Xylariaceous endophytes are commonly encountered in plants,and it has recently been found out that insect vectors play a major role in their life cycle,as well as in the apparent host-specificity of the fungal stromat...Xylariaceous endophytes are commonly encountered in plants,and it has recently been found out that insect vectors play a major role in their life cycle,as well as in the apparent host-specificity of the fungal stromata.In this study,a new insect-associated,endophytic anamorph species of Daldinia is recognised from a comparison of (a)morphological and ecological data;(b)molecular phylogenetic data based on rDNA,alpha-actin and beta-tubulin genes;and (c)secondary metabolite profiles based on high performance liquid chromatography/diode array/mass spectrometry(HPLC-DAD/MS)and gas chromatography/mass spectrometry(GC-MS)in comparison with authentic strains of Daldinia and other Xylariaceae.The new species,Daldinia hawksworthii,is a symbiont of the willow woodwasp,Xiphydria prolongata,which is in turn preferentially associated with Salix.A comparison of HPLCDAD/MS profiles from standardised cultures revealed the presence of a specific compound,which was not encountered in any of the ca.250 Daldinia strains studied for comparison.This compound was isolated after fermentation of the fungus in 10 l scale by preparative chromatography.Structure elucidation by NMR spectroscopy revealed a novel pyrone,for which the name dalsymbiopyrone is proposed.The compound showed weak antimicrobial and cytotoxic effects and might be a signal molecule involved in the trilateral ecological interaction between the host plant,the insect,and its fungal symbiont.展开更多
基金support from COST Action FA1103“Endophytes in Biotechnologiy and Agriculture”.
文摘Xylariaceous endophytes are commonly encountered in plants,and it has recently been found out that insect vectors play a major role in their life cycle,as well as in the apparent host-specificity of the fungal stromata.In this study,a new insect-associated,endophytic anamorph species of Daldinia is recognised from a comparison of (a)morphological and ecological data;(b)molecular phylogenetic data based on rDNA,alpha-actin and beta-tubulin genes;and (c)secondary metabolite profiles based on high performance liquid chromatography/diode array/mass spectrometry(HPLC-DAD/MS)and gas chromatography/mass spectrometry(GC-MS)in comparison with authentic strains of Daldinia and other Xylariaceae.The new species,Daldinia hawksworthii,is a symbiont of the willow woodwasp,Xiphydria prolongata,which is in turn preferentially associated with Salix.A comparison of HPLCDAD/MS profiles from standardised cultures revealed the presence of a specific compound,which was not encountered in any of the ca.250 Daldinia strains studied for comparison.This compound was isolated after fermentation of the fungus in 10 l scale by preparative chromatography.Structure elucidation by NMR spectroscopy revealed a novel pyrone,for which the name dalsymbiopyrone is proposed.The compound showed weak antimicrobial and cytotoxic effects and might be a signal molecule involved in the trilateral ecological interaction between the host plant,the insect,and its fungal symbiont.
