.........................................................................................................9 Introduction ..................................................................................................10 Materials and Methods .................................................................................13 Plant Materials .........................................................

Evidence for de novo synthesis of isocitratase and malate synthetase in cotyledons of germinating peanut (Arachis hypogaea L.) was obtained by the density labeling method. When dry peanut cotyledons were cultured in H(2) (18)O, a 2.4% increase in the buoyant density of malate synthetase in a cesium chloride gradient was observed. In 100% D(2)O the buoyant density shift was 5.5% for isocitratase...

Stomata regulate gas exchange through the aerial plant epidermis by controlling the width of a pore bordered by two guard cells. Little is known about the genes that regulate stomatal development. We screened cotyledons from ethyl methanesulfonate-mutagenized seeds of Arabidopsis by light microscopy to identify mutants with altered stomatal morphology. Two mutants, designated too many mouths (t...

Co(2+) promoted elongation of hypocotyl segments of light-grown cucumber (Cucumis sativus) seedlings. Time course and dose response data are presented and interactions with IAA, gibberellin, cyclohexanol, and cotyledons described. Segments without cotyledons responded to Co(2+) only if grown in gas-tight vessels with IAA added. When bases of cotyledons were ringed with an inhibitor of auxin tra...

The incorporation of phospholipids specifically labeled with glycerol-2(3)H and acyl-(14)C by whole cell tissues of developing soybean cotyledons (Glycine max L.) reveals that phosphatidylinositol, phosphatidylcholine, phosphatidylethanolamine, N-acylphosphatidylethanolamine, and phosphatidic acid can be metabolized to diglyceride. The diglyceride formed may be recylced into phospholipid or acy...

A fate map has been constructed for the shoot apical region of the embryo of the dicotyledonous plant Arabidopsis thaliana using spontaneously arising clonal albino sectors caused by the chloroplast mutator 1-2 mutation. Chimeric seedlings exhibiting albino sectors shared between the cotyledons and first true leaves revealed patterns of organ inclusion and exclusion. Frequencies of clone sharin...

The assimilation of nitrate in plants involves the reduction of nitrate to ammonia in two steps. The first step requires nitrate reductase, a nitrate-inducible enzyme. When seedlings of squash (Cucurbita maxima L.) were treated with nitrate, both nitrate reductase activity and protein were induced in the cotyledons. Poly(A)(+) RNA was prepared from cotyledons of nitrate-treated seedlings and wa...

l-Leucine-U-(14)C was incorporated into mitochondrial protein in pea (Pisum sativum var. Alaska) cotyledons during the imbibing stages. Incorporation was almost completely inhibited by cycloheximide but not by chloramphenicol. Both antibiotics did not affect increases in mitochondrial activities and components of the cotyledons during imbibition. Therefore, mitochondrial development seems to be...

Albumin and globulin fractions of Indian bean seeds exhibit different mobilization patterns during the 8-day germination period. The albumin degradation was lesser in the early stage and reached a maximum in the later stages of germination. However, the globulins were degraded steadily from the start of imbibition. The influence of the embryonic axis on albumin and globulin degradation was also...

Thionins are antimicrobial proteins that are thought to be involved in plant defense. Concordant with this view, we have recently shown that the Arabidopsis thionin Thi2.1 gene is inducible by phytopathogenic fungi. Here, we demonstrate that constitutive overexpression of this thionin enhances the resistance of the susceptible ecotype Columbia (Col-2) against attack by Fusarium oxysporum f sp m...