CYTOKININ BIOSYNTHESIS IN ENDOSPERM OF SECHIUM EDULE SW

Endosperm of Sechium edule seed was incubated with [U-C-14]adenine and [C-13]mevalonic acid for 17 h. Following incubation, cytokinins were extracted and purified by HPLC. Using GC-MS, incorporation of [C-13]MV A into isopentenyladenine and zeatin riboside was demonstrated. This i s the first unequivocal demonstration of cytokinin biosynthesis in a n ormal plant tissue because precursors incorporation into cytokinins wa s demonstrated by MS. The significance of these results is also discus sed in relation to a possible mononucleotide-independent pathway of cy tokinin biosynthesis. (C) 1997 Elsevier Science Ireland Ltd.