Distribution analysis of jasmonic acid‐related compounds in developing Glycine max L. (soybean) seeds using mass spectrometry imaging and liquid chromatography–mass spectrometry

Abstract

Introduction 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. Objective 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. Methods 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). Results 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. Conclusion 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.

The Mechanism of Ochratoxin Contamination of Artificially Inoculated Licorice Roots

“…A Synapt XS HDMS Q-TOF mass spectrometer, equipped with a two-dimensional DESI ion source (Waters, Milford, MA, USA), was used for DESI-MS/MSI [ 36 ]. DESI solvent (95% methanol containing 10 mM acetic acid) and the following DESI ion source conditions were used: capillary voltage, 3.0 kV; spray impact angle, 80°; spatial resolution, 300 µm; and scanning speed, 200 µm s −1 .…”

Applications of ambient ionization mass spectrometry in 2022: An annual review

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