Membrane deterioration in plant senescence is commonly associated with progressive decreases in membrane phospholipid content. This study investigated the expression and regulation of phospholipase D (PLD; EC 3.1.4.4) during senescence in castor bean (Ricinus communis L. cv Hale) leaf discs. The rate of leaf senescence was accelerated by 50 [mu]M abscisic acid and was attenuated by 50 [mu]M cyt...

Tomato seedlings (Lycopersicon esculentum Mill. cv Vendor) were grown hydroponically with their root systems maintained at a constant temperature for a 2-week period commencing with the appearance of the first true leaf. Based on fresh and dry weight and leaf area, the optimal root-zone temperature for seedling growth was 30 degrees C. The carbon exchange rate of the leaves was also found to in...

Wilhelm, W.W., McMaster, G.S., Rickrnan, R.W. and Klepper, B., 1993. Above-ground vegetative development and growth of winter wheat as influenced by nitrogen and water availability. Ecol. Modelling, 68: 183-203. Assessing the influence of nitrogen and water availability on development and growth of individual organs of winter wheat (Triticum aestivum L.) is critical in evaluating the response o...

The aim of this work was to analyse the response of Rosa rubiginosa to salinity induced by different concentrations of sodium chloride and calcium chloride (0, 25, 50, 100, 150 and 200 mM). Besides salt accumulation and pH changes, other parameters were investigated including photosynthetic activity, leaf water content, the dynamics of necrosis and chlorosis appearance and leaf drying. The stud...

Physiological effects of different nitrate applications were studied using the C(4) plant, Amaranthus powellii Wats. Plants were grown in a controlled environment chamber and watered daily with nutrient solutions containing 45, 10, 5, or 1 millimolar nitrate. Chloride and sulfate were used to keep the cation and phosphate concentrations constant. Total leaf nitrogen concentration, chlorophyll c...

Rising temperatures under climate change are projected to have negative impacts on crop growth and production. These conclusions are not based on direct observations but on projected model results. A study conducted comparing normal seasonal temperatures (1980–2010) for Ames, IA, to a normal + 4°C environment with the same water vapor deficit evaluated the impacts of temperature on maize (Zea m...