During studies on the chemistry of plant surfaces, we observed that concomitant with the development of cucumber (Cucumis sativus L. cv ;ELEM') cotyledons an agglutinin that agglutinates human erythrocytes appeared on epicuticular surfaces. The agglutinin was released from cotyledon surfaces into distilled water by a 1-minute immersion (or even less). Homogenization of the washed cotyledons rel...

Exogenous jasmonic acid (JA) and methyl jasmonate (MJ) induced accumulation of isoflavone constituents in cotyledons prepared from imbibed seeds of white lupin (Lupinus albus L.). Exogenous 0.2 mM MJ enhanced the levels of 7-O-(6"-O-malonyl)glucosylgenistein and 7-O-glucosylgenistein in the cotyledons of etiolated seedlings that had been incubated in the dark for 48 h. Regarding isoflavone indu...

Seniescenice at the cellular, organ, and organism levels is a poorly understood but nonetheless well established fact. Regardless of the level at which senescence is studied and regardless of the possible interactions between different organs and cells of different ages and functions, senescence is an expression of events at the cellular and subcellular levels. An ideal material, therefore, for...

In cork oak (Quercus suber L.), recurrent embryogenesis is produced in vitro through autoembryony without exogenous plant growth regulators (PGRs); secondary embryos appear on the embryo axis but seldom on cotyledons. Focusing mainly on the histological origin of neoformations, we investigated the influence of the embryo axis and exogenous PGRs on the embryogenic potential of somatic embryo cot...

The ureides, allantoin and allantoic acid, are the major nitrogenous substances transported within the xylem of N(2)-fixing soybeans (Glycine max L. Merr. cv Amsoy 71). The ureides accumulated in the cotyledons, roots and shoots of soybean seedlings inoculated with Rhizobium or grown in the presence of 10 millimolar nitrate. The patterns of activity for uricase and allantoinase, enzymes involve...

Six Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size. Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and red...

We studied the localization of alpha-amylase with indirect fluorescence microscopy in transversely sectioned cotyledons of Vigna mungo seedlings. Tissue sections were fixed in periodate-lysine-paraformaldehyde and treated with anti-alpha-amylase immunoglobulin G followed by fluorescein isothiocyanate labeled goat anti-rabbit immunoglobulin G. alpha-Amylase appeared in the cells farthest from va...

Seedling growth of mung bean is accompanied by the rapid catabolism of the three major phospholipids in the cotyledons (phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol). The decline starts 24 hours after the beginning of imbibition and by the 4th day of growth more than 50% of the phospholipids have been catabolized. Extracts of cotyledons of 24-hour-imbibed beans contai...

Plant regeneration was achieved using somatic embryos obtained from the Vitis vinifera cvs Sugraone, Crimson Seedless and Don Mariano. White somatic embryos, 1.5-3 mm in length, were cultured on embryo germination medium with or without IAA (10 μM) + GA3 (1 μM). Germinated embryos showed 5 different morphologies, (1) one cotyledon, (2) two cotyledons, (3) three cotyledons, (4) trumpet-like and ...

Water potential (psi), the osmotic potential (psi(pi)), and the pressure potential (psi(p)) of detached cotyledons isolated from Cucumis sativus L. cv Marketer seedlings after 0, 1.5, and 3 days growth with and without zeatin were determined. From zero time to 3 days, cotyledons incubated without exogenous zeatin exhibited a slight decrease in psi (from -0.4 to -1.0 bars), while those grown wit...