ABSTRACT
Objective: To clone the leucoanthocyanidin reductase (LAR) gene of Lithocarpus polystachyus, and analyze the relationship between LAR gene expression level and phloridzin content. Methods: According to the results of L. polystachyus transcriptome sequencing (unigene: DN30711_c0_g1_i1), the full-length cDNA sequence of LAR gene was amplified by PCR and the bioinformatics analysis was carried out. Its expression was detected by quantitative Real-time PCR (qRT-PCR). The phloridzin content of L. polystachyus was measured by UPLC method and the correlation between LAR gene expression and phloridzin content was analyzed by SPSS 18.0 software. Results: The full-length cDNA of the LAR gene was 1 053 bp and contained a complete open reading frame that encoded 350 amino acids. This protein did not exist a transmembrane domain and was localized in the cytoplasm. The LAR protein of L. polystachyus was the number of PCBER_SDR_a family and had a high similarity (95%) to the LAR protein of Quercus suber and their genetic relationship was close. The phloridzin content of L. polystachyus was positively correlated with the expression of LAR gene (P < 0.05). Conclusion: The LAR gene of L. polystachyus was cloned for the first time. It was confirmed that the content of phloridzin was positively correlated with the expression of LAR gene of L. polystachyus, which laid a theoretical and technical basis for revealing the biosynthesis mechanism of phloridzin of L. polystachyus.