-
Article
Relations between Logical Positivism and the Cambridge School of Analysis
-
Article
Photoperiodic Control of Germination in Seed of Birch (Betula pubescens Ehrh.)
IT is well known that the flowering response of both short-day and long-day herbaceous species is governed by the day-length conditions to which the mature leaves are exposed, and that the meristematic tissue ...
-
Article
Interrelationships of Germination Inhibitors and Oxygen in the Dormancy of Seed of Betula
IT has been shown that for ‘seeds’ (achenes) of Betula pubescens a much higher percentage germination is obtained in long days than in short days (approximately 90 and 25 per cent respectively)1. The effect of li...
-
Article
Sensitivity of Light-inhibited Seeds to Certain Spectral Regions
IN recent years important progress has been made in our knowledge of the light-dependent processes in plant development. Detailed studies of the action spectrum for the photoperiodic control of flowering and f...
-
Article
Similar Effects of Blue and Infra-Red Radiation on Light-sensitive Seeds
EVIDENCE that blue spectral regions affect the germination of light-sensitive seeds has existed for some years, and has recently been confirmed for both light-inhibited1 and light-promoted seeds2,3. Borthwick et ...
-
Article
Prevention of the Onset of Seed Dormancy by Gibberellic Acid
ONE of the striking properties of gibberellic acid is its ability to curtail the rest period of seeds and other dormant organs. For example, dormant seeds of lettuce1, peach2, Arabidopsis 3 and barley4 germinate ...
-
Article
Promotion of Germination in Light-requiring Seed by Chloramphenicol
IN this laboratory we are investigating germination processes in light-requiring seeds of Latuca sativa L. (var. ‘Grand Rapids’) including protein and nucleic acid synthesis in relation to the photocontrol of ger...
-
Article
Immediate Action of Phytochrome in Light-stimulated Lettuce Seeds
SEEDS of Lactuca sativa (var. ‘Grand Rapids’), which we have used in these studies, require a short exposure to red light in order to germinate at 25° C. The promotive effect of red light can be completely nullif...
-
Article
Effect of Inhibitors of Protein Synthesis on the Plastic Deformation and Growth of Plant Tissues
MANY workers have confirmed that auxin increases the irreversible deformability (“plasticity”) of plant tissues, for example, coleoptiles or storage tissue1–3. A primary effect of auxin in growth may therefore be...
-
Article
Germination of lettuce induced by inhibitors of protein synthesis
L-threo chloramphenicol and actinomycin D act like D-chloramphenicol in being able to promote germination of light-requiring seeds of Lactuca sativa in darkness. The two isomers of chloramphenicol at relatively l...
-
Article
Immediate phytochrome action in lettuce seeds and its interaction with gibberellins and other germination promoters
An immediate action of phytochrome (PFR) was found by a technique of adding subthreshold concentrations of gibberellic acid (GA3) after irradiation. It was shown that phytochrome (PFR) is active within 5 mins aft...
-
Article
The effect of indole-3-acetic acid on coleoptile extension growth in the absence of protein synthesis
In wheat coleoptile sections cycloheximide inhibited over 90% of 14C-leucine incorporation into protein within 10 minutes of its application. Even after 2-hour pretreatments with cycloheximide, IAA stimulated ext...
-
Article
The role of the cotyledons in the photocontrol of hypocotyl extension in Cucumis sativus L.
Extension growth of the hypocotyl of de-etiolated cucumber seedlings is inhibited by blue and red light, the latter operating through the phytochrome system. The major part of the inhibition due to red light i...
-
Article
Lettuce seed germination and cytokinins: their entry and formation
Cytokinins overcome the inhibitory effect of abscisic acid on the germination of isolated embryos of Grand Rapids lettuce. We have used this fact to assess the content of cytokinins in embryos removed from int...
-
Chapter
Absorption, Distribution, Excretion, and Response to the Drug in the Presence of Chronic Renal Failure
Chronic renal failure (CRF) produces a complex metabolic disturbance that impairs the function of many organs involved in the absorption, distribution, excretion, and response of drugs. However, the small amou...
-
Article
A re-examination of the reputed control of cotyledonary metabolism by the axis
A re-examination has been made of the supposed regulation by the axis of cotyledonary isocitrate lyase (EC 4.1.3.1) activity in Cucumis sativas L. and Cucurbita maxima Duch. and greening in cucumis. When precauti...
-
Article
The role of cotyledons in phototropism of de-etiolated seedlings
Simulated “phototropic” curvatures caused by differential masking of the cotyledons of de-etiolated seedlings exposed to white light are unconnected with true phototropism. In Cucumis sativus L. and Helianthus an...
-
Article
The control of food mobilisation in seeds of Cucumis sativus L.
The degradation of neutral lipid and the development of lipase activity in cucumber cotyledons is stimulated by white light. Malate synthase and isocitrate lyase activities show no stimulation. Lipase activity...
-
Chapter
The Control of Cell Growth by Light
The photocontrol of growth in higher plants depends on the participation of cell enlargement, as revealed by measurements of cell length, diameter or volume. Although many studies of the photocontrol of growth...
-
Article
Cadmium effects on the kidney
