Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudom...Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.展开更多
Plant viruses are mainly transmitted by insect vectors in the non-persistent,semi-persistent,or persistent modes.In the non-persistent mode,plant viruses are retained in the stylets of their insect vectors.In the semi...Plant viruses are mainly transmitted by insect vectors in the non-persistent,semi-persistent,or persistent modes.In the non-persistent mode,plant viruses are retained in the stylets of their insect vectors.In the semi-persistent mode,plant viruses are carried to vector foreguts or salivary glands,but they cannot spread to salivary glands.In the persistent mode,plant viruses are retained in vector guts and can spread to salivary glands.In the non-persistent and semi-persistent modes,plant viruses are retained for a short time and cannot enter the hemolymph of insect vectors,whereas in the persistent mode,plant viruses are retained for a relatively long time and can be found in the hemolymph.Here,we reviewed recent studies that uncovered molecular mechanisms of how plant viruses manipulate host traits for efficient transmission by insect vectors.Normally,plants that are infected with viruses,regardless of the transmission mode,tend to release more attractive volatiles to vectors.However,plant defensive systems are regulated differently by viruses in these three modes.In the non-persistent mode,virus infections significantly induce plant defense responses,which probably trigger vectors(e.g.,winged aphids)to disperse and transmit viruses in a short time.In the semi-persistent mode,virus infections frequently suppress plant defense responses,resulting in an increase of vector population and facilitating viral transmissions during vector outbreaks.In the persistent mode,virus infections reduce plant defense responses and manipulate plant traits to become suitable feeding sites in a relatively long period of time.Understanding the underlying mechanisms of virus–vector–plant interactions will lay a foundation for preventing virus transmission.展开更多
Among the viruses Cucumber mosaic virus (CMV) has been rated worldwide as one of the five most important viruses infecting vegetable species. CMV is a tripartite virus with high sequence variability, classified into t...Among the viruses Cucumber mosaic virus (CMV) has been rated worldwide as one of the five most important viruses infecting vegetable species. CMV is a tripartite virus with high sequence variability, classified into three subgroups with 80% to 97% identical nucleotides in their coat protein. Due to the absence of natural resistance CMV is the plant virus with longest history in genetic engineering using pathogen induced approaches. However, the transformation and regeneration for some very important crops like chili is difficult. Therefore it will be an advantage to screen in model plants for gene constructs which might be independent of the target of final transformation and other parameters having an influence on the efficiency of a biotechnological approach. In our study we compared the resistance for all combinations of five different antiviral constructs, two different transformation vectors and two model host plants. From these approaches we identified the most effective construct which might also be applicable to transform eventually chili plants.展开更多
Accelerating the establishment of a new development paradigm in which domestic and overseas markets reinforce each other,with the domestic market as the mainstay,has posed new requirements for deepening the consumptio...Accelerating the establishment of a new development paradigm in which domestic and overseas markets reinforce each other,with the domestic market as the mainstay,has posed new requirements for deepening the consumption tax reform.Therefore,we need to focus on accelerating the establishment of a new development paradigm,combined with the establishment of a modern fiscal and tax system and tax attributes,and make effective institutional arrangements for comprehensively promoting consumption,expanding domestic demand and then forming a strong domestic market.It is meaningful to reduce tax on consumer goods involved in upgrading consumption to meet people’s needs for a better life and to raise tax on high energy-consuming,highly polluting and unhealthy consumer goods to enhance the regulatory role of consumption tax and to promote the overall optimization and upgrading of the industrial structure.The revenue of consumption tax on key tax items(categories)should belong to the central government to facilitate the smooth flow of the economic circulation.展开更多
In recent years,the risks and challenges at home and abroad have increased significantly,and the downward pressure on the economy has increased,especially the implementation of larger-scale tax and fee cuts under the ...In recent years,the risks and challenges at home and abroad have increased significantly,and the downward pressure on the economy has increased,especially the implementation of larger-scale tax and fee cuts under the proactive fiscal policy,while the rigidity of local fiscal expenditure has not been reduced,and the sustainable development of local finance is facing greater challenges.In particular,the COVID-19 pandemic has had a serious impact on the already stressed local finance,which has led to the intensifi ed contradiction between local fiscal revenue and expenditure.This paper analyzes the challenges to the sustainable development of local finance under the impact of COVID-19 from four angles:the greater economic downward pressure combined with larger-scale tax and fee cuts,the fiscal relationship between the central and local governments,land finance,and transfer payment,then puts forward the corresponding policy recommendations.展开更多
基金supported by the National Key R&D Program of China(2022YFD1400700)the Key Research and Development Program of Hunan Province,China(2022NK2014)+2 种基金the Hunan Natural Science Foundation,China(2022JJ40234)the Agricultural Science and Technology Innovation Fund Project of Hunan Province,China(2022CX1)the Changsha Natural Science Foundation,China(kq2202338).
文摘Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.
基金the Hunan Natural Science Foundation(Grant No.2019JJ30014)National Natural Science Foundation of China(Grant Nos.31872932 and 31571981)Agriculture Research System of China(Grant No.CARS-23-D-02)。
文摘Plant viruses are mainly transmitted by insect vectors in the non-persistent,semi-persistent,or persistent modes.In the non-persistent mode,plant viruses are retained in the stylets of their insect vectors.In the semi-persistent mode,plant viruses are carried to vector foreguts or salivary glands,but they cannot spread to salivary glands.In the persistent mode,plant viruses are retained in vector guts and can spread to salivary glands.In the non-persistent and semi-persistent modes,plant viruses are retained for a short time and cannot enter the hemolymph of insect vectors,whereas in the persistent mode,plant viruses are retained for a relatively long time and can be found in the hemolymph.Here,we reviewed recent studies that uncovered molecular mechanisms of how plant viruses manipulate host traits for efficient transmission by insect vectors.Normally,plants that are infected with viruses,regardless of the transmission mode,tend to release more attractive volatiles to vectors.However,plant defensive systems are regulated differently by viruses in these three modes.In the non-persistent mode,virus infections significantly induce plant defense responses,which probably trigger vectors(e.g.,winged aphids)to disperse and transmit viruses in a short time.In the semi-persistent mode,virus infections frequently suppress plant defense responses,resulting in an increase of vector population and facilitating viral transmissions during vector outbreaks.In the persistent mode,virus infections reduce plant defense responses and manipulate plant traits to become suitable feeding sites in a relatively long period of time.Understanding the underlying mechanisms of virus–vector–plant interactions will lay a foundation for preventing virus transmission.
文摘Among the viruses Cucumber mosaic virus (CMV) has been rated worldwide as one of the five most important viruses infecting vegetable species. CMV is a tripartite virus with high sequence variability, classified into three subgroups with 80% to 97% identical nucleotides in their coat protein. Due to the absence of natural resistance CMV is the plant virus with longest history in genetic engineering using pathogen induced approaches. However, the transformation and regeneration for some very important crops like chili is difficult. Therefore it will be an advantage to screen in model plants for gene constructs which might be independent of the target of final transformation and other parameters having an influence on the efficiency of a biotechnological approach. In our study we compared the resistance for all combinations of five different antiviral constructs, two different transformation vectors and two model host plants. From these approaches we identified the most effective construct which might also be applicable to transform eventually chili plants.
文摘Accelerating the establishment of a new development paradigm in which domestic and overseas markets reinforce each other,with the domestic market as the mainstay,has posed new requirements for deepening the consumption tax reform.Therefore,we need to focus on accelerating the establishment of a new development paradigm,combined with the establishment of a modern fiscal and tax system and tax attributes,and make effective institutional arrangements for comprehensively promoting consumption,expanding domestic demand and then forming a strong domestic market.It is meaningful to reduce tax on consumer goods involved in upgrading consumption to meet people’s needs for a better life and to raise tax on high energy-consuming,highly polluting and unhealthy consumer goods to enhance the regulatory role of consumption tax and to promote the overall optimization and upgrading of the industrial structure.The revenue of consumption tax on key tax items(categories)should belong to the central government to facilitate the smooth flow of the economic circulation.
文摘In recent years,the risks and challenges at home and abroad have increased significantly,and the downward pressure on the economy has increased,especially the implementation of larger-scale tax and fee cuts under the proactive fiscal policy,while the rigidity of local fiscal expenditure has not been reduced,and the sustainable development of local finance is facing greater challenges.In particular,the COVID-19 pandemic has had a serious impact on the already stressed local finance,which has led to the intensifi ed contradiction between local fiscal revenue and expenditure.This paper analyzes the challenges to the sustainable development of local finance under the impact of COVID-19 from four angles:the greater economic downward pressure combined with larger-scale tax and fee cuts,the fiscal relationship between the central and local governments,land finance,and transfer payment,then puts forward the corresponding policy recommendations.
