FgVELB is associated with vegetative differentiation, secondary metabolism and virulence in Fusarium graminearum.
The velvet complex containing VeA, VelB and LaeA has been showed to play critical roles in the regulation of secondary metabolism and diverse cellular processes in Aspergillus spp. In this study, we identified FgVelB, a homolog of Aspergillus nidulans VelB, from Fusarium graminearum using the BLASTP program. Disruption of FgVELB gene led to several phenotypic defects, including suppression of aerial hyphae formation, reduced hyphal hydrophobicity and highly increased conidiation. The mutant showed increased resistance to osmotic stress and cell wall-damaging agents, which may be related to a high level of glycerol accumulation in the mutant. Additionally, the mutant exhibited increased sensitivity to the phenylpyrrole fungicide fludioxonil. Ultrastructural and histochemical analyses revealed that conidia of FgVELB deletion mutant contained numerous lipid droplets. Pathogenicity assays showed FgVELB deletion mutant was impaired in virulence on flowering wheat head, which is consistent with the observation that FgVelB is involved in the regulation of deoxynivalenol biosynthesis in F. graminearum. All of the defects were restored by genetic complementation of the mutant with wild-type FgVELB gene. Yeast two hybrid assays showed that FgVelB does not interact with FgVeA. Taken together, results of this study indicated that FgVelB plays a critical role in the regulation of various cellular processes in F. graminearum.
Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
Jinhua
J
Jiang
Yingzi
Y
Yun
Ye
Y
Liu
Zhonghua
Z
Ma
D000935:Antifungal Agents / Q000494:pharmacology; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005670:Fusarium / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D023061:Gene Order; D018390:Gene Targeting; D025301:Hyphae / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D009997:Osmotic Pressure; D010860:Pigments, Biological / Q000096:biosynthesis; D010935:Plant Diseases / Q000382:microbiology; D017422:Sequence Analysis, DNA; D014255:Trichothecenes / Q000096:biosynthesis; D014908:Triticum / Q000382:microbiology; D014774:Virulence
D000935:Antifungal Agents; D005656:Fungal Proteins; D010860:Pigments, Biological; D014255:Trichothecenes; C007262:deoxynivalenol