Most legume plants can associate with diazotrophic soil bacteria called rhizobia,resulting in new root organs called nodules that enable N2 fixation.Nodulation is an energy-consuming process,and nodule number is tight...Most legume plants can associate with diazotrophic soil bacteria called rhizobia,resulting in new root organs called nodules that enable N2 fixation.Nodulation is an energy-consuming process,and nodule number is tightly regulated by independent systemic signaling pathways controlled by CLE/SUNN and CEP/CRA2.Moreover,nitrate inhibits legume nodulation via local and systemic regulatory pathways.In Medicago truncatula,NLP1 plays important roles in nitrate-induced inhibition of nodulation,but the relationship between systemic and local pathways in mediating nodulation inhibition by nitrate is poorly understood.In this study,we found that nitrate induces CLE35 expression in an NLP1-dependent manner and that NLP1 binds directly to the CLE35 promoter to activate its expression.Grafting experiments revealed that the systemic control of nodule number involves negative regulation by SUNN and positive regulation by CRA2 in the shoot,and that NLP1’s control of the inhibition of rhizobial infection,nodule development,and nitrogenase activity in response to nitrate is determined by the root.Unexpectedly,grafting experiments showed that loss of CRA2 in the root increases nodule number at inhibitory nitrate levels,probably because of CEP1/2 upregulation in the cra2 mutants,suggesting that CRA2 exerts active negative feedback regulation in the root.展开更多
Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an ...Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an alternative,given its ease of recycling,composting,and even-tual biodegradation.In this work,we aims to study the pulp properties of sunn hemp and its usage as molded pulp products.For this purpose,unbleached beaten and unbeaten soda pulps de-rived from the whole stem of sunn hemp were examined for their fiber morphology,fibrillation,fiber classification,and physical properties.The sunn hemp pulp was subsequently molded using a batch molding machine.To determine the hydrophobicity of the molded pulp products,the molded samples were manufactured with and without additives.Finally,some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products.It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products.In terms of general usage,the molded products from sunn hemp pulp with additives were found to be capable of storing hot water,hot cooking oil,as well as microwaving water.We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.展开更多
A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib(SNBMR)(Sorghum bicolor L Moench),sorghum-brown mid rib(SBMR),sunn hemp(Crotalaria juncea L)and kenaf(Gossypiumhirsutum L),focusing on ra...A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib(SNBMR)(Sorghum bicolor L Moench),sorghum-brown mid rib(SBMR),sunn hemp(Crotalaria juncea L)and kenaf(Gossypiumhirsutum L),focusing on rates of xylose monomer and furfural formation.The kinetics was investigated using two independent variables,reaction temperature(150°C and 160°C)and acid concentration(1 and 2 wt%),with a constant dry biomass loading of 10 wt%and a treatment time up to 20 min while sampling the mixture every 2 min.The experimental data were fitted using a two-step kinetic model based on irreversible pseudo first order kinetics at each step.Varied kinetic orders on the acid concentration,ranging from 0.2 to>3,were observed for both xylose and furfural formation,the values depending on the feedstock.The crystallinity index of raw biomass was shown to be a major factor influencing the rate of both xylose and furfural formation.A positive correlation was observed between the activation energy and biomass crystallinity index for xylose formation.展开更多
The sunn pest Eurygaster integriceps is the most important insect of cereals in Iraq and other countries. In this study, the field efficacy of 10 different kinds of insecticides with various mode of action was evaluat...The sunn pest Eurygaster integriceps is the most important insect of cereals in Iraq and other countries. In this study, the field efficacy of 10 different kinds of insecticides with various mode of action was evaluated against sunn pest E. integriceps infested wheat on field at middle oflraq. Experiments were conducted in 11 wheat fields with each field 0.5 ha, located in the middle of Iraq （Wasit and Salahudain govemorates） during season 2015-2016. The wheat fields contained common varieties of wheat planted in Iraq. The population density of the pest was at its highest level （start of April 2015） of mostly nymphs, adults and eggs. The results indicated that the recommended dose for each insecticide used showed high efficacy （80.1%-93.8%） in reducing number of E. integriceps adults after one week of treatment, reaching 0.2-0.8 insects/m^2 compared to 3.6 insects/m2 in the control treatment. These results will assist the control program of this pest and in implementing pest management practices to reduce resistance development chances.展开更多
基金supported by grants from The National Key Research&Development Program of China(2016YFA0500500 and 2016YFD0100702)the NSFC(31670242)to F.X.
文摘Most legume plants can associate with diazotrophic soil bacteria called rhizobia,resulting in new root organs called nodules that enable N2 fixation.Nodulation is an energy-consuming process,and nodule number is tightly regulated by independent systemic signaling pathways controlled by CLE/SUNN and CEP/CRA2.Moreover,nitrate inhibits legume nodulation via local and systemic regulatory pathways.In Medicago truncatula,NLP1 plays important roles in nitrate-induced inhibition of nodulation,but the relationship between systemic and local pathways in mediating nodulation inhibition by nitrate is poorly understood.In this study,we found that nitrate induces CLE35 expression in an NLP1-dependent manner and that NLP1 binds directly to the CLE35 promoter to activate its expression.Grafting experiments revealed that the systemic control of nodule number involves negative regulation by SUNN and positive regulation by CRA2 in the shoot,and that NLP1’s control of the inhibition of rhizobial infection,nodule development,and nitrogenase activity in response to nitrate is determined by the root.Unexpectedly,grafting experiments showed that loss of CRA2 in the root increases nodule number at inhibitory nitrate levels,probably because of CEP1/2 upregulation in the cra2 mutants,suggesting that CRA2 exerts active negative feedback regulation in the root.
文摘Petroleum-based materials are often used in the packaging industry.However,the single use value of such products can be problematic with regard to proper waste disposal.As such,molded pulp packaging can be used as an alternative,given its ease of recycling,composting,and even-tual biodegradation.In this work,we aims to study the pulp properties of sunn hemp and its usage as molded pulp products.For this purpose,unbleached beaten and unbeaten soda pulps de-rived from the whole stem of sunn hemp were examined for their fiber morphology,fibrillation,fiber classification,and physical properties.The sunn hemp pulp was subsequently molded using a batch molding machine.To determine the hydrophobicity of the molded pulp products,the molded samples were manufactured with and without additives.Finally,some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products.It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products.In terms of general usage,the molded products from sunn hemp pulp with additives were found to be capable of storing hot water,hot cooking oil,as well as microwaving water.We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.
文摘A kinetic study of acid pretreatment was conducted for sorghum non-brown mid rib(SNBMR)(Sorghum bicolor L Moench),sorghum-brown mid rib(SBMR),sunn hemp(Crotalaria juncea L)and kenaf(Gossypiumhirsutum L),focusing on rates of xylose monomer and furfural formation.The kinetics was investigated using two independent variables,reaction temperature(150°C and 160°C)and acid concentration(1 and 2 wt%),with a constant dry biomass loading of 10 wt%and a treatment time up to 20 min while sampling the mixture every 2 min.The experimental data were fitted using a two-step kinetic model based on irreversible pseudo first order kinetics at each step.Varied kinetic orders on the acid concentration,ranging from 0.2 to>3,were observed for both xylose and furfural formation,the values depending on the feedstock.The crystallinity index of raw biomass was shown to be a major factor influencing the rate of both xylose and furfural formation.A positive correlation was observed between the activation energy and biomass crystallinity index for xylose formation.
文摘The sunn pest Eurygaster integriceps is the most important insect of cereals in Iraq and other countries. In this study, the field efficacy of 10 different kinds of insecticides with various mode of action was evaluated against sunn pest E. integriceps infested wheat on field at middle oflraq. Experiments were conducted in 11 wheat fields with each field 0.5 ha, located in the middle of Iraq （Wasit and Salahudain govemorates） during season 2015-2016. The wheat fields contained common varieties of wheat planted in Iraq. The population density of the pest was at its highest level （start of April 2015） of mostly nymphs, adults and eggs. The results indicated that the recommended dose for each insecticide used showed high efficacy （80.1%-93.8%） in reducing number of E. integriceps adults after one week of treatment, reaching 0.2-0.8 insects/m^2 compared to 3.6 insects/m2 in the control treatment. These results will assist the control program of this pest and in implementing pest management practices to reduce resistance development chances.
