Fire blight disease,caused by the bacterium Erwinia amylovora(E.amylovora),is responsible for substantial losses in cultivated apples worldwide.An important mechanism of plant immunity is based on the recognition of c...Fire blight disease,caused by the bacterium Erwinia amylovora(E.amylovora),is responsible for substantial losses in cultivated apples worldwide.An important mechanism of plant immunity is based on the recognition of conserved microbial molecules,named pathogen-associated or microbe-associated molecular patterns(PAMPs or MAMPs),through pattern recognition receptors(PRRs),leading to pattern-triggered immunity(PTI).The interspecies transfer of PRRs represents a promising strategy to engineer broad-spectrum and durable disease resistance in crops.EFR,the Arabidopsis thaliana PRR for the PAMP elf18 derived from the elongation factor thermal unstable(EF-Tu)proved to be effective in improving bacterial resistance when expressed into Solanaceae and other plant species.In this study,we tested whether EFR can affect the interaction of apple with E.amylovora by its ectopic expression in the susceptible apple rootstock M.26.Stable EFR expression led to the activation of PAMP-triggered immune response in apple leaves upon treatment with supernatant of E.amylovora,as measured by the production of reactive oxygen species and the induction of known defense genes.The amount of tissue necrosis associated with E.amylovora infection was significantly reduced in the EFR transgenic rootstock compared to the wild-type.Our results show that the expression of EFR in apple rootstock may be a valuable biotechnology strategy to improve the resistance of apple to fire blight.展开更多
Malus x domestica microRNA MdmiR285N is a potential key regulator of plant immunity,as it has been predicted to target 35 RNA transcripts coding for different disease resistance proteins involved in plant defense to p...Malus x domestica microRNA MdmiR285N is a potential key regulator of plant immunity,as it has been predicted to target 35 RNA transcripts coding for different disease resistance proteins involved in plant defense to pathogens.In this study,the promoter region of MdmiR285N was isolated from the apple genome and analyzed in silico to detect potential regulatory regions controlling its transcription.A complex network of putative regulatory elements involved in plant growth and development,and in response to different hormones and stress conditions,was identified.Activity of theβ-Glucoronidase(GUS)reporter gene driven by the promoter of MdmiR285N was examined in transgenic apple,demonstrating that MdmiR285N was expressed during the vegetative growth phase.Similarly,in transgenic Arabidopsis thaliana,spatial and temporal patterns of GUS expression revealed that MdmiR285N was differentially regulated during seed germination,vegetative phase change,and reproductive development.To elucidate the role of MdmiR285N in plant immunity,MdmiR285N expression in wild-type apple plants and GUS activity in transgenic apple and Arabidopsis thaliana plants were monitored in response to Erwinia amylovora and Pseudomonas syringae pv.Tomato DC3000.A significant decrease of MdmiR285N levels and GUS expression was observed during host-pathogen infections.Overall,these data suggest that MdmiR285N is involved in the biotic stress response,plant growth,and reproductive development.展开更多
基金This work was funded by the Autonomous Province of Trento.
文摘Fire blight disease,caused by the bacterium Erwinia amylovora(E.amylovora),is responsible for substantial losses in cultivated apples worldwide.An important mechanism of plant immunity is based on the recognition of conserved microbial molecules,named pathogen-associated or microbe-associated molecular patterns(PAMPs or MAMPs),through pattern recognition receptors(PRRs),leading to pattern-triggered immunity(PTI).The interspecies transfer of PRRs represents a promising strategy to engineer broad-spectrum and durable disease resistance in crops.EFR,the Arabidopsis thaliana PRR for the PAMP elf18 derived from the elongation factor thermal unstable(EF-Tu)proved to be effective in improving bacterial resistance when expressed into Solanaceae and other plant species.In this study,we tested whether EFR can affect the interaction of apple with E.amylovora by its ectopic expression in the susceptible apple rootstock M.26.Stable EFR expression led to the activation of PAMP-triggered immune response in apple leaves upon treatment with supernatant of E.amylovora,as measured by the production of reactive oxygen species and the induction of known defense genes.The amount of tissue necrosis associated with E.amylovora infection was significantly reduced in the EFR transgenic rootstock compared to the wild-type.Our results show that the expression of EFR in apple rootstock may be a valuable biotechnology strategy to improve the resistance of apple to fire blight.
文摘Malus x domestica microRNA MdmiR285N is a potential key regulator of plant immunity,as it has been predicted to target 35 RNA transcripts coding for different disease resistance proteins involved in plant defense to pathogens.In this study,the promoter region of MdmiR285N was isolated from the apple genome and analyzed in silico to detect potential regulatory regions controlling its transcription.A complex network of putative regulatory elements involved in plant growth and development,and in response to different hormones and stress conditions,was identified.Activity of theβ-Glucoronidase(GUS)reporter gene driven by the promoter of MdmiR285N was examined in transgenic apple,demonstrating that MdmiR285N was expressed during the vegetative growth phase.Similarly,in transgenic Arabidopsis thaliana,spatial and temporal patterns of GUS expression revealed that MdmiR285N was differentially regulated during seed germination,vegetative phase change,and reproductive development.To elucidate the role of MdmiR285N in plant immunity,MdmiR285N expression in wild-type apple plants and GUS activity in transgenic apple and Arabidopsis thaliana plants were monitored in response to Erwinia amylovora and Pseudomonas syringae pv.Tomato DC3000.A significant decrease of MdmiR285N levels and GUS expression was observed during host-pathogen infections.Overall,these data suggest that MdmiR285N is involved in the biotic stress response,plant growth,and reproductive development.
