Department of Biosciences, Faculty of Science and Engineering, Teikyo University, Utsunomiya, Japan.
Division of Integrated Science and Engineering, Graduate School of Science and Engineering, Teikyo University, Utsunomiya, Japan.
Phytochem Anal. 2022 Mar;33(2):194-203. doi: 10.1002/pca.3079. Epub 2021 Jul 26.
Jasmonic acid (JA) and its precursors are oxylipins derived from α-linolenic acid (αLA) and hexadecatrienoic acid, and regulate seed development. However, their spatial distribution in the developing Glycine max L. (soybean) seeds has not been elucidated.
To investigate the distribution of JA-related compounds in the developing soybean seeds using desorption electrospray ionisation-mass spectrometry imaging (DESI-MSI) and liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS) analyses.
Cryosections of developing seeds were prepared using adhesive films, and subjected to DESI-MSI analysis. Verification of the DESI-MSI ion images were performed using DESI-tandem MSI (MS/MSI), LC-ESI-MS and tandem MS (MS/MS).
In the DESI-MSI mass spectrum, peaks matching the chemical formulae of αLA, 12-oxo-phytodienoic acid (OPDA), and 3-oxo-2-(2-(Z)-pentenyl)-cyclopentane-1-octanoic acid (OPC-8:0) were detected. These compounds were mainly distributed in the seed coat, especially near the hilum. This was consistent with the quantitative results obtained by LC-ESI-MS. While, DESI-MS/MSI and LC-ESI-MS/MS suggested the presence of isomers for OPDA and OPC-8:0. The effect of isomers on the DESI-MSI ion images was small for OPDA, and considerable for OPC-8:0.
These results demonstrated that free αLA, OPDA, and OPC-8:0 were the abundant JA-related compounds mainly distributed in the seed coat of the developing soybeans. OPDA and OPC-8:0 might exert a biological role in the seed coat. To the best of my knowledge, this is the first report on the accumulation of OPDA and OPC-8:0 in the seed coat. The combination of DESI-MSI and LC-ESI-MS is a useful tool for distribution analysis of JA-related compounds in the developing seeds.
茉莉酸（JA）及其前体是由α-亚麻酸（αLA）和十六碳三烯酸衍生的氧化脂类，调节种子发育。然而，它们在发育中的大豆（大豆）种子中的空间分布尚未阐明。
使用解吸电喷雾电离-质谱成像（DESI-MSI）和液相色谱-电喷雾电离-质谱（LC-ESI-MS）分析研究 JA 相关化合物在发育中的大豆种子中的分布。
使用粘性膜制备发育中种子的冷冻切片，并进行 DESI-MSI 分析。使用 DESI-串联 MSI（MS/MSI）、LC-ESI-MS 和串联 MS（MS/MS）验证 DESI-MSI 离子图像。
在 DESI-MSI 质谱中，检测到与 αLA、12-氧代-植物二烯酸（OPDA）和 3-氧代-2-（2-（Z）-戊烯基）-环戊烷-1-辛酸（OPC-8：0）化学公式匹配的峰。这些化合物主要分布在种皮中，特别是靠近种脐附近。这与通过 LC-ESI-MS 获得的定量结果一致。然而，DESI-MS/MSI 和 LC-ESI-MS/MS 表明 OPDA 和 OPC-8：0 存在异构体。OPDA 的异构体对 DESI-MSI 离子图像的影响较小，而 OPC-8：0 的影响则相当大。
这些结果表明，游离的 αLA、OPDA 和 OPC-8：0 是发育中大豆中丰富的 JA 相关化合物，主要分布在种皮中。OPDA 和 OPC-8：0 可能在种皮中发挥生物作用。据我所知，这是关于 OPDA 和 OPC-8：0 在种皮中积累的首次报道。DESI-MSI 和 LC-ESI-MS 的结合是分析发育中种子中 JA 相关化合物分布的有用工具。
