Visualized Localization And Function Analysis Of Small Cysteine-rich Secreted (SCRiS) Proteins In Magnaporthe Oryzae

Fungal pathogens use secreted proteins as virulence factors that are required to infect plants.A newly research found that fungal proteins secreted into this membrane complex are then delivered into the living plant cell where they may suppress host defense mechanisms and promote cell-to-cell colonization.Comparing the genomes among the Magaporthe grisea species complex,Dr.Ebbole identified a novel gene family from larger families of cysteine-rich proteins with 180 amino Acids.We renamed it as small cysteine-rich secreted(SCRiS)family.The sequence diversity of the gene family members demonstrates that the gene family is diverse and most paralogs have presence or absence,frameshift,and premature stop codon polymorphisms in different isolates.We used RT-PCR to detect the expression level of these genes at different stages.With a high differential expression threshold in infection period,we identified them as candidate effectors.When Rp27 used as a promoter of MoSCRiS1 fluorescently labeled MoSCRiS1 expressed at the stages of appresoria,conidia,mycelia and:inoculated rice sheath.MoSCRiSl also demonstrated the diversity location and pathogenicity on different host.As known avirulence effectors,Mo SCRiS2 proteins preferentially accumulated in the BICs.MoSCRiS3、MoSCRiS5 and MoSCRiS6 have the same location with MoSCRiS2,but signals are very weak.MoSCRiS4 localized near cell wall crossing points.The fluorescent signal of other members cannot be detected,and the deletion of each of the genes from this family cannot make detectable phenotype changes.Rice protoplast transient expression results showed that they cannot cause the apoptosis of rice cells.MoSCRiS1 had a plant-location sequence,MoSCRiS2 did not have other transmembrane signals except signal peptide.The location of SCRiS proteins and their sequence characteristics hit the evolution traces of this family protein.They may involve in the compatible interaction with rice through specific membrane system,and then control fungal infection and colonization.