Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, Anhui, China.
Anhui Microanaly Gene Limited Liability Company, Hefei, Anhui, China.
PLoS One. 2021 Oct 28;16(10):e0259119. doi: 10.1371/journal.pone.0259119. eCollection 2021.
Flowering and fruit set are important traits affecting fruit quality and yield in rabbiteye blueberry (Vaccinium ashei). Intense efforts have been made to elucidate the influence of vernalization and phytohormones on flowering, but the molecular mechanisms of flowering and fruit set remain unclear. To unravel these mechanisms, we performed transcriptome analysis to explore blueberry transcripts from flowering to early fruit stage. We divided flowering and fruit set into flower bud (S2), initial flower (S3), bloom flower (S4), pad fruit (S5), and cup fruit (S6) based on phenotype and identified 1,344, 69, 658, and 189 unique differentially expressed genes (DEGs) in comparisons of S3/S2, S4/S3, S5/S4, and S6/S5, respectively. There were obviously more DEGs in S3/S2 and S5/S4 than in S4/S3, and S6/S5, suggesting that S3/S2 and S5/S4 represent major transitions from buds to fruit in blueberry. GO and KEGG enrichment analysis indicated these DEGs were mostly enriched in phytohormone biosynthesis and signaling, transporter proteins, photosynthesis, anthocyanins biosynthesis, disease resistance protein and transcription factor categories, in addition, transcript levels of phytohormones and transporters changed greatly throughout the flowering and fruit set process. Gibberellic acid and jasmonic acid mainly acted on the early stage of flowering development like expression of the florigen gene FT, while the expression of auxin response factor genes increased almost throughout the process from bud to fruit development. Transporter proteins were mainly associated with minerals during the early flowering development stage and sugars during the early fruit stage. At the early fruit stage, anthocyanins started to accumulate, and the fruit was susceptible to diseases such as fungal infection. Expression of the transcription factor MYB86 was up-regulated during initial fruit development, which may promote anthocyanin accumulation. These results will aid future studies exploring the molecular mechanism underlying flowering and fruit set of rabbiteye blueberry.
开花和坐果是影响兔眼蓝莓果实品质和产量的重要性状。人们已经做出了巨大的努力来阐明春化和植物激素对开花的影响，但开花和坐果的分子机制仍不清楚。为了解开这些机制，我们进行了转录组分析，以探索从开花到早期果实阶段的蓝莓转录本。我们根据表型将开花和坐果分为花蕾（S2）、初花（S3）、盛花（S4）、花托果（S5）和杯状果（S6），并在 S3/S2、S4/S3、S5/S4 和 S6/S5 的比较中分别鉴定出 1344、69、658 和 189 个独特的差异表达基因（DEGs）。S3/S2 和 S5/S4 中的 DEGs 明显多于 S4/S3 和 S6/S5，这表明 S3/S2 和 S5/S4 代表蓝莓中从芽到果的主要转变。GO 和 KEGG 富集分析表明，这些 DEGs 主要富集在植物激素生物合成和信号转导、转运蛋白、光合作用、花青素生物合成、抗病蛋白和转录因子类别中，此外，植物激素和转运蛋白的转录水平在整个开花和坐果过程中变化很大。赤霉素和茉莉酸主要作用于开花发育的早期阶段，如花发育基因 FT 的表达，而生长素响应因子基因的表达在从芽到果实发育的整个过程中增加。转运蛋白主要与开花发育早期阶段的矿物质和早期果实阶段的糖有关。在早期果实阶段，花青素开始积累，果实容易受到真菌感染等疾病的影响。在初果发育过程中，转录因子 MYB86 的表达上调，这可能促进了花青素的积累。这些结果将有助于未来探索兔眼蓝莓开花和坐果的分子机制的研究。
