Table 1.
Original, ITS GenBank accession number, collection date and host plant of fungi used in this study.
Fig 1.
Identification of indole compounds produced by ectomycorrhizal fungi using thin layer chromatography technique under UV light (A), and chromogenic reaction reagents; Salkowski (B), Ehrlich (C) and Ehmann (D). Lane 1 = L-tryptophan (L-Trp), Lane 2 = tryptamine (TAM), Lane 3 = indole-3-acetamide (IAM), Lane 4 = indole-3-lactic acid (ILA), Lane 5 = indole-3-pyruvic acid (IPyA), Lane 6 = indole-3-acetic acid (IAA), Lane 7 = indole-3-ethanol (IOL), Lane 8 = indole-3-acetonitrile (IAN), Lane 9 = uncultivated liquid medium, Lane 10 = crude culture extract of Astraeus odoratus, Lane 11 = crude culture extract of Gyrodon suthepensis, Lane 12 = crude culture extract of Phlebopus portentosus, Lane 13 = crude culture extract of Pisolithus albus, Lane 14 = crude culture extract of Pisolithus orientalis and Lane 15 = crude culture extract of Scleroderma suthepense.
Table 2.
Identification of indole compounds extracted from a culture of ectomycorrhizal fungi using chromogenic reagents after TLC separation.
Fig 2.
Identification of indole compounds produced by ectomycorrhizal fungi using high performance liquid chromatography technique.
A. Indole compounds standard, B. Uncultivated liquid medium. C. Crude culture extract of Astraeus odoratus. D. Crude culture extract of Gyrodon suthepensis. E. crude culture extract of Phlebopus portentosus. F. Crude culture extract of Pisolithus albus. G. Crude culture extract of Pisolithus orientalis. H. crude culture extract of Scleroderma suthepense. L-Trp = L-tryptophan, TAM = tryptamine, IAM = indole-3-acetamide, ILA = indole-3-lactic acid, IPyA = indole-3-pyruvic acid, IAA = indole-3-acetic acid, IOL = indole-3-ethanol and IAN = indole-3-acetonitrile. The analyses were performed in triplicate.
Fig 3.
Indole compounds produced by ectomycorrhizal fungi in different cultivation periods.
A. L- tryptophan, B. Indole-3-lactic acid. C. Indole-3-acetic acid. D. Indole-3-ethanol. The results are means of three replicates ± SD. Different letters above each graph indicate the significant difference (P < 0.05).
Fig 4.
Tryptophan aminotransferase activity of crude enzyme extract of ectomycorrhizal fungi and high performance liquidchromatography detection.
A. Buffer containing of L-tryptophan (L-Trp). B. Indole-3-pyruvic acid (IPyA). C. Reaction mixture of L-Trp and enzyme extract of Astraeus odoratus. D. Reaction mixture of L-Trp and enzyme extract of Gyrodon suthepensis. E. Reaction mixture of L-Trp and enzyme extract of Phlebopus portentosus. F. Reaction mixture of L-Trp and enzyme extract of Pisolithus albus. G. Reaction mixture of L-Trp and enzyme extract of Pisolithus orientalis. H. Reaction mixture of L-Trp and enzyme extract of Scleroderma suthepense. L-Trp = L-tryptophan and IPyA = indole-3-pyruvic acid. The analyses were performed in triplicate.
Fig 5.
Proposed indole-3-acetic acid biosynthetic pathway of A. odoratus, G. suthepensis, Ph. Portentosus, Pi. orientalis Pi. albus and Sc. suthepense.
The proposed pathway is based on experimental evidence observed in this study and the evidence of the intermediate compounds.
Fig 6.
Coleoptile elongation of oat and rice.
WA = distilled water treatment, IAA = IAA standard treatment, AS = crude culture extract of Astraeus odoratus treatment, GY = crude culture extract of Gyrodon suthepensis treatment, PP = crude culture extract of Phlebopus portentosus treatment, PA = crude IAA of Pisolithus albus treatment, PO = crude culture extract of Pisolithus orientalis treatment and SC = crude culture extract of Scleroderma suthepense treatment. The results are means of five replicates ± SD. Different letters above each graph indicate the significant difference (P < 0.05).