UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the in...UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the interplays between UPR and plant DNA viruses remain unknown.Using tomato yellow leaf curl China virus(TYLCCNV)and its associated betasatellite(TYLCCNB)as a model,we indicate that TYLCCNBβC1 is a major inducer of UPR and can upregulate the expression of b ZIP60,a transcription factor in Nicotiana benthamiana plants.Treatment using ER stress inducers or overexpression of Nbb ZIP60 increasesβC1 accumulation and benefits TYLCCNV/TYLCCNB infection in N.benthamiana plants,and vice versa.In the TYLCCNV/TYLCCNB-infected or theβC1-expressing cells,Nbb ZIP60 is exported from the nucleus to the nuclear periphery via the XPO1 pathway,and blocking the XPO1 pathway inhibited TYLCCNV/TYLCCNB infection.We have found that the Nbb ZIP60-regulated pro-survival genes could promote virus infection,and the pro-death gene plays a contrasting role in virus infection.This study reveals that geminivirus infection activates UPR and utilizes the up-regulated molecular chaperons to promote viral infection,and then induces the nuclear export of Nbb ZIP60 to evade plant defense response,which is a distinct virulence strategy exploited by plant pathogens.展开更多
Pennisetum plants(Pennisetum alopecuroides L.),displaying a dwarfing phenotype along with delayed flowering and mosaic symptom on leaves,were found in Beijing,China.Flexuous filamentous particles with a size of approx...Pennisetum plants(Pennisetum alopecuroides L.),displaying a dwarfing phenotype along with delayed flowering and mosaic symptom on leaves,were found in Beijing,China.Flexuous filamentous particles with a size of approximate 15×850 nm were observed in symptomatic leaves via transmission electron microscopy.Deep sequencing of small RNAs(sRNA)from symptomatic leaves and analysis of sRNA populations were then conducted to determine the genome sequence of the viral agent in diseased plant tissues.It showed that the viral agent had one positive-sense and single-stranded RNA genome,which consisted of 9717 nucleotides(nts)excluding poly(A)tail.The complete viral genome contained a large open reading frame,encoding a polyprotein of 3131 amino acids(aa).Sequence comparison and phylogenetic analysis demonstrated that the viral agent belonged to the genus Potyvirus in the family Potyviridae.In the cladogram it was most closely related to johnsongrass mosaic virus,sharing 72%nt and 65%aa sequence identity.This viral agent was provisionally named pennisetum alopecuroides mosaic virus(PalMV).Subsequently,it was confirmed that PalMV is the causal agent of this new disease in P.alopecuroides by Koch’s postulates and reverse transcription-polymerase chain reaction analysis.Moreover,maize,millet,wheat,sorghum and rice plants were experimentally infected by PalMV via rub inoculation.Consequently,we proposed that PalMV could be a potentially dangerous virus threating a wide range of cereal crops.展开更多
Co-infection of maize chlorotic mottle virus(MCMV)with a virus in the Potyviridae family,such as sugarcane mosaic virus,usually leads to maize lethal necrosis(MLN).Over the past decade,MCMV/MLN has emerged in many cou...Co-infection of maize chlorotic mottle virus(MCMV)with a virus in the Potyviridae family,such as sugarcane mosaic virus,usually leads to maize lethal necrosis(MLN).Over the past decade,MCMV/MLN has emerged in many countries/regions of the world and resulted in serious yield loss in maize production.Although partial functions of some MCMV-encoded proteins have been identified,the host factors related to MCMV replication are poorly understood.Here,we show that maize peroxisomes can form aggregated bodies in MCMV-infected leaf cells.The dsRNA binding-dependent fluorescence complementation assay indicated that the aggregated peroxisomes in maize served as the major replication site of MCMV.In addition,our results revealed that all the three maize catalases were present mostly in peroxisomes in the presence or absence of MCMV.Furthermore,we determined that inhibition of catalase activity or induction of reactive oxygen species(ROS)in maize protoplasts significantly reduced the accumulation of MCMV RNA.In summary,this research reveals the replication site of MCMV and an important role of maize catalases in supporting virus replication.Our results are conducive to understanding the pathogenesis of MCMV and identifying targets for resistance breeding or gene regulation strategies.展开更多
Maize chlorotic mottle virus(MCMV)is one of the important quarantine pathogens in China.It often co-infects with one or two viruses in the family Potyviridae and causes maize lethal necrosis disease.Therefore,an accur...Maize chlorotic mottle virus(MCMV)is one of the important quarantine pathogens in China.It often co-infects with one or two viruses in the family Potyviridae and causes maize lethal necrosis disease.Therefore,an accurate and sensitive method for the detection of MCMV is urgently needed.Combined with reverse transcription and recombinaseaided amplification,we developed a CRISPR/Cas12a-based visual nucleic acid detection system targeting the MCMV coat protein gene.The whole process can be completed within 45 min with high sensitivity.This system could detect cDNAs diluted up to 10^(-5)when 2000 ng of total RNA was used for reverse transcription.The Cas12a/crRNA complex designed for MCMV detection could recognize and cleave the targeted double-stranded DNA,and ultimately cleave the single-stranded DNA probes and produce fluorescent signals.The green fluorescence produced under blue light(440-460 nm)in this procedure could be observed by the naked eye.Since this novel method is specific,rapid,sensitive and does not require special instruments and technical expertise,it should be suitable for on-site visual detection of MCMV in seeds,plants of maize and potentially in its insect vectors.展开更多
Maize lethal necrosis(MLN)is a devastating disease of maize caused by synergistic infection with maize chlorotic mottle virus(MCMV)and at least one potyvirid(e.g.,sugarcane mosaic virus,SCMV).MLN results in leaf necro...Maize lethal necrosis(MLN)is a devastating disease of maize caused by synergistic infection with maize chlorotic mottle virus(MCMV)and at least one potyvirid(e.g.,sugarcane mosaic virus,SCMV).MLN results in leaf necrosis,premature aging,and even whole plant death and can cause up to 100%losses in yield.MLN has emerged worldwide and resulted in serious loss in maize production.Over the past decade,extensive research has been conducted to understand the epidemic and pathogenic mechanisms of MLN.In this review,we summarize recent findings in understanding the biological functions of proteins from both viruses and discuss recent advances in molecular plantvirus interactions,particularly the co-evolutionary arms race between maize anti-viral defense and viral pathogenesis(counter-defense).Based on recent research progress,we discuss how to combine different strategies for enhancing the effectiveness of maize resistance to MCMV/SCMV,and the possible approaches for effective control of MLN.展开更多
Diaporthe helianthi is one of the main fungal pathogens responsible for causing phomopsis stem canker and significant yield losses of sunflowers.In this study,the calmodulin(Cal)gene of D.helianthi was selected to dev...Diaporthe helianthi is one of the main fungal pathogens responsible for causing phomopsis stem canker and significant yield losses of sunflowers.In this study,the calmodulin(Cal)gene of D.helianthi was selected to develop a rapid detection method involving recombinase polymerase amplification(RPA)combined with CRISPR/Cas12a-based detection at 37℃.The developed detection system could complete the specific detection of D.helianthi in 45 min,including 25 min for RPA and 20 min for CRISPR/Cas12 reaction.The detection system could be coupled with both lateral flow test strips and fluorescence signal reading modes.The detection limit for lateral flow assay was 1 pg/μL genomic D.helianthi DNA(14 copies/μL);The detection limit for fluorescence signal was 0.1 pg/μL genomic DNA(1.4 copies/μL),approximately 100 times higher than that of the real-time PCR.Thus,the developed RPA/CRISPR-Cas12a system meets the need for portable detection of D.helianthi on-site at ports and in the field.展开更多
基金supported by the National Key Research and Development Program of China (2021YFD1400400)the National Natural Science Foundation of China (32172385,31930089)。
文摘UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the interplays between UPR and plant DNA viruses remain unknown.Using tomato yellow leaf curl China virus(TYLCCNV)and its associated betasatellite(TYLCCNB)as a model,we indicate that TYLCCNBβC1 is a major inducer of UPR and can upregulate the expression of b ZIP60,a transcription factor in Nicotiana benthamiana plants.Treatment using ER stress inducers or overexpression of Nbb ZIP60 increasesβC1 accumulation and benefits TYLCCNV/TYLCCNB infection in N.benthamiana plants,and vice versa.In the TYLCCNV/TYLCCNB-infected or theβC1-expressing cells,Nbb ZIP60 is exported from the nucleus to the nuclear periphery via the XPO1 pathway,and blocking the XPO1 pathway inhibited TYLCCNV/TYLCCNB infection.We have found that the Nbb ZIP60-regulated pro-survival genes could promote virus infection,and the pro-death gene plays a contrasting role in virus infection.This study reveals that geminivirus infection activates UPR and utilizes the up-regulated molecular chaperons to promote viral infection,and then induces the nuclear export of Nbb ZIP60 to evade plant defense response,which is a distinct virulence strategy exploited by plant pathogens.
基金supported by grants from Ministry of Agriculture and Rural Affairs of China(2018YFD020062)the Chinese Universities Scientific Fund(2019TC064).
文摘Pennisetum plants(Pennisetum alopecuroides L.),displaying a dwarfing phenotype along with delayed flowering and mosaic symptom on leaves,were found in Beijing,China.Flexuous filamentous particles with a size of approximate 15×850 nm were observed in symptomatic leaves via transmission electron microscopy.Deep sequencing of small RNAs(sRNA)from symptomatic leaves and analysis of sRNA populations were then conducted to determine the genome sequence of the viral agent in diseased plant tissues.It showed that the viral agent had one positive-sense and single-stranded RNA genome,which consisted of 9717 nucleotides(nts)excluding poly(A)tail.The complete viral genome contained a large open reading frame,encoding a polyprotein of 3131 amino acids(aa).Sequence comparison and phylogenetic analysis demonstrated that the viral agent belonged to the genus Potyvirus in the family Potyviridae.In the cladogram it was most closely related to johnsongrass mosaic virus,sharing 72%nt and 65%aa sequence identity.This viral agent was provisionally named pennisetum alopecuroides mosaic virus(PalMV).Subsequently,it was confirmed that PalMV is the causal agent of this new disease in P.alopecuroides by Koch’s postulates and reverse transcription-polymerase chain reaction analysis.Moreover,maize,millet,wheat,sorghum and rice plants were experimentally infected by PalMV via rub inoculation.Consequently,we proposed that PalMV could be a potentially dangerous virus threating a wide range of cereal crops.
基金supported by grants from the Ministry of Science and Technology(2016YFD0300710)the National Natural Science Foundation of China(no.31571980)+1 种基金the Ministry of Education(the 111 Project B13006)State Key Laboratory of Agrobiotechnology(2019SKLAB6–19).
文摘Co-infection of maize chlorotic mottle virus(MCMV)with a virus in the Potyviridae family,such as sugarcane mosaic virus,usually leads to maize lethal necrosis(MLN).Over the past decade,MCMV/MLN has emerged in many countries/regions of the world and resulted in serious yield loss in maize production.Although partial functions of some MCMV-encoded proteins have been identified,the host factors related to MCMV replication are poorly understood.Here,we show that maize peroxisomes can form aggregated bodies in MCMV-infected leaf cells.The dsRNA binding-dependent fluorescence complementation assay indicated that the aggregated peroxisomes in maize served as the major replication site of MCMV.In addition,our results revealed that all the three maize catalases were present mostly in peroxisomes in the presence or absence of MCMV.Furthermore,we determined that inhibition of catalase activity or induction of reactive oxygen species(ROS)in maize protoplasts significantly reduced the accumulation of MCMV RNA.In summary,this research reveals the replication site of MCMV and an important role of maize catalases in supporting virus replication.Our results are conducive to understanding the pathogenesis of MCMV and identifying targets for resistance breeding or gene regulation strategies.
基金supported by grants from the Administration Bureau of Sanya Yazhou Bay Science and Technology City(SYND-2021-03)China Agricultural Research System of MOF and MARA(CARS-02).
文摘Maize chlorotic mottle virus(MCMV)is one of the important quarantine pathogens in China.It often co-infects with one or two viruses in the family Potyviridae and causes maize lethal necrosis disease.Therefore,an accurate and sensitive method for the detection of MCMV is urgently needed.Combined with reverse transcription and recombinaseaided amplification,we developed a CRISPR/Cas12a-based visual nucleic acid detection system targeting the MCMV coat protein gene.The whole process can be completed within 45 min with high sensitivity.This system could detect cDNAs diluted up to 10^(-5)when 2000 ng of total RNA was used for reverse transcription.The Cas12a/crRNA complex designed for MCMV detection could recognize and cleave the targeted double-stranded DNA,and ultimately cleave the single-stranded DNA probes and produce fluorescent signals.The green fluorescence produced under blue light(440-460 nm)in this procedure could be observed by the naked eye.Since this novel method is specific,rapid,sensitive and does not require special instruments and technical expertise,it should be suitable for on-site visual detection of MCMV in seeds,plants of maize and potentially in its insect vectors.
基金supported by the Administration Bureau of Sanya Yazhou Bay Science and Technology City(SYND-2021-03)China Agricultural Research System of MOF and MARA(CARS-02).
文摘Maize lethal necrosis(MLN)is a devastating disease of maize caused by synergistic infection with maize chlorotic mottle virus(MCMV)and at least one potyvirid(e.g.,sugarcane mosaic virus,SCMV).MLN results in leaf necrosis,premature aging,and even whole plant death and can cause up to 100%losses in yield.MLN has emerged worldwide and resulted in serious loss in maize production.Over the past decade,extensive research has been conducted to understand the epidemic and pathogenic mechanisms of MLN.In this review,we summarize recent findings in understanding the biological functions of proteins from both viruses and discuss recent advances in molecular plantvirus interactions,particularly the co-evolutionary arms race between maize anti-viral defense and viral pathogenesis(counter-defense).Based on recent research progress,we discuss how to combine different strategies for enhancing the effectiveness of maize resistance to MCMV/SCMV,and the possible approaches for effective control of MLN.
基金supported by the National Key Research and Development Program of China(2021YFC2600400&2021YFC2600402)Basic Scientific Research Foundation of Chinese Academy of Inspection and Quarantine(2022JK20)the Subject Construction Project of Dalian University(DLUXK-2022-ZD-002).
文摘Diaporthe helianthi is one of the main fungal pathogens responsible for causing phomopsis stem canker and significant yield losses of sunflowers.In this study,the calmodulin(Cal)gene of D.helianthi was selected to develop a rapid detection method involving recombinase polymerase amplification(RPA)combined with CRISPR/Cas12a-based detection at 37℃.The developed detection system could complete the specific detection of D.helianthi in 45 min,including 25 min for RPA and 20 min for CRISPR/Cas12 reaction.The detection system could be coupled with both lateral flow test strips and fluorescence signal reading modes.The detection limit for lateral flow assay was 1 pg/μL genomic D.helianthi DNA(14 copies/μL);The detection limit for fluorescence signal was 0.1 pg/μL genomic DNA(1.4 copies/μL),approximately 100 times higher than that of the real-time PCR.Thus,the developed RPA/CRISPR-Cas12a system meets the need for portable detection of D.helianthi on-site at ports and in the field.
