PHENYLALANINE AMMONIA-LYASE AND CHALCONE SYNTHASE IN GLANDS OF PRIMULA-KEWENSIS (WATS,W) - IMMUNOFLUORESCENCE AND IMMUNOGOLD LOCALIZATION

Phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) were loc alized by indirect immunofluorescence and immunogold labeling in gland s of Primula kewensis. Both enzymes were exclusively present in the he ad cells of the glands. Phenylalanine ammonialyase was located in the regions of the dense tubular endoplasmic reticulum and occasionally fo und in more or less spherical organelles that have not yet been identi fied. Furthermore, an appreciable proportion of the enzyme protein was associated with the plasmalemma and the cell wall of the head cell. I n contrast, the occurrence of CHS was restricted to the spherical, uni dentified cell compartments. Our findings indicate that the gland cell s have the potential for flavonoid biosynthesis. When a mutant of P. k ewensis forming structurally intact glands but incapable of farina exc retion was studied, neither PAL nor CHS were found in the head cells.