Understanding the role of ectomycorrhizal fungi in plant communities is hampered by a lack of knowledge about fungal diversity.DNA barcoding of the ectomycorrhizal fungal genus Cortinarius was used to compare fungal d...Understanding the role of ectomycorrhizal fungi in plant communities is hampered by a lack of knowledge about fungal diversity.DNA barcoding of the ectomycorrhizal fungal genus Cortinarius was used to compare fungal diversity in soil from four plant communities:(i)Nothofagus forest(where Cortinarius is common and diverse),(ii)Kunzea forest(where Cortinarius is present but with low diversity),(iii)a Pinus radiata plantation(Cortinarius is not thought to be present)and(iv)a sub-Antarctic island(where known ectomycorrhizal hosts are absent).PCR primers specific for the ITS region of Cortinarius species were developed.Specificity was tested in vitro and in silico against DNA from basidiocarps of Cortinarius and non-Cortinarius species.The primers were tested for their ability to amplify Cortinarius DNA in soil from forests of the three ectomycorrhizal forest communities and a range of soils from the ectomycorrhiza-free subantarctic Campbell Island.High diversity of Cortinarius was associated with soil of all three ectomycorrhizal communities,despite Cortinarius being previously unrecorded from Pinus.Soil from all three communities share some ectomycorrhizal fungi(including fungi shared between native and exotic hosts),having implications for community succession,introduction of exotic fungi and biodiversity assessment.No Cortinarius was detected from Campbell Island samples.The validated molecular protocol assessed species diversity in a rapid and cost effective way.Baseline biodiversity assessment based on DNA barcoding is more effective at detecting diversity than traditional methods,but requires careful consideration of the difference between ectomycorrhizal fungal diversity in soil versus root-tips.展开更多
Intoxication with Cortinarius orellanus Fr. is often lethal or, at the least, disabling for the victim. Orellanine is recognized as the prime toxic substance in this mushroom. Poisoning by other toxic mushrooms can be...Intoxication with Cortinarius orellanus Fr. is often lethal or, at the least, disabling for the victim. Orellanine is recognized as the prime toxic substance in this mushroom. Poisoning by other toxic mushrooms can be occasionally mistaken as poisoning by C. orellanus or vice versa. The C. orellanus toxins have a prolonged latent period after ingestion and onset in the appearance of symptoms. These properties of the toxin together with the chemo-, thermo- and photolability have made it difficult to develop a direct analytical method for diagnosing poisoning with orellanine, which in turn is needed to administer the correct medication. The aim of this study was to develop a direct analytical method for the detection of orellanine present in stomach content. Gas chromatography-mass spectrometry with supersonic molecular beams (GC-MS with SMB) was used for the direct detection of orellanine in the stomach fluids of rats after they were fed with food containing C. orellanus. This method can be used as a platform for the future development of analytical procedures for the direct analytical detection of orellanine in humans intoxicated by ingestion of toxic mushrooms. The standard orellanine was isolated from C. orellanus following the procedure described by Prast et al. [1] and was used as an authentic comparison.展开更多
基金supported through funding to DAO and PLG from the Shore Fund and Performance-Based Research Fund,University of Otago.SET is supported by a University of Otago Pacific Island Masters Scholarship.
文摘Understanding the role of ectomycorrhizal fungi in plant communities is hampered by a lack of knowledge about fungal diversity.DNA barcoding of the ectomycorrhizal fungal genus Cortinarius was used to compare fungal diversity in soil from four plant communities:(i)Nothofagus forest(where Cortinarius is common and diverse),(ii)Kunzea forest(where Cortinarius is present but with low diversity),(iii)a Pinus radiata plantation(Cortinarius is not thought to be present)and(iv)a sub-Antarctic island(where known ectomycorrhizal hosts are absent).PCR primers specific for the ITS region of Cortinarius species were developed.Specificity was tested in vitro and in silico against DNA from basidiocarps of Cortinarius and non-Cortinarius species.The primers were tested for their ability to amplify Cortinarius DNA in soil from forests of the three ectomycorrhizal forest communities and a range of soils from the ectomycorrhiza-free subantarctic Campbell Island.High diversity of Cortinarius was associated with soil of all three ectomycorrhizal communities,despite Cortinarius being previously unrecorded from Pinus.Soil from all three communities share some ectomycorrhizal fungi(including fungi shared between native and exotic hosts),having implications for community succession,introduction of exotic fungi and biodiversity assessment.No Cortinarius was detected from Campbell Island samples.The validated molecular protocol assessed species diversity in a rapid and cost effective way.Baseline biodiversity assessment based on DNA barcoding is more effective at detecting diversity than traditional methods,but requires careful consideration of the difference between ectomycorrhizal fungal diversity in soil versus root-tips.
文摘Intoxication with Cortinarius orellanus Fr. is often lethal or, at the least, disabling for the victim. Orellanine is recognized as the prime toxic substance in this mushroom. Poisoning by other toxic mushrooms can be occasionally mistaken as poisoning by C. orellanus or vice versa. The C. orellanus toxins have a prolonged latent period after ingestion and onset in the appearance of symptoms. These properties of the toxin together with the chemo-, thermo- and photolability have made it difficult to develop a direct analytical method for diagnosing poisoning with orellanine, which in turn is needed to administer the correct medication. The aim of this study was to develop a direct analytical method for the detection of orellanine present in stomach content. Gas chromatography-mass spectrometry with supersonic molecular beams (GC-MS with SMB) was used for the direct detection of orellanine in the stomach fluids of rats after they were fed with food containing C. orellanus. This method can be used as a platform for the future development of analytical procedures for the direct analytical detection of orellanine in humans intoxicated by ingestion of toxic mushrooms. The standard orellanine was isolated from C. orellanus following the procedure described by Prast et al. [1] and was used as an authentic comparison.
