背景回顾：Seedlessness in grapes is one of the features most appreciated by consumers. 

提出问题：However, the mechanisms underlying seedlessness in grapes remain obscure.

结果1-表型观察有籽和无籽葡萄：Here, we observe small globular embryos and globular embryos in Pinot Noir and Thompson Seedless from 20 to 30 days after flowering (DAF). From 40 to 50 DAF, we observe torpedo embryos and cotyledon embryos in Pinot Noir but aborted embryos and endosperm in Thompson Seedless. 

结果2-比较转录组：Thus, RNA‐Seq analyses of seeds at these stages from Thompson Seedless and Pinot Noir were performed. A total of 6442 differentially expressed genes were identified. Among these, genes involved in SA biosynthesis, VvEDS1 and VvSARD1, were more highly expressed in Thompson Seedless than in Pinot Noir. 

结果3-内源激素：Moreover, the content of endogenous SA is at least five‐ imes higher in Thompson Seedless than in Pinot Noir. 

结果4-基因甲基化与激素水平：Increased trimethylation of H3K27 of VvEDS1 and VvSARD1 may be correlated with lower SA content in Pinot Noir. 

结果5-关键调控因子鉴定：We also demonstrate thatVvHDZ28 positively regulates the expression of VvEDS1. Moreover, over‐expression of VvHDZ28 results in seedless fruit and increased SA contents in Solanum lycopersicum. 

结论：Our results reveal the potential role of SA and feedback regulation of VvHDZ28 in seedless grapes.

 摘 要 

无籽是葡萄最受消费者青睐的一个特征之一。但是，葡萄无籽背后潜在的分子机制还不清楚。本文中，作者对黑皮诺（Pinot Noir）葡萄和汤普森无籽（Thompson Seedless）葡萄在开花20到30天后进行胚胎观察，发现这两个品种均能发育至球形胚时期。但是，在开花后40到50天时，黑皮诺葡萄的胚胎发育至鱼雷胚或子叶胚时期，但是汤普森无籽葡萄的胚胎和胚乳均停止了发育。因此，作者进一步对这一时期的黑皮诺和汤普森无籽葡萄进行了RNA-Seq分析。作者共共鉴定了6442个差异表达基因。在这些基因中，两个参与SA合成的基因VvEDS1和VvSARD1在汤普森无籽葡萄中，显著要比在黑皮诺葡萄中表达量高。此外，汤普森无籽葡萄内源的SA浓度至少要比黑皮诺高出5个数量级。作者还发现，黑皮诺葡萄中较低的SA含量可能与其VvEDS1和VvSARD1基因上增强的H3K27三甲基化有关。此外，作者还发现VvHDZ28基因能够正向调控VvEDS1基因的表达。在番茄中过表达VvHDZ28基因，会导致其果实无籽，并增加SA的含量。本文的研究揭示了SA及VvHDZ28的反馈调节在无籽葡萄中的作用。