Classification and characterization of unknown cytokinins into essential types by in-source collision-induced dissociation electrospray ionization ion trap mass spectrometry

Authors

  • Shichang Liu,

    1. College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, P.R. China
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    • These authors contributed equally to this work.

  • Weiqi Chen,

    1. College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, P.R. China
    2. Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, P.R. China
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    • These authors contributed equally to this work.

  • Kai Fang,

    1. College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, P.R. China
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  • Xiangning Jiang,

    Corresponding author
    1. College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, P.R. China
    • The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of Chinese Forestry Administration, National Engineering Laboratory for Tree Breeding, Beijing, P.R. China
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  • Ying Gai

    Corresponding author
    1. College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing, P.R. China
    • The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of Chinese Forestry Administration, National Engineering Laboratory for Tree Breeding, Beijing, P.R. China
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X. N. Jiang and Y. Gai, College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P.R. China.

E-mail: gaiying@bjfu.edu.cn; jiangxn@bjfu.edu.cn

Abstract

RATIONALE

Mass spectrometry is effective for determination of cytokinins, which are bioactive compounds with an adenine-core structure. However, it is difficult to characterize any cytokinin compound without the relevant standard or known molecular structure information. With a limited number of standards, an in-source collision-induced dissociation (CID) method for characterization and classification of unknown cytokinins was described in this study.

METHODS

Cytokinins were separated by high-performance liquid chromatography and then analyzed by electrospray ionization ion trap mass spectrometry using an in-source CID technique and multiple reaction monitoring (MRM) mode.

RESULTS

Based on the properties of multi-stage fragmentation in mass spectrometry, naturally occurring cytokinins were classified into four types (zeatin, dihydrogen zeatin, isopentenyl adenine and benzyl adenine) by losing their conjugated sugar, sugar phosphate and other substituents in the source region. Following this technique, seven unknown cytokinins were characterized from roots of maize (Zea mays) without standards and one of them was finally confirmed to be cis-zeatin-riboside.

CONCLUSIONS

An in-source CID technique combined with MRM mass spectrometry was developed to provide product ion information for identification of cytokinins and to afford guidance for the discovery of unknown cytokinins. Copyright © 2012 John Wiley & Sons, Ltd.

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