Localization and Composition of Fructans in Stem and Rhizome of Agave tequilana Weber var. azul

Abstract

Methodology combining mass spectrometry imaging (MSI) with ion mobility separation (IMS) has emerged as a biological imaging technique due to its versatility, sensitivity and label-free approach. This technique has been shown to separate isomeric compounds such as lipids, amino acids, carboxylic acids and carbohydrates. This report describes mass spectrometry imaging in combination with traveling-wave ion mobility separation and matrix-assisted laser desorption/ionization (MALDI). Positive ionization mode was used to locate fructans on tissue printed sections of Agave rhizome and stem tissue and distinguished fructan isoforms. Here we show the location of fructans ranging from DP3 to DP17 to be differentially abundant across the stem tissue and for the first time, experimental collision cross sections of endogenous fructan structures have been collected, revealing at least two isoforms for fructans of DP4, DP5, DP6, DP7, DP8, DP10, and DP11. This demonstrates that complex fructans such as agavins can be located and their isoforms resolved using a combination of MALDI, IMS, and MSI, without the need for extraction or derivatization. Use of this methodology uncovered patterns of fructan localization consistent with functional differences where higher DP fructans are found toward the central section of the stem supporting a role in long term carbohydrate storage whereas lower DP fructans are concentrated in the highly vascularized central core of rhizomes supporting a role in mobilization of carbohydrates from the mother plant to developing offsets. Tissue specific patterns of expression of genes encoding enzymes involved in fructan metabolism are consistent with fructan structures and localization.

β(2→1) chicory and β(2→1)-β(2→6) agave fructans protect the human intestinal barrier function in vitro in a stressor-dependent fashion

“…Moreover, fructans from the neo-series have also been found in the mixtures extracted from agave. 26 Their barrier-protective effects have never been studied. Since fructans from agave represent one of the most complex fructan types described to date, we compared their effects on gut epithelial barrier function with those of fructans with a linear structure and by which pathways they protect against barrier disruption.…”

“…[23][24][25] These graminan-type fructans (GTFs) are extracted from plants of the Asparagaceae family such as Agave tequilana and are one of the most complex fructans described to date. 26 It is unknown whether these branched fructans have any effect on gut barrier function.…”

Image to insight: exploring natural products through mass spectrometry imaging

“…IMS is a gasphase separation technique that separates ions based on the form, size, and charge of the ions and has shown great potential in resolving the isobaric/isomeric metabolites. 107 Tandem MS imaging is another widely used strategy to bypass isomeric interference, in which MS/MS imaging is performed to distinguish isomeric species in tissues, and the specic fragment is used to represent the spatial localization of the targeted metabolite. 60,108 Multiple reaction monitoring (MRM) imaging (e.g., MRM-DESI imaging) can be regarded as a variant of tandem MS imaging, which has demonstrated improved sensitivity and specicity for the targeted metabolites.…”

Omics applications in plant-microorganism interactions: A view from plant genomics

“…In silico expression patterns based on transcriptome data indicate which genes are expressed in specific tissues or during specific developmental stages indicating their relative importance in different processes or metabolism. Based on these data we have determined and compared expression patterns for each of the fructan metabolism genes and most of these in silico expression patterns have now been confirmed by qRT-PCR (Ávila de Dios et al, 2019, Pérez-López et al, 2021.…”

“…Basados en estos datos, hemos determinado y comparado los patrones de expresión de cada uno de los genes del metabolismo de los fructanos. La mayoría de estos patrones de expresión in silico han sido confirmados por qRT-PCR (Ávila de Dios et al, 2019, Pérez-López et al, 2021.…”