椪柑果肉挥发性物质及枯水时其萜烯类合成途径基因表达特征研究

This project uses GC - MS and RNA - Seq technologies to study the changing characteristics of the components and contents of volatile substances in the pulp and the expression of genes related to the synthesis pathway of terpenoids when the Ponkan fruits experience granulation. The research results show that: ① There are a total of 13 volatile components in the Ponkan pulp, among which there are 7 terpenoids, and the relative content exceeds 85%. ② When the Ponkan is granulated, the content of volatile substances in the pulp is reduced to 32% of that of normal fruits, among which the terpenoids are reduced to 22% of that of normal fruits, and the types of volatile substance components remain unchanged; the contents of 5 volatile substances change significantly, namely β - myrcene, d - limonene, γ - terpinene, valencene and dodecanal. ③ 8 differentially expressed genes in the terpenoid synthesis pathway are identified and all are down - regulated during granulation. This study indicates that the content of volatile substances in the pulp of Ponkan is significantly down - regulated during granulation, which is closely related to the decreased expression of genes related to the terpenoid synthesis pathway, providing a basis for further in - depth study of the molecular mechanism of citrus granulation.

本项目运用GC-MS和RNA-Seq技术研究椪柑果实在发生枯水时，果肉挥发性物质组分及含量和萜烯类化合物合成途径相关基因表达的变化特征。研究结果发现：① 椪柑果肉挥发性组分一共13种，其中萜烯类物质7种，相对含量超过85%。② 椪柑枯水时，果肉挥发性物质含量降为正常果实的32%，其中萜烯类物质下降为正常果实的22%，另外挥发性物质的组分种类不变；有5种挥发性物质的含量发生显著改变，分别是β-月桂烯、d-柠檬烯、γ-松油烯、瓦伦西亚烯和十二醛。③ 鉴定到8个萜烯类化合物合成途径的差异表达基因，在枯水时全部下调。本研究表明椪柑枯水时果肉挥发性物质的含量显著下调，与萜烯类合成途径相关基因表达降低密切相关，为进一步深入研究柑橘枯水发生的分子机制提供依据。