Abstract

Ribosome assembly factors have been extensively studied in yeast, and their abnormalities may affect the assembly process of ribosomes and cause severe damage to cells. However, it is not clear whether mRNA turnover protein 4 (MRT4) functions in the fungal growth and pathogenicity inSclerotinia sclerotiorum. Here, we identified the nucleus-located geneSsMRT4using reverse genetics, and found that knockdown ofSsMRT4resulted in retard mycelia growth and complete loss of pathogenicity. Furthermore,mrt4knockdown mutants showed almost no appressorium formation and oxalic acid production comparing to the wild-type and complementary strains. In addition, the abilities to ROS elimination and resistance to oxidative and osmotic stresses were also seriously compromised inmrt4mutants. Overall, our study clarified the role ofSsMRT4 inS. sclerotiorum, providing new insights into ribosome assembly in regulating pathogenicity and resistance to environmental stresses of fungi.Keywords:Sclerotinia sclerotiorum;SsMRT4;ribosome assembly;ROS;pathogenicity