Spatiotemporal Dynamics of Oligofructan Metabolism and Suggested Functions in Developing Cereal Grains

Abstract

Oligofructans represent one of the most important groups of sucrose-derived water–soluble carbohydrates in the plant kingdom. In cereals, oligofructans accumulate in above ground parts of the plants (stems, leaves, seeds) and their biosynthesis leads to the formation of both types of glycosidic linkages [β(2,1); β(2,6)-fructans] or mixed patterns. In recent studies, tissue- and development- specific distribution patterns of the various oligofructan types in cereal grains have been shown, which are possibly related to the different phases of grain development, such as cellular differentiation of grain tissues and storage product accumulation. Here, we summarize the current knowledge about oligofructan biosynthesis and accumulation kinetics in cereal grains. We focus on the spatiotemporal dynamics and regulation of oligofructan biosynthesis and accumulation in developing barley grains (deduced from a combination of metabolite, transcript and proteome analyses). Finally, putative physiological functions of oligofructans in developing grains are discussed.

Overexpression of HvCslF6 in barley grain alters carbohydrate partitioning plus transfer tissue and endosperm development

“…Fructans in the endosperm cavity are involved in detoxification of hydroxyl radicals (Peukert et al , 2014; Matros et al , 2015) and maintaining the sucrose gradient between the vascular bundle and sink tissues (Pollock and Cairns, 1991; Peukert et al , 2016b). In 18-6 transgenic grain, ETCs were irregularly formed and the sucrose uptake pathway was likely to have been compromised.…”

Sweet Immunity: The Effect of Exogenous Fructans on the Susceptibility of Apple (Malus × domestica Borkh.) to Venturia inaequalis

“…These carbohydrates occur in approximately 15% of higher plants, including some economically important families (Poaceae and Asteraceae) [ 47 ]. Fructan accumulation is frequently correlated with an increased tolerance to abiotic stresses such as cold and water deficits [ 48 , 49 , 50 , 51 ]. Fructans are subdivided into different classes, mainly based on the linkage type between adjacent Fru moieties.…”

The Immunomodulatory Properties of β-2,6 Fructans: A Comprehensive Review

“…Plants utilise fructosyltransferases to synthesise fructans by adding fructose residues on to sucrose leading to the production of different fructofuranose-linked structures [ 44 , 45 , 46 , 47 , 48 ]. Plant fructans (β-2,6 fructans or β-2,1 inulin-type fructans) are polymers of fructose found as storage PS in ~15% of higher plants such as forage grasses, cereals and vegetables [ 49 ]. Ιnulin, known as a common dietary fibre and prebiotic [ 17 ], has received much attention for its immunomodulatory properties including the ability to induce beneficial effects via the gut microbiota or through direct interactions with the immune system [ 41 , 43 , 46 , 50 , 51 ], however, these effects are less known in plant fructans containing β-2,6 linkages.…”