Omics Research Of The Main Active Substances In Saffron(Crocus Sativus)

As people pay more attention to health problems and the multiple and younger trends of chronic diseases are becoming more and more obvious,the development of traditional Chinese medicine becomes the first choice for many modern people’s health care and disease prevention.As a valuable Chinese medicine,saffron(Crocus sativus)has powerful physiological functions.Its red stigmas are rich in unique carotenoids,such as safranal,crocetin and picrocrocin,etc.,which can promote blood circulation,reduce stasis,relieve pain and help to detoxify the body.Because the factors of origin,processing methods,and metabolism pathways can all affect the accumulation of main active substances,relevant omics analysis is particularly important.In this study,saffrons from Bozhou,Anhui,Jiaxing,Zhejiang and Iran were used as experimental materials.Metabolomics methods such as principal component analysis and orthogonal partial least squares analysis were used to analyze the differences of active substances in saffron produced from three different regions.For comparing the quantities of the main active substances(safranal,crocetin and picrocrocin),we obtained spectras through comparison with the Metlin database.The results showed that saffron produced from Bozhou,Anhui contained higher quantities of safranal,crocetin and picrocrocin than that from Jiaxing,Zhejiang,which strongly indicated that the growing environment has a great influence on the inner quality of saffron.Furthermore,traditional processing methods of heating and drying clearly reduced the amount of safranal,crocetin and picrocrocin,but enhanced the content of some flavor amino acids.This study can be used as a reference for choosing cultivation methods for different regions and the improvement of processing technology by saffron grower in the future.In addition,Pac Bio SMRT sequencing technology was used to sequence the transcriptome of saffron,and further sequences assembly and annotation was done to obtain high-quality full-length transcriptome of the sterile triploid C.sativus.A total of138,773 deduplicated sequences and 31,755 protein-coding genes were obtained.Together,1,130 transcription factor members,226,616 simple sequence repeats,and1277 RNA genes were annotated and analyzed.Furthermore,the distribution of CCDs necessary for carotenoid biosynthesis were analyzed in five plant species,and the results showed that a total of 13 gene members belonging to the CCD family from saffron with specific cleavage cite,which is greater than those from Z.mays,D.carota,S.lycopersicum and A.officinalis.Gene expression profiling analysis showed that theexpression level of CCD family in stigma is higher than other tissues,which may play an extremely important role in the synthesis of active saffron metabolites.It indicated that CCDs may play an extremely important role in the synthesis of saffron active metabolites.These findings may pave the way for saffron genome improvement and promote germplasm utilization of saffron breeding varieties,thereby improving saffron quality.