About this Research Topic
Fructans are plant polysaccharides consisting of repeating fructose residues linked to either the fructose and/or the glucose moiety of a sucrose unit. Being water soluble, fructans increase the osmotic pressure inside the cell when specific enzymes hydrolyze oligo- and poly-fructans to smaller oligosaccharides and monosaccharides. Fructans are generally considered to have a role as storage polysaccharides in plants. The degree of polymerization (DP) of the fructan chain varies considerably depending on the species and environmental conditions. Under water-limiting conditions, as well as under cold and saline stress, fructan biosynthesis is induced and the degree of polymerization typically increases. This is thought to enhance cellular osmotic potential and reduce oxidative stress via direct interaction with the plasma membrane. Fructans are therefore considered as protective molecules for cell membranes of plants and other organisms. On the other hand, fructans are excellent prebiotic molecules, promoting growth of beneficial colon bacteria and possibly assisting to protect humans from colorectal cancer. Fructans may also play a role against obesity by increasing the synthesis of short chain fatty acids and were reported to exhibit direct immunomodulatory effects on mammals.
Despite the causal relation of fructan content to carbohydrate partitioning, storage, and the general protection against various abiotic stresses, understanding the regulatory and functional context of protective actions of fructans on plants has to date received little attention. The number of studies available is limited to a handful of plant species and structure-function relationships are mostly neglected. Similarly, the impact of the various fructan structures on human health has been investigated sparsely. Since most results so far relate to linear fructan structures (mainly inulin), it has been hypothesized that other fructan structures could be more resistant to microbial degradation and thus may affect microbial composition and immune reactions differently.
Submissions are welcome on the protective roles of fructans for plants and humans. Studies could be related to fructans and plant stress and human health benefits. Reports may represent physiological, genetic, and molecular studies as well as structural, functional, and/or physicochemical investigations on plant, bacterial or fungal fructans. Contributions on microbial fructans are welcome, however these should have a clear focus on plant metabolism, e.g. comparing functions of fructan structures from various species in plants or investigating the effect on plants such as during priming. Reviews, Mini Reviews and Original Research papers are welcome, which may also describe methodological/technological developments.
Submissions are invited around:
• Plant fructan biosynthesis and function under stress conditions
• Synthesis of fructans in CAM plants
• Fructans as priming agents in agronomy
• Beneficial effects of fructans on human obesity, as prebiotics, and others
• Fungal or bacterial fructans related to plants: comparison on fructan structure-function relationships and fructan biosynthetic genes, etc.
• Fructans in food and feed with beneficial effects on mammalian health
Please note that descriptive studies are outside the scope of Frontiers in Plant Science. Comparative studies must be accompanied by relevant functional/physiological characterization.
Keywords: Fructans, osmoprotectant, plant stress, prebiotics, membrane stabilization, monosaccharides, polysaccharides
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.