De novo assembly and transcriptome characterization: novel insights into catechins biosynthesis in Camellia sinensis

BMC Plant Biology

Research Article

Zhi-Sheng Xu¹  Zhi-Wei Liu²  Zhi-Jun Wu²  Xing-Hui Li²  Jing Zhuang² 

[1] State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 210095, Nanjing, China;Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, 210095, Nanjing, China;

关键词: Camellia sinensis;    Transcriptome;    High-throughput sequencing;    Catechins;    RP-HPLC;    Genetic diversity;   

DOI  :  10.1186/s12870-014-0277-4

 received in 2014-07-04, accepted in 2014-10-06,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundTea is a popular natural non-alcoholic beverage consumed worldwide due to its bioactive ingredients, particularly catechins (flavan-3-ols). Catechins not only contribute to tea quality but also serve important functions in the anti-stress regulation of secondary metabolic pathways. However, the percentages of various catechins are different among tea plant [Camellia sinensis (L.) O. Kuntze] cultivars. This study aimed to elucidate the biosynthetic mechanism of catechins. Transcriptomes from leaf tissues of four tea plant cultivars, ‘Yunnanshilixiang’, ‘Chawansanhao’, ‘Ruchengmaoyecha’, and ‘Anjibaicha’, were sequenced using the high-throughput sequencing platform Illumina HiSeq™ 2000. De novo assemble were also performed. Catechins contents were measured through reversed-phase high-performance liquid chromatography (RP-HPLC), and the biosynthetic pathway was also surveyed.ResultsWe constructed a unified unigene database. A total of 146,342 pairs of putative orthologs from the four tea plant cultivars, ‘Yunnanshilixiang’, ‘Chawansanhao’, ‘Ruchengmaoyecha’, and ‘Anjibaicha’ were generated. Approximately 68,890 unigenes (47.1%) were aligned to the sequences of seven public databases with a cut-off E-value of 1E-5. A total of 217 differentially expressed genes were found through RPKM values, and 150 unigenes were assigned to the flavonoid biosynthetic pathway using the integrated function annotation. The (−)-EGC and (−)-EC contents were significantly lower and the (+)-GC and (+)-C contents were abnormally higher in ‘Ruchengmaoyecha’ than in ‘Yunnanshilixiang’, ‘Chawansanhao’, and ‘Anjibaicha’. The proportion of catechins was confirmed by selecting critical genes (ANS, ANR, and LAR) for qRT-PCR analysis.ConclusionsThis study provided a global survey of transcriptomes from four tea plant cultivars and serves as an available resource of genetic diversity. The analyses of transcriptome profiles and physiological indicators not only identified the putative genes involved in the flavonoid biosynthetic pathway but also provided some novel insights for the mechanisms of catechins biosynthesis.

【 授权许可】

Unknown   
© Wu et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.