Possible Involvement of Reactive Oxygen Species in Ectomycorrhizal Association between Rhizopogon roseolus and Pinus thunbergii
Possible involvement of reactive oxygen species in ectomycorrhizal association between Rhizopogon roseolus and Pinus thunbergii was microscopically investigated after nitroblue tetrazolium (NBT) staining. Roots of P. thunbergii were aseptically infected with R. roseolus mycelia by using the Petri dish technique. Initial mycorrhizal formation could be observed from 2 to 4 weeks after inoculation. NBTtreated lateral root tips were then observed under a light microscope. Blue formazan depositions indicating O2~ accumulation were detected mainly in hyphal cells in contact with the root surface. Observations of a transverse section of the root revealed blue formazan depositions at the plasma membranes of epidermal cells to which fungal hyphae were adhesively attached. In the non-inoculated P. thunbergii roots, formazan depositions were observed in root hair cells, but not in epidermal cells. Dichotomous mycorrhizas and extraradical mycelia were clearly observed from 4 to 8 weeks after inoculation. A section of NBT-treated mycorrhizas showed that the root tissue was surrounded by the fungal mantle sheath in which highly intensive reaction with NBT was observed. Reactive formazan complexes were apparent in Hartig net hyphae between root epidermal and cortical cells. After 16 weeks following inoculation, morphology of mycorrhizas became variable, viz. , initial, dichotomous and browned mycorrhizas. The browned mycorrhizas were characterized by wrinkled surfaces and sparse extraradical mycelia. A section of NBT-treated browned mycorrhizas showed slight formazon depositions only in a part of extraradical mycelia. These results suggest that O2- generation in both fungi and plants is involved in the early mycorrhizal association between R. roseolus and P. thunbergii.
Ectomycorrhiza Pinus thunbergii Reactive Oxygen Species Rhizopogon roseolus
Norihiro Shimomura Yuuki Nakanishi Tadanori Aimi Hiroshi Otani
Faculty of Agriculture, Tottori University ,4 - 101 Koyama,Tottori 680-8553 ,Japan
国际会议
The 18th Congress of the International Society for Mushroom Science(第十八届国际食用菌大会 ISMS18)
北京
英文
908-913
2012-08-27（万方平台首次上网日期，不代表论文的发表时间）