Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)...Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)markers and insertion/deletion(In Del)markers were developed to fine map the Me3 gene.Analysis of 2272 individuals(F2progenies)revealed that Me3 was located in a 45-kb DNA region between markers SSR784 and SSR339,in which there were three candidate genes.Among them,as a novel nucleotide binding site and leucine rich repeat(NBS-LRR)family gene,the DNA sequence of Capana09g000163 of pepper line‘HDA149’was 6348 bp in length,with a 2802-bp open reading frame encoding 933 amino acids,including NB-ARC and LRR domains.Tobacco transient expression assays demonstrated that expression of Capana09g000163 triggered a hypersensitive response(HR)in Nicotiana benthamiana leaves.Subcellular localization results showed that the Capana09g000163 protein was localized in the cell nucleus.Ectopic expression of Capana09g000163 in Arabidopsis significantly increased resistance against Meloidogyne incognita compared with the wild-type(WT)Arabidopsis.Furthermore,M.incognita was almost unable to develop in transgenic Arabidopsis expressing Capana09g000163.Taken together,we cloned the Me3 gene and verified that it induced resistance against M.incognita with the methods of map-based cloning and transgenic technology,which may be of great significance to pepper breeding for resistance against RKNs.展开更多
The dominant frequency modes of pre-summer extreme precipitation events(EPEs)over South China(SC)between1998 and 2018 were investigated.The 67 identified EPEs were all characterized by the 3-8-d(synoptic)frequency ban...The dominant frequency modes of pre-summer extreme precipitation events(EPEs)over South China(SC)between1998 and 2018 were investigated.The 67 identified EPEs were all characterized by the 3-8-d(synoptic)frequency band.However,multiscale combined modes of the synoptic and three low-frequency bands[10-20-d(quasi-biweekly,QBW);15-40-d(quasi-monthly,QM);and 20-60-d(intraseasonal)]accounted for the majority(63%)of the EPEs,and the precipitation intensity on the peak wet day was larger than that of the single synoptic mode.It was found that EPEs form within strong southwesterly anomalous flows characterized by either lower-level cyclonic circulation over SC or a deep trough over eastern China.Bandpass-filtered disturbances revealed the direct precipitating systems and their life cycles.Synoptic-scale disturbances are dominated by mid-high latitude troughs,and the cyclonic anomalies originate from downstream of the Tibetan Plateau(TP).Given the warm and moist climate state,synoptic-scale northeasterly flows can even induce EPEs.At the QBW and QM scales,the disturbances originate from the tropical Pacific,downstream of the TP,or mid-high latitudes(QBW only).Each is characterized by cyclonic-anticyclonic wave trains and intense southwesterly flows between them within a region of large horizontal pressure gradient.The intraseasonal disturbances are confined to tropical regions and influence SC by marginal southwesterly flows.It is concluded that low-frequency disturbances provide favorable background conditions for EPEs over SC and synoptic-scale disturbances ultimately induce EPEs on the peak wet days.Both should be simultaneously considered for EPE predictions over SC.展开更多
A new local kinetic energy(KE)budget for the Madden−Julian Oscillation(MJO)is constructed in a multi-scale framework.This energy budget framework allows us to analyze the local energy conversion processes of the MJO w...A new local kinetic energy(KE)budget for the Madden−Julian Oscillation(MJO)is constructed in a multi-scale framework.This energy budget framework allows us to analyze the local energy conversion processes of the MJO with the high-frequency disturbances and the low-frequency background state.The KE budget analysis is applied to a pronounced MJO event during the DYNAMO field campaign to investigate the KE transport path of the MJO.The work done by the pressure gradient force and the conversion of available potential energy at the MJO scale are the two dominant processes that affect the MJO KE tendency.The MJO winds transport MJO KE into the MJO convection region in the lower troposphere while it is transported away from the MJO convection region in the upper troposphere.The energy cascade process is relatively weak,but the interaction between high-frequency disturbances and the MJO plays an important role in maintaining the high-frequency disturbances within the MJO convection.The MJO KE mainly converts to interaction KE between MJO and high-frequency disturbances over the area where the MJO zonal wind is strong.This interaction KE over the MJO convection region is enhanced through its flux convergence and further transport KE to the high-frequency disturbances.This process is conducive to maintaining the MJO convection.This study highlights the importance of KE interaction between the MJO and the high-frequency disturbances in maintaining the MJO convection.展开更多
Root-knot nematodes(RKNs)cause huge agricultural losses every year.They secrete a repertoire of effectors to facilitate parasitism through the induction of plant-derived giant feeding cells,which serve as their sole s...Root-knot nematodes(RKNs)cause huge agricultural losses every year.They secrete a repertoire of effectors to facilitate parasitism through the induction of plant-derived giant feeding cells,which serve as their sole source of nutrients.However,the mode of action of these effectors and their targeted host pro-teins remain largely unknown.In this study,we investigated the role of the effector Mi2G02 in Meloidogyne incognita parasitism.Host-derived Mi2G02 RNA interference in Arabidopsis thaliana affected giant cell development,whereas ectopic expression of Mi2G02 promoted root growth and increased plant sus-ceptibility to M.incognita.We used various combinations of approaches to study the specific interactions between Mi2G02 and A.thaliana GT-3a,a trihelix transcription factor.GT-3a knockout in A.thaliana affected feeding-site development,resulting in production of fewer egg masses,whereas GT-3a overex-pression in A.thaliana increased susceptibility to M.incognita and also root growth.Moreover,we demon-strated that Mi2G02 plays a role in maintaining GT-3a protein stabilization by inhibiting the 26S proteasome-dependent pathway,leading to suppression of TOZ and RAD23C expression and thus promoting nematode parasitism.This work enhances our understanding of how a pathogen effector manipulates the role and regulation of a transcription factor by interfering with a proteolysis pathway to reprogram gene expression for development of nematode feeding cells.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.31672010,31871942 and 32172366)Hainan Yazhou Bay Seed Lab(Grant No.B21HJ0214)China Agriculture Research System(Grant No.CARS-25)。
文摘Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)markers and insertion/deletion(In Del)markers were developed to fine map the Me3 gene.Analysis of 2272 individuals(F2progenies)revealed that Me3 was located in a 45-kb DNA region between markers SSR784 and SSR339,in which there were three candidate genes.Among them,as a novel nucleotide binding site and leucine rich repeat(NBS-LRR)family gene,the DNA sequence of Capana09g000163 of pepper line‘HDA149’was 6348 bp in length,with a 2802-bp open reading frame encoding 933 amino acids,including NB-ARC and LRR domains.Tobacco transient expression assays demonstrated that expression of Capana09g000163 triggered a hypersensitive response(HR)in Nicotiana benthamiana leaves.Subcellular localization results showed that the Capana09g000163 protein was localized in the cell nucleus.Ectopic expression of Capana09g000163 in Arabidopsis significantly increased resistance against Meloidogyne incognita compared with the wild-type(WT)Arabidopsis.Furthermore,M.incognita was almost unable to develop in transgenic Arabidopsis expressing Capana09g000163.Taken together,we cloned the Me3 gene and verified that it induced resistance against M.incognita with the methods of map-based cloning and transgenic technology,which may be of great significance to pepper breeding for resistance against RKNs.
基金supported by the National Key R&D Program of China(Grant No.2018YFC1507403)。
文摘The dominant frequency modes of pre-summer extreme precipitation events(EPEs)over South China(SC)between1998 and 2018 were investigated.The 67 identified EPEs were all characterized by the 3-8-d(synoptic)frequency band.However,multiscale combined modes of the synoptic and three low-frequency bands[10-20-d(quasi-biweekly,QBW);15-40-d(quasi-monthly,QM);and 20-60-d(intraseasonal)]accounted for the majority(63%)of the EPEs,and the precipitation intensity on the peak wet day was larger than that of the single synoptic mode.It was found that EPEs form within strong southwesterly anomalous flows characterized by either lower-level cyclonic circulation over SC or a deep trough over eastern China.Bandpass-filtered disturbances revealed the direct precipitating systems and their life cycles.Synoptic-scale disturbances are dominated by mid-high latitude troughs,and the cyclonic anomalies originate from downstream of the Tibetan Plateau(TP).Given the warm and moist climate state,synoptic-scale northeasterly flows can even induce EPEs.At the QBW and QM scales,the disturbances originate from the tropical Pacific,downstream of the TP,or mid-high latitudes(QBW only).Each is characterized by cyclonic-anticyclonic wave trains and intense southwesterly flows between them within a region of large horizontal pressure gradient.The intraseasonal disturbances are confined to tropical regions and influence SC by marginal southwesterly flows.It is concluded that low-frequency disturbances provide favorable background conditions for EPEs over SC and synoptic-scale disturbances ultimately induce EPEs on the peak wet days.Both should be simultaneously considered for EPE predictions over SC.
基金This study was supported by the National Key R&D Program of China through Grant Nos.2018YFC1505901 and 2018YFA0606203the National Nature Science Foundation of China through Grant Nos.41922035,41575062,41520104008+1 种基金Key Research Program of Frontier Sciences of CAS through Grant No.QYZDB-SSW-DQC017the Youth Innovation Promotion Association,Chinese Academy of Sciences.The first author acknowledges the support from the China Scholarship Council(CSC)Grant No.201904910516.
文摘A new local kinetic energy(KE)budget for the Madden−Julian Oscillation(MJO)is constructed in a multi-scale framework.This energy budget framework allows us to analyze the local energy conversion processes of the MJO with the high-frequency disturbances and the low-frequency background state.The KE budget analysis is applied to a pronounced MJO event during the DYNAMO field campaign to investigate the KE transport path of the MJO.The work done by the pressure gradient force and the conversion of available potential energy at the MJO scale are the two dominant processes that affect the MJO KE tendency.The MJO winds transport MJO KE into the MJO convection region in the lower troposphere while it is transported away from the MJO convection region in the upper troposphere.The energy cascade process is relatively weak,but the interaction between high-frequency disturbances and the MJO plays an important role in maintaining the high-frequency disturbances within the MJO convection.The MJO KE mainly converts to interaction KE between MJO and high-frequency disturbances over the area where the MJO zonal wind is strong.This interaction KE over the MJO convection region is enhanced through its flux convergence and further transport KE to the high-frequency disturbances.This process is conducive to maintaining the MJO convection.This study highlights the importance of KE interaction between the MJO and the high-frequency disturbances in maintaining the MJO convection.
基金supported by the Youth Innovation Program of the Chinese Academy of Agricultural Sciences (grant no.Y2022QC06)the National Natural Science Foundation of China (grant nos.32001878,32172366)+2 种基金the Natural Science Foundation of Beijing (grant no.6222054)the China Agricultural Research System (CARS-23)the French Government (National Research Agency,ANR)through"Investments for the Future"LabEx SIGNALIFE (#ANR-11-LABX-0028-01),IDEX UCAJedi (#ANR-15-IDEX-0).
文摘Root-knot nematodes(RKNs)cause huge agricultural losses every year.They secrete a repertoire of effectors to facilitate parasitism through the induction of plant-derived giant feeding cells,which serve as their sole source of nutrients.However,the mode of action of these effectors and their targeted host pro-teins remain largely unknown.In this study,we investigated the role of the effector Mi2G02 in Meloidogyne incognita parasitism.Host-derived Mi2G02 RNA interference in Arabidopsis thaliana affected giant cell development,whereas ectopic expression of Mi2G02 promoted root growth and increased plant sus-ceptibility to M.incognita.We used various combinations of approaches to study the specific interactions between Mi2G02 and A.thaliana GT-3a,a trihelix transcription factor.GT-3a knockout in A.thaliana affected feeding-site development,resulting in production of fewer egg masses,whereas GT-3a overex-pression in A.thaliana increased susceptibility to M.incognita and also root growth.Moreover,we demon-strated that Mi2G02 plays a role in maintaining GT-3a protein stabilization by inhibiting the 26S proteasome-dependent pathway,leading to suppression of TOZ and RAD23C expression and thus promoting nematode parasitism.This work enhances our understanding of how a pathogen effector manipulates the role and regulation of a transcription factor by interfering with a proteolysis pathway to reprogram gene expression for development of nematode feeding cells.
