Gene cloning and expression analysis of limonene synthase in Syringa oblata and S. oblata var. alba

• 作 者: Zifei Yan Ying Qin Jian Zheng Pingsheng Leng Zenghui Hu
• 机 构: College of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, People’s Repub
• 出 处: 林业研究（英文版）
• 发表日期: 2019年4期
• 关键词: Floral scent Syringa oblata Syringa oblata var. alba Limonene synthase gene

Syringa species are important amentals with strong floral scent, of which monoterpenes are the main component. In this study, a new monoterpene synthase gene, named SoLIM, was collected from the flowers of Syringa oblata and S. oblata var. alba using a homologous cloning method. The full-length cDNA of SoLIM was 1746 bp and encoded 581 amino acids. Sequence analysis showed that SoLIM contained the DDxxD and RRx8W motifs, which are two typical conserved monoterpene synthase motifs, and was thus classified as belonging to the Tpsb subfamily. Using quantitative reverse-transcription PCR, SoLIM was significantly expressed in the petals and pistils of S. oblata and S. oblata var. alba, respectively. SoLIM expression peaked earlier than the D-limonene emissions in the dial experiments, but occurred later when D-limonene had peaked during the flowering phase, indicating that differences in SoLIM gene expression and D-limonene emissions existed. The synthesis of floral scent is thus associated with diverse regulatory mechanisms that require further investigation.