Signal intensities of floral cyanogenic glycosides obtained via MALDI-MSI
Fresh florets of four Australian native Proteaceae species (Grevillea robusta, Macadamia tetraphylla, Neorites kevedianus and Telopea speciosissima) were collected and prepared for matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to visualise cyanogenic glycosides within floral sections using the methods described in Ritmejerytė et al. (2020, 2022) [1,2]. Acquired MSI data were imported into SCiLS Lab software 2017a, in which regions of interest were selected for comparing distributions of two identified cyanogenic glycosides between different tissue types. The signal intensities for each tissue type were then exported as .csv files, with each individual data point indicating the signal intensity of a specific cyanogenic glycoside at each pixel of the imaged section. The data were plotted as box-dot plots using RStudio code "Intensities". Floral developmental stages for each dataset: G. robusta - fertilised floret M. tetraphylla - partially open flower with pollen presenter embedded in perianth N. kevedianus - fertilised floret T. speciosissima - open floret .xlsx files contain raw signal intensities and an image of the floral section imaged with marked regions (tissue types). .csv files contain modified signal intensities (divided by 100,000) which is then noted in the y axis title in the figure. Column "Compound" contains two cyanogenic glycosides each detected as +Na and +K adducts, and "Compound2" column contains the ID of cyanogenic glycoside without noting its adduct, which was used to create the plots. References: 1. Ritmejerytė E, Miller RE, Bayly MJ, Boughton BA. Chapter 3 - Visualization of cyanogenic glycosides in floral tissues. In: Beale DJ, Hillyer KE, Warden AC, Jones OAH, editors. Applied Environmental Metabolomics: Academic Press; 2022. p. 29-44. 2. Ritmejerytė E, Boughton BA, Bayly MJ, Miller RE. Unique and highly specific cyanogenic glycoside localisation in stigmatic cells and pollen in the genus Lomatia (Proteaceae). Annals of Botany. 2020;126(3):387-400. doi: 10.1093/aob/mcaa038.