Imaging of Multiple Plant Hormones in Roots of Rice (Oryza sativa) Using Nanoparticle-Assisted Laser Desorption/Ionization Mass Spectrometry

• DOI: 10.1021/acs.jafc.0c00749
• Publication Date: 2020-05-21T18:05:46Z
• Authors: Katsuhiro Shiono; Shu Taira
• Keywords: Jasmonic acid; Brassinosteroid; Mass spectrometry imaging; Plant hormone

Plant hormones can act in synergistic and antagonistic ways response to biotic abiotic stresses plant growth development. Thus, a technique is needed simultaneously determine the distributions concentrations of several hormones. Previously, we reported that localizations two [cytokinin (CK) abscisic acid (ABA)] be visualized tissue using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). In MALDI-MS, however, self-ionization an organic matrix occasionally interferes with ionizations small molecules (<500 m/z) including most Another technique, nanoparticle-assisted (Nano-PALDI), avoid nanoparticles assist ionization analytes. Here, compared efficiencies common by MALDI-MS Nano-PALDI-MS. For comparison, prepared standard mix seven [ABA, auxin (IAA), brassinosteroid (Br), CKs (trans-zeatin, tZ, 6-(γ,γ-dimethylallylamino) purine, iP), jasmonic acid, salicylic (SA)], ethylene precursor (1-aminocyclopropane-1-carboxylic ACC), heavy hydrogen-labeled ABA (D6-ABA). Basic detected all compounds except IAA, Br, D6-ABA, while Nano-PALDI-MS nine compounds. By imaging (MSI), each abovementioned ACC were also root cross sections rice which incubated hormone for 2 h. elongation zone untreated roots, Nano-PALDI-MSI revealed high levels outer part roots much lower stele, but SA, broadly distributed section. IAA seemed epidermis, cortex, stele. Multiple-hormone has great potential investigating roles signaling crop development stress responses.