Functional Analysis Of The Calcium Ion Channel Mid1 And Cch1 In Phytophthora Capsici

Phytophthora capsici(Phytophthora capsici Leonian),belongs to the Phytophthora genus,Oomycota phyla and Stramenopilia kingdoms.It has an extensive host range,covering more than 3000 host plants which belong to 22 families.It can give rises to 500 kinds of disease which caused huge economic losses in the production in the worldwide every year.Studies have shown that calcium channel protein has an important role in cell morphology,vegetative growth,cell wall synthesis and pathogenicity.Currently,the function of Mid1 and Cchl are unclear in Phytophthora capsici.In order to analyze the function of calcium channel protein in Phytophthora capsici in growth and pathogenicity,gene silencing method were used.Expression of Mid1 and Cchl were silenced by introducing sense and antisense constructs into P.capisici(LT1534).Research results indicate that Midl and Cchl silencing transformants demonstrated the hyphal growth rate reduced around 60%Compared to the wild-type.Apart from this,the cell size and morphology of sporangia and hyphae have significant difference.Midl and Cchl silencing silencing transformants were also damaged in the production of swimming zoospores.Furthermore,we found Mid1 and Cchl deficient mutants lost the portion of virulence on the host pepper and tobacco leaves.Mid1 and Cchl silenced mutants are very similar in phenotypes of mycelia growth,morphology and sporangium.However,Midl silenced mutants showed fewer in the production of swimming zoospores and weaker pathogenicity in pepper and tobacco leaves than Cch1 silenced mutants.The complementation test showed the Mid1 and Cchl was able to recover its own knock-out mutant.In addition,the Mid1 and Cchl may be involved in the exogenous H2O2 stress response.Our all results indicated that calcium channel proteins Mid1 and Cchl played key roles in the growth,development and pathogenesis.