Laboratory of Fruit Genetic Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Yamanashi, Japan.
NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo, Japan.
PLoS One. 2018 Mar 22;13(3):e0194807. doi: 10.1371/journal.pone.0194807. eCollection 2018.
Koshu is indigenous to Japan and considered the most important wine grape in Japan. Koshu grape berry possesses characteristics that make it unique from European V. vinifera as wine grape. However, the physiological characteristics of Koshu leaf and internode remain unknown. An understanding of those characteristics would contribute to improvements in Koshu cultivation, thereby enhancing grape berry and wine quality. To identify the genes responsible for the physiological characteristics of Koshu, we comprehensively analyzed leaf and internode differences at the transcriptome level between Koshu and Pinot Noir by RNA sequencing. A total of 248 and 131 differentially expressed genes (DEGs) were detected in leaves and internodes, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of these DEGs revealed that "flavonoid biosynthesis" and "glutathione metabolism" pathways were significantly enriched in Koshu leaves. On the other hand, when internodes were compared, "flavonoid"-related GO terms were specifically detected in Koshu. KEGG pathway enrichment analysis suggested that the expression of such genes as leucoanthocyanidin reductase and flavonol synthase in the flavonoid biosynthesis pathway was higher in Koshu than Pinot Noir. Measurement of the relative expression levels of these genes by RT-qPCR validated the results obtained by RNA sequencing. The characteristics of Koshu leaf and internode, which are expected to produce flavonoids with antibacterial activity and UV protection function, would suit Japanese climate as a survival strategy.
甲州是日本原产的品种，被认为是日本最重要的酿酒葡萄。甲州葡萄果实具有不同于欧洲 V. vinifera 酿酒葡萄的特点。然而，甲州叶片和节间的生理特性尚不清楚。了解这些特性将有助于改进甲州葡萄的栽培，从而提高葡萄浆果和葡萄酒的质量。为了鉴定与甲州叶片和节间生理特性相关的基因，我们通过 RNA 测序对甲州和黑皮诺的叶片和节间进行了转录组水平的综合分析。在叶片和节间中分别检测到 248 个和 131 个差异表达基因（DEGs）。这些 DEGs 的基因本体（GO）和京都基因与基因组百科全书（KEGG）通路富集分析表明，“类黄酮生物合成”和“谷胱甘肽代谢”通路在甲州叶片中显著富集。另一方面，当比较节间时，在甲州中特异性地检测到与“类黄酮”相关的 GO 术语。KEGG 通路富集分析表明，类黄酮生物合成途径中的苯丙氨酸解氨酶和类黄酮合酶等基因的表达在甲州中高于黑皮诺。通过 RT-qPCR 测量这些基因的相对表达水平验证了 RNA 测序的结果。甲州叶片和节间的特性预计具有抗菌活性和紫外线保护功能的类黄酮，这将是其适应日本气候的生存策略。
