Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena , Humboldtstrasse 10, 07743 Jena, Germany.
Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena , Philosophenweg 7, 07743 Jena, Germany.
J Agric Food Chem. 2017 May 3;65(17):3559-3568. doi: 10.1021/acs.jafc.7b00584. Epub 2017 Apr 24.
Flavonoids are important metabolites in strawberries (Fragaria × ananassa) because they accomplish an extensive collection of physiological functions and are valuable for human health. However, their localization within the fruit tissue has not been extensively explored. Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was employed to shed light on the spatial distribution of flavonoids during fruit development. One wild-type (WT) and two transgenic lines were compared, wherein the transgenic enzymes anthocyanidin reductase (ANRi) and flavonol synthase (FLSi), respectively, were down-regulated using an RNAi-based silencing approach. In most cases, fruit development led to a reduction of the investigated flavonoids in the fruit tissue; as a consequence, they were exclusively present in the skin of mature red fruits. In the case of (epi)catechin dimer, both the ANRi and the WT phenotypes revealed low levels in mature red fruits, whereas the ANRi line bore the lowest relative concentration, as analyzed by liquid chromatography-electrospray ionization multiple-step mass spectrometry (LC-ESI-MS).
类黄酮是草莓（Fragaria ×ananassa）中的重要代谢物，因为它们具有广泛的生理功能，对人类健康具有重要价值。然而，它们在果实组织中的定位尚未得到广泛探索。基质辅助激光解吸/电离质谱成像（MALDI-MSI）被用于阐明类黄酮在果实发育过程中的空间分布。对一个野生型（WT）和两个转基因系进行了比较，其中，通过基于 RNAi 的沉默方法分别下调了花色苷还原酶（ANRi）和类黄酮合酶（FLSi）这两种转基因酶。在大多数情况下，果实发育导致果实组织中被研究的类黄酮减少；因此，它们仅存在于成熟红色果实的表皮中。对于（表）儿茶素二聚体，ANRi 和 WT 表型在成熟的红色果实中均显示出低水平，而 ANRi 系的相对浓度最低，这是通过液相色谱-电喷雾电离多级质谱（LC-ESI-MS）分析得出的。
