Challenging the term symbiosis in plant-microbe associations to create an understanding across sciences

THE IMPORTANCE OF WELL DEFINED TERMINOLOGY,Effective communication across fields and disciplines relies on well defined terminology.Standardized use of accurate definitions has been advocated by scientists across various disciplines(PySek,1995;RabinandBrownson,2017;Tipton et al.,2019;Dubrovsky,2022;Rillig,2023).

Multigene phylogeny and taxonomy of the genus Melanconiella(Diaporthales)

Molecular phylogenetic analyses of LSU rDNA demonstrate monophyly of the genus Melanconiella,and its status as a genus distinct from Melanconis is confirmed.Data of macro-and microscopic morphology,pure cultures and phylogenetic analyses of partial SSU-ITS-LSU rDNA,tef1 and rpb2 sequences revealed 13 distinct species of Melanconiella,six of which are described as new(M.chrysodiscosporina,M.chrysomelanconium,M.chrysorientalis,M.echinata,M.elegans,M.meridionalis).Melanconiella hyperopta var.orientalis is described as a new variety.Diaporthe carpinicola,D.ellisii,D.flavovirens,D.hyperopta and D.ostryae are formally combined into Melanconiella.The name Melanconiella chrysostroma is excluded from Melanconiella,as it is an obligate synonym of Wuestneia xanthostroma.The type of Melanconiella is confirmed as M.spodiaea.Several species are lecto-and/or epitypified.A key to all treated species ofMelanconiella is provided,and the circumscriptions of the genera Melanconis and Melanconiella are emended.Most Melanconiella species revealed by molecular phylogenetic analyses can be well characterised by a suite of morphological traits including ascospore shape,length and width,colour,absence/presence and shape of appendages and the anamorph.Anamorph-teleomorph connections were confirmed by pure culture and DNA data,revealing the presence of a single melanconium-or discosporina-like anamorph for each species.Colony growth was found to be characteristic of the respective species.Melanconiella is shown to be confined to the host family Betulaceae,and all species are found to be highly host-specific,mostly confined to a single host species.The biodiversity ofMelanconiella was determined to be centred on the genus Carpinus with nine species,five of which have been confirmed on C.betulus.Europe appears to be the geographic centre of Melanconiella biodiversity.

Phylogenetic relationships of five genera of Xylariales and Rosasphaeria gen.nov.(Hypocreales)

Eight inconspicuous non-stromatic perithecial fungi immersed in plant tissue are assessed with respect to their morphology,ecology and phylogenetic position.Emphasis is laid on two genera now and then placed in the family Hyponectriaceae,Xylariales:Leiosphaerella with its type species L.praeclara occurring on Vaccinium,and Pseudomassaria with its type species P.chondrospora occurring on Tilia.In molecular phylogenetic analyses of LSU and ITS sequences,the generic types of these genera are closely related,but their familial affiliation within Xylariales remains unresolved.Pseudomassaria sepincoliformis clusters with P.chondrospora,whereas P.fallax is not congeneric with Pseudomassaria and P.lycopodina is combined in Leiosphaerella despite its apiospores.Three species thought to belong to Leiosphaerella are re-assessed:L.moravica that occurs on Rosa,is disposed in the new genus Rosasphaeria,which is close to Eucasphaeria in the Niessliaceae(Hypocreales),according to multi-gene phylogenetic analyses(ITS,LSU,rpb2 and tef1).For L.vexata the genus Pseudomassariella is revived.A Leiosphaerellalike fungus on Lycopodium is described as the new species Monographella lycopodina.In addition the phylogenetic relationships of two fungi forming superficial stromata are here clarified:Collodiscula japonica belongs to the Xylariaceae,while Melogramma campylosporum may currently be interpreted as representing a family of its own,the Melogrammataceae.

Front line defenders of the ecological niche!Screening the structural diversity of peptaibiotics from saprotrophic and fungicolous Trichoderma/Hypocrea species

Approximately 950 individual sequences of nonribosomally biosynthesised peptides are produced by the genus Trichoderma/Hypocreathat belong to a perpetually growing class of mostly linear antibiotic oligopeptides,which are rich in the non-proteinogenic α-aminoisobutyric acid(Aib).Thus,they are comprehensively named peptaibiotics.Notably,peptaibiotics represent ca.80% of the total inventory of secondarymetabolites currently known from Trichoderma/Hypocrea.Their unique membrane-modifying bioactivity results from amphipathicity and helicity,thus making them ideal candidates in assisting both colonisation and defence of the natural habitats by their fungal producers.Despite this,reports on the in vivo-detection of peptaibiotics have scarcely been published in the past.In order to evaluate the significance of peptaibiotic production for a broader range of potential producers,we screened nine specimens belonging to seven hitherto uninvestigated fungicolous or saprotrophic Trichoderma/Hypocrea species by liquid chromatography coupled to electrospray high resolution mass spectrometry.Sequences of peptaibiotics found were independently confirmed by analysing the peptaibiome of pure agar cultures obtained by single-ascospore isolation from the specimens.Of the nine species examined,five were screened positive for peptaibiotics.A total of 78 peptaibiotics were sequenced,56(=72%)of which are new.Notably,dihydroxyphenylalaninol and O-prenylated tyrosinol,two C-terminal residues,which have not been reported for peptaibiotics before,were found as well as new and recurrent sequences carrying the recently described tyrosinol residue at their C-terminus.The majority of peptaibiotics sequenced are 18-or 19-residue peptaibols.Structural homologies with‘classical representatives’of subfamily 1(SF1)-peptaibiotics argue for the formation of transmembrane ion channels,which are prone to facilitate the producer capture and defence of its substratum.

The Longibrachiatum Clade of Trichoderma:a revision with new species

The Longibrachiatum Clade of Trichoderma is revised.Eight new species are described(T.aethiopicum,T.capillare,T.flagellatum,T.gillesii,T.gracile,T.pinnatum,T.saturnisporopsis,T.solani).The twenty-one species known to belong to the Longibrachiatum Clade are included in a synoptic key.Trichoderma parareesei and T.effusum are redescribed based on new collections or additional observations.Hypocrea teleomorphs are reported for T.gillesii and T.pinnatum.Previously described species are annotated.