INOSITOL PHOSPHATES IN THE DUCKWEED SPIRODELA-POLYRHIZA L

We have undertaken an analysis of the inositol phosphates of Spirodela polyrhiza at a developmental stage when massive accumulation of InsP( 6) indicates that a large net synthesis is occurring. We have identifi ed Ins3P, Ins(1,4)P-2, Ins(3,4)P-2 and possibly Ins(4,6)P-2, Ins(3,4,6 )P-3, Ins(3,4,5,6)P-4, Ins(1,3,4,5,6)P-5, D- and/or L-Ins(1,2,4,5,6)P- 5 and InsP(6) and revealed the likely presence of a second InsP(3) wit h chromatographic properties similar to Ins(1,4,5)P-3. The higher inos itol phosphates identified show no obvious direct link to pathways of metabolism of second messengers purported to operate in higher plants, nor do they resemble the immediate products of plant phytase action o n InsP(6).