Mass spectrometric measurements were made of free-base CKs in Col and pAS1:GFP-TCP14 (GFP-TCP14) inflorescences. iP, N6-(Δ2-isopentenyl)adenine; tZ, trans-zeatin; cZ, cis-zeatin; DHZ, dihydrozeatin. Values are means of three biological replicates ± se. ND, Not detected