An efficient method to prepare barcoded cDNA libraries from plant callus for long-read sequencing

Background: Long-read sequencing methods allow a comprehensive analysis of transcriptomes in identifying full-length transcripts. This revolutionary method represents a considerable breakthrough for non-model species since it allows enhanced gene annotation and gene expression studies. However, some plant tissues are recalcitrant to the successful preparation of cDNA libraries thus impairing further analyses. Results: A detailed protocol for preparing cDNA libraries suitable for high throughput RNA sequencing using Oxford Nanopore Technologies® was developed. Through this method, 8 barcoded cDNA libraries from two tamarillo ( Solanum betaceum Cav.) types of callus (friable and compact) and with distinct embryogenic competencies (embryogenic non-embryogenic) have been successfully prepared and sequenced. Conclusions: An efficient method for preparing barcoded cDNA libraries from plant callus is presented. Long-read sequencing using these libraries allows a comprehensive analysis of plant transcriptomes.