The Asian citrus psyllid,Diaphorina citri is the principal vector of huanglongbing,which transmits Candidatus Liberibacter asiaticus.Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important ro...The Asian citrus psyllid,Diaphorina citri is the principal vector of huanglongbing,which transmits Candidatus Liberibacter asiaticus.Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important role in insect growth and development.The specific functions of this enzyme in D.citri have not been determined.In this study,three trehalase genes(DcTreJ-1,DcTrel-2,and DcTre2)were identified based on the D.citri genome database.Bioinformatic analysis showed that DcTrel-1 and DcTrel-2 are related to soluble trehalase,whereas DcTre2 is associated with membrane-bound trehalase.Spatiotemporal expression analysis indicated that DcTrel-1 and DcTrel-2 had the highest expression levels in the head and wing,respectively,and DcTre2 had high expression levels in the fat body.Furthermore,DcTrel-1 and DcTrel-2 expression levels were induced by 20-hydroxyecdysone and juvenile hormone III,but DcTre2 was unaffected.The expression levels of DcTrel-1,DcTrel-2,and DcTre2 were significantly up-regulated,which resulted in high mortality after treatment with validamycin.Trehalase activities and glucose contents were downregulated,but the trehalose content increased after treatment with validamycin.In addition,the expression levels of chitin metabolism-related genes significantly decreased at 24 and 48 h after treatment with validamycin.Furthermore,silencing of DcTrel-1,DcTrel-2,and DcTre2 reduced the expression levels of chitin metabolism-related genes and led to a malformed phenotype of D.citri.These results indicate that D.citri trehalase plays an essential role in regulating chitin metabolism and provides a new target for control of D.citri.展开更多
Severe epidemic of false smut, caused by Ustilaginoidea virens （Cooke） Takahashi （teleomorph Villosiclava virens） has been reported in different parts of Asia and America. Different fungicides or bio-control agent...Severe epidemic of false smut, caused by Ustilaginoidea virens （Cooke） Takahashi （teleomorph Villosiclava virens） has been reported in different parts of Asia and America. Different fungicides or bio-control agents against false smut were applied at different times before heading on a susceptible rice variety Pu-6. A control efficiency as high as 91.92% was resulted from spraying 2.5% Wenquning, a suspension of Bacillus subtilis in solution of validamycin with 4.5 L/hm2 at 6 d before heading. Among the 186 hybrid rice screened in 2010, low significant correlations between the dates of full heading, rates of infected plants and panicles as well as the number of infected florets were found, with the correlation coefficients ranging from 0.2331 to 0.5212. However, significant difference in susceptibility coefficients was also found between the varieties which had the same dates of full heading. In the plot experiments to compare the susceptibility in 2011, the average rates of infected panicles of Yixiangyou 2168, Chuanxiangyou 3, Dexiang 4103, Yixiangyou 2115, Nei5you 317, Yangxinyou 1 were significantly lower than those of the control varieties Gangyou 725 and Gangyou 188 at the disease nursery located at Qionglai, Sichuan Province, China. When Neixiangyou 8156 and Nei5you 317 were sprayed with 2.5% Wenquning at 4.5 L/hm2 for two times at 6 d before and 1 d after heading, respectively, the control efficiencies of Nei5you 317 and Neixiangyou 8156 were respectively 100% and 82.24% compared to that of Gangyou 725. Satisfactory control effects had also obtained by single spray of 2.5% Wenquning at 4.5 L/hm2 at 5-6 d before heading. Therefore, less susceptible hybrid rice in combination with spraying Wenquning at 5-6 d before heading was suggested for the disease control in Sichuan Province, China.展开更多
基金the National Natural Science Foundation of China(31960116)the Educational Commission of Jiangxi Province of China(GJJ180747)+1 种基金the National Key Research and Development Program of China(2018YFD0201504,the earmarked fund for Jiangxi Agriculture Research System(JXARS-07)Key Research and Development Plan of Jiangxi Province(20192BBF60057).
文摘The Asian citrus psyllid,Diaphorina citri is the principal vector of huanglongbing,which transmits Candidatus Liberibacter asiaticus.Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important role in insect growth and development.The specific functions of this enzyme in D.citri have not been determined.In this study,three trehalase genes(DcTreJ-1,DcTrel-2,and DcTre2)were identified based on the D.citri genome database.Bioinformatic analysis showed that DcTrel-1 and DcTrel-2 are related to soluble trehalase,whereas DcTre2 is associated with membrane-bound trehalase.Spatiotemporal expression analysis indicated that DcTrel-1 and DcTrel-2 had the highest expression levels in the head and wing,respectively,and DcTre2 had high expression levels in the fat body.Furthermore,DcTrel-1 and DcTrel-2 expression levels were induced by 20-hydroxyecdysone and juvenile hormone III,but DcTre2 was unaffected.The expression levels of DcTrel-1,DcTrel-2,and DcTre2 were significantly up-regulated,which resulted in high mortality after treatment with validamycin.Trehalase activities and glucose contents were downregulated,but the trehalose content increased after treatment with validamycin.In addition,the expression levels of chitin metabolism-related genes significantly decreased at 24 and 48 h after treatment with validamycin.Furthermore,silencing of DcTrel-1,DcTrel-2,and DcTre2 reduced the expression levels of chitin metabolism-related genes and led to a malformed phenotype of D.citri.These results indicate that D.citri trehalase plays an essential role in regulating chitin metabolism and provides a new target for control of D.citri.
基金supported by the Special Fund for Agroscientific Research in the Public Interest, China (Grant No. 200903039-5)the Sichuan Program for Major Crop, Poultry and Livestock Breeding, China (Grant No. 2012YZGG-25-3)
文摘Severe epidemic of false smut, caused by Ustilaginoidea virens （Cooke） Takahashi （teleomorph Villosiclava virens） has been reported in different parts of Asia and America. Different fungicides or bio-control agents against false smut were applied at different times before heading on a susceptible rice variety Pu-6. A control efficiency as high as 91.92% was resulted from spraying 2.5% Wenquning, a suspension of Bacillus subtilis in solution of validamycin with 4.5 L/hm2 at 6 d before heading. Among the 186 hybrid rice screened in 2010, low significant correlations between the dates of full heading, rates of infected plants and panicles as well as the number of infected florets were found, with the correlation coefficients ranging from 0.2331 to 0.5212. However, significant difference in susceptibility coefficients was also found between the varieties which had the same dates of full heading. In the plot experiments to compare the susceptibility in 2011, the average rates of infected panicles of Yixiangyou 2168, Chuanxiangyou 3, Dexiang 4103, Yixiangyou 2115, Nei5you 317, Yangxinyou 1 were significantly lower than those of the control varieties Gangyou 725 and Gangyou 188 at the disease nursery located at Qionglai, Sichuan Province, China. When Neixiangyou 8156 and Nei5you 317 were sprayed with 2.5% Wenquning at 4.5 L/hm2 for two times at 6 d before and 1 d after heading, respectively, the control efficiencies of Nei5you 317 and Neixiangyou 8156 were respectively 100% and 82.24% compared to that of Gangyou 725. Satisfactory control effects had also obtained by single spray of 2.5% Wenquning at 4.5 L/hm2 at 5-6 d before heading. Therefore, less susceptible hybrid rice in combination with spraying Wenquning at 5-6 d before heading was suggested for the disease control in Sichuan Province, China.
