Study On The Expression Of Genes Involved In Trap Formation Of Arthrobotrys Oligospora

Arthrobotrys oligospora is one of the best studied nematode-trapping fungi.It could develop adhesive networks to capture nematodes,which is a key indicator of the switch from saprophytic lifestyle to parasitic lifestyle.In this study,high-throughput sequencing technology was used to study the gene expression profiles at key time points of trap induction by nematodes.We had performed many times that the key time points of trap induction were 0h,4h,8h,12h and 16h after induction.In this study,we chose all these key time points and a few other time points,including control time point,1h,2h,3h and 6h,then carried out RNA-seq focus on all these time points.Each time point had repeated three times.Transcriptomic analysis showed that the pathogenic genes were significantly regulated at the key time points.Real time PCR was used to confirm the expressive level of adhesive genes,and the results showed consistency with RNA-seq,which further suggests that adhesive genes are involved in trap induction.Transcriptomic analysis also showed that as many as 2003 genes were significantly regulated at Oh after nematodes were added instantly,suggesting that the fungus responds to the induction immediately and changes the lifestyle.In addition,more genes were regulated at the early stage of trap induction than later stages,such as Oh,1h,4h and 8h.This indicates that the development of trapping devices is related to the regulation of gene expression and the number of regulated genes.In order to classify possilble functions,the regulated genes were annotated by using COG database and GOterms.Among the regulated genes,48%-50.2%were assigned to 25 COG categories,and 67-125 genes were found to participate in the process of mycelium development.The metabolism and function of proteins,amino acids,carbohydrates and fats had an important influence on the trap formation of A.oligospora.The transport and metabolism of zinc ions played an important role in the formation of traps.At the key time points of lh,4h,8h,the metabolism within the organism will have distinct peaks.In this work,we carried out both experiments and high-throughput sequence data and discovered many potential functional genes involved in trap formation of A.oligospora induced by nematodes.The results showed that trap induction was the consequence by combining both genetic and environmental factors.Our results will be helpful to reveal the genetic mechanisms underlying capture of nematodes by nematode-trapping fungi,and provide insights into the lifestyle change and adaptation of the nematode-trapping fungi.