Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in ag...Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in agriculture.In this study,we sequenced and characterized the complete genome of ToLCNDV isolates from melon plants showing leaf curling and stunting symptoms in Jiangsu Province of China.We constructed a full-length infectious cDNA clone of ToLCNDV,which could induce systemic infection with typical symptoms in Nicotiana benthamiana,Cit-rullus melo,and Citrullus lanatus plants through agrobacterium-mediated inoculation.Further experimental evidence demonstrated that the virions produced in plants infected with the infectious clone of ToLCNDV are biologically active and sap-transmissible.We also evaluated the resistance of commercial melon cultivars to ToLCNDV and found all testing melon cultivars were susceptible to ToLCNDV.Collectively,the reverse genetic system developed herein will facilitate further research on biological functions of proteins encoded by ToLCNDV and plant-ToLCNDV interactions,which might provide new insights into breeding resistance germplasm in crops.展开更多
Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically...Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.展开更多
Two sequencing batch reactors(SBRs) were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater(USBR), and the other fed with sterilized municipal wastewater(SSBR...Two sequencing batch reactors(SBRs) were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater(USBR), and the other fed with sterilized municipal wastewater(SSBR). Respirometric assays and fluorescence in situ hybridization(FISH) results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate(AUR) and nitrite utilization rate(NUR) of the unsterilized influent were 0.32 ± 0.12 mg NH4+-N/(L·hr) and0.71 ± 0.18 mg NO2--N/(L·hr). Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) of the USBR was 0.08 g AOB/(g AOB·day) and 0.20 g NOB/(g NOB·day) respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35% ± 2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.展开更多
Geminiviruses are a family of plant viruses that cause devastating diseases in many economically important crops worldwide. These pathogens encapsidate circular,single-stranded DNAs (ssDNAs)of 2.5-3.0 kb that replicat...Geminiviruses are a family of plant viruses that cause devastating diseases in many economically important crops worldwide. These pathogens encapsidate circular,single-stranded DNAs (ssDNAs)of 2.5-3.0 kb that replicate through double-stranded DNA (dsDNA)intermediates.Members of the genus Begomovirus,which comprises by far the largest number of species in the family,are transmitted by whiteflies and have genomes consisting of one or two DNAs.展开更多
Geminiviruses are a group of plant viruses that cause severe diseases in many economically important crops worldwide, leading to devastating losses to agricultural production. Here we summarize the occurrence and dist...Geminiviruses are a group of plant viruses that cause severe diseases in many economically important crops worldwide, leading to devastating losses to agricultural production. Here we summarize the occurrence and distribution of geminiviruses in China,which provides valuable information for further epidemiological studies and supports the development of effective disease management strategies.展开更多
Geminiviruses are a group of circular single-stranded DNA viruses that constitute the largest family of plant viruses. Many diseases resulting from geminivirus infections, such as maize streak disease, cassava mosaic ...Geminiviruses are a group of circular single-stranded DNA viruses that constitute the largest family of plant viruses. Many diseases resulting from geminivirus infections, such as maize streak disease, cassava mosaic disease, tomato yellow leaf curl disease and cotton leaf curl diseases, cause significant problems in terms of economic losses, posing a serious threat to global crop productivity (Hanley-Bowdoin et al., 2013;Yang et al., 2019). As obligate intracellular parasites, geminiviruses cannot be controlled chemically. Conventional strategies to control geminiviruses rely heavily on the application of pesticides to limit insect vector populations, but it causes environmental concerns. To date, developing novel crop germplasms with durable disease resistance to geminiviruses is still the best strategy to manage viral infections due to its environmental friendliness. However, traditional breeding programs are time-intensive and labor-consuming processes, and transgene-based modern approaches by overexpressing the geminiviral proteins (e.g., the truncated form of the replication initiator protein) failed to confer resistance to geminiviruses due to activated virusinduced transgene silencing.展开更多
Heart transplantation is an effective treatment for endstage heart failure;however,problems such as the severe shortage of donor hearts,rejection,the toxic effects of immunosuppressants,and serious postoperative compl...Heart transplantation is an effective treatment for endstage heart failure;however,problems such as the severe shortage of donor hearts,rejection,the toxic effects of immunosuppressants,and serious postoperative complications remain.[1]Heart xenotransplantation is one of the most promising alternatives to address the shortage of allogeneic donor hearts.However,the recipient survival rate and quality of life are affected by major obstacles,including immune rejection,complement and coagulation dysfunction,and infection.[2,3]Owing to the continuous improvement of gene editing strategies for donor pigs and anti-immune rejection strategies for non-human primate recipients.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(31930089).
文摘Tomato leaf curl New Delhi virus(ToLCNDV)is a member of the genus Begomovirus,and causes devastating disease in the world.In recent years,ToLCNDV was rapidly spreading in China and induces severe economic losses in agriculture.In this study,we sequenced and characterized the complete genome of ToLCNDV isolates from melon plants showing leaf curling and stunting symptoms in Jiangsu Province of China.We constructed a full-length infectious cDNA clone of ToLCNDV,which could induce systemic infection with typical symptoms in Nicotiana benthamiana,Cit-rullus melo,and Citrullus lanatus plants through agrobacterium-mediated inoculation.Further experimental evidence demonstrated that the virions produced in plants infected with the infectious clone of ToLCNDV are biologically active and sap-transmissible.We also evaluated the resistance of commercial melon cultivars to ToLCNDV and found all testing melon cultivars were susceptible to ToLCNDV.Collectively,the reverse genetic system developed herein will facilitate further research on biological functions of proteins encoded by ToLCNDV and plant-ToLCNDV interactions,which might provide new insights into breeding resistance germplasm in crops.
基金grants from the National Natural Science Foundation of China (31720103914 and 31390422).
文摘Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.
基金supported by the National Natural Science Foundation for Young Scholars of China(No.51208414)the Education Department of Shaanxi Province Special Scientific Research(No.12JK0650)
文摘Two sequencing batch reactors(SBRs) were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater(USBR), and the other fed with sterilized municipal wastewater(SSBR). Respirometric assays and fluorescence in situ hybridization(FISH) results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate(AUR) and nitrite utilization rate(NUR) of the unsterilized influent were 0.32 ± 0.12 mg NH4+-N/(L·hr) and0.71 ± 0.18 mg NO2--N/(L·hr). Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) of the USBR was 0.08 g AOB/(g AOB·day) and 0.20 g NOB/(g NOB·day) respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35% ± 2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.
基金The National Natural Science Foundation of China (31390422 and 31720103914)The Bisaro laboratory is supported by grants from the US National Science Foundation (NSF IOS-1354636)the US Department of Agriculture and National Institute of Food and Agriculture (USDA/NIFA 2015-6703-22999).
文摘Geminiviruses are a family of plant viruses that cause devastating diseases in many economically important crops worldwide. These pathogens encapsidate circular,single-stranded DNAs (ssDNAs)of 2.5-3.0 kb that replicate through double-stranded DNA (dsDNA)intermediates.Members of the genus Begomovirus,which comprises by far the largest number of species in the family,are transmitted by whiteflies and have genomes consisting of one or two DNAs.
基金supported by the National Natural Science Foundation of China (31720103914, 32172385)the National Key Research and Development Program of China (2021YFD1400400)the China National Tobacco Corporation (110202001030(JY-13))。
文摘Geminiviruses are a group of plant viruses that cause severe diseases in many economically important crops worldwide, leading to devastating losses to agricultural production. Here we summarize the occurrence and distribution of geminiviruses in China,which provides valuable information for further epidemiological studies and supports the development of effective disease management strategies.
文摘Geminiviruses are a group of circular single-stranded DNA viruses that constitute the largest family of plant viruses. Many diseases resulting from geminivirus infections, such as maize streak disease, cassava mosaic disease, tomato yellow leaf curl disease and cotton leaf curl diseases, cause significant problems in terms of economic losses, posing a serious threat to global crop productivity (Hanley-Bowdoin et al., 2013;Yang et al., 2019). As obligate intracellular parasites, geminiviruses cannot be controlled chemically. Conventional strategies to control geminiviruses rely heavily on the application of pesticides to limit insect vector populations, but it causes environmental concerns. To date, developing novel crop germplasms with durable disease resistance to geminiviruses is still the best strategy to manage viral infections due to its environmental friendliness. However, traditional breeding programs are time-intensive and labor-consuming processes, and transgene-based modern approaches by overexpressing the geminiviral proteins (e.g., the truncated form of the replication initiator protein) failed to confer resistance to geminiviruses due to activated virusinduced transgene silencing.
基金Xijing Hospital Clinical New Technology Project(grant Nos.XJSZ03 and XJSM02)
文摘Heart transplantation is an effective treatment for endstage heart failure;however,problems such as the severe shortage of donor hearts,rejection,the toxic effects of immunosuppressants,and serious postoperative complications remain.[1]Heart xenotransplantation is one of the most promising alternatives to address the shortage of allogeneic donor hearts.However,the recipient survival rate and quality of life are affected by major obstacles,including immune rejection,complement and coagulation dysfunction,and infection.[2,3]Owing to the continuous improvement of gene editing strategies for donor pigs and anti-immune rejection strategies for non-human primate recipients.