Tissue-specific immunofluorescent localization of zein and globulin in Zea Mays (L) seeds

Abstract

Zein is the most abundant storage protein of maize seeds, and is made in the endosperm where it is deposited inside vesiculate protein bodies of l-2 pm diam., as characterized by electron microscopy [ 1,2]. Most investigations dealing with kinetic aspects of zein synthesis utilize seeds of < 25 days after pollination. While the endosperm is almost fully developed at this time, the embryo is still very small. The expression of the zein genes has therefore been assumed to be limited to the endosperm. The possibility of zein biosynthesis occurring in embryos has in fact not been contemplated until significant amounts of zein were extracted from mature embryos [3,4]. This raised the question of whether zein was also synthesized in the embryos. Tissue-specificity is critical when studying developmental regulation of zein or hormonal control at a molecular level. As we had raised antibodies against zein, we investigated zein localization by employing an immunofluorescent technique on thin sections of whole maize kernels: (9