Knockdown of MLO genes reduces susceptibility to powdery mildew in grapevine

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.

Evolution of personality and locomotory performance traits during a late Pleistocene island colonization in a tree frog

Recent empirical and theoretical studies suggest that personality and locomotory performance traits linked to dispersal abilities are crucial components of the dispersal syndromes,and that they can evolve during range expansions and colonization processes.Island colonization is one of the best characterized processes in dispersal biogeography,and its implication in the evolution of phenotypic traits has been investigated over a wide range of temporal scales.However,the effect of island colonization on personality and performance traits of natural populations,and how these traits could drive island colonization,has been little explored.Noteworthy,no studies have addressed these processes in the context of late Pleistocene range expansions.Here,we investigated the contribution of island colonization triggered by postglacial range expansions to intraspecific variation in personality and locomotory performance traits.We compared boldness,exploration,jumping performance,and stickiness abilities in populations from 3 equidistant areas of the Tyrrhenian tree frog Hyla sarda,2 from the main island(Corsica Island),and 1 from the recently colonized island of Elba.Individuals from Elba were significantly bolder than individuals from Corsica,as they emerged sooner from a shelter(P=0.028),while individuals from Corsica showed markedly higher jumping and stickiness performance(both P<0.001),resulting as more performing than those of Elba.We discuss these results in the context of the major microevolutionary processes at play during range expansion,including selection,spatial sorting,founder effects,and their possible interaction with local adaptation processes.

Forecasting the number of species of asexually reproducing fungi(Ascomycota and Basidiomycota)

Asexually reproducing fungi play a significant role in essential processes in managed and wild ecosystems such as nutrients cycling and multitrophic interactions.A large number of such taxa are among the most notorious plant and animal pathogens.In addition,they have a key role in food production,biotechnology and medicine.Taxa without or rare sexual reproduction are distinguished based on their sporulating structures and conidiomata in traditional morphology-based taxonomy.The number,variation and diversity of asexually reproducing taxa are insufficiently known,even though fungi capable of asexual reproduction may provide an untapped,rich biological resource for future exploitation.Currently,ca.30,000 asexual species belonging to ca.3800 genera have been reported(including 1388 coelomycetous and 2265 hyphomycetous genera).Recent reports(2017–2020)reiterate that the number of asexually producing fungi is higher than the number of frequently sexually-reproducing fungi.With the advent of molecular tools and the abandonment of the dual nomenclature system for pleomorphic fungi,priority criteria were established and revisited in the latest outline of fungi and fungus-like taxa.However,species numbers and taxonomic boundaries of pleomorphic taxa and their synanamorphs or synasexual morphs have yet to be addressed.The number of species of speciose genera(e.g.Alternaria,Aspergillus,Cercospora,Fusarium,Phoma and Pseudocercospora),cryptic species,species of pleomorphic genera,less studied life modes(such as lichenicolous taxa,taxa from extreme environments)and species from biodiversity-rich areas still need evaluation to achieve more reliable estimates of their diversity.This paper discusses the current knowledge on the matter,with diversity estimates,and potential obstacles in several chapters on(1)speciose genera;(2)pleomorphic genera;(3)cryptic species;(4)well-studied but insufficiently resolved taxa,e.g.leaf inhabiting species,marine fungi,(5)less studied life modes,e.g.lichenicolous,rock-inhabiting fungi,insect-associated and yeast-forming taxa and(6)species from biodiversity-rich areas.