The spatial location and timing of plant developmental events are largely regulated by the well balanced effects of auxin and cytokinin phytohormone interplay. Together with transport, localized metabolism regulates the concentration gradients of their bioactive forms, ultimately eliciting growth responses. In order to explore the dynamics of auxin and cytokinin metabolism during early seedling growth in Theobroma cacao (cacao), we have performed auxin and cytokinin metabolite profiling in hypocotyls and root developmental sections at different times by using ultra-high-performance liquid chromatography-electrospray tandem mass spectrometry (UHPLC-MS/MS). Our work provides quantitative characterization of auxin and cytokinin metabolites throughout early root and hypocotyl development and identifies common and distinctive features of auxin and cytokinin metabolism during cacao seedling development.

Department of Biochemistry Faculty of Science University of Douala Douala P O Box 24157 Cameroon

Laboratory of Growth Regulators Faculty of Science Institute of Experimental Botany of the Czech Academy of Sciences Palacký University Šlechtitelů 27 CZ 78371 Olomouc Czech Republic

Laboratory of Plant Physiology and Biochemistry Department of Biological Science Higher Teachers' Training College University of Yaounde 1 Yaounde P O Box 47 Cameroon

Umeå Plant Science Centre Department of Forest Genetics and Plant Physiology Swedish University of Agricultural Sciences 90183 Umeå Sweden

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