Novel BAP degradation pathway during adventitious caulogenesis in Pinus pineaL. cotyledons

Abstract

Cytokinins (CKs) are a group of phytohormones which probably regulate the growth, development, and metabolism of all plants. The aromatic CK benzyladenine (BA) has been widely applied in in vitro culture for inducing shoot organogenesis. Our study of endogenous cytokinin profiles during the caulogenic process based on mature cotyledons of stone pine (Pinus pinea L.) showed a novel metabolic pathway of aromatic cytokinins based on modification of purine skeleton. Methods Three-year-old mature seeds from two half-sibling selected families and open-pollinated trees of P. pinea were used [1] and the samples were collected following the Alonso et al.[2] procedure. Extraction and purification of cytokinins was based on the method described by Novak et al. [3], including modifications published later [4]. The samples were purified using a combination of a cation (SCX-cartridge) and anion [DEAE-Sephadex/ C18-cartridge] exchangers. Combination of high performance liquid chromatography (HPLC) with quadrupoletime of flight mass spectrometry (QqTOF) was used for accurate and sensitive identification and quantification of cytokinins.