Identification of soybean circular RNAs in response to low nitrogen and phosphorus stresses

Soybean, one of the most important sources of edible oil and protein in the world, is exposed to various environmental biotic and abiotic stresses. These stresses can negatively impact the quality and quantity of soybean production. This study aimed to identify genes that express circular RNAs in response to low phosphorus and nitrogen stresses in soybean roots. Soybean seeds were grown under different low phosphorus and nitrogen treatments, and sampling was done from the root tissues for total RNA isolation. After measuring the quality and quantity of the isolated RNA, samples were sequenced using next-generation sequencing. After obtaining the sequencing data, the quality of RNA-seq data measured, and then circular RNAs were identified and characterized using five different programs. Finally, to identify the expression pattern and putative function of circular RNAs, differential expression analysis and functional analysis of circular RNAs’ parent genes was done using bioinformatics approaches. RNA-seq experiment produced more than 360 million reads, and in total, 2033 circular RNAs were identified in all treatments. Although some circular RNAs were co-expressed in two or more treatments, most of the circular RNAs had a stress-responsive expression. Our results were revealed that circular RNAs may play their roles by binding to their target molecules. Identified genes can be used in plant breeding programs for producing tolerant soybean cultivars to low phosphorus and nitrogen stresses.