CPPU对‘阳光玫瑰’葡萄品质及香气合成相关基因表达的影响

[目的]研究不同质量浓度细胞分类素（CPPU）对葡萄果实香气组分及合成相关基因表达的影响，为阐明香气物质的合成提供理论依据。[方法]以‘阳光玫瑰’葡萄为材料，在花期时用25 mg？L-1 GA3处理花序，花后2周时用25 mg？L-1 GA3+0 mg？L-1 CPPU处理果穗作为对照（CK），设置25 mg？L-1 GA3+5 mg？L-1 CPPU（Ⅰ）、25 mg？L-1 GA3+10 mg？L-1 CPPU（Ⅱ）、25 mg？L-1 GA3+15 mg？L-1 CPPU（Ⅲ）3个处理，采用实时荧光定量PCR法研究香气合成相关基因脱氧木酮糖磷酸合酶基因（DXS3）、香叶基二磷酸合酶基因（GPPS）和里那醇合成酶基因（LIS）的表达变化，并利用GC-MS技术测定葡萄香气组分。[结果]与对照相比，处理Ⅰ和Ⅱ的果实显著增大、增重，可滴定酸含量和可溶性固形物有所下降，外观品质提高，处理Ⅲ因CPPU浓度过高而引起葡萄品质下降。与对照相比，香气种类减少，萜类物质特征香气里那醇、顺式氧化里那醇、香叶醇等相对含量降低，风味变淡，且CPPU浓度过高，不利于香气的产生。与对照相比，经不同浓度CPPU处理的果实中香气合成相关基因DXS3、GPPS、LIS表达量高峰推迟且峰值下调，浓度越高，推迟时间越久，峰值更低，基因表达受抑制，这与萜类物质相对含量降低相一致。[结论]25 mg？L-1 GA3+5 mg？L-1 CPPU处理能够改善‘阳光玫瑰’葡萄外观品质并保证内在品质。
[Objectives] This paper is to investigate the effects of CPPU on aroma components and biosynthetic genes expression in‘Shine Muscat’grapes,providing theoretical bases for illumination of the aroma components biosynthesis. [Methods] Taking the grape cultivar‘Shine Muscat’as the material,this experiment was treated by the 25 mg？L-1 GA3+0 mg？L-1 CPPU at the florescence firstly. Then it was investigated with the treatments of 25 mg？L-1 GA3+5 mg？L-1 CPPU(Ⅰ),25 mg？L-1 GA3+10 mg？L-1 CPPU(Ⅱ),25 mg？L-1 GA3+15 mg？L-1 CPPU(Ⅲ),and 25 mg？L-1 GA3+0 mg？L-1 CPPU was the control. The aroma component and the expression of biosynthetic genes,DXS3,GPPS and LIS,were determined by RT-PCR and GC-MS. [Results] The fruits of treatmentsⅡand Ⅱ were bigger and heavier significantly compared with the control. It was beneficial to improving the quality. The content of titrable acidity and soluble solid were decreased. Treatment Ⅲ declined the quality because of the high CPPU concentration. The CPPU treatment decreased the species of aromatic compositions,reduced the terpenoids relative content,such as linalool,cis-linaloloxide,geraniol,and weakened the flavor. The high CPPU concentration was not conducive to the production of aroma components. Compared with the control,the peaks of the expression of biosynthetic genes of DXS3,GPPS,LIS were delayed and down-regulated,and they were delayed longer and down-regulated lower with the increasing CPPU concentration. The gene expressions were suppressed. They were consistent with the decrease of the content of the terpenoids relative content. [Conclusions] It indicated that 25 mg？L-1 GA3+5 mg？L-1 CPPU treatment was the best in terms of the quality of the appearance and inner