Showing papers on "Arabitol published in 1979"

Phosphoglucose isomerase mutant of Rhizobium meliloti.

Abstract: A mutant strain of complex phenotype was selected in Rhizobium meliloti after nitrosoguanidine mutagenesis. It failed to grow on mannitol, sorbitol, fructose, mannose, ribose, arabitol, or xylose, but grew on glucose, maltose, gluconate, L-arabinose, and many other carbohydrates. Assay showed the enzyme lesion to be in phosphoglucose isomerase (pgi), and revertants, which were of normal growth phenotype, contained the enzyme again. Nonpermissive substrates such as fructose and xylose prevented growth on permissive ones such as L-arabinose, and in such situations there was high accumulation of fructose 6-phosphate. The mutant strain had about 20% as much exopolysaccharide as the parent. Nitrogen fixation by whole plants was low and delayed when the mutant strain was the inoculant.

Carbohydrate composition and invertase activity in poplar leaf tissues infected by millampsora aecidioides (d.c.) schroeter

Abstract: Summary Qualitative analyses of ethanol-soluble carbohydrates of rust-infected poplar leaves were similar to those of other rust infections. Sucrose was the most abundant ethanol-soluble carbohydrate in both healthy and infected leaf tissues. Mannitol, arabitol and trehalose were detected in low concentrations at the site of infection. Mannose formed a significant proportion of the insoluble carbohydrates in the pustule disc. Activities of both acid and alkaline invertase, assayed by two methods, were similar in both healthy and infected tissues. These results are discussed in relation to those of other biotrophic infections and it is suggested that the Populus canescens Aiton Sm./Melampsora aecidioides (D.C.) Schroeter relationship may be a benign one.