C. Niesternyveld et al., IMMUNOCYTOCHEMICAL LOCALIZATION OF PHENOLIC-COMPOUNDS IN POLLEN WALLSUSING ANTIBODIES AGAINST P-COUMARIC ACID COUPLED TO BOVINE SERUM-ALBUMIN, Protoplasma, 197(3-4), 1997, pp. 148-159
Two different antibodies against bovine serum albumin (BSA)-p-coumaric
acid-conjugates were produced and used to localize phenolic compounds
in exines of pollen from different species. p-Coumaric acid (pC) was
coupled to BSA either via the carboxy group (BSA-pC) or directly to th
e aromatic ring system (BSA-azo-pC). The polyclonal antibodies raised
in rabbits were characterized by ELISA with homologous and heterologou
s antigens using turkey ovalbumin as carrier protein. The results show
ed that the two immune sera directed against BSA-pC and BSA-azo-pC, re
spectively, were specific for p-coumaric acid and structurally similar
compounds. Only a very poor binding by acetic acid-ovalbumin-conjugat
es gates and no binding by turkey ovalbumin was detectable. The antibo
dies reacted with partially purified pollen walls and with highly puri
fied exines. The intensity of the immune reaction was proved to be dep
endent upon the pollen source and the preparation of the pollen walls.
Using light and electron microscopy, it was shown for the first time
that, in the exines of Cucurbita maxima, antibody binding was predomin
antly observed in the region of the germ pore apertures, the outer foo
t layers, and in the micro- and macrospines. We conclude from this and
other earlier published data that phenols are important structural co
mpounds of sporopollenin.