@Article{IPB-350,
author = {Jäckel, L. and Schnabel, A. and Stellmach, H. and Klauß, U. and Matschi, S. and Hause, G. and Vogt, T.},
title = {{The terminal enzymatic step in piperine biosynthesis is co‐localized with the product piperine in specialized cells of black pepper (Piper nigrum
            L.)}},
year = {2022},
pages = {731–747},
journal = {Plant J.},
doi = {10.1111/tpj.15847},
url = {https://doi.org/10.1111/tpj.15847},
volume = {111},
abstract = {Piperine (1-piperoyl piperidine) is responsible for the pungent perception of dried black pepper (Pipernigrum) fruits and essentially contributes to the aromatic properties of this spice in combination with ablend of terpenoids. The final step in piperine biosynthesis involves piperine synthase (PS), which catalyzesthe reaction of piperoyl CoA and piperidine to the biologically active and pungent amide. Nevertheless, experimental data on the cellular localization of piperine and the complete biosynthetic pathway are missing. Not only co-localization of enzymes and products, but also potential transport of piperamides to thesink organs is a possible alternative. This work, which includes purification of the native enzyme, immunolocalization, laser microdissection, fluorescence microscopy, and electron microscopy combinedwith liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), providesexperimental evidence that piperine and PS are co-localized in specialized cells of the black pepper fruit peri-sperm. PS accumulates during early stages of fruit development and its level declines before the fruits arefully mature. The product piperine is co-localized to PS and can be monitored at the cellular level by itsstrong bluish fluorescence. Rising piperine levels during fruit maturation are consistent with the increasingnumbers of fluorescent cells within the perisperm. Signal intensities of individual laser-dissected cells whenmonitored by LC-ESI-MS/MS indicate molar concentrations of this alkaloid. Significant levels of piperineand additional piperamides were also detected in cells distributed in the cortex of black pepper roots. Insummary, the data provide comprehensive experimental evidence of and insights into cell-specific biosyn-thesis and storage of piperidine alkaloids, specific and characteristic for the Piperaceae. By a combination offluorescence microscopy and LC-MS/MS analysis we localized the major piperidine alkaloids to specific cellsof the fruit perisperm and the root cortex. Immunolocalization of native piperine and piperamide synthasesshows that enzymes are co-localized with high concentrations of products in these idioblasts.}    
}