Global atmospheric CO2 concentrations have risen rapidly since the Industrial Revolution and are considered as a primary factor in climate change. The effects of elevated CO2 on herbivore insects were found to be prim...Global atmospheric CO2 concentrations have risen rapidly since the Industrial Revolution and are considered as a primary factor in climate change. The effects of elevated CO2 on herbivore insects were found to be primarily through the CO2-induced changes occurring in their host plants, which then possibly affect the intensity and frequency of pest outbreaks on crops. This paper reviews several ongoing research models using primary pests of crops （cotton bollworm, whitefly, aphids） and their natural enemies （ladybeetles, parasitoids） in China to examine insect responses to elevated CO2. It is generally indicated that elevated CO2 prolonged the development of cotton bollworm, Helicoverpa armigera, a chewing insect, by decreasing the foliar nitrogen of host plants. In contrast, the phloemsucking aphid and whitefly insects had species-specific responses to elevated CO2 because of complex interactions that occur in the phloem sieve elements of plants. Some aphid species, such as cotton aphid, Aphis gossypii and wheat aphid, Sitobion avenae, were considered to represent the only feeding guild to respond positively to elevated CO2 conditions. Although whitefly, Bemisia tabaci, a major vector of Tomato yellow leaf curl virus, had neutral response to elevated CO2, the plants became less vulnerable to the virus infection under elevated CO2. The predator and parasitoid response to elevated CO2 were frequently idiosyncratic. These documents from Chinese scientists suggested that elevated CO2 initially affects the crop plant and then cascades to a higher trophic level through the food chain to encompass herbivores （pests）, their natural enemies, pathogens and underground nematodes, which disrupt the natural balance observed previously in agricultural ecosystems.展开更多
Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the bro...Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the brown planthopper, and were given the designations of Nlcryl and Nlcry2, with the accession numbers KM108578 and KM108579 in GenBank. The complementary DNA sequences ofNlcryl andNlcry2 are 1935 bp and 2463 bp in length, and they contain an open reading frame of 1629 bp and 1872 bp, encoding amino acids of 542 and 623, with a predicted molecular weight of 62.53 kDa and 70.60 kDa, respectively. Well-conserved motifs such as DNA-photolyase and FAD-binding-7 domains were observed in Nlcry1 and Nlcry2. Phylogenetic analysis demonstrated the proteins of Nlcry1 and Nlcry2 to be clustered into the insect＇s cryptochrome 1 and cryptochrome 2, respectively. Quantitative polymerase chain reaction showed that the daily oscillations of messenger RNA （mRNA） expression in the head of the brown planthopper were mild for Nlcryl, and modest for Nlcry2. Throughout all developmental stages, Nlcryl and Nlcry2 exhibited extreme fluctuations and distinctive expression profiles. Cryptochrome mRNA expression peaked immediately after adult emergence and then decreased subsequently. The tissue expression profiles of newly emerged brown planthopper adults showed higher expression levels of CRYs in the head than in the thorax or abdomen, as well as significantly higher levels of CRYs in the heads of the macropterous strain than in the heads of the brachypterous strain. Taken together, the results of our study suggest that the two cryptochrome genes characterized in the brown planthopper might be associated with developmental physiology and migration.展开更多
The widespread planting of insect-resistant crops has caused a dramatic shift in agricultural landscapes, thus raising concerns about the potential impacts on both target and non-target pests. In this study, we examin...The widespread planting of insect-resistant crops has caused a dramatic shift in agricultural landscapes, thus raising concerns about the potential impacts on both target and non-target pests. In this study, we examined the potential effects of intra-specific seed mixture sowing with transgenic Bt rice (Bt) and its parental non-transgenic line (Nt)(100% Bt rice [Bt100], 5% Nt+95% Bt [Nt05Bt95], 10% Nt+90% Bt [Nt|0Bt90], 20% Nt+80% Bt [Nt2oBtso], 40% Nt+60% Bt [Nt4oBt6O] and 100% Nt rice [Ntjoo]) on target and non-target pests in a 2-year field trial in southern China. The occurrence of target pests, Sesamia inf evens. Chilo suppressalis and Cnaphalocrocis medinalis, decreased with the increased ratio of Bt rice, and the mixture ratios with more than 90% Bt rice (Btjoo and Nt()5Bt95) significantly increased the pest suppression efficiency, with the lowest occurrences of non-target planthoppers, Nilaparvata lugens and Sogatella jurcijera in Ntioo and NtosBtgs. Furthermore, there were no significant differences in 1000?grain dry weight and grain dry weight per 100 plants between Btjoo and NtosBtgs,Seed mixture sowing of Bt rice with <10%(especially 5%) of its parent line was sufficient to overcome potential compliance issues that exist with the use of block or structured refuge to provide most effective control of both target and non-target pests without compromising the grain yield. It is also expected that the strategy of seed mixture sowing with transgenic Bt rice and the nontransgenic parental line would provide rice yield stability while decreasing the insecticide use frequency in rice production.展开更多
Sometimes, extreme weather is vital for the population survival of migratory insects by causing sudden population collapse or outbreak. Several studies have shown that rice planthopper migration was significantly infl...Sometimes, extreme weather is vital for the population survival of migratory insects by causing sudden population collapse or outbreak. Several studies have shown that rice planthopper migration was significantly influenced by typhoons in eastern Asia. Most typhoons occur in the summer, especially in August. In August, brown planthopper Nilaparvata lugens （Stal） migrates northward or southward depending on wind direc- tion, and thus typhoons can potentially influence its migration process and population distribution. However, this has not yet been studied. This paper reported a case study on the effects of Typhoon Soudelor on the summer migration of N. lugens in eastern China in 2015. The migration pathways of N. lugens were reconstructed for the period under the influence of a typhoon by calculating the trajectories and migration events in eight counties of the Yangtze River Valley region with ancillary information. Trajectory mod- elling showed that most migrants took short distance migrations （less than 200 km） under the influence of the Typhoon Soudelor. Numerous N. lugens migrants were concentrated and deposited at the rear of the typhoon during the last 5 days of Typhoon Soudelor on August 9-13 due to horizontal convergence, and this led to an outbreak population. These results indicated that the N. lugens population was redistributed by the typhoon in the sum- mer and that the population dynamics at the rear of a typhoon should be kept under close surveillance. This study provided insight into migratory organisms adapting to atmospheric features.展开更多
A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protei...A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton （46% in 2008; 56% in 2009） and alfalfa （46% in 2008; 71% in 2009） contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa （5% in 2008 and 6% in 2009） and from alfalfa to cotton （9% in 2008 and 14% in 2009）. The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles （bidirectional and unidirectional combined） was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa of- fered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.展开更多
A field study was carried out to quantify plant growth and the foliar chemistry of transgenic Bacillus thuringiensis （Bt） cotton （cv. GK-12） exposed to ambient CO2 and elevated （double-ambient） CO2 for different...A field study was carried out to quantify plant growth and the foliar chemistry of transgenic Bacillus thuringiensis （Bt） cotton （cv. GK-12） exposed to ambient CO2 and elevated （double-ambient） CO2 for different lengths of time （1, 2 and 3 months） in 2004 and 2005. The results indicated that CO2 levels significantly affected plant height, leaf area per plant and leaf chemistry of transgenic Bt cotton. Significantly, higher plant height and leaf area per plant were observed after cotton plants that were grown in elevated CO2 were compared with plants grown in ambient CO2 for 1, 2 and 3 months in the investigation. Simultaneously, significant interaction between CO2 level x investigating year was observed in leaf area per plant. Moreover, foliar total amino acids were increased by 14%, 13%, 11% and 12%, 14%, 10% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 in 2004 and 2005, respectively. Condensed tannin occurrence increased by 17%, 11%, 9% in 2004 and 12%, 11%, 9% in 2005 in transgenic Bt cotton after being exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 for the same time. However, Bt toxin decreased by 3.0%, 2.9%, 3.1% and 2.4%, 2.5%, 2.9% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3months compared with ambient CO2 for same time in 2004 and 2005, respectively. Furthermore, there was prominent interaction on the foliar total amino acids between the CO2 level and the time of cotton plant being exposed to elevated CO2. It is presumed that elevated CO2 can alter the plant growth and hence ultimately the phenotype allocation to foliar chemistical components of transgenic Bt cotton, which may in turn, affect the plant-herbivore interactions.展开更多
Effects of elevated CO2 （twice ambient vs. ambient） and Bt CrylAc transgene （Bt cotton cv. 33B vs. its nontransgenic parental line cv. DP5415） on the interspecific competition between two ecologically similar spec...Effects of elevated CO2 （twice ambient vs. ambient） and Bt CrylAc transgene （Bt cotton cv. 33B vs. its nontransgenic parental line cv. DP5415） on the interspecific competition between two ecologically similar species of cotton aphid Aphis gossypii and whitefly biotype-Q Bemisia tabaci were studied in open-top chambers. The results indicated that elevated CO2 and Bt cotton both affected the population abundances of A. gossypii and biotype-Q B. tabaci when introduced solely （i.e., without interspecific competition） or two species coexisted （i.e., with interspecific competition）. Compared with ambient CO2, elevated COe increased the population abundances ofA. gossypii and biotype-Q B. tabaci as fed on Bt and nontransgenic cotton on 45 （i.e., seedling stage） and 60 （i.e., flowering stage） days after planting （DAP）, but only significantly enhanced aphid abundance without interspecific competition on the 45-DAP nontransgenic cotton and 60-DAP Bt cotton, and significantly increased whitefly abundance with interspecific competition on the 45-DAP Bt cotton and 60-DAP nontransgenic cotton. In addition, compared with nontransgenic cotton at elevated CO2, Bt cotton significantly reduced biotype-Q B. tabaci abundances without and with interspecific competition during seedling and flowering stage, while only significantly decreasing A. gossypii abundances without interspecific competition during the seedling stage. When the two insect species coexisted, the proportions ofbiotype-Q B. tabaci were significantly higher than those ofA. gossypii on Bt and nontransgenic cotton at the same CO2 levels, and elevated CO2 only significantly increased the percentages of biotype-Q B. tabaci and significantly reduced the proportions of A. gossypii on seedling and flowering nontransgenic cotton. Therefore, the effects of elevated CO2 were favorable for biotype-Q B. tabaci to out-compete A. gossypii under the predicted global climate change.展开更多
Plant allocation to defensive compounds by elevated CO2-grown nontransgenic and transgenic Bt cotton in response to infestation by cotton aphid, Aphis gossypii （Glover） in open-top chambers under elevated CO2 were s...Plant allocation to defensive compounds by elevated CO2-grown nontransgenic and transgenic Bt cotton in response to infestation by cotton aphid, Aphis gossypii （Glover） in open-top chambers under elevated CO2 were studied. The results showed that significantly lower foliar nitrogen concentration and Bt toxin protein occurred in transgenic Bt cotton with and without cotton aphid infestation under elevated CO2. However, significantly higher carbon/nitrogen ratio, condensed tannin and gossypol were observed in transgenic Bt cotton ＂GK-12＂ and non-transgenic Bt cotton ＇Simian-3＇ under elevated CO2. The CO2 level and cotton variety significantly influenced the foliar nitrogen, condensed tannin and gossypol concentrations in the plant leaves after feeding by A. gossypii. The interaction between CO2 level x infestation time （24 h, 48 h and 72 h） showed a significant increase in cotton condensed tannin concentrations, while the interaction between CO2 level x cotton variety significantly decreased the true choline esterase （TChE） concentration in the body ofA. gossypi. This study exemplified the complexities of predicting how transgenic and non-transgenic plants will allocate defensive compounds in response to herbivorous insects under differing climatic conditions. Plant defensive compound allocation patterns and aphid enzyme changes observed in this study appear to be broadly applicable across a range of plant and herbivorous insect interactions as CO2 atmosphere rises.展开更多
The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA...The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA1) may be involved. However, little is known about the association among the molecules. Here we investigated the molecular characterization and the mRNA expression of IscA1 in different developmental stages, tissues and magnetic fields in the migratory brown planthopper (BPH), Nilaparvata lugens. NlIscA1 contains an open reading frame of 390 bp, encoding amino acids of 129, with the predicted molecular weight of 14.0 kDa and the isoelectric point of 9.10. Well-conserved Fe-S cluster binding sites were observed in the predicted protein. Phylogenetic analysis demonstrated NlIscA1 to be clustered into the insect's IscA1. NlIscA1 showed up-regulated mRNA expression during the period of migration. The mRNA expression of NlIscA1 could be detected in all the three tissues of head, thorax and abdomen, with the highest expression level in the abdomen. For the macropterous migratory Nilaparvata lugens, mRNA expression of NlIscA1 and N. lugens cryptochromel (Nlcry1) were up-regulated under the magnetic fields of 5 Gauss and 10 Gauss in strength (vs. local geomagnetic field), while N. lugens cryptochrome 2 (Nlcry2) remained stable. For the brachyterous non-migratory Nilaparvata lugens, no significant changes were found in mRNA expression of NlIscA1, Nlcry1 and Nlcry2 among different magnetic fields. These findings preliminarily reveal that the expression of NlIscA1 and Nlcry1 exhibited coordinated responses to the magnetic field. It suggests some potential associations among the putative magneto-sensitive molecules of cryptochrome and iron-sulfur cluster assembly.展开更多
The rising trend in the cultivation of Bacillus thuringiensis (Bt) transgenic crops may cause a destabilization of agroecosystems, thus increasing concerns about the sustainability of Bt crops as a valid pest manageme...The rising trend in the cultivation of Bacillus thuringiensis (Bt) transgenic crops may cause a destabilization of agroecosystems, thus increasing concerns about the sustainability of Bt crops as a valid pest management method. Azotobacter can be used as a biological regulator to increase environmental suitability and improve the soil nitrogen utilization efficiency of crops, especially Bt cotton. A laboratory test investigated effects on the development and food utilization of Helicoverpa armigera fed with different Cry1Ab/Cry1Ac proteins and nitrogen metabolism-related compounds from cotton (transgenic variety SCRC 37 vs non-Bt cotton cv. Yu 2067) inoculated with Azospirillum brasilense (Ab) and Azotobacter chroococcum (Ac). The findings indicate that inoculation with Azotobacter significantly decreased the partial development and food utilization indexes (pupal weight;pupation rate;adult longevity;fecundity;relative growth rate, RGR;efficiency of conversion of digested food, ECD;and efficiency of conversion of ingested food, ECI) of H. armigera fed on Bt cotton, but contrasting trends were found among these indexes in H. armigera fed on non-Bt cotton inoculated with Azotobacter, as a result of differences in Bt toxin production. Overall, the results showed that inoculation with Azotobacter had negative effects on the development and food utilization of H. armigera fed on Bt cotton, leading to enhanced target insect resistance. Presumably, Azotobacter inoculation can be used to stimulate plant soil nitrogen uptake to increase nitrogen metabolism-related compounds and promote plant growth for Bt and non-Bt cotton, simultaneously raising Bt protein expression and enhancing resistance efficacy against cotton bollworm in Bt cotton.展开更多
The geomagnetic field(GMF)is well documented for its essential role as a cue used in animal orientation or navigation.Recent evidence indicates that the absence of GMF(mimicked by the near-zero magnetic field,NZMF)can...The geomagnetic field(GMF)is well documented for its essential role as a cue used in animal orientation or navigation.Recent evidence indicates that the absence of GMF(mimicked by the near-zero magnetic field,NZMF)can trigger stress-like responses such as reduced body weight,as we have previously shown in the brown planthopper,Nilaparvata lugens.In this study,we found that consistent with the significantly decreased body weight of newly emerged female(—14.67%)and male(—13.17%)adult N.lugens,the duration of the phloem ingestion feeding waveform was significantly reduced by 32.02%in 5th instar nymphs reared under the NZMF versus GMF.Interestingly,5th instar nymphs that exhibited reduced feeding had significantly higher glucose levels(+16.98%and+20.05%;24 h and 48 h after molting),which are associated with food aversion,and expression patterns of their appetite-related neuropeptide genes(neuropeptide F,dow regulated overall;short neuropeptide F,dowregulated overall;adipokinetic hormone up-regulated overall;and adipokinetic hormone receptor,down-regulated overall)were also altered under the absence of GMF in a manner consistent with diminishing appetite.Moreover,the expressions of the potential magnetosensor croptochromes(Crys)were found significantly altered under the absence of GMF,indicating the likely upstream signaling of the Cry-mediated magnetoreception mechanisms.These findings support the hypothesis that strong changes in GMF intensity can reduce adult body weight through affecting insect feeding behavior and underlying regulatory processes including appetite regulation.Our results highlight that GMF could be necessary for the maintenanee of energy homeostasis in insects.展开更多
Effects of elevated CO2 on the foraging behavior of cotton bollworm Helicoverpa arrnigera Hübner reared on milky grains of spring wheat grown in ambient, 550μL/L and 750μL/L CO2 concentration atmospheres in ope...Effects of elevated CO2 on the foraging behavior of cotton bollworm Helicoverpa arrnigera Hübner reared on milky grains of spring wheat grown in ambient, 550μL/L and 750μL/L CO2 concentration atmospheres in open-top chambers （OTC） were studied. The results indicated that： （i） elevated CO2 significantly affected both the type and amount of food eaten by H.arrnigera reared on milky grains of ambient CO2-grown wheat were significant higher than those for bollworm larvae reared on wheat grains grown in 550 and 750μL/L CO2 atmospheres; （ii） when bollworm larvae were reared on mixed milky grains from different CO2-grown wheat （food-choice condition）, larval duration increased significantly-pupal weight, adult longevity, and fecundity decreased significantly, comparing with those reared on milky grains of ambient CO2-grown wheat, 550μL/L CO2-grown wheat and 750μL/L CO2-grown wheat respectively; （iii） significant decreases in the contents of fructose and gross protein （GP） and significant increases in the contents of glucose, amylose, total saccharides （TSC）, TSC： GP ratio, free amino acids and soluble protein in the wheat grains with CO2 rising; （iv） and selected-foraging amount/food-choice index of cotton bollworm H.armigera were significantly positive correlated with the contents of fructose and GP of wheat grains, but they had significantly negative relationships with the contents of glucose, amylose, TSC and TSC： GP ratio of wheat grains.展开更多
The geomagnetic field(GMF)is an environmental cue that provides directional information for animals.The intensity of GMF is varied over space and time.Variations in the GMF intensity afect the navigation of animals an...The geomagnetic field(GMF)is an environmental cue that provides directional information for animals.The intensity of GMF is varied over space and time.Variations in the GMF intensity afect the navigation of animals and their physiology.In this study,the phototaxis of the migratory insect rice planthopper Nilaparvata lugens(N.lugens)and frataxin in N.lugens(NI-fh),which is a mitochondrial protein required for cellular iron homeostasis and iron-sulfur cluster assembly,were investigated by using different intensities of magnetic field.From the results,individuals of N.lugens showed decreased phototaxis when reared and tested in a behavioral arena under a strong magnetic field.Besides the reduction in performance,an accompanying ffect of the strong magnetic field condition was a reduced level of Nl-fh-messenger RNA,and a NI-fh knockdown indeed impaired the phototactic behavior in a tested sample of insects.This leads to the conclusion that the expression of frataxin is dependent on the strength of the surrounding magnetic field and that functional frataxin facilitates phototactic behavior in N.lugens.展开更多
文摘Global atmospheric CO2 concentrations have risen rapidly since the Industrial Revolution and are considered as a primary factor in climate change. The effects of elevated CO2 on herbivore insects were found to be primarily through the CO2-induced changes occurring in their host plants, which then possibly affect the intensity and frequency of pest outbreaks on crops. This paper reviews several ongoing research models using primary pests of crops （cotton bollworm, whitefly, aphids） and their natural enemies （ladybeetles, parasitoids） in China to examine insect responses to elevated CO2. It is generally indicated that elevated CO2 prolonged the development of cotton bollworm, Helicoverpa armigera, a chewing insect, by decreasing the foliar nitrogen of host plants. In contrast, the phloemsucking aphid and whitefly insects had species-specific responses to elevated CO2 because of complex interactions that occur in the phloem sieve elements of plants. Some aphid species, such as cotton aphid, Aphis gossypii and wheat aphid, Sitobion avenae, were considered to represent the only feeding guild to respond positively to elevated CO2 conditions. Although whitefly, Bemisia tabaci, a major vector of Tomato yellow leaf curl virus, had neutral response to elevated CO2, the plants became less vulnerable to the virus infection under elevated CO2. The predator and parasitoid response to elevated CO2 were frequently idiosyncratic. These documents from Chinese scientists suggested that elevated CO2 initially affects the crop plant and then cascades to a higher trophic level through the food chain to encompass herbivores （pests）, their natural enemies, pathogens and underground nematodes, which disrupt the natural balance observed previously in agricultural ecosystems.
基金We thank the staff in the Beijing READ BIO Bioinformatic Technology Company for their assistance in the phylogenetic inference and bioinformatic analysis of brown planthopper CRY proteins. This research was supported by the Key Program of National Natural Science of China （51037006）, the National Basic Research Program of China ＂973＂ （2010CB126200） and the National Nature Science Foundations of China （31170362, 31272051, 31470454 and 31070755）.
文摘Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the brown planthopper, and were given the designations of Nlcryl and Nlcry2, with the accession numbers KM108578 and KM108579 in GenBank. The complementary DNA sequences ofNlcryl andNlcry2 are 1935 bp and 2463 bp in length, and they contain an open reading frame of 1629 bp and 1872 bp, encoding amino acids of 542 and 623, with a predicted molecular weight of 62.53 kDa and 70.60 kDa, respectively. Well-conserved motifs such as DNA-photolyase and FAD-binding-7 domains were observed in Nlcry1 and Nlcry2. Phylogenetic analysis demonstrated the proteins of Nlcry1 and Nlcry2 to be clustered into the insect＇s cryptochrome 1 and cryptochrome 2, respectively. Quantitative polymerase chain reaction showed that the daily oscillations of messenger RNA （mRNA） expression in the head of the brown planthopper were mild for Nlcryl, and modest for Nlcry2. Throughout all developmental stages, Nlcryl and Nlcry2 exhibited extreme fluctuations and distinctive expression profiles. Cryptochrome mRNA expression peaked immediately after adult emergence and then decreased subsequently. The tissue expression profiles of newly emerged brown planthopper adults showed higher expression levels of CRYs in the head than in the thorax or abdomen, as well as significantly higher levels of CRYs in the heads of the macropterous strain than in the heads of the brachypterous strain. Taken together, the results of our study suggest that the two cryptochrome genes characterized in the brown planthopper might be associated with developmental physiology and migration.
文摘The widespread planting of insect-resistant crops has caused a dramatic shift in agricultural landscapes, thus raising concerns about the potential impacts on both target and non-target pests. In this study, we examined the potential effects of intra-specific seed mixture sowing with transgenic Bt rice (Bt) and its parental non-transgenic line (Nt)(100% Bt rice [Bt100], 5% Nt+95% Bt [Nt05Bt95], 10% Nt+90% Bt [Nt|0Bt90], 20% Nt+80% Bt [Nt2oBtso], 40% Nt+60% Bt [Nt4oBt6O] and 100% Nt rice [Ntjoo]) on target and non-target pests in a 2-year field trial in southern China. The occurrence of target pests, Sesamia inf evens. Chilo suppressalis and Cnaphalocrocis medinalis, decreased with the increased ratio of Bt rice, and the mixture ratios with more than 90% Bt rice (Btjoo and Nt()5Bt95) significantly increased the pest suppression efficiency, with the lowest occurrences of non-target planthoppers, Nilaparvata lugens and Sogatella jurcijera in Ntioo and NtosBtgs. Furthermore, there were no significant differences in 1000?grain dry weight and grain dry weight per 100 plants between Btjoo and NtosBtgs,Seed mixture sowing of Bt rice with <10%(especially 5%) of its parent line was sufficient to overcome potential compliance issues that exist with the use of block or structured refuge to provide most effective control of both target and non-target pests without compromising the grain yield. It is also expected that the strategy of seed mixture sowing with transgenic Bt rice and the nontransgenic parental line would provide rice yield stability while decreasing the insecticide use frequency in rice production.
基金We thank the plant protection stations of Jiangxi, Fujian, Anhui, Jiangsu, Zhejiang, Hunan, Hubei, Guang- dong and Guangxi provinces for providing insect scouting data. This study was supported by the National Natural Science Foundation of China （31471763） and the Fundamental Research Funds for the Central Universities （KJQN201434）. GH＇s visiting scholarship at the University of Exeter was funded by the China Scholarship Council.
文摘Sometimes, extreme weather is vital for the population survival of migratory insects by causing sudden population collapse or outbreak. Several studies have shown that rice planthopper migration was significantly influenced by typhoons in eastern Asia. Most typhoons occur in the summer, especially in August. In August, brown planthopper Nilaparvata lugens （Stal） migrates northward or southward depending on wind direc- tion, and thus typhoons can potentially influence its migration process and population distribution. However, this has not yet been studied. This paper reported a case study on the effects of Typhoon Soudelor on the summer migration of N. lugens in eastern China in 2015. The migration pathways of N. lugens were reconstructed for the period under the influence of a typhoon by calculating the trajectories and migration events in eight counties of the Yangtze River Valley region with ancillary information. Trajectory mod- elling showed that most migrants took short distance migrations （less than 200 km） under the influence of the Typhoon Soudelor. Numerous N. lugens migrants were concentrated and deposited at the rear of the typhoon during the last 5 days of Typhoon Soudelor on August 9-13 due to horizontal convergence, and this led to an outbreak population. These results indicated that the N. lugens population was redistributed by the typhoon in the sum- mer and that the population dynamics at the rear of a typhoon should be kept under close surveillance. This study provided insight into migratory organisms adapting to atmospheric features.
文摘A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton （46% in 2008; 56% in 2009） and alfalfa （46% in 2008; 71% in 2009） contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa （5% in 2008 and 6% in 2009） and from alfalfa to cotton （9% in 2008 and 14% in 2009）. The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles （bidirectional and unidirectional combined） was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa of- fered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.
基金Supported by the State Key Basic Research and Development Plan of China （2006CB102002）the Innovation Program of the Chinese Academy of Sciences （KSCX2-YW-N-006）+1 种基金the National Natural Science Foundation of China （30571253 and 30621003） the Exoteric Foundation from the National Key Laboratory of Integrated Management of Pest Insects and Rodents （Chinese-IPM-0601）.
文摘A field study was carried out to quantify plant growth and the foliar chemistry of transgenic Bacillus thuringiensis （Bt） cotton （cv. GK-12） exposed to ambient CO2 and elevated （double-ambient） CO2 for different lengths of time （1, 2 and 3 months） in 2004 and 2005. The results indicated that CO2 levels significantly affected plant height, leaf area per plant and leaf chemistry of transgenic Bt cotton. Significantly, higher plant height and leaf area per plant were observed after cotton plants that were grown in elevated CO2 were compared with plants grown in ambient CO2 for 1, 2 and 3 months in the investigation. Simultaneously, significant interaction between CO2 level x investigating year was observed in leaf area per plant. Moreover, foliar total amino acids were increased by 14%, 13%, 11% and 12%, 14%, 10% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 in 2004 and 2005, respectively. Condensed tannin occurrence increased by 17%, 11%, 9% in 2004 and 12%, 11%, 9% in 2005 in transgenic Bt cotton after being exposed to elevated CO2 for 1, 2 or 3 months compared with ambient CO2 for the same time. However, Bt toxin decreased by 3.0%, 2.9%, 3.1% and 2.4%, 2.5%, 2.9% in transgenic Bt cotton after exposed to elevated CO2 for 1, 2 or 3months compared with ambient CO2 for same time in 2004 and 2005, respectively. Furthermore, there was prominent interaction on the foliar total amino acids between the CO2 level and the time of cotton plant being exposed to elevated CO2. It is presumed that elevated CO2 can alter the plant growth and hence ultimately the phenotype allocation to foliar chemistical components of transgenic Bt cotton, which may in turn, affect the plant-herbivore interactions.
基金Acknowledgments Thanks are given to two anonymous reviewers for their great input into this manuscript. This research was supported by the National Basic Research Program of China （973） （2010CB126200）, the National Nature Science Foundation of China （30700527）, and the Major Project of Cultivate New Varieties of Genetically Modified Organisms （2009ZX08011-007B, 2009ZX08012-005B and 2011ZX08012-005）, Fok Ying Tung Education Foundation （122033）, and the Doctoral Subject Foundation for the New Teachers of the Ministry of Education of the People＇s Republic of China （20070307002）.
文摘Effects of elevated CO2 （twice ambient vs. ambient） and Bt CrylAc transgene （Bt cotton cv. 33B vs. its nontransgenic parental line cv. DP5415） on the interspecific competition between two ecologically similar species of cotton aphid Aphis gossypii and whitefly biotype-Q Bemisia tabaci were studied in open-top chambers. The results indicated that elevated CO2 and Bt cotton both affected the population abundances of A. gossypii and biotype-Q B. tabaci when introduced solely （i.e., without interspecific competition） or two species coexisted （i.e., with interspecific competition）. Compared with ambient CO2, elevated COe increased the population abundances ofA. gossypii and biotype-Q B. tabaci as fed on Bt and nontransgenic cotton on 45 （i.e., seedling stage） and 60 （i.e., flowering stage） days after planting （DAP）, but only significantly enhanced aphid abundance without interspecific competition on the 45-DAP nontransgenic cotton and 60-DAP Bt cotton, and significantly increased whitefly abundance with interspecific competition on the 45-DAP Bt cotton and 60-DAP nontransgenic cotton. In addition, compared with nontransgenic cotton at elevated CO2, Bt cotton significantly reduced biotype-Q B. tabaci abundances without and with interspecific competition during seedling and flowering stage, while only significantly decreasing A. gossypii abundances without interspecific competition during the seedling stage. When the two insect species coexisted, the proportions ofbiotype-Q B. tabaci were significantly higher than those ofA. gossypii on Bt and nontransgenic cotton at the same CO2 levels, and elevated CO2 only significantly increased the percentages of biotype-Q B. tabaci and significantly reduced the proportions of A. gossypii on seedling and flowering nontransgenic cotton. Therefore, the effects of elevated CO2 were favorable for biotype-Q B. tabaci to out-compete A. gossypii under the predicted global climate change.
文摘Plant allocation to defensive compounds by elevated CO2-grown nontransgenic and transgenic Bt cotton in response to infestation by cotton aphid, Aphis gossypii （Glover） in open-top chambers under elevated CO2 were studied. The results showed that significantly lower foliar nitrogen concentration and Bt toxin protein occurred in transgenic Bt cotton with and without cotton aphid infestation under elevated CO2. However, significantly higher carbon/nitrogen ratio, condensed tannin and gossypol were observed in transgenic Bt cotton ＂GK-12＂ and non-transgenic Bt cotton ＇Simian-3＇ under elevated CO2. The CO2 level and cotton variety significantly influenced the foliar nitrogen, condensed tannin and gossypol concentrations in the plant leaves after feeding by A. gossypii. The interaction between CO2 level x infestation time （24 h, 48 h and 72 h） showed a significant increase in cotton condensed tannin concentrations, while the interaction between CO2 level x cotton variety significantly decreased the true choline esterase （TChE） concentration in the body ofA. gossypi. This study exemplified the complexities of predicting how transgenic and non-transgenic plants will allocate defensive compounds in response to herbivorous insects under differing climatic conditions. Plant defensive compound allocation patterns and aphid enzyme changes observed in this study appear to be broadly applicable across a range of plant and herbivorous insect interactions as CO2 atmosphere rises.
基金the National Natural Science Foundation of China(31670855,31470454 and 31170362)the China Postdoctoral Scienee Foun?dation(2016M590470).
文摘The mechanisms of magnetoreception have been proposed as the magnetitebased, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA1) may be involved. However, little is known about the association among the molecules. Here we investigated the molecular characterization and the mRNA expression of IscA1 in different developmental stages, tissues and magnetic fields in the migratory brown planthopper (BPH), Nilaparvata lugens. NlIscA1 contains an open reading frame of 390 bp, encoding amino acids of 129, with the predicted molecular weight of 14.0 kDa and the isoelectric point of 9.10. Well-conserved Fe-S cluster binding sites were observed in the predicted protein. Phylogenetic analysis demonstrated NlIscA1 to be clustered into the insect's IscA1. NlIscA1 showed up-regulated mRNA expression during the period of migration. The mRNA expression of NlIscA1 could be detected in all the three tissues of head, thorax and abdomen, with the highest expression level in the abdomen. For the macropterous migratory Nilaparvata lugens, mRNA expression of NlIscA1 and N. lugens cryptochromel (Nlcry1) were up-regulated under the magnetic fields of 5 Gauss and 10 Gauss in strength (vs. local geomagnetic field), while N. lugens cryptochrome 2 (Nlcry2) remained stable. For the brachyterous non-migratory Nilaparvata lugens, no significant changes were found in mRNA expression of NlIscA1, Nlcry1 and Nlcry2 among different magnetic fields. These findings preliminarily reveal that the expression of NlIscA1 and Nlcry1 exhibited coordinated responses to the magnetic field. It suggests some potential associations among the putative magneto-sensitive molecules of cryptochrome and iron-sulfur cluster assembly.
基金supported by the Shandong Provin-cial Natural Science Foundation,China(grant no.ZR2020QC134)the National Natural Science Foun-dation of China(grant no.32202405)+2 种基金the State Key Laboratory of Integrated Management of Pest Insects and Rodents(grant no.IPM2001)the Agricultural Sci-entific and Technological Innovation Project of Shan-dong Academy of Agricultural Sciences(grant no.CXGC2022E04)the Shandong-Chongqing Sci-ence&Technology Cooperation Program,Shandong Technological Innovation Guidance Plan(grant no.2020LYXZ030).
文摘The rising trend in the cultivation of Bacillus thuringiensis (Bt) transgenic crops may cause a destabilization of agroecosystems, thus increasing concerns about the sustainability of Bt crops as a valid pest management method. Azotobacter can be used as a biological regulator to increase environmental suitability and improve the soil nitrogen utilization efficiency of crops, especially Bt cotton. A laboratory test investigated effects on the development and food utilization of Helicoverpa armigera fed with different Cry1Ab/Cry1Ac proteins and nitrogen metabolism-related compounds from cotton (transgenic variety SCRC 37 vs non-Bt cotton cv. Yu 2067) inoculated with Azospirillum brasilense (Ab) and Azotobacter chroococcum (Ac). The findings indicate that inoculation with Azotobacter significantly decreased the partial development and food utilization indexes (pupal weight;pupation rate;adult longevity;fecundity;relative growth rate, RGR;efficiency of conversion of digested food, ECD;and efficiency of conversion of ingested food, ECI) of H. armigera fed on Bt cotton, but contrasting trends were found among these indexes in H. armigera fed on non-Bt cotton inoculated with Azotobacter, as a result of differences in Bt toxin production. Overall, the results showed that inoculation with Azotobacter had negative effects on the development and food utilization of H. armigera fed on Bt cotton, leading to enhanced target insect resistance. Presumably, Azotobacter inoculation can be used to stimulate plant soil nitrogen uptake to increase nitrogen metabolism-related compounds and promote plant growth for Bt and non-Bt cotton, simultaneously raising Bt protein expression and enhancing resistance efficacy against cotton bollworm in Bt cotton.
基金the National Natural Science Foundation of China(31701787,31470454 and 31670855)the Natural Science Foundation of Jiangsu Province(BK20160717 and BK20170026)+3 种基金the Fundame ntal Research Funds for the Central Universi-ties(KJQN201820)the Nanjing Agricultural University Start-up Fund(82162045)the Jiangsu Province Postdoctoral Science Foundation(1601196C)the National Basic Research Program of China(973)(2010CB126200).
文摘The geomagnetic field(GMF)is well documented for its essential role as a cue used in animal orientation or navigation.Recent evidence indicates that the absence of GMF(mimicked by the near-zero magnetic field,NZMF)can trigger stress-like responses such as reduced body weight,as we have previously shown in the brown planthopper,Nilaparvata lugens.In this study,we found that consistent with the significantly decreased body weight of newly emerged female(—14.67%)and male(—13.17%)adult N.lugens,the duration of the phloem ingestion feeding waveform was significantly reduced by 32.02%in 5th instar nymphs reared under the NZMF versus GMF.Interestingly,5th instar nymphs that exhibited reduced feeding had significantly higher glucose levels(+16.98%and+20.05%;24 h and 48 h after molting),which are associated with food aversion,and expression patterns of their appetite-related neuropeptide genes(neuropeptide F,dow regulated overall;short neuropeptide F,dowregulated overall;adipokinetic hormone up-regulated overall;and adipokinetic hormone receptor,down-regulated overall)were also altered under the absence of GMF in a manner consistent with diminishing appetite.Moreover,the expressions of the potential magnetosensor croptochromes(Crys)were found significantly altered under the absence of GMF,indicating the likely upstream signaling of the Cry-mediated magnetoreception mechanisms.These findings support the hypothesis that strong changes in GMF intensity can reduce adult body weight through affecting insect feeding behavior and underlying regulatory processes including appetite regulation.Our results highlight that GMF could be necessary for the maintenanee of energy homeostasis in insects.
基金Acknowledgments We are grateful to Mrs Ding Yu Lei, the dean of Beiai Science and Technology Center of Hebei Province for her help in the field 0TC experiments. This experiment was funded by the National Key Basic Research Project on pest management （G200016209） and Innovation Research of Chinese Academy of Science （Project KSCX2-01-02 and KSCX2-sw-103） and National Natural Science Foundation of China （39970137）.
文摘Effects of elevated CO2 on the foraging behavior of cotton bollworm Helicoverpa arrnigera Hübner reared on milky grains of spring wheat grown in ambient, 550μL/L and 750μL/L CO2 concentration atmospheres in open-top chambers （OTC） were studied. The results indicated that： （i） elevated CO2 significantly affected both the type and amount of food eaten by H.arrnigera reared on milky grains of ambient CO2-grown wheat were significant higher than those for bollworm larvae reared on wheat grains grown in 550 and 750μL/L CO2 atmospheres; （ii） when bollworm larvae were reared on mixed milky grains from different CO2-grown wheat （food-choice condition）, larval duration increased significantly-pupal weight, adult longevity, and fecundity decreased significantly, comparing with those reared on milky grains of ambient CO2-grown wheat, 550μL/L CO2-grown wheat and 750μL/L CO2-grown wheat respectively; （iii） significant decreases in the contents of fructose and gross protein （GP） and significant increases in the contents of glucose, amylose, total saccharides （TSC）, TSC： GP ratio, free amino acids and soluble protein in the wheat grains with CO2 rising; （iv） and selected-foraging amount/food-choice index of cotton bollworm H.armigera were significantly positive correlated with the contents of fructose and GP of wheat grains, but they had significantly negative relationships with the contents of glucose, amylose, TSC and TSC： GP ratio of wheat grains.
基金We thank Wei Pan for generous assistance in the setup and maintenance of magnetic field equipment of solenoidal coils.This research was supported by the National Nat-ural Science Foundation of China(3167085,31870367,31470454)the Natural Science Foundation of Jiangsu Province Youth Fund(BK20160717)the Natural Sci-ence Foundation ofChina for Young Scholars(31701787).
文摘The geomagnetic field(GMF)is an environmental cue that provides directional information for animals.The intensity of GMF is varied over space and time.Variations in the GMF intensity afect the navigation of animals and their physiology.In this study,the phototaxis of the migratory insect rice planthopper Nilaparvata lugens(N.lugens)and frataxin in N.lugens(NI-fh),which is a mitochondrial protein required for cellular iron homeostasis and iron-sulfur cluster assembly,were investigated by using different intensities of magnetic field.From the results,individuals of N.lugens showed decreased phototaxis when reared and tested in a behavioral arena under a strong magnetic field.Besides the reduction in performance,an accompanying ffect of the strong magnetic field condition was a reduced level of Nl-fh-messenger RNA,and a NI-fh knockdown indeed impaired the phototactic behavior in a tested sample of insects.This leads to the conclusion that the expression of frataxin is dependent on the strength of the surrounding magnetic field and that functional frataxin facilitates phototactic behavior in N.lugens.
