Journal of Experimental Botany vol:47 issue:304 pages:1797-1803
At low concentrations of purified chicory root 1-SST, only 1-kestose was produced from a physiologically relevant sucrose concentration. As the 1-SST concentration increased, some higher oligofructans were also detected, showing that 1-SST has some 1-FFT activity after sucrose exhaustion in the reaction mixtures. The consequences for the interpretation of fructan synthesizing activities in vitro are discussed. With a mixture of both purified 1-SST and 1-FFT it was found that the higher the enzyme concentration, the higher the maximal DP of the fructans that could be synthesized. The higher the enzyme concentration, the higher the relative abundance of the larger DP fructans and fructose in the reaction mixtures, Taken together with previous results, there is confidence that the final fructan pattern obtained in vitro is a function of the (1-SST + 1-FFT)/sucrose ratio and suggest that the latter ratio in situ could affect the highly variable tissue- or species-specific pattern of fructans produced in vivo.