Background:In our previous study,a strain EBS03 with good biocontrol potential was screened out of 48 strains of cotton endophyte Bacillus subtilis by evaluating the controlling effect against cotton Verticillium wilt...Background:In our previous study,a strain EBS03 with good biocontrol potential was screened out of 48 strains of cotton endophyte Bacillus subtilis by evaluating the controlling effect against cotton Verticillium wilt.However,its mechanism for controlling Verticillium wilt remains unclear.The objective of this study was to further clarify its con-trolling effect and mechanism against cotton Verticillium wilt.Results:The results of confrontation culture test and double buckle culture test showed that the inhibitory effects of EBS03 volatile and nonvolatile metabolite on mycelium growth of Verticillium dahliae were 70.03%and 59.00%,respectively;the inhibitory effects of sporulation and microsclerotia germination were 47.16%and 70.06%,respec-tively.In the greenhouse test,the EBS03 fermentation broth root irrigation had the highest controlling effect at 87.11%on cotton Verticillium wilt,and significantly promoted the growth of cotton seedlings.In the field experi-ment,the controlling effect of EBS03 fermentation broth to cotton Verticillium wilt was 42.54%at 60 days after cotton sowing,and the boll number per plant and boll weight in EBS03 fermentation broth seed soaking,root irrigation,and spraying treatments significantly increased by 19.48%and 7.42%,30.90%and 2.62%,15.99%and 9.20%,respec-tively.Furthermore,EBS03 improved the resistance of cotton leaves against the infection of V.dahliae,and induced the outbreak of reactive oxygen species and accumulation of callose.In addition,the results of real time fluorescent quantitative polymerase chain reaction(RT-qPCR)detection showed that EBS03 significantly induced upregulation expression level of defense-related genes PAL,POD,PPO,and PR10 in cotton leaves,enhanced cotton plant resistance to V.dahliae,and inhibited colonization level of this fungal pathogen in cotton.Conclusion:Bacillus subtilis EBS03 has a good biological defense capability,which can inhibit the growth and coloni-zation level of V.dahliae,and activate the resistance of cotton to Verticillium wilt,thus increase cotton yield.展开更多
This study measured the antioxidant enzyme activities of Pyrola under cold and endophytic fungal infection conditions[i.e.,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)],and the contents of malondialdehyd...This study measured the antioxidant enzyme activities of Pyrola under cold and endophytic fungal infection conditions[i.e.,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)],and the contents of malondialdehyde(MDA),soluble sugar and soluble protein.In addition,the changes in the anatomical structure of Pyrola vegetable organ during cold stress upon inoculation with a synergistic endophytic fungus were also analyzed.It was found that the soluble sugar and soluble protein contents and POD,SOD and CAT activies of Pyrola all increased,when the plants were exposed to temperature of-5℃.In particular,the MDA contents and the POD activies significantly increased compared with those of the control.In addition,the soluble sugar and soluble protein contents increased during the treatment,which involved in both inoculation with an endophytic fungus and low temperature;however,with a reduction in the concentration of endophytic fungus,those two indicators decreased.The optimal concentration of endophytic fungus was 5×10^(7) cfu·mL^(-1).From the anatomical structure of Pyrola root,endophytic fungi were found to improve the health of.Pyrola in cold weather.These results showed that endophytic fungi played a vital role in the growth of Pyrola,which was an evergreen plant that could survive exposure to low temperature.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.32201752)the Central Public-interest Scientific Institution Basal Research Fund(No.1610162022018),Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.
文摘Background:In our previous study,a strain EBS03 with good biocontrol potential was screened out of 48 strains of cotton endophyte Bacillus subtilis by evaluating the controlling effect against cotton Verticillium wilt.However,its mechanism for controlling Verticillium wilt remains unclear.The objective of this study was to further clarify its con-trolling effect and mechanism against cotton Verticillium wilt.Results:The results of confrontation culture test and double buckle culture test showed that the inhibitory effects of EBS03 volatile and nonvolatile metabolite on mycelium growth of Verticillium dahliae were 70.03%and 59.00%,respectively;the inhibitory effects of sporulation and microsclerotia germination were 47.16%and 70.06%,respec-tively.In the greenhouse test,the EBS03 fermentation broth root irrigation had the highest controlling effect at 87.11%on cotton Verticillium wilt,and significantly promoted the growth of cotton seedlings.In the field experi-ment,the controlling effect of EBS03 fermentation broth to cotton Verticillium wilt was 42.54%at 60 days after cotton sowing,and the boll number per plant and boll weight in EBS03 fermentation broth seed soaking,root irrigation,and spraying treatments significantly increased by 19.48%and 7.42%,30.90%and 2.62%,15.99%and 9.20%,respec-tively.Furthermore,EBS03 improved the resistance of cotton leaves against the infection of V.dahliae,and induced the outbreak of reactive oxygen species and accumulation of callose.In addition,the results of real time fluorescent quantitative polymerase chain reaction(RT-qPCR)detection showed that EBS03 significantly induced upregulation expression level of defense-related genes PAL,POD,PPO,and PR10 in cotton leaves,enhanced cotton plant resistance to V.dahliae,and inhibited colonization level of this fungal pathogen in cotton.Conclusion:Bacillus subtilis EBS03 has a good biological defense capability,which can inhibit the growth and coloni-zation level of V.dahliae,and activate the resistance of cotton to Verticillium wilt,thus increase cotton yield.
基金Supported by Postdoctoral Scientific Research Foundation Project Settled in Heilongjiang Province(LBH-Q11153)。
文摘This study measured the antioxidant enzyme activities of Pyrola under cold and endophytic fungal infection conditions[i.e.,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)],and the contents of malondialdehyde(MDA),soluble sugar and soluble protein.In addition,the changes in the anatomical structure of Pyrola vegetable organ during cold stress upon inoculation with a synergistic endophytic fungus were also analyzed.It was found that the soluble sugar and soluble protein contents and POD,SOD and CAT activies of Pyrola all increased,when the plants were exposed to temperature of-5℃.In particular,the MDA contents and the POD activies significantly increased compared with those of the control.In addition,the soluble sugar and soluble protein contents increased during the treatment,which involved in both inoculation with an endophytic fungus and low temperature;however,with a reduction in the concentration of endophytic fungus,those two indicators decreased.The optimal concentration of endophytic fungus was 5×10^(7) cfu·mL^(-1).From the anatomical structure of Pyrola root,endophytic fungi were found to improve the health of.Pyrola in cold weather.These results showed that endophytic fungi played a vital role in the growth of Pyrola,which was an evergreen plant that could survive exposure to low temperature.
