Planta Med 2006; 72 - P_271
DOI: 10.1055/s-2006-950071

The identification of new aromatic cytokinins in Arabidopsis thaliana by hybrid Q-Tof mass spectrometry

E Hauserova 1, K Dolezal 1, O Novak 1, M Strnad 1
  • 1Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71, Olomouc, Czech Republic

Cytokinins [1] are plant hormones that affect a wide array of biological processes. They are involved in the growth and development of plants. Some of the cytokinin-derived compounds are also specific inhibitors of cyclin-dependent kinases and exhibit an interesting therapeutical effect against various types of diseases.

This work is focused on the isolation of new di- and tri-substituted aromatic cytokinins in Arabidopsis thaliana (L.) Heynh. and their identification by mass spectrometry.

In general, preparation of cytokinin samples constitutes of 3 individual steps – extraction of target analytes, solid phase extraction and immunoaffinity purification step. An efficient batch immunoaffinity extraction (IAE) method [2] was developed and optimized for the purification of new cytokinins and their corresponding ribosides. The combination of simple C18 solid phase extraction with batch IAE provides fast, easy to use and cost-effective technique for routine samples processing.

A general screening for new cytokinins was performed on Acquity Ultra Performance Liquid Chromatography (UPLC) linked to a Quattro micro API mass spectrometer equipped with an electrospray interface and photodiode array detector (Waters). The daughter ion spectra in positive ion mode were obtained for all tested standard compounds and their monitoring was based on multiple reactions monitoring (MRM).

The high-resolution measurement was done on a hybrid mass analyser Q-Tof micro with electrospray ionisation technique, connected to capLC instrument (Waters). The accurate masses of the parent ions and its fragments were calculated and used for the determination of the elementary composition and the structure confirmation. Using this technique we were able to identify new aromatic cytokinin ribosides.

References: 1. Mok, D.W.S., Mok, M.C. (2001), Ann. Rev. Plant Physiol. Plant Mol. Biol. 52: 89–118. 2. Hauserova, E. et al. (2005), J. Chromatography A 1100: 116–125.