Reconstruction Of Abiotic Stress Responsive Gene Co-expression Network In Brassica Napus

The Science journal published the genome map of the Brassica napus in 2014,however,there are few studies on the gene co-expression network(GCN)among Brassica napus genes.The construction and establishment of GCN is one of the main tools of functional genomics.So,It is of great significance to study GCN of the Brassica napus gene.Our research team has cooperated with life science researchers to study the molecular mechanism of Brassica napus stress response.Through experimental design and transcriptome sequencing,transcriptome data of 75,704 genes were obtained.This paper uses cluster analysis,gene expression profiling and GO enrichment analysis to select 422 genes that associate with abiotic stress and hormone responses in Brassica napus.We summarize the network reconstruction methods,construct GCN of Brassica napus gene,and compare with the Arabidopsis homologous gene regulatory network.The main works of this paper are as follows:Firstly,we summarize the commonly used statistical methods of inferring GCNs,and discuss the advantages and disadvantages of them.These is significant to study network reconstruction.Secondly,using Piecewise Granger Causal analysis construct a co-expression network of Brassica napus.Totaly 546 co-expression pairs are detected between 422 genes.Next,using the Arabidopsis thaliana homologous gene information,we infer that BnaC03g49940D plays an important role under salt stress,BnaC08g123860D plays an important role under salt and cold stress,BnaC03g48290D plays an important under the drought stress and hormone stimulation,BnaC06g42900D plays an important role under cold stress.Our results suggest that genes which have co-expressed edges with these four genes in Brassica napus may have similar functions.And the GCN of the Brassica napus plays an important role in the abiotic stress and hormone response in Brassica napus.At last,GCN of Brassica napus is compared with the Arabidopsis homologous gene regulatory network.It is found that the two networks have no overlapping edges,which indicates that the genes with co-expression relationships may unnecessarily have a regulatory relationship,and the regulatory relationship between genes may unnecessarily have a co-expression relationship.The study can help us to understand stress tolerance mechanisms in Brassica napus and breeding new varieties with stress tolerance.