Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests.The toxicity effects of four essential oils peppermint,thyme,ca...Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests.The toxicity effects of four essential oils peppermint,thyme,camphor and sage oils were tested against the fourth instar larvae of Agrotis ipsilon to select the most effective essential oil to be converted to the nano form.According to the results obtained,peppermint oil was the most toxic compound,which has been used in the present investigation compared with neem oil.The toxicity of bulk and nano-formulations of neem and pepper mint oils were tested against 2nd and 4th instar larvae of A.ipsilon under laboratory conditions of 25±2°C&65-70%R.H.relative humidity The results show that the LC50 value(the concentration used which kill 50%of the tested individuals)of loaded neem or pepper mint were lower(0.62 and 36.47 ppm)compared with neem or pepper mint oil nano-emulsion and bulk neem for the second larval instar.The different formulations of neem are more potent than in case of peppermint oil,as LC50 and LC90 values were significantly lower.The same trend was found concerning the 4th larval instar.Age of treated larvae had a detrimental effect on the response to the compounds tested.It was noticed that the younger larvae were much more sensitive to the prepared compounds compared to the older ones.The least LC50 value for loaded neem nano-emulsion was 6.68 ppm compared with the highest value for bulk neem oil(16.68 ppm).Also,LC90 values followed the same trend as in case ofLC50.Again,the toxicity of loaded peppermint oil had the most insecticidal activity as expressed by the lowest LC50 value(51.9 ppm)with more insecticidal effect than the bulk(125.43 ppm)or nano-emulsion(85.43 ppm).The present results indicated that these novel systems could be used in integrated pest management program for A.ipsilon control.展开更多
Sex determination has been studied in the model lepidopteran species Bombyx mori, but it remains poorly understood in lepidopteran pests. In the present study, we identified and characterized the Masculinizer (Masc) g...Sex determination has been studied in the model lepidopteran species Bombyx mori, but it remains poorly understood in lepidopteran pests. In the present study, we identified and characterized the Masculinizer (Masc) gene in a Noctuidae pest species, Agrotis ipsilon. Sequence analysis revealed that AiMasc encodes a protein of 658 amino acids that has two CCCH-type zinc finger domains and two conserved cysteine residues (Cys-277 and Cys-280). We assessed the masculinizing activity AiMasc in BmN cells and found that/z'Masc induced expression of the male-specific doublesex isoform. Disruption of Masc via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) in A. ipsilon caused abnormalities in abdominal segments and external genitalia, resulting in male-specific sterility. These results suggest that Masc participates in the process of sex determination in A. ipsilon. Successful identification of sex-determination gene in a pest species may enable the development of novel genetic approaches for pest control.展开更多
Tyrosine hydroxylase (TH)is involved in insect melanin and the catecholamine biosynthesis pathway.TH as an enzyme catalyzing the conversion of tyrosine to 3,4- dihydroxyphenylalanine is the first step reaction in the ...Tyrosine hydroxylase (TH)is involved in insect melanin and the catecholamine biosynthesis pathway.TH as an enzyme catalyzing the conversion of tyrosine to 3,4- dihydroxyphenylalanine is the first step reaction in the pathway.Although TH has been proven to affect the pigmentation of the epidermis and development in many insects,there is no report about physiological function of the THgene inAgrotis ipsilon.Here we cloned the TH gene from A.ipsilon.Semi-quantitative real-time polymerase chain reaction (PCR) analysis showed that AiTH was expressed at all development stages.Moreover,its high expression levels in the head and epidermis suggest that it is mainly related to pigment deposition and insect development.Then,we used the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9system to target the AiTH gene:deletion events were detected at the target sites.Compared with the control group,a few mutants with the phenomenon of narrowing in the egg shell and embryos can develop but cannot hatch;the other hatched embryos were seriously dehydrated after hatching and died within the first day.Quantitative real-time PCR analysis revealed that THwas down-regulated inAiTHmutants.Here,our work demonstrated thatAiTHplays an important role in growth and development of newly hatched larvae;meanwhile,it would be a promising target to explore a control strategy for A.ipsilon.展开更多
文摘Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests.The toxicity effects of four essential oils peppermint,thyme,camphor and sage oils were tested against the fourth instar larvae of Agrotis ipsilon to select the most effective essential oil to be converted to the nano form.According to the results obtained,peppermint oil was the most toxic compound,which has been used in the present investigation compared with neem oil.The toxicity of bulk and nano-formulations of neem and pepper mint oils were tested against 2nd and 4th instar larvae of A.ipsilon under laboratory conditions of 25±2°C&65-70%R.H.relative humidity The results show that the LC50 value(the concentration used which kill 50%of the tested individuals)of loaded neem or pepper mint were lower(0.62 and 36.47 ppm)compared with neem or pepper mint oil nano-emulsion and bulk neem for the second larval instar.The different formulations of neem are more potent than in case of peppermint oil,as LC50 and LC90 values were significantly lower.The same trend was found concerning the 4th larval instar.Age of treated larvae had a detrimental effect on the response to the compounds tested.It was noticed that the younger larvae were much more sensitive to the prepared compounds compared to the older ones.The least LC50 value for loaded neem nano-emulsion was 6.68 ppm compared with the highest value for bulk neem oil(16.68 ppm).Also,LC90 values followed the same trend as in case ofLC50.Again,the toxicity of loaded peppermint oil had the most insecticidal activity as expressed by the lowest LC50 value(51.9 ppm)with more insecticidal effect than the bulk(125.43 ppm)or nano-emulsion(85.43 ppm).The present results indicated that these novel systems could be used in integrated pest management program for A.ipsilon control.
基金the National Basic Research Program of China (2015CB755703)the National Science Foundation of China (31522053,31501648,3142010391 & and 91631103)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB11010600).
文摘Sex determination has been studied in the model lepidopteran species Bombyx mori, but it remains poorly understood in lepidopteran pests. In the present study, we identified and characterized the Masculinizer (Masc) gene in a Noctuidae pest species, Agrotis ipsilon. Sequence analysis revealed that AiMasc encodes a protein of 658 amino acids that has two CCCH-type zinc finger domains and two conserved cysteine residues (Cys-277 and Cys-280). We assessed the masculinizing activity AiMasc in BmN cells and found that/z'Masc induced expression of the male-specific doublesex isoform. Disruption of Masc via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) in A. ipsilon caused abnormalities in abdominal segments and external genitalia, resulting in male-specific sterility. These results suggest that Masc participates in the process of sex determination in A. ipsilon. Successful identification of sex-determination gene in a pest species may enable the development of novel genetic approaches for pest control.
基金the National Basic Research Program of China (2015CB755703,the National Natural Science Foundation of China ( No .31772517) the Science and Technology Comm ission of Shanghai Municipality (No. 18140902200).
文摘Tyrosine hydroxylase (TH)is involved in insect melanin and the catecholamine biosynthesis pathway.TH as an enzyme catalyzing the conversion of tyrosine to 3,4- dihydroxyphenylalanine is the first step reaction in the pathway.Although TH has been proven to affect the pigmentation of the epidermis and development in many insects,there is no report about physiological function of the THgene inAgrotis ipsilon.Here we cloned the TH gene from A.ipsilon.Semi-quantitative real-time polymerase chain reaction (PCR) analysis showed that AiTH was expressed at all development stages.Moreover,its high expression levels in the head and epidermis suggest that it is mainly related to pigment deposition and insect development.Then,we used the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9system to target the AiTH gene:deletion events were detected at the target sites.Compared with the control group,a few mutants with the phenomenon of narrowing in the egg shell and embryos can develop but cannot hatch;the other hatched embryos were seriously dehydrated after hatching and died within the first day.Quantitative real-time PCR analysis revealed that THwas down-regulated inAiTHmutants.Here,our work demonstrated thatAiTHplays an important role in growth and development of newly hatched larvae;meanwhile,it would be a promising target to explore a control strategy for A.ipsilon.
