The joint action between chlorsulfuron and haloxyfop R was evaluated by bioassay with wheat and corn,respectivly.The dose response curve derived from wheat bioassay showed that the inhibition of haloxyfop R to whea...The joint action between chlorsulfuron and haloxyfop R was evaluated by bioassay with wheat and corn,respectivly.The dose response curve derived from wheat bioassay showed that the inhibition of haloxyfop R to wheat root growth wasn't affected by the increasing rate of chlorsulfuron.It indicated that chlorsulfuron had no antagonism to haloxyfop R.Meanwhile,the variation analysis of corn bioassay indicated that these two herbicides had joint action on inhibition to corn primary root growth.The joint action was evaluated as additive action by using Isobole Method.So chlorsulfuron and haloxyfop R could be used as tank mixture.展开更多
Background: Earlier we have reported that the exclusion of solar UV-B increased the growth and yield of cotton plants as compared with ambient UV-B. The UV-B radiation effects on the saponins and the impact of ambient...Background: Earlier we have reported that the exclusion of solar UV-B increased the growth and yield of cotton plants as compared with ambient UV-B. The UV-B radiation effects on the saponins and the impact of ambient and reduced UV-B on the accumulation of saponins has not been investigated yet. Thus a field experiment was conducted to study the influence of solar UV-B on the growth response and saponin synthesis in cotton(Gossypium hirsutum) var. Vikram plants by the exclusion of UV-B. The cotton plants were grown in specially designed iron chambers, wrapped with filters that excluded UV-B(<315 nm), or transmitted ambient UV-B.Results: Exclusion of ambient UV-B enhanced the growth of cotton plants in terms of plant height and leaf area.Greater plant height in UV-B excluded plants was due to elongated internode and more number of nodes.Enhancement in growth was accompanied by a decrease in the accumulation of saponins, which was quantified by the spectrophotometric, TLC and HPLC methods. Solvent extraction of saponins from the internodes and leaves were used for the bioassay of Amaranthus hypocotyl growth and expansion of cucumber cotyledons. Extracts obtained from the UV-B excluded plants(leaves and internodes) promoted the growth to a larger extent as compared with the extracts obtained from ambient grown plants.Conclusions: The result indicates that solar UV-B may possibly suppress the plant growth by regulating the synthesis of natural growth inhibitor’s like saponin.展开更多
Vegetative Insecticidal Proteins(VIPs), a large family of insecticidal proteins, are produced from Bacillus thuringiensis(Bt) during the vegetative growth stage. VIPs represent the second generation of bio-insecticide...Vegetative Insecticidal Proteins(VIPs), a large family of insecticidal proteins, are produced from Bacillus thuringiensis(Bt) during the vegetative growth stage. VIPs represent the second generation of bio-insecticides that confer a wider insecticidal spectrum and have stronger activity. This work compared the geographical distribution of Bt strains and their vip3 genes in different climatic zones in China, the tropical(Hainan Province), subtropical(Guangxi Province) and temperate zones(Heilongjiang Province). A total of 156 Bt strains were isolated from 841 soil samples in Hainan Province tropical region, 356 Bt strains from 1 420 soil samples in Guangxi Province and 167 Bt strains from 1 010 soil samples in different geographical regions in Heilongjiang Province. Twenty-two out of 156 strains from tropical Hainan Province and two out of 356 from subtropical Guangxi Province were found to express vip3 genes, while vip3 genes were not expressed from temperate zone in Heilongjiang Province. Restriction Fragment Length Polymorphism(RFLP) was used to identify different types of vip3 genes that were within the same family and three fulllength vip3 genes were isolated. The genes cloned from Bacillus thuringiensis strain SL3 expressed in the transformed E. coli BL21 strain. Through SDS-PAGE, 88.6 ku insecticidal protein was expressed. The bioassays used two-instar larva of Lepidoptera insects(Spodoptera exigua and Agrotis ipsilon) were performed. The results of the bioassays showed that the protein strongly inhibited the body weight increasement on Spodoptera exigua and Agrotis ipsilon in a standard bioassay. Taken together, the results indicated that the distribution of Bt strains and vip3 genes had regional preference. Tropical and subtropical regions were the rich resources of Bt strains and vip3 genes compared with temperate region. These results would undoubtedly facilitate the studies of insecticidal proteins and expand the list of the pest-killing candidates to make fully use of the extremely rich microbial resources. The new vip3 genes isolated in the current study might also help resolve the emerging insecticidal resistance problems.展开更多
Background Chitinase is an enzyme that hydrolyzes chitin,a major component of the exoskeleton of insects,including plant pests like whiteflies.The present study aimed to investigate the expression of chemically synthe...Background Chitinase is an enzyme that hydrolyzes chitin,a major component of the exoskeleton of insects,including plant pests like whiteflies.The present study aimed to investigate the expression of chemically synthesized barley ch1 and chi2 genes in cotton(Gossypium hirsutum)through Agrobacterium-mediated transformation.Fifty-five putative transgenic cotton plants were obtained,out of which fifteen plants successfully survived and were shifted to the field.Using gene-specific primers,amplification of 447 bp and 401 bp fragments confirmed the presence of the ch1 and chi2 genes in five transgenic cotton plants of the T0 generation.These five plants were further evalu-ated for their mRNA expression levels.The T0 transgenic cotton plants with the highest mRNA expression level and better yield performance in field,were selected to raise their subsequent progenies.Results The T1 cotton plants showed the highest mRNA expression levels of 3.5-fold in P10(2)for the ch1 gene and 3.7-fold in P2(1)for the chi2 gene.Fluorescent in situ hybridization(FISH)confirmed a single copy number of ch1 and chi2(hemizygous)on chromosome no.6.Furthermore,the efficacy of transgenes on whitefly was evaluated through an insect bioassay,where after 96 h of infestation,mortality rates of whitefly were calculated to be 78%–80%in transgenic cotton plants.The number of eggs on transgenic cotton plants were calculated to be 0.1%–0.12 per plant compared with the non-transgenic plants where egg number was calculated to be 0.90–1.00 per plant.Conclusion Based on these findings,it can be concluded that the chemically synthesized barley chitinase genes(ch1 and chi2)have the potential to be effective against insects with chitin exoskeletons,including whiteflies.The transgenic cotton plants expressing these genes showed increased resistance to whiteflies,resulting in reduced egg numbers and higher mortality rates.展开更多
Bacillus thuringiensis （Bt） is widely used in insecticides. Bt is a gram positive sporulation bacterium belonging to Bacillaceae family. It produces different insecticidal proteins like Cry toxin, Vip toxin, β-exot...Bacillus thuringiensis （Bt） is widely used in insecticides. Bt is a gram positive sporulation bacterium belonging to Bacillaceae family. It produces different insecticidal proteins like Cry toxin, Vip toxin, β-exotoxin and chitinase, etc. Bt insecticidal crystal proteins （ICPs） are not homologous to other known Vip protein and then act against lepidopteran, dipteran, coleopteran and nematodeslarvae via a unique process. In this experiment, modern high-throughput sequencing technique and sequencing were used and the whole genome sequence of BtLTS290 was obtained. The results compared to the database of GenBank showed that there was a cry57 gene in the genome sequence of BtLTS290. A novel cry57 gene was cloned and named cry57Ab1 （accession number is KF638650） by International Nomenclature Committee of Bt Endotoxin. cry57Ab1 gene could be expressed with the molecular weight of 90 ku. Cry57Ab1 protein had no obvious activity against Spodoptera exigua and Helicoverpa armigera. And Cry57Ab1 protein had a slight insecticidal activity against Ostrinia furnacalis and Plutella xylostella. Furthermore, the domain Ⅱof Cry57Ab1 and Cry1Bb were exchanged by overlapping extension PCR. SDS-PAGE showed that the molecular weight of Cry57Ab/1Bb/57Ab was about 90 ku. The insecticidal activity of Cry57Ab1 protein and Cry57Ab/1Bb/57Ab recombinant protein were determined. The results showed that the insecticidal activity of the recombinant protein to Spodoptera exigua and Helicoverpa armigera was very low, and the corrected mortality was less than 10%. The insecticidal activities against Ostrinia furnacalis and Plutella xylostella were reduced. The corrected mortality of Ostrinia furnacalis was 4.4%, and the corrected mortality rate for Plutella xylostella was 6.7%. Domain Ⅱof cry toxin played a key role on affecting host specifcity.展开更多
文摘The joint action between chlorsulfuron and haloxyfop R was evaluated by bioassay with wheat and corn,respectivly.The dose response curve derived from wheat bioassay showed that the inhibition of haloxyfop R to wheat root growth wasn't affected by the increasing rate of chlorsulfuron.It indicated that chlorsulfuron had no antagonism to haloxyfop R.Meanwhile,the variation analysis of corn bioassay indicated that these two herbicides had joint action on inhibition to corn primary root growth.The joint action was evaluated as additive action by using Isobole Method.So chlorsulfuron and haloxyfop R could be used as tank mixture.
基金Financial support by UGC Research Fellowship(F.4-1/2006(BSR)to Dehariya P.)Department of Science Technology Women Scientists-A Scheme(SR/WOS-A/LS-674/2013-2016) to Kataria S.
文摘Background: Earlier we have reported that the exclusion of solar UV-B increased the growth and yield of cotton plants as compared with ambient UV-B. The UV-B radiation effects on the saponins and the impact of ambient and reduced UV-B on the accumulation of saponins has not been investigated yet. Thus a field experiment was conducted to study the influence of solar UV-B on the growth response and saponin synthesis in cotton(Gossypium hirsutum) var. Vikram plants by the exclusion of UV-B. The cotton plants were grown in specially designed iron chambers, wrapped with filters that excluded UV-B(<315 nm), or transmitted ambient UV-B.Results: Exclusion of ambient UV-B enhanced the growth of cotton plants in terms of plant height and leaf area.Greater plant height in UV-B excluded plants was due to elongated internode and more number of nodes.Enhancement in growth was accompanied by a decrease in the accumulation of saponins, which was quantified by the spectrophotometric, TLC and HPLC methods. Solvent extraction of saponins from the internodes and leaves were used for the bioassay of Amaranthus hypocotyl growth and expansion of cucumber cotyledons. Extracts obtained from the UV-B excluded plants(leaves and internodes) promoted the growth to a larger extent as compared with the extracts obtained from ambient grown plants.Conclusions: The result indicates that solar UV-B may possibly suppress the plant growth by regulating the synthesis of natural growth inhibitor’s like saponin.
基金Supported by National Key R&D Projects(2017YFD0201200)Heilongjiang Provincial National Science Foundation(C2016025)
文摘Vegetative Insecticidal Proteins(VIPs), a large family of insecticidal proteins, are produced from Bacillus thuringiensis(Bt) during the vegetative growth stage. VIPs represent the second generation of bio-insecticides that confer a wider insecticidal spectrum and have stronger activity. This work compared the geographical distribution of Bt strains and their vip3 genes in different climatic zones in China, the tropical(Hainan Province), subtropical(Guangxi Province) and temperate zones(Heilongjiang Province). A total of 156 Bt strains were isolated from 841 soil samples in Hainan Province tropical region, 356 Bt strains from 1 420 soil samples in Guangxi Province and 167 Bt strains from 1 010 soil samples in different geographical regions in Heilongjiang Province. Twenty-two out of 156 strains from tropical Hainan Province and two out of 356 from subtropical Guangxi Province were found to express vip3 genes, while vip3 genes were not expressed from temperate zone in Heilongjiang Province. Restriction Fragment Length Polymorphism(RFLP) was used to identify different types of vip3 genes that were within the same family and three fulllength vip3 genes were isolated. The genes cloned from Bacillus thuringiensis strain SL3 expressed in the transformed E. coli BL21 strain. Through SDS-PAGE, 88.6 ku insecticidal protein was expressed. The bioassays used two-instar larva of Lepidoptera insects(Spodoptera exigua and Agrotis ipsilon) were performed. The results of the bioassays showed that the protein strongly inhibited the body weight increasement on Spodoptera exigua and Agrotis ipsilon in a standard bioassay. Taken together, the results indicated that the distribution of Bt strains and vip3 genes had regional preference. Tropical and subtropical regions were the rich resources of Bt strains and vip3 genes compared with temperate region. These results would undoubtedly facilitate the studies of insecticidal proteins and expand the list of the pest-killing candidates to make fully use of the extremely rich microbial resources. The new vip3 genes isolated in the current study might also help resolve the emerging insecticidal resistance problems.
文摘Background Chitinase is an enzyme that hydrolyzes chitin,a major component of the exoskeleton of insects,including plant pests like whiteflies.The present study aimed to investigate the expression of chemically synthesized barley ch1 and chi2 genes in cotton(Gossypium hirsutum)through Agrobacterium-mediated transformation.Fifty-five putative transgenic cotton plants were obtained,out of which fifteen plants successfully survived and were shifted to the field.Using gene-specific primers,amplification of 447 bp and 401 bp fragments confirmed the presence of the ch1 and chi2 genes in five transgenic cotton plants of the T0 generation.These five plants were further evalu-ated for their mRNA expression levels.The T0 transgenic cotton plants with the highest mRNA expression level and better yield performance in field,were selected to raise their subsequent progenies.Results The T1 cotton plants showed the highest mRNA expression levels of 3.5-fold in P10(2)for the ch1 gene and 3.7-fold in P2(1)for the chi2 gene.Fluorescent in situ hybridization(FISH)confirmed a single copy number of ch1 and chi2(hemizygous)on chromosome no.6.Furthermore,the efficacy of transgenes on whitefly was evaluated through an insect bioassay,where after 96 h of infestation,mortality rates of whitefly were calculated to be 78%–80%in transgenic cotton plants.The number of eggs on transgenic cotton plants were calculated to be 0.1%–0.12 per plant compared with the non-transgenic plants where egg number was calculated to be 0.90–1.00 per plant.Conclusion Based on these findings,it can be concluded that the chemically synthesized barley chitinase genes(ch1 and chi2)have the potential to be effective against insects with chitin exoskeletons,including whiteflies.The transgenic cotton plants expressing these genes showed increased resistance to whiteflies,resulting in reduced egg numbers and higher mortality rates.
基金Supported by the National Key R&D Projects(2017YFD0201200)Heilongjiang Provincial National Science Foundation(C2016025)
文摘Bacillus thuringiensis （Bt） is widely used in insecticides. Bt is a gram positive sporulation bacterium belonging to Bacillaceae family. It produces different insecticidal proteins like Cry toxin, Vip toxin, β-exotoxin and chitinase, etc. Bt insecticidal crystal proteins （ICPs） are not homologous to other known Vip protein and then act against lepidopteran, dipteran, coleopteran and nematodeslarvae via a unique process. In this experiment, modern high-throughput sequencing technique and sequencing were used and the whole genome sequence of BtLTS290 was obtained. The results compared to the database of GenBank showed that there was a cry57 gene in the genome sequence of BtLTS290. A novel cry57 gene was cloned and named cry57Ab1 （accession number is KF638650） by International Nomenclature Committee of Bt Endotoxin. cry57Ab1 gene could be expressed with the molecular weight of 90 ku. Cry57Ab1 protein had no obvious activity against Spodoptera exigua and Helicoverpa armigera. And Cry57Ab1 protein had a slight insecticidal activity against Ostrinia furnacalis and Plutella xylostella. Furthermore, the domain Ⅱof Cry57Ab1 and Cry1Bb were exchanged by overlapping extension PCR. SDS-PAGE showed that the molecular weight of Cry57Ab/1Bb/57Ab was about 90 ku. The insecticidal activity of Cry57Ab1 protein and Cry57Ab/1Bb/57Ab recombinant protein were determined. The results showed that the insecticidal activity of the recombinant protein to Spodoptera exigua and Helicoverpa armigera was very low, and the corrected mortality was less than 10%. The insecticidal activities against Ostrinia furnacalis and Plutella xylostella were reduced. The corrected mortality of Ostrinia furnacalis was 4.4%, and the corrected mortality rate for Plutella xylostella was 6.7%. Domain Ⅱof cry toxin played a key role on affecting host specifcity.
