Showing papers on "Arabidopsis published in 1969"

Thiamine mutants of the crucifer, Arabidopsis.

Abstract: In higher plants the only obligate organoauxotrophic mutants available are concerned with the synthesis of thiamine, vitamin B1. In Arabidopsis 65 mutants, representing four loci controlling four different steps in the thiamine pathway, have been obtained and identified. Heteroalleles were distinguished within two loci by qualitative and quantitative responses to low and high temperatures. The availability of auxotrophs in higher plants makes it possible to employ highly selective genetic techniques in well-differentiated diploid organisms.

Gene Locus Specificity of the Glucose Effect in the Thiamine Pathway of the Angiosperm, Arabidopsis

Abstract: All mutants at 3 loci in Arabidopsis thaliana (L.) Heynh., a higher plant, that are associated with the synthesis or coupling of the thiazole moiety of thiamine are susceptible to reversible glucose inhibition. In contrast, several different alleles involved in the synthesis of the pyrimidine moiety of the vitamin are insensitive to glucose. Glucose and maltose are equally effective inhibitors while fructose, lactose, ribose, and xylose are toxic. This toxicity is not released by added thiamine.