| Magnaporthe oryzae is a fungal pathogen causing blast disease in different developmental stages of rice.Three genes encode an extremely conserved protein kinase CK2 complex in M.oryzae.GFP-Mo CKa,GFP-fused Mo CKa which encoding catalytic subunit of CK2,was constructed and pull-down several protein phosphatases.MoPpz1 and MoStpp,two serine/threonine protein phosphatases obtained by pull-down assay of GFP-Mo CKa in M.oryzae,were knocked out and analysed by reverse genetics strategy and homologous recombination principle.It was found that MoPpz1 and MoStpp with their homolog proteins in various fungi had high identity in protein sequences respectively by bioinformatics analysis.The mutants of two genes were obtained by gene knockout method.ΔMoppz1 was not affected at growth rate and conidiation and so on,however,showed development delay of conidium from germination to appressorium and reduced pathogenicity to rice,and lower penetration frequency comparing with wild type strain Ku80.Confocal laser scanning microscopy showed that MoPpz1 was localized in cytoplasm of hyphae,conidium and appressorium.And there was no interaction of MoPpz1 with Mo CK2 by yeast two hybrid system.While,ΔMostpp showed reduction of growth rate,conidiation,and condiophores comparing with Ku80,and some malformed conidia had a single septum or no septum.ΔMostpp had growth defects under cell wall stress conditions and was showed development delay of conidium from germination to appressorium.It was reduced pathogenicity to rice and barley,also displayed lower penetration frequency to rice leaf sheath.In conclusion,protein phosphatase MoPpz1 and MoStpp may be involved in regulation of development in M.oryzae and pathogenicity to rice.Meanwhile,there was no interaction of MoPpz1 with Mo CK2. |
