Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we ...Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we report the function of HvMKK1-HvMPK4-HvWRKY1 module in barley immune system.HvMPK4 is identified to play a negative role in barley immune response against Bgh,as virus-induced gene silencing of HvMPK4 results in enhanced disease resistance whilst stably overexpressing HvMPK4 leads to super-susceptibility to Bgh infection.Furthermore,the barley MAPK kinase HvMKK1 is found to specifically interact with HvMPK4,and the activated HvMKK1^(DD) variant specifically phosphorylates HvMPK4 in vitro.Moreover,the transcription factor HvWRKY1 is identified to be a downstream target of HvMPK4 and phosphorylated by HvMPK4 in vitro in the presence of HvMKK1^(DD).Phosphorylation assay coupled with mutagenesis analyses identifies S122,T284,and S347 in HvWRKY1 as the major residues phosphorylated by HvMPK4.HvWRKY1 is phosphorylated in barley at the early stages of Bgh infection,which enhances its suppression on barley immunity likely due to enhanced DNA-binding and transcriptional repression activity.Our data suggest that the HvMKK1-HvMPK4 kinase pair acts upstream of HvWRKY1 to negatively regulate barley immunity against powdery mildew.展开更多
Triticum urartu(AA,2n=2x=14),a wild grass endemic to the Fertile Crescent(FC),is the progenitor of the A subgenome in common wheat.It belongs to the primary gene pool for wheat improvement.Here,we evaluated the yellow...Triticum urartu(AA,2n=2x=14),a wild grass endemic to the Fertile Crescent(FC),is the progenitor of the A subgenome in common wheat.It belongs to the primary gene pool for wheat improvement.Here,we evaluated the yellow rust(caused by Puccinia striiformis f.sp.tritici,Pst)reactions of 147 T.urartu accessions collected from different parts of the FC.The reactions varied from susceptibility to strong resistance.In general,there were more accessions with stronger resistance to race CYR33 than to CYR 32.In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves.Forty two accessions displayed resistance to both races.Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response.Gene silencing mediated by Barley stripe mosaic virus was effective in two T.urartu accessions with different resistance responses,indicating that this method can expedite future functional analysis of resistance genes.Our data suggest that T.urartu is a valuable source of resistance to yellow rust,and represents a model for studying the genetic,genomic and molecular basis underlying interaction between wheat and Pst.展开更多
Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a me...Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a metabolic regulator that is essential for plant growth and stress responses.Here,we identify barley SnRK1 and a WRKY3 transcription factor by screening a cDNA library.SnRK1 interacts with WRKY3 in yeast,as confirmed by pull-down and luciferase complementation assays.Förster resonance energy transfer combined with noninvasive fluorescence lifetime imaging analysis indicates that the interaction occurs in the barley nucleus.Transient expression and virus-induced gene silencing analyses indicate that WRKY3 acts as a repressor of disease resistance to the Bgh fungus.Barley plants overexpressing WRKY3 have enhanced fungal microcolony formation and sporulation.Phosphorylation assays show that SnRK1 phosphorylates WRKY3 mainly at Ser83 and Ser112 to destabilize the repressor,and WRKY3 non-phosphorylation-null mutants at these two sites are more stable than the wild-type protein.SnRK1-overexpressing barley plants display enhanced disease resistance to Bgh.Transient expression of SnRK1 reduces fungal haustorium formation in barley cells,which probably requires SnRK1 nuclear localization and kinase activity.Together,these findings suggest that SnRK1 is directly involved in plant immunity through phosphorylation and destabilization of the WRKY3 repressor,revealing a new regulatory mechanism of immune derepression in plants.展开更多
基金funded by the National Key R&D Program of China(2018YFD1000703 and 2018YFD1000700)the Strategic Priority Research Program of Chinese Academy of Sciences(XDPB16)National Program on Research and Development of Transgenic Plants(2016ZX08009-003-001).
文摘Mitogen-activated protein kinase(MAPK)cascades play important roles in disease resistance in model plant species.However,the functions of MAPK signaling pathways in crop disease resistance are largely unknown.Here we report the function of HvMKK1-HvMPK4-HvWRKY1 module in barley immune system.HvMPK4 is identified to play a negative role in barley immune response against Bgh,as virus-induced gene silencing of HvMPK4 results in enhanced disease resistance whilst stably overexpressing HvMPK4 leads to super-susceptibility to Bgh infection.Furthermore,the barley MAPK kinase HvMKK1 is found to specifically interact with HvMPK4,and the activated HvMKK1^(DD) variant specifically phosphorylates HvMPK4 in vitro.Moreover,the transcription factor HvWRKY1 is identified to be a downstream target of HvMPK4 and phosphorylated by HvMPK4 in vitro in the presence of HvMKK1^(DD).Phosphorylation assay coupled with mutagenesis analyses identifies S122,T284,and S347 in HvWRKY1 as the major residues phosphorylated by HvMPK4.HvWRKY1 is phosphorylated in barley at the early stages of Bgh infection,which enhances its suppression on barley immunity likely due to enhanced DNA-binding and transcriptional repression activity.Our data suggest that the HvMKK1-HvMPK4 kinase pair acts upstream of HvWRKY1 to negatively regulate barley immunity against powdery mildew.
基金the National Key Research and Development Program of China (2017YFD0101000)Key Project of Henan Province of China (161100110400)
文摘Triticum urartu(AA,2n=2x=14),a wild grass endemic to the Fertile Crescent(FC),is the progenitor of the A subgenome in common wheat.It belongs to the primary gene pool for wheat improvement.Here,we evaluated the yellow rust(caused by Puccinia striiformis f.sp.tritici,Pst)reactions of 147 T.urartu accessions collected from different parts of the FC.The reactions varied from susceptibility to strong resistance.In general,there were more accessions with stronger resistance to race CYR33 than to CYR 32.In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves.Forty two accessions displayed resistance to both races.Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response.Gene silencing mediated by Barley stripe mosaic virus was effective in two T.urartu accessions with different resistance responses,indicating that this method can expedite future functional analysis of resistance genes.Our data suggest that T.urartu is a valuable source of resistance to yellow rust,and represents a model for studying the genetic,genomic and molecular basis underlying interaction between wheat and Pst.
基金supported by the National Key R&D Program of China(2016YFD0100602,2018YFD1000703)the National Natural Science Foundation of China(31530061)the Ministry of Agriculture and Rural Affairs of China(2016ZX08009-003-001).
文摘Plants recognize pathogens and activate immune responses,which usually involve massive transcriptional reprogramming.The evolutionarily conserved kinase,Sucrose non-fermenting-related kinase 1(SnRK1),functions as a metabolic regulator that is essential for plant growth and stress responses.Here,we identify barley SnRK1 and a WRKY3 transcription factor by screening a cDNA library.SnRK1 interacts with WRKY3 in yeast,as confirmed by pull-down and luciferase complementation assays.Förster resonance energy transfer combined with noninvasive fluorescence lifetime imaging analysis indicates that the interaction occurs in the barley nucleus.Transient expression and virus-induced gene silencing analyses indicate that WRKY3 acts as a repressor of disease resistance to the Bgh fungus.Barley plants overexpressing WRKY3 have enhanced fungal microcolony formation and sporulation.Phosphorylation assays show that SnRK1 phosphorylates WRKY3 mainly at Ser83 and Ser112 to destabilize the repressor,and WRKY3 non-phosphorylation-null mutants at these two sites are more stable than the wild-type protein.SnRK1-overexpressing barley plants display enhanced disease resistance to Bgh.Transient expression of SnRK1 reduces fungal haustorium formation in barley cells,which probably requires SnRK1 nuclear localization and kinase activity.Together,these findings suggest that SnRK1 is directly involved in plant immunity through phosphorylation and destabilization of the WRKY3 repressor,revealing a new regulatory mechanism of immune derepression in plants.
