Transcriptome Analysis Of Gerbera Delavayi Based On High-throughput Sequencing Technology And Differential Expression Analysis

Gerbera delavayi Franch.was a kind of Compositae,Gerbera herb which is perennial.In antient times,people used the white penniform in abaxial leaves as combustion-supporting material,so it was known as "fireweed".G.delavayi is endemic in Yunnan province and southern Sichuan,as well as in southern Vietnam.Its abaxial leaf surface was covered with white penniform fiber which could be torn up for twisting,and the thread was flexible.It became the raw material of fireweed costume of southwestern minorities.The firefeed clothing was light and hardwearing,at the same time,it was warm and breathable.It already had history of more than 300 years up to now.The fireweed textile technology was listed as a intangible heritage in Yunnan and Sichuan province.In this study,the leaves of G.delavayi were sequenced based on Illumina Hi-Seq2500.The results showed that 108694 unegenes were found.N50 was 593.90bp,and the mean length was 912bp.By comparing with Nr and Swiss-prot database,40915 unigenes were annotated,and 67779 unigenes were unannotated.In addition,31 unigenes had homology with CesA family,20 unigenes had homology with Csl family,and 11 unigenes had homology with SuSy.11369 unigenes were assigned to 25 categories with COG database,and 21378 unigenes were divided into 52 GO terms.Function annotation against KEGG database obtained 8087 unigenes and 118 pathways.47 unigenes were found at "phenylpropanoid biosynthesis"pathway.Furthermore,4908 unigenes contained 5179 SSRs,1 SSR occurred every 12.46 kb.The largest number of SSR type was mono-nucleotide repeat,and its frequency was 54.37%;the next was di-nucleotide repeat and tri-nucleotide repeat,respectively with the frequencies of 22.90%and 21.70%.These results greatly enriched the genetic information of G.delavayi,and provided basic data for genetic breeding and exploitation of this unique plant resource.In the present study,two samples(abaxial leaves with and without penniform fiber)'s cDNA were sequenced based on Illumina Hi-Seq2500 so as to analyze the fiber development mechanism.The results indicated that 108694 unigenes were obtained.Then,1 605 differential expressed genes(DEGs)were selected.830 DEGs were divided into 39 GO terms,512 DEGs were assigned to 25 categories with COG database.Function annotation against KEGG database obtained 294 DEGs.10 significantly reliable enrichment pathways were selected by enrichment analysis of 79 KEGG pathways.DEGs in "starch and sucrose metabolism" which control hemicellulose biosynthesis,DEGs in "phenylpropanoid biosynthesis" which control lignin biosynthesis and DEGs in;"plant hormone signal transduction" which control auxin response,cytokinin negative regulation,and abscisic acid negative regulation were down-regulated.While,in "plant hormone signal transduction" which control auxin negative response was up-regulated.These results greatly enriched genetic information of G.delavayi and provided basic data for function verification and genetic improvement of fiber traits in the future.The result of Q-PCR showed that the variety tendency of 8 DEGs expression value was exactly identical.It indicated sequencing database was reliable,and could be used for subsequent research.