Changes in soluble sugars in relation to desiccation tolerance in cauliflower seeds

Abstract

Changes in soluble sugars in cauliflower seeds were followed during 50 h of imbibition in relation to desiccation tolerance Sucrose and stachyose contents decreased, and glucose and fructose accumulated This occurred in radicles first and subsequently in hypocotyls and cotyledons Loss of desiccation tolerance in the various seed parts coincided with an increase in glucose and fructose and the complete loss of stachyose, but sucrose content, the major sugar, was still high Drying imbibed seeds over silica gel did not evoke resynthesis of stachyose, but did increase sucrose and decrease glucose and fructose contents Seeds primed in solutions of 30% polyethylene glycol for 10 days showed a loss of stachyose, while sucrose remained high and glucose and fructose contents were still very low Redrying of primed seeds did not change the sugar contents The primed seeds were still tolerant of desiccation We conclude that stachyose is not a prerequisite for desiccation tolerance, but that sucrose may be We suggest that glucose and fructose may be involved in desiccation damage

Fourier Transform Infrared Microspectroscopy Detects Changes in Protein Secondary Structure Associated with Desiccation Tolerance in Developing Maize Embryos1

“…Nevertheless, a considerable percentage (74%) of the 25-DAP embryos survived rapid drying, in spite of the fact that raffinose was almost absent. Therefore, raffinose is not a prerequisite for desiccation tolerance, as was stipulated earlier for immature maize embryos (Bochicchio et al, 1994b) and primed cauliflower seeds (Hoekstra et al, 1994). As expected, membrane permeability of the rehydrated, 25-DAP, rapidly dried embryos was much lower than that of the rapidly dried, 20-DAP embryos.…”

Biological glasses: nature's way to preserve life

“…Soluble sugars of isolated axes were extracted in a solution of 80% methanol (v:v) containing lactose as internal standard according to Hoekstra et al (1994). Sugar concentrations were determined by HPLC using pulsed amperometric detection on a Carbopac PA-1 column (Dionex Corp., Sunnyvale, CA, USA).…”

“…The causes for this reduced longevity are not well understood. Hoekstra et al (1994) found that priming of cauliflower seeds resulted in a decrease in oligosaccharide content. Considering the proposed role of oligosaccharides in increasing glass stability, it is possible that the reduced longevity of primed seeds may be attributed to the decrease in oligosaccharide content resulting in a decrease in cytoplasmic viscosity.…”

“…However, it might be that there is no specific role for oligosaccharides in longevity. Oligosaccharides could simply be an indicator of seed maturity and could serve as a storage reserve (Kuo et al, 1988;Hoekstra et al, 1994).…”

“…The liquid was evaporated under vacuum (Speedvac AES1010, Savant Instruments). The residue was dissolved in distilled water, and after appropriate dilution, sugars were analysed by HPLC on a Carbopac PA-1 column (Dionex Corp., Sunnyvale, CA, USA) using pulsed amperometric detection, as described by Hoekstra et al (1994). Data are the average of three extractions.…”