Specific effects of fructo- and gluco-oligosaccharides in the preservation of liposomes during drying

Abstract

The fructan family of oligo- and polysaccharides is a group of molecules that have long been implicated as protective agents in the drought and freezing tolerance of many plant species. However, it has been unclear whether fructans have properties that make them better protectants for cellular structures than other sugars. We compared the effects of fructans and glucans on membrane stability during air-drying. Although glucans of increasing chain length were progressively less able to stabilize liposomes against leakage of aqueous content after rehydration, fructans showed increased protection. On the other hand, glucans became more effective in protecting liposomes against membrane fusion with increasing chain length, whereas fructans became less effective. Fourier transform infrared spectroscopy showed a reduction of the gel to liquid-crystalline phase transition temperature (T(m)) of air-dried liposomes by approximately 25 degrees C in the presence of sucrose and maltose. For the respective pentasaccharides, the reduction of T(m) of the lipids was 9 degrees C lower for samples containing fructan than for those containing glucan, indicating increased sugar--membrane interactions for the fructan compared to the glucan. A reduced interaction of the longer-chain glucans and an increased interaction of the respective fructans with the phospholipid head groups in the dry state was also indicated by dramatic differences in the phosphate asymmetric stretch region of the infrared spectrum. Collectively, our data indicate that the fructo-oligosaccharides accumulated in many plant species under stress conditions could indeed play an important role in cellular dehydration tolerance.

Cloning, Functional Expression, and Characterization of the Raffinose Oligosaccharide Chain Elongation Enzyme, Galactan:Galactan Galactosyltransferase, from Common Bugle Leaves

“…Recent in vitro studies have provided direct evidence that both RFOs and fructans may be involved in cell membrane stabilization (Hincha et al, 2002Vereyken et al, 2003). In vivo studies showed that down-regulation of a-Gal activities resulted in both enhanced raffinose content and freezing tolerance in transgenic petunia (Petunia hybrida; Pennycooke et al, 2003).…”

How can forage production in Nordic and Mediterranean Europe adapt to the challenges and opportunities arising from climate change?

“…The reduction in leaf tissue reduces total plant water loss (Gepstein, 2004;Munne Bosch and Alegre, 2004). A minimum water supply to the meristematic tissues is maintained (Karcher et al, 2008;McWilliam and Kramer, 1968;Volaire and Lelievre, 2001), and high concentrations of fructans and dehydrins contribute to osmoregulation and membrane stabilisation of these tissues (Hincha et al, 2000(Hincha et al, , 2002. High carbohydrate reserves are associated with superior plant resilience and recovery after severe drought (Boschma et al, 2003).…”

Disordered Cold Regulated15 Proteins Protect Chloroplast Membranes during Freezing through Binding and Folding, But Do Not Stabilize Chloroplast Enzymes in Vivo

“…Liposome destabilization leads to leakage of the dye into the surrounding medium, where it is diluted sufficiently to allow fluorescence emission. CF leakage was determined with a Fluoroscan Ascent fluorescence plate reader (excitation wavelength of 444 nm and emission wavelength of 555 nm; Labsystems) before and after liposome disruption by the addition of Triton X-100 (Hincha et al, 2002).…”