| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Research Abstract |
The present study aims to detect and identify the antifungal compound(s) formed in the Betula platyphylla var. japonica plantlets which are infected with a canker fungus of Betula spp., Inonotus obliquus. At first, sterile birch plantlet No.8 was cultured to multiply it in large quantities, I. obliquus IO-U1 and IO-B2 strains were inoculated to them (TREATMENT), and then growth amount of TREATMENT was compared between the sterile and uninjured plantlets (CONTROL(1)) and the injured plantlets (CONTROL(2)). As a result, infection of the fungus was proved to inhibit growth of the birch plantlets, especially growth of the taproot. In the next place, CONTROL(1), (2), and TREATMENT plantlets were extracted with organic solvents, and then the obtained extracts were analyzed by a gas chromatograph-mass spectrometer to compare the extractives between them. In result, an unidentified compound, which was suggested to be a phytoanticipin, was detected, although no phytoalexins were detected. In ad
… More
dition, β-sitosterol, which was suggested to be a phytoanticipin, was also quantified in the extracts. As a result, the amount of the free-form one increased by injury, while the amount decreased by the fungal infection. On the other hand, the amount of the esterified-form one increased by both injury and fungal infection. From these results, it is conceived that β-sitosterol may be a precursor which is converted to another phytoanticipin. As the 3^<rd> experiment, antifungal test of β-sitosterol was performed by using liquid and solid agar media. In result, the concentration of β-sitosterol at 100 μg/mL gave the most distinct antifungal activity. It is considered, therefore, that β-sitosterol acts as a phytoanticipin to some extent. As the 4^<th> experiment, crude enzyme solutions were prepared from CONTROL(1), (2), and TREATMENT plantlets, followed by proteome analysis with using two-dimensional electrophoresis. As a result. Many protein spots appeared within the range of pH 3〜7 and molecular weight less than 100 kDa in all crude enzyme solutions. In addition, 9 spots disappeared or became faint, 4 spots became deep. And one spot newly appeared on the 2D electrophoresis gel of TREATMENT 1 day after the fungal infection. On the other hand, 6 spots disappeared or became faint, and 2 spots became deep on the 2D electrophoresis gel of TREATMENT 6 days after the fungal infection. These proteins are considered to be involved in the metabolic changes of birch plantlets infected with the fungus. Less
|
