| Summary: | 博士 === 國立臺灣大學 === 農業化學系 === 81 === Rhizobia can infect leguminous plants to form symbiotic no-
dules in which nitrogen gas is transferred to ammonium
nitrogen, a natural nutrition to host plant. In this
symbiotic process, there is specific infection existing
between Rhizobium and le- gume host. Some researchers have
suggested a lectin-polysaccha- ride recognition hypothesis,
which could interpret this specific symbiosis. However, there
are many results contradictory to this hypothesis recently.
Rhizobia, infecting soybean, can be classi- fied to types. One
is R. fredii, the fast-growing type, and the other B.
japonicum, slow-growing type. Whether or not a relation- ship
that exist between soybean lectin and polysaccharides of
these Rhizobium species. In these experiments, we tried to
clari- fy the hypothesis of soybean as common host. Firstly, we
isolated and purified soybean lectin. This soy- bean lectin
was analyzed by gel permeation chromatography and SDS-PAGE
analysis. The rhizobia which exopolysaccharide was re- moved
could bind with FITC-labeled soybean lectin. Results showed
every Rhizobium strain could bind with soybean lectin.
Exo- polysaccharide removed rhizobia were reacted with soybean
lectin, then, bound with anti-soybean lectin antisera,
finally stained with immunogold. We obtained the same results
through TEM obser- vation. Rhizobial lipopolysaccharides were
purified through gel per- meation chromatography. We can
distinguish them by different strains. The purified
lipopolysaccharides were analyzed with SDS- PAGE. These
lipopolysaccharides were analyzed by GLC after being
hydrolyzed, reduced, and acetylated. Major hexose
compositions were glucose, galactose and mannose. However, B.
japonicum USDA 110 was devoid of galactose and bound with
soybean lectin. There- fore, it was shown that our results did
not support lectin-poly- saccharide recognition hypothsis.
|
|---|
