No abstract

Previous studies indirectly indicated that phytochrome plays a role in peanut (Arachis hypogaea L. cv. Virginia) gynophore elongation and in ovule and embryo development. Recent advances in the use of monoclonal antibody procedures used in this study have allowed precise localization of phytochrome in the developing peanut gynophore and ovular tissues. Peanut phytochrome from etiolated tissues was found to have a molecular weight of 124 kD as determined by immunoblotting procedures using a monoclonal antibody to pea (Pisum sativum L. cv. Alaska) phytochrome. Immunoblotting procedures revealed that no detectable phytochrome was present in the gynophore tissues or immature ovules during the elongation of the peanut gynophores. After the gynophores penetrated the soil for 8–12 d, phytochrome was detected in increasing amounts in the ovular tissues but not the gynophore tissues. Immunohistological analysis revealed that phytochrome was localized in the developing embryo and adjacent integument tissues. These findings contradict earlier reports that suggested phytochrome was initially present in the gynophore tissues after fertilization where it was believed to inhibit ovular development and stimulate gynophore elongation.