| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Saprophytic and natural microbial inhabitants were isolated from the seeds and seedlings of radish and tomato. Resultant isolates were dvided into several groups such as gram-positive spore forming rods (Bacillus spp.) aerobic and facultative anaerobic gram-negative rods, and so on. Their diversity was high but not random, indicating that some loose ties are existing between the microbes and plants. From the diseased or injured parts of plants, Erwinia herbicola group bacteria were isolated abundantly. Homology to the hrp genes were detected on the genome of an isolates of Pseudomonas fluorescens, one of the common saprophytes. The homologous genes were cloned and sequenced. They were similar to those of plant pathogenic P.syringae but lacking hrp pilus gene and harpin gene homologues. The homology to hrp genes was detected in many saprophytic flourescent pseudomonads. A mutant of P.fluorescens having transposon insertion in the hrp homologues was successfully constracted to elucidate their roles in survival on plant surface. Some isolates of the saprophytic E.herbicola group bacteria were also shown to posess hrp genes, iaaM, iaaH, etz, and ipdC genes which are thought to concerning on habitational activity of bacteria, Some of them were successfully cloned and now are under analysis.
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