDNA sequence of about 1 kb in length of Min GGPPSssu. By sequencing, multiple alignment and cluster analysis, it was confirmed that the fragment belongs to the full-length gene of GGPPSssu and is the largest ORF. The homology of the amino acid sequence of GGPPS1 (KM108317) with the related species Melilotus aurea was 83%. Protein sequence analysis showed that this sequence contained one DDx_ (2-4) D conserved motif and one Cxxx C motif. We selected 12 GGPPS genes from Arabidopsis thaliana, 2 FPPS genes, 2 SPPS genes, one GPS gene and other related genes. By clustering analysis, Min GGPPSssu was clustered into geranylgeranyl coke Phosphoric acid synthase small subunit belongs to the branch. Expression analysis showed that the gene was expressed highest in leaves and lower in stems. Pericarp and flesh expressed similar amounts before and after ripening, but their expression in the pericarp was about 3 times higher than that in the flesh, suggesting that it is related to the regulation of the peel and the leaf aroma.