Comprehensive transcriptome analysis of Crocus sativus for discovery and expression of genes involved in apocarotenoid biosynthesis

BMC Genomics

Research Article

Mohit Kumar Swarnkar¹  Anil Kumar Singh¹  Nazia Abbas²  Tabasum Mohiuddin³  Nasheeman Ashraf³  Zahoor Ahmed Wani³  Aubid Hussain Malik³  Shoib Ahmad Baba³  Swaraj Basu⁴ 

[1] Division of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, 176061, Palampur, India;Plant Biotechnology Division, CSIR- Indian Institute of Integrative Medicine, Sanat Nagar, J&K-190005, Srinagar, India;Plant Biotechnology Division, CSIR- Indian Institute of Integrative Medicine, Sanat Nagar, J&K-190005, Srinagar, India;Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 110 001, New Delhi, India;Stazione Zoologica Anton Dohrn di Napoli, Naples, Italy;

关键词: Crocus;    Saffron;    Apocarotenoids;    Illumina;    De novo;   

DOI  :  10.1186/s12864-015-1894-5

 received in 2015-04-09, accepted in 2015-09-01,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundCrocus sativus stigmas form rich source of apocarotenoids like crocin, picrocrocin and saffranal which besides imparting color, flavour and aroma to saffron spice also have tremendous pharmacological properties. Inspite of their importance, the biosynthetic pathway of Crocus apocarotenoids is not fully elucidated. Moreover, the mechanism of their stigma specific accumulation remains unknown. Therefore, deep transcriptome sequencing of Crocus stigma and rest of the flower tissue was done to identify the genes and transcriptional regulators involved in the biosynthesis of these compounds.ResultsTranscriptome of stigma and rest of the flower tissue was sequenced using Illumina Genome Analyzer IIx platform which generated 64,604,402 flower and 51,350,714 stigma reads. Sequences were assembled de novo using trinity resulting in 64,438 transcripts which were classified into 32,204 unigenes comprising of 9853 clusters and 22,351 singletons. A comprehensive functional annotation and gene ontology (GO) analysis was carried out. 58.5 % of the transcripts showed similarity to sequences present in public databases while rest could be specific to Crocus. 5789 transcripts showed similarity to transcription factors representing 76 families out of which Myb family was most abundant. Many genes involved in carotenoid/apocarotenoid pathway were identified for the first time in this study which includes zeta-carotene isomerase and desaturase, carotenoid isomerase and lycopene epsilon-cyclase. GO analysis showed that the predominant classes in biological process category include metabolic process followed by cellular process and primary metabolic process. KEGG mapping analysis indicated that pathways involved in ribosome, carbon and starch and sucrose metabolism were highly represented. Differential expression analysis indicated that key carotenoid/apocarotenoid pathway genes including phytoene synthase, phytoene desaturase and carotenoid cleavage dioxygenase 2 are enriched in stigma thereby providing molecular proof for stigma to be the site of apocarotenoid biosynthesis.ConclusionsThis data would provide a rich source for understanding the carotenoid/apocarotenoid metabolism in Crocus. The database would also help in investigating many questions related to saffron biology including flower development.

【 授权许可】

CC BY   
© Baba et al. 2015