AUTHOR=Zeng Wenping , Wang Jie , Wang Ying , Lin Jing , Fu Yanping , Xie Jiatao , Jiang Daohong , Chen Tao , Liu Huiquan , Cheng Jiasen 

TITLE=Dicer-Like Proteins Regulate Sexual Development via the Biogenesis of Perithecium-Specific MicroRNAs in a Plant Pathogenic Fungus Fusarium graminearum

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.00818

DOI=10.3389/fmicb.2018.00818

ISSN=1664-302X

ABSTRACT=<p>Ascospores act as the primary inoculum of <italic>Fusarium graminearum</italic>, which causes the destructive disease Fusarium head blight (FHB), or scab. MicroRNAs (miRNAs) have been reported in the <italic>F. graminearum</italic> vegetative stage, and <italic>Fgdcl2</italic> is involved in microRNA-like RNA (milRNA) biogenesis but has no major impact on vegetative growth, abiotic stress or pathogenesis. In the present study, we found that ascospore discharge was decreased in the <italic>Fgdcl1</italic> deletion mutant, and completely blocked in the double-deletion mutant of <italic>Fgdcl1</italic> and <italic>Fgdcl2</italic>. Besides, more immature asci were observed in the double-deletion mutant. Interestingly, the up-regulated differentially expressed genes (DEGs) common to <italic>ΔFgdcl1</italic> and <italic>ΔFgdcl1/2</italic> were related to ion transmembrane transporter and membrane components. The combination of small RNA and transcriptome sequencing with bioinformatics analysis predicted 143 novel milRNAs in wild-type perithecia, and 138 of these milRNAs partly or absolutely depended on <italic>Fgdcl1</italic>, while only 5 novel milRNAs were still obtained in the <italic>Fgdcl1</italic> and <italic>Fgdcl2</italic> double-deletion mutant. Furthermore, 117 potential target genes were predicted. Overall, <italic>Fgdcl1</italic> and <italic>Fgdcl2</italic> genes were partly functionally redundant in ascospore discharge and perithecium-specific milRNA generation in <italic>F. graminearum</italic>, and these perithecium-specific milRNAs play potential roles in sexual development.</p>