Transcriptomic profiling of two Pak Choivarieties with contrasting anthocyanin contents provides an insight into structural and regulatory genes in anthocyanin biosynthetic pathway

作   者：Lu Zhang , Bin Xu, Tao Wu, Yanfang Yang, Lianxue Fan, Muxuan Wen and Jiaxin Sui
期刊名称：BMC genomics
影响因子：3.729
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关键词： Anthocyanin, Brassica campestris L. ssp. chinensis L. Makino, Transcriptome, RNA-Seq
论文摘要：
Background: The accumulation of anthocyanin in horticultural crops not only improves their stress tolerances but also their nutritional values. Many key regulatory and structural genes in anthocyanin biosynthesis have been identified in model plants, but limited information is available for non-model plant species featured with colored leaves. In this study, two Pak Choi varieties with green or purple leaves were selected to analyze the anthocyanin biosynthesis through RNA-Seq.
Results: A total of 2475 unigenes were differentially expressed between these tested varieties, including 1303 downregulated
and 1172 up-regulated genes in the purple-leafed one. The reliability of the RNA-Seq was further confirmed by using real-time quantitative PCR. Kyoto Encyclopedia of Genes and Genomes enrichment analysis of the differentially expressed genes revealed ‘flavonoid biosynthesis’ was the only enriched pathway in the purple-leafed variety: In the pathway of phenylpropanoid metabolism, Bra017210, Bra039777, and Bra021637 were expressed at higher levels in the purple-leafed variety; among the early anthocyanin biosynthetic genes, Bra037747 transcripts were only detected in the
purple-leafed variety but not in the green-leafed one; among the late anthocyanin biosynthetic genes, Bra027457, Bra013652, Bra019350, Bra003021, Bra035004, and Bra038445 were all up-regulated in purple-leafed variety; and genes encoding anthocyanin-related transcription factors, such as Bra016164, and genes encoding anthocyanin transportation, such as GST F12, were also identified as up-regulated ones in the purple-leafed variety. Conclusions: The current result provided a valuable insight into the anthocyanin accumulation in the purple-leafed variety of Pak Choi and a bioinformatic resource for further functional identification of key allelic genes determining the
difference of anthocyanin content between Pak Choi varieties.