Cloning And Biological Function Of G-Protein Family Genes In Colletotrichum Gloeosporioides

Colletotrichum gloeosporioides is an important pathogen of rubber anthracnose,which is also one of the important biological factors threatening the development of natural rubber industry in our country.G protein,which has the activity of GTPase,is able to bind to guanine nucleotide,and has the ability to hydrolyze GTP to GDP.G protein plays an important role in gowth,development and pathogenicity of plant pathogen,while there has been no study on the biological function of G protein in C.gloeosporioides so far.In the previous work,we identified five G protein subunits from C.gloeosporioides.In this study,the five subunit genes were cloned and analyzed its protein sequences on the basis of this study,and their biological functions were clarified through the phenotypic analysis.The research indicates:Three kinds of G protein a subunits were identified from C.gloeosporioides.They were named CgGa1,CgGa2 and CgGa3.The CgGal,CgGa2 and CgGa3 were encode 353,354,355aa protein,respectively.Comparing to the wild type,the knockout mutant of CgGal had slow growth,autolyzed hyphae,decreased conidium production,germination rate and extracellular laccase,and the knockout mutant of CgGal had no appressorium form,showed more sensitive to NaCl and H2O2,and more tolerance to SDS and weakened pathogenicity.The knockout mutant of CgGa2 had slow growth,hyphae autolyzed,decreased conidium production,more sensitive to NaCl and H2O2,and more tolerance to SDS.The knockout mutant of CgGa3 had slow growth on nutrient-poor media,autolyzed hyphae,decreased conidium production,more sensitive to SDS,and more tolerance to NaCl and H2O2.These results suggest that G protein a subunit is involved in regulating vegetative growth,conidiation,osmotic pressure,oxidative stress response and pathogenicity of C.gloeosporioides.A kind of G protein ? subunit was identified from C.gloeosporioides and named CgGb.The CgGb was encodes a 287aa protein.Comparing to the wild type,the knockout mutant of CgGb had slow growth,more sensitive to NaCl and glycerol,and more tolerance to H2O2.It can be concluded that CgGb might be related to the regulation vegetative growth and osmotic pressure of C.gloeosporioides.A kind of G protein y subunit was identified from C.gloeosporioides and named CgGr.The CgGr was encodes 93aa protein.Comparing to the wild type,the knockout mutant had slow growth,decreased conidium production and extracellular laccase,the conidium of mutant did not germinate,and the mutant showed more sensitive to NaCl,more tolerance to H2O2 and weakened pathogenicity.It can be concluded that CgGr is involved in the regulation of vegetative growth,conidium germination,osmotic pressure,oxidative stress response and pathogenicity of C.gloeosporioides.The study will contribute to deeply understanding the molecular pathogenesis of C.gloeosporioides,providing scientific basis for the prevention and control of rubber anthracnose.