Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009, People's Republic of China.
BMC Plant Biol. 2023 Mar 31;23(1):171. doi: 10.1186/s12870-023-04191-1.
Fruit aroma is an important quality with respect to consumer preference, but the most important aroma compounds and their genetic regulatory mechanisms remain elusive.
In this study, we qualitatively analysed volatile compounds in the pulp and skin of five table grape cultivars with three aroma types (muscat, strawberry, and neutral) using solid-phase microextraction gas chromatography/mass spectrometry. We identified 215 aroma compounds, including 88 esters, 64 terpenes, and 29 alcohols, and found significant differences in the number of compounds between the pulp and skin, especially for terpenes. Skin transcriptome data for the five grape cultivars were generated and subjected to aroma compound-gene correlation analysis. The combined transcriptomic analysis and terpene profiling data revealed 20 candidate genes, which were assessed in terms of their involvement in aroma biosynthetic regulation, including 1 VvCYP (VIT_08s0007g07730), 2 VvCCR (VIT_13s0067g00620, VIT_13s0047g00940), 3 VvADH (VIT_00s0615g00010, VIT_00s0615g00030, VIT_ 00s0615g00020), and 1 VvSDR (VIT_08s0040g01200) in the phenylpropanoids synthesis pathway, and 1 VvDXS (VIT_05s0020g02130) and 6 VvTPS (VIT_13s0067g00370, Vitis_vinifera_newGene_3216, VIT_13s0067g00380, VIT_13s0084g00010, VIT_00s0271g00010, and VIT_13s0067g00050) in the methylerythritol phosphate pathway (involved in the production and accumulation of aromatic compounds). Additionally, 2 VvMYB (VIT_17s0000g07950, VIT_03s0063g02620) and 1 VvGATA (VIT_15s0024g00980) transcription factor played important regulatory roles in the accumulation of key biosynthetic precursors of these compounds in grapes. Our results indicated that downstream genes, specifically 1 VvBGLU (VIT_03s0063g02490) and 2 VvUGT (VIT_17s0000g07070, VIT_17s0000g07060) are involved in regulating the formation and volatilization of bound compounds in grapes.
The results of this study shed light on the volatile compounds and "anchor points" of synthetic pathways in the pulp and skin of muscat and strawberry grapes, and provide new insight into the regulation of different aromas in grapes.
水果香气是消费者偏好的一个重要品质，但最重要的香气化合物及其遗传调控机制仍不清楚。
本研究采用固相微萃取-气相色谱/质谱联用技术，对 5 个具有 3 种香气类型（麝香、草莓和中性）的葡萄品种的果肉和果皮中的挥发性化合物进行了定性分析。共鉴定出 215 种香气化合物，包括 88 种酯类、64 种萜类和 29 种醇类，且果肉和果皮之间的化合物数量存在显著差异，特别是萜类化合物。对 5 个葡萄品种的果皮转录组数据进行了生成，并进行了香气化合物-基因相关性分析。综合转录组分析和萜类化合物分析数据揭示了 20 个候选基因，评估了它们在香气生物合成调控中的参与情况，包括 1 个 VvCYP（VIT_08s0007g07730）、2 个 VvCCR（VIT_13s0067g00620、VIT_13s0047g00940）、3 个 VvADH（VIT_00s0615g00010、VIT_00s0615g00030、VIT_00s0615g00020）和 1 个 VvSDR（VIT_08s0040g01200）在苯丙烷生物合成途径中，以及 1 个 VvDXS（VIT_05s0020g02130）和 6 个 VvTPS（VIT_13s0067g00370、Vitis_vinifera_newGene_3216、VIT_13s0067g00380、VIT_13s0084g00010、VIT_00s0271g00010 和 VIT_13s0067g00050）在甲基赤藓醇磷酸途径（参与芳香化合物的产生和积累）中。此外，2 个 VvMYB（VIT_17s0000g07950、VIT_03s0063g02620）和 1 个 VvGATA（VIT_15s0024g00980）转录因子在葡萄中这些化合物关键生物合成前体的积累中发挥了重要的调节作用。我们的结果表明，下游基因，特别是 1 个 VvBGLU（VIT_03s0063g02490）和 2 个 VvUGT（VIT_17s0000g07070、VIT_17s0000g07060）参与了调节葡萄中结合化合物的形成和挥发。
本研究结果揭示了麝香葡萄和草莓葡萄果肉和果皮中挥发性化合物和合成途径的“锚定点”，为葡萄不同香气的调控提供了新的见解。
