Evaluation of small ncRNAs as a possible epigenetic mechanism mediating the transition from biotrophy to necrotrophy in the life cycle of Phytophthora infestans

Abstract

Abstract Background Phytophthora infestans, the causal agent of late blight disease of potato and tomato, is responsible for billions of dollars in losses worldwide each year. This plant pathogen is a hemibiotroph, meaning that in the early stages of infection, it feeds on living host tissue, and later in the infection cycle, it kills the host. Even though the transcription dynamics of this transition are well characterized, information on the role of small noncoding RNAs (ncRNAs) during this process is still being obtained. Furthermore, a methodological pipeline useful for searching and analyzing small ncRNAs in this pathogen is needed. Results Using the proposed pipeline, a set of 146 small ncRNAs were found to be significantly differentially expressed among the analyzed samples. From these, 100 small ncRNAs were successfully annotated to specific genes, some of them encoding effector proteins produced by the pathogen during its life cycle. Other molecular regulatory processes, mainly mediated by enzymes and transporters, were also identified. Conclusions The pipeline presented here is an easy-to-use, comprehensive and efficient option for analyzing small ncRNA profiles of P. infestans small RNA-seq data sets. Additionally, the results presented here may further contribute to elucidating the specific molecular and epigenetic mechanisms controlling the life cycle of P. infestans.