Imaging of Plant Hormones with Nanoparticle-Assisted Laser Desorption/Ionization Mass Spectrometry

Plant hormones can act in synergistic and antagonistic ways in response to biotic and abiotic stresses and during plant growth and development. Thus, a technique is needed to simultaneously determine the distribution and concentration of several plant hormones. A relatively new technology, mass spectrometry imaging (MSI), enables the direct mapping and imaging of biomolecules on tissue sections. MSI permits simultaneous detection of multiple analytes on a single section of plant tissue, even in the absence of target-specific markers such as antibodies. Recently, MSI has been used to localize multiple, small molecule (m/z < 500) plant hormones by the nanoparticle-assisted laser desorption/ionization (Nano-PALDI) mass spectrometry (MS) method. Here, we illustrate a technology for multiple-hormone imaging using Nano-PALDI MSI and discuss its potential in investigating the role of hormone signaling in plant development and stress responses.