Erysiphe necator is the causal agent of powdery mildew(PM),one of the most destructive diseases of grapevine.PM is controlled by sulfur-based and synthetic fungicides,which every year are dispersed into the environmen...Erysiphe necator is the causal agent of powdery mildew(PM),one of the most destructive diseases of grapevine.PM is controlled by sulfur-based and synthetic fungicides,which every year are dispersed into the environment.This is why PM-resistant varieties should become a priority for sustainable grapevine and wine production.PM resistance can be achieved in other crops by knocking out susceptibility S-genes,such as those residing at genetic loci known as MLO(Mildew Locus O).All MLO S-genes of dicots belong to the phylogenetic clade V,including grapevine genes VvMLO7,11 and 13,which are upregulated during PM infection,and VvMLO6,which is not upregulated.Before adopting a gene-editing approach to knockout candidate S-genes,the evidence that loss of function of MLO genes can reduce PM susceptibility is necessary.This paper reports the knockdown through RNA interference of VvMLO6,7,11 and 13.The knockdown of VvMLO6,11 and 13 did not decrease PM severity,whereas the knockdown of VvMLO7 in combination with VvMLO6 and VvMLO11 reduced PM severity up to 77%.The knockdown of VvMLO7 and VvMLO6 seemed to be important for PM resistance,whereas a role for VvMLO11 does not seem likely.Cell wall appositions(papillae)were present in both resistant and susceptible lines in response to PM attack.Thirteen genes involved in defense were less upregulated in infected mlo plants,highlighting the early mlo-dependent disruption of PM invasion.展开更多
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
基金This work was funded by the autonomous province of Trento(Italy)and the GMPF PhD program.
文摘Erysiphe necator is the causal agent of powdery mildew(PM),one of the most destructive diseases of grapevine.PM is controlled by sulfur-based and synthetic fungicides,which every year are dispersed into the environment.This is why PM-resistant varieties should become a priority for sustainable grapevine and wine production.PM resistance can be achieved in other crops by knocking out susceptibility S-genes,such as those residing at genetic loci known as MLO(Mildew Locus O).All MLO S-genes of dicots belong to the phylogenetic clade V,including grapevine genes VvMLO7,11 and 13,which are upregulated during PM infection,and VvMLO6,which is not upregulated.Before adopting a gene-editing approach to knockout candidate S-genes,the evidence that loss of function of MLO genes can reduce PM susceptibility is necessary.This paper reports the knockdown through RNA interference of VvMLO6,7,11 and 13.The knockdown of VvMLO6,11 and 13 did not decrease PM severity,whereas the knockdown of VvMLO7 in combination with VvMLO6 and VvMLO11 reduced PM severity up to 77%.The knockdown of VvMLO7 and VvMLO6 seemed to be important for PM resistance,whereas a role for VvMLO11 does not seem likely.Cell wall appositions(papillae)were present in both resistant and susceptible lines in response to PM attack.Thirteen genes involved in defense were less upregulated in infected mlo plants,highlighting the early mlo-dependent disruption of PM invasion.
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.
