Background Polygalacturonase inhibiting proteins(PGIPs)play a pivotal role in plant defense against plant patho-gens by inhibiting polygalacturonase(PG),an enzyme produced by pathogens to degrade plant cell wall pecti...Background Polygalacturonase inhibiting proteins(PGIPs)play a pivotal role in plant defense against plant patho-gens by inhibiting polygalacturonase(PG),an enzyme produced by pathogens to degrade plant cell wall pectin.PGIPs,also known as leucine-rich repeat pathogenesis-related(PR)proteins,activate the host’s defense response upon interaction with PG,thereby reinforcing the host defense against plant pathogens attacks.In Egyptian or extra-long staple cotton(Gossypium barbadense),the interaction between PGIP and PG is one of the crucial steps in the defense mechanism against major pathogens such as Xanthomonas citri pv.malvacearum and Alternaria mac-rospora,which are responsible for bacterial leaf blight and leaf spot diseases,respectively.Results To unravel the molecular mechanisms underlying these PR proteins,we conducted a comprehensive study involving molecular modeling,protein-protein docking,site-specific double mutation(E169G and F242K),and molec-ular dynamics simulations.Both wild-type and mutated cotton PGIPs were examined in the interaction with the PG enzyme of a bacterial and fungal pathogen.Our findings revealed that changes in conformations of double-mutated residues in the active site of PGIP lead to the inhibition of PG binding.The molecular dynamics simulation studies provide insights into the dynamic behaviour and stability of the PGIP-PG complexes,shedding light on the intricate details of the inhibitory and exhibitory mechanism against the major fungal and bacterial pathogens of G.barbadense,respectively.Conclusions The findings of this study not only enhance our understanding of the molecular interactions between PGs of Xanthomonas citri pv.malvacearum and Alternaria macrospora and PGIP of G.barbadense but also pre-sent a potential strategy for developing the disease-resistant cotton varieties.By variations in the binding affinities of PGs through specific mutations in PGIP,this research offers promising avenues for the development of enhanced resistance to cotton plants against bacterial leaf blight and leaf spot diseases.展开更多
Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with des...Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with desirable traits that wouldn’t be possible through conventional breeding methods.Transgenic crops have been developed for various traits globally.Whitefly,Bemisia tabaci(Gennadius)is one of the major sucking pests of cotton that cause significant damage to the cotton production.To combat whitefly infestations,researchers have developed four transgenic cotton lines expressing the fern protein.And those transgenic lines need to be evaluated for their performance against the target pest—whitefly.The evaluation was designed as controlled trials in polyhouse or muslin cloth cages under open-choice and no-choice conditions by comparing four transgenic cotton lines(A,B,C,and D)with three control groups,including untransformed cotton plants with a same genetic background of the transgenic line,conventionally bred whitefly-resistant cotton,and whitefly-susceptible cotton.In order to study the generational effect,the evaluation also involved studies on whitefly development in laboratory,muslin cloth cage,and polyhouse conditions.Results Both open-choice and no-choice experiments had shown that all the four transgenic cotton lines(A,B,C,and D)expressing the fern protein reduced adult whitefly numbers significantly compared with the control lines,except for the no-choice conditions in 2021,where the transgenic line C was non-significant different from the resistant control line.Notably,the nymphal population on the resistant control line was relatively low and nonsignificant different from the transgenic line C in 2021;and the transgenic lines A and C in 2022 under open-choice conditions.Under no-choice condition,the nymphal counts in the resistant control line was non-significant different from transgenic lines C and D in 2021;and transgenic line D in 2022.All transgenic lines showed significant decrease in egg hatching in 2021 and nymphal development in 2022,except for the transgenic line C which had no significant different in the nymphal development comparing with non-transgenic control lines in 2022.Adult emergence rates in both years of evaluation showed significant decrease in transgenic lines A and B comparing with the control lines.Additionally,the results showed a significant reduction in cotton leaf curl disease and sooty mold development in all the four transgenic lines compared with susceptible control under open-choice conditions,indicating potential benefits of transgenic lines beyond direct effect on whitefly control.Furthermore,the research explored the generational effects of the fern protein on whitefly which revealed the lowest fecundity in the transgenic line C across F0,F1 and F3 generations,lower egg hatching in F1 and F2 generations in transgenic lines A and B,shorter nymphal duration in F1 and F2 generations in transgenic line B,and the least total adult emergence in the transgenic line C in F0 and F3 generations.Conclusions These findings suggest that the transgenic cotton lines expressing fern protein disrupts whitefly populations and the life cycle to a certain extent.However,results are not consistent over generations and years of study,indicating these transgenic lines were not superior over control lines and need to be improved in future breeding.展开更多
Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(B...Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(Bt)toxins posed a serious threat to transgenic cotton cultivation.This necessitated determining the critical timing of spray applications on the control effectiveness.This study assessed the influence of egg age(freshly laid vs.three-day-old)and the loca-tion of larvae(directly exposed to the insecticide residues on the boll rind vs.burrowed inside the bolls)on insecticide control efficacy.Results The results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old(paired t-test,P<0.05).The larvae directly exposed to the insec-ticide residues on the boll rind were more susceptible(>80%mortality)than the larvae exposed after they had bur-rowed inside the bolls(<49%mortality).The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.Conclusion Egg age influences the insecticide susceptibility,as does the larval location,directly exposed vs bur-rowed inside the bolls.Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments.The toxic effects of insecticides on egg and larval stages were primar-ily ephemeral.These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.展开更多
Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s interna...Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s internal feeding habit.This study refines the economic injury level(EIL)for pink bollworm using pest-infestation gradients and yield loss-damage functions.The EILs were estimated and converted to action thresholds(75%of EIL).The sensitivity to control costs,cotton prices,and control efficacy was considered in calculating the EIL.Additionally,the relationship between national pheromone-trap data(2015-2023)and green boll infestation was examined.Results Based on the average cotton prices,optimum control cost,and desirable control efficacy,EILs ranged from 7.1%to 8.6%of boll infestation,with corresponding action thresholds of 5.3%and 6.4%for<120 days after sowing(DAS)and>120 DAS crop stages,respectively.Control efficacy emerged as the most influential factor on EILs.Corresponding pheromone trap catch-based action thresholds were revised to 4.5 and 5.7 moths per trap per night,lower than the existing 8.0 moths per trap per night tied to a 10%boll infestation threshold.Validation using multi-location data supported refined estimates.Conclusions The study demonstrates that maintaining high control efficacy is central to keeping EILs low and enabling timely intervention against pink bollworm.Effective control reduces the pest’s damage potential,lowers the onset of economic loss,and supports earlier,more reliable ET-based actions.These results collectively ensure better suppression of pests and promote economically efficient,agronomically robust pest management.展开更多
基金CABin grant(F.no.Agril.Edn.4-1/2013-A&P)Indian Council of Agricul-tural Research,Ministry of Agriculture and Farmers’Welfare,Govt.of India and Department of Biotechnology,Govt.of India for BIC project grant(BT/PR40161/BTIS/137/32/2021)。
文摘Background Polygalacturonase inhibiting proteins(PGIPs)play a pivotal role in plant defense against plant patho-gens by inhibiting polygalacturonase(PG),an enzyme produced by pathogens to degrade plant cell wall pectin.PGIPs,also known as leucine-rich repeat pathogenesis-related(PR)proteins,activate the host’s defense response upon interaction with PG,thereby reinforcing the host defense against plant pathogens attacks.In Egyptian or extra-long staple cotton(Gossypium barbadense),the interaction between PGIP and PG is one of the crucial steps in the defense mechanism against major pathogens such as Xanthomonas citri pv.malvacearum and Alternaria mac-rospora,which are responsible for bacterial leaf blight and leaf spot diseases,respectively.Results To unravel the molecular mechanisms underlying these PR proteins,we conducted a comprehensive study involving molecular modeling,protein-protein docking,site-specific double mutation(E169G and F242K),and molec-ular dynamics simulations.Both wild-type and mutated cotton PGIPs were examined in the interaction with the PG enzyme of a bacterial and fungal pathogen.Our findings revealed that changes in conformations of double-mutated residues in the active site of PGIP lead to the inhibition of PG binding.The molecular dynamics simulation studies provide insights into the dynamic behaviour and stability of the PGIP-PG complexes,shedding light on the intricate details of the inhibitory and exhibitory mechanism against the major fungal and bacterial pathogens of G.barbadense,respectively.Conclusions The findings of this study not only enhance our understanding of the molecular interactions between PGs of Xanthomonas citri pv.malvacearum and Alternaria macrospora and PGIP of G.barbadense but also pre-sent a potential strategy for developing the disease-resistant cotton varieties.By variations in the binding affinities of PGs through specific mutations in PGIP,this research offers promising avenues for the development of enhanced resistance to cotton plants against bacterial leaf blight and leaf spot diseases.
文摘Background Transgenic research in crops involves using genetic engineering techniques to introduce specific genes of interest from other organisms,or even entirely new genes into plant genomes to create crops with desirable traits that wouldn’t be possible through conventional breeding methods.Transgenic crops have been developed for various traits globally.Whitefly,Bemisia tabaci(Gennadius)is one of the major sucking pests of cotton that cause significant damage to the cotton production.To combat whitefly infestations,researchers have developed four transgenic cotton lines expressing the fern protein.And those transgenic lines need to be evaluated for their performance against the target pest—whitefly.The evaluation was designed as controlled trials in polyhouse or muslin cloth cages under open-choice and no-choice conditions by comparing four transgenic cotton lines(A,B,C,and D)with three control groups,including untransformed cotton plants with a same genetic background of the transgenic line,conventionally bred whitefly-resistant cotton,and whitefly-susceptible cotton.In order to study the generational effect,the evaluation also involved studies on whitefly development in laboratory,muslin cloth cage,and polyhouse conditions.Results Both open-choice and no-choice experiments had shown that all the four transgenic cotton lines(A,B,C,and D)expressing the fern protein reduced adult whitefly numbers significantly compared with the control lines,except for the no-choice conditions in 2021,where the transgenic line C was non-significant different from the resistant control line.Notably,the nymphal population on the resistant control line was relatively low and nonsignificant different from the transgenic line C in 2021;and the transgenic lines A and C in 2022 under open-choice conditions.Under no-choice condition,the nymphal counts in the resistant control line was non-significant different from transgenic lines C and D in 2021;and transgenic line D in 2022.All transgenic lines showed significant decrease in egg hatching in 2021 and nymphal development in 2022,except for the transgenic line C which had no significant different in the nymphal development comparing with non-transgenic control lines in 2022.Adult emergence rates in both years of evaluation showed significant decrease in transgenic lines A and B comparing with the control lines.Additionally,the results showed a significant reduction in cotton leaf curl disease and sooty mold development in all the four transgenic lines compared with susceptible control under open-choice conditions,indicating potential benefits of transgenic lines beyond direct effect on whitefly control.Furthermore,the research explored the generational effects of the fern protein on whitefly which revealed the lowest fecundity in the transgenic line C across F0,F1 and F3 generations,lower egg hatching in F1 and F2 generations in transgenic lines A and B,shorter nymphal duration in F1 and F2 generations in transgenic line B,and the least total adult emergence in the transgenic line C in F0 and F3 generations.Conclusions These findings suggest that the transgenic cotton lines expressing fern protein disrupts whitefly populations and the life cycle to a certain extent.However,results are not consistent over generations and years of study,indicating these transgenic lines were not superior over control lines and need to be improved in future breeding.
文摘Background The cryptic nature of pink bollworm Pectinophora gossypiella(Saunders)larvae enables its reduced vul-nerability to insecticidal control.Further,the development of resistance against Bacillus thuringiensis(Bt)toxins posed a serious threat to transgenic cotton cultivation.This necessitated determining the critical timing of spray applications on the control effectiveness.This study assessed the influence of egg age(freshly laid vs.three-day-old)and the loca-tion of larvae(directly exposed to the insecticide residues on the boll rind vs.burrowed inside the bolls)on insecticide control efficacy.Results The results revealed a significant decrease in the ovicidal activity of tested insecticides with an increase in the age of eggs from one day old to three days old(paired t-test,P<0.05).The larvae directly exposed to the insec-ticide residues on the boll rind were more susceptible(>80%mortality)than the larvae exposed after they had bur-rowed inside the bolls(<49%mortality).The inhibitory effects of tested insecticides on developmental biology were more pronounced in the experiment on pre-larval release insecticide treatment compared with insecticide treatment given post-larval release and entry inside the bolls.Conclusion Egg age influences the insecticide susceptibility,as does the larval location,directly exposed vs bur-rowed inside the bolls.Older eggs and the larvae that had burrowed inside the green bolls of cotton were relatively less susceptible to the insecticide treatments.The toxic effects of insecticides on egg and larval stages were primar-ily ephemeral.These findings are significant for devising a comprehensive strategy for pink bollworm management on a sustainable basis.
基金funded by the Indian Council of Agricultural Research(ICAR),Department of Agricultural Research and Education,Government of India to ICAR-Central Institute for Cotton Research(ICAR-CICR),Nagpur,Maharashtra,for the in-house research project titled“Revisiting the ETLs and yield loss assessment due to pink bollworm and boll rot in cotton”(Institute project code:IXX15662).
文摘Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s internal feeding habit.This study refines the economic injury level(EIL)for pink bollworm using pest-infestation gradients and yield loss-damage functions.The EILs were estimated and converted to action thresholds(75%of EIL).The sensitivity to control costs,cotton prices,and control efficacy was considered in calculating the EIL.Additionally,the relationship between national pheromone-trap data(2015-2023)and green boll infestation was examined.Results Based on the average cotton prices,optimum control cost,and desirable control efficacy,EILs ranged from 7.1%to 8.6%of boll infestation,with corresponding action thresholds of 5.3%and 6.4%for<120 days after sowing(DAS)and>120 DAS crop stages,respectively.Control efficacy emerged as the most influential factor on EILs.Corresponding pheromone trap catch-based action thresholds were revised to 4.5 and 5.7 moths per trap per night,lower than the existing 8.0 moths per trap per night tied to a 10%boll infestation threshold.Validation using multi-location data supported refined estimates.Conclusions The study demonstrates that maintaining high control efficacy is central to keeping EILs low and enabling timely intervention against pink bollworm.Effective control reduces the pest’s damage potential,lowers the onset of economic loss,and supports earlier,more reliable ET-based actions.These results collectively ensure better suppression of pests and promote economically efficient,agronomically robust pest management.
