Small RNA sequencing identifies miRNA roles in fiber development

Working group session: 
Functional Genomics
Presentation type: 
oral
Authors: 
Zhang, Baohong; Xie, Fuliang; Wang , Qinglian ; Jones, Don
Presenter: 
Zhang, Baohong
Correspondent: 
Zhang, Baohong
Abstract: 
Recently microRNAs (miRNAs) have been found to be differentially expressed during cotton fiber development. However, what specific miRNAs and how they are involved in fiber development is unclear. Here, using deep sequencing, 65 conserved miRNA families were identified; 32 families were differentially expressed between leaf and ovule. A total of 128 pre-miRNAs, including 120 conserved and 8 novel pre-miRNAs were found in cotton. At least 40 miRNAs were either leaf or ovule-specific, whereas 62 miRNAs were shared in both leaf and ovule. A total of 863 genes were potentially targeted by 120 identified miRNAs, whose functions are involved in a series of biological processes including transcription factors, fiber development, metabolism, and signal transduction. GO and KEGG analyses showed that the identified miRNAs and their targets were classified to 1,119 GO terms including 563 biological processes, 416 molecular functions, and 140 cellular components, and were enriched to 74 KEGG pathways. At least 7 unique miRNAs participate in trichome regulatory interaction network. Eleven tasiRNA-derived candidate genes were identified in cotton. One has never been found in other plant species and two of them are MYB and ARF, both play important role in cotton fiber development. Sixteen genes were predicted to be tasiRNA targets, including sucrose synthase, polyphenol oxidase, MYB2, and glycosyl hydrolase. Together, this study discovered new miRNAs in cotton and offered evidences that miRNAs play important roles in cotton fiber development. The identification of tasiRNAs and their targets broadens our understanding of the complicated regulatory mechanism of miRNAs in cotton.