Wu Xinxin, Gong Qinghua, Ni Xiaopeng, Zhou Yong, Gao Zhihong
Laboratory of Fruit Tree Biotechnology, College of Horticulture, Nanjing Agricultural UniversityNanjing, China; Jiangsu Key Laboratory for Horticultural Crop Genetic ImprovementNanjing, China.
The Administration Bureau of Sun Yat-sen's Mausoleum Nanjing, China.
Front Plant Sci. 2017 Feb 7;8:108. doi: 10.3389/fpls.2017.00108. eCollection 2017.
Japanese apricot ( Sieb.et Zucc.) is an important ornamental plant in China. One of the traits of petals color variegation is attractive, but its formation mechanism is unclear. In our study, RNA-seq technology was employed to characterize the transcriptome response to the mutation of "Fuban Tiaozhi" associated with petals variegation in Japanese apricot. As a result, 4,579,040 (white-flowered, WF) and 7,269,883 (red-flowered, RF) reads were mapped to genes, while 5,006,676 (WF) and 7,907,436 (RF) were mapped to genomes. There were 960 differentially expressed genes (DEGs) identified. Gene ontology analysis showed that these genes involved in 37 functional groups including 19 biological processes, 10 cellular components and eight molecular functions. Pathway enrichment annotation demonstrated that highly ranked genes were associated with flavonoid biosynthesis, anthocyanin biosynthesis, anthocyanins transports, plant hormone signal transduction, and transcriptional factors. The expression patterns part of them were validated by qRT-PCR. We found that UDP-glucose: flavonoid 3--glucosyltransferase () gene showed differential expression pattern. The UFGT enzyme activities in RF had a significantly higher than that of WF and lower in the initial stage and increased when the red appeared in the petals, which is identical to the accumulation of anthocyanins. And we also validated the SNPs, leading to the nonsynonymous mutations, in the by Sanger sequencing which may affect the enzyme activity. In summary, our results provide molecular candidates for better understanding the mechanisms of the variegation in Japanese Apricot.
梅（Sieb.et Zucc.）是中国一种重要的观赏植物。花瓣颜色斑驳是其吸引人的特征之一，但其形成机制尚不清楚。在我们的研究中，采用RNA测序技术来表征对与梅花花瓣斑驳相关的“复瓣跳枝”突变的转录组反应。结果，4,579,040条（白花，WF）和7,269,883条（红花，RF） reads被映射到基因上，而5,006,676条（WF）和7,907,436条（RF）被映射到基因组上。共鉴定出960个差异表达基因（DEGs）。基因本体分析表明，这些基因涉及37个功能组，包括19个生物学过程、10个细胞成分和8个分子功能。通路富集注释表明，排名靠前的基因与类黄酮生物合成、花青素生物合成、花青素转运、植物激素信号转导和转录因子有关。其中部分基因的表达模式通过qRT-PCR进行了验证。我们发现UDP-葡萄糖：类黄酮3-O-葡萄糖基转移酶（UFGT）基因呈现出差异表达模式。RF中的UFGT酶活性显著高于WF，且在初始阶段较低，当花瓣出现红色时增加，这与花青素的积累情况一致。并且我们还通过Sanger测序验证了UFGT中导致非同义突变的单核苷酸多态性（SNPs），这可能会影响酶的活性。总之，我们的结果为更好地理解梅花斑驳的机制提供了分子候选依据。
