FgCDC14 regulates cytokinesis, morphogenesis, and pathogenesis in Fusarium graminearum

Abstract

SummaryMembers of Cdc14 phosphatases are common in animals and fungi, but absent in plants. Although its orthologs are conserved in plant pathogenic fungi, their functions during infection are not clear. In this study, we showed that the CDC14 ortholog is important for pathogenesis and morphogenesis in Fusarium graminearum. FgCDC14 is required for normal cell division and septum formation and FgCdc14 possesses phosphatase activity with specificity for a subset of Cdk-type phosphorylation sites. The Fgcdc14 mutant was reduced in growth, conidiation, and ascospore formation. It was defective in ascosporogenesis and pathogenesis. Septation in Fgcdc14 was reduced and hyphal compartments contained multiple nuclei, indicating defects in the coordination between nuclear division and cytokinesis. Interestingly, foot cells of mutant conidia often differentiated into conidiogenous cells, resulting in the production of inter-connected conidia. In the interphase, FgCdc14-GFP localized to the nucleus and spindlepole-body. Taken together, our results indicate that Cdc14 phosphatase functions in cell division and septum formation in F. graminearum, likely by counteracting Cdk phosphorylation, and is required for plant infection.

MoCDC14 is important for septation during conidiation and appressorium formation in Magnaporthe oryzae

“…Vegetative hyphae show fewer and unevenly distributed septa and individual hyphal compartments often contain multiple nuclei. Therefore, it is likely that deletion of MoCDC14 affects cytokinesis and nuclear distribution in vegetative hyphae, which is similar to the defects of the Fgcdc14 mutant in F. graminearum (Li et al ., ). MoCdc14 may also be important for cell division and septum formation by counteracting CDK phosphorylation on its substrate in M. oryzae during vegetative growth.…”

“…In F. graminearum , conidia normally have more than five septa and uni‐nucleate compartments. The conidia of the Fgcdc14 mutant show reduced septum formation and an increased number of nuclei per conidial compartment (Li et al ., ). Nevertheless, the majority of Fgcdc14 mutant conidia still contain three or more septa.…”

“…In M. oryzae , MoCDC14 encodes a typical Cdc14 phosphatase protein, with the HCX5R catalytic site sequence (Mocciaro and Schiebel, ). The Mocdc14 mutant is viable, but shows a significantly reduced growth rate, which is similar to the cdc14 mutants in F. graminearum and B. bassiana (Li et al ., ; Wang et al ., ). However, deletion of the CDC14 orthologue produces no obvious defects in growth rate in A. nidulans (Son and Osmani, ) or C. albicans (Clemente‐Blanco et al ., ).…”

“…Clp1 reverses Cdk1‐mediated phosphorylation of the mitotic inducer Cdc25 and promotes its degradation by the anaphase‐promoting complex at the end of mitosis (Esteban et al ., ; Wolfe and Gould, ). In the filamentous fungi Aspergillus nidulans , F. graminearum and Beauveria bassiana , the CDC14 orthologues are also dispensable for viability, but important for asexual development (Li et al ., ; Son and Osmani, ; Wang et al ., ). In the human pathogen Candida albicans , deletion of CaCDC14 has no effect on growth rate, but results in defects in cell separation, mitotic exit and morphogenesis (Clemente‐Blanco et al ., ).…”

RNA editing of the AMD1 gene is important for ascus maturation and ascospore discharge in Fusarium graminearum

“…For each head, the fifth spikelet from the base of the inflorescence was inoculated with 10 μl of conidium suspensions as described 36, 37 . FHB symptoms were examined at 14 day post-infection to estimate the disease index 38, 39 .…”