Characterization of circular RNAs and their role in wilt stress tolerance in soybean

Abstract

Soybean (Glycine max) is an important oil seed crop and widely grown legume in India as well as in the world. The yield of soybean is severely affected by Wilt disease caused by a fungus Fusarium oxysporum. Several coding and non-coding RNAs in plant cells may directly or indirectly play a role in exhibiting stress tolerance to wilt. Here, an attempt has been made to identify the role of circular RNAs (circRNAs), a type of non-coding RNAs, in wilt stress tolerance mechanism. The study also aims at identification of circRNAs that act as endogenous target mimics (eTMs) or as sponges to miRNAs that may regulate the genes involved in wilt stress tolerance. The study reveals the presence of 24 differentially expressed circRNAs (DEcircRNAs) between the transcriptomes of wilt affected and control samples out of which 18 were acted as eTMs for 10 microRNAs (miRNAs). These miRNAs in turn found to regulate 275 genes that fall under 14 Gene Ontology (GO) based functional categories. The GO analysis further shown the annotation term ‘stimulus response’ for most of the DEcircRNAs, which were found in various vital activities like polygalacturonase activity, carbohydrate metabolic process. Hence, it is predicted that the identified miRNAs got absorbed by the circRNAs that acted as sponges or eTMs and the miRNA regulated genes are likely to be freed up in cell to exhibit wilt stress tolerance mechanism in soybean.