Uptake, Distribution and Translocation of 32P Absorbed through Roots of Cotton Seedlings as Affected with CCC Treatment

The effects of CCC on the ³² P amounts absorbed by cotton seedlings were studied. CCC was applied to the seedlings either as spray or as addition to the nutrient solution in concentrations of 0, 25, 50, 100 and 200 mg/1. ³²P was added to the medium as KH₂³²P O₄ in the concentration of 40 μCi/50 ml. During the experimental period, no morphological changes were observed. The total ³²P uptake was inhibited in CCC treated seedlings. The application of CCC, both as spray and as addition to the medium, led to an accumulation of ³²P in stem, but to a decrease in root. The leaves showed different responses to different methods of application; spraying increased, while an addition of CCC to the medium decerases the ³²P content in the leaves. It is concluded that CCC inhibits ³²P uptake, whereas it ac accelerates the ³²P translocation from root to the aerial parts.     

Carboxylating enzymes and carbonic anhydrase functions were suppressed by zinc deficiency in maize and chickpea plants

Maize and chickpea plants were grown in a controlled environment with 0.5 M Zn or without Zn and various photosynthetic reactions were studied. The chlorophyll level, the rate of photosynthesis and photosystem II activity, the activity of carboxylating enzymes and that of carbonic anhydrase were suppressed by Zn deficiency in both plant species. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was quantified using polyacrylamide gel electrophoresis. Growing plants in a medium without Zn caused a decrease in the total protein level and in the levels of large and small subunits of Rubisco.     

Scrape-loading and dye transfer : A rapid and simple technique to study gap junctional intercellular communication

Gap junction-mediated intercellular communication has been recognized in cells from different tissues of various organisms and has been implicated in a variety of cellular functions and dysfunctions. Here we describe a new, direct and rapid technique with which to study this cellular phenomenon. It employs scrape-loading to introduce a low molecular weight (MW) fluorescent dye, Lucifer yellow CH (MW 457.2) into cells in culture and allows the monitoring of its transfer into contiguous cells. In communication-competent cells the dye transmission occurred within minutes after loading. The involvement of membrane junctions in Lucifer yellow transfer was verified by the concurrent loading of a high MW marker dye conjugate, rhodamine dextran (MW 10,000). Once introduced intracellularly the rhodamine dextran is unable to cross the relatively narrow membrane junctions. Chemicals of variable potency known to block junctional communication were tested in Chinese hamster V79 cells and other mammalian cells. The results showed effective blockage of the dye transfer at non-cytotoxic doses. This new technique can be applied to a wide variety of mammalian (including human) cells. In addition, it has the potential to be utilized as a rapid screening assay to detect chemicals that can modulate intercellular communication and to study their mechanism of action.     

Efficiency of asbestos shading for growth of Barki rams during hot summer

Twenty-four growing Barki rams, 5–6 months old with an average body weight of 22 kg, were divided into asbestos shaded and unshaded groups during summer. Ad libitum feeding on roughage with 0.5 kg of concentrates per head per day was practiced. Drinking water was available twice daily in the early morning and afternoon. Biweekly observations included rectal temperature (RT; °C), and respiration rate (RR; breaths per minute) at 06:00 h and 14:00 h were recorded. Meteorological data, plasma glucose, calcium, inorganic phosphorus and packed cell volume were also measured. Results indicated that experimental animals developed hyperthermia during June to September, as evidenced by higher (P < 0.01) RT and RR than normal (40 ± 0.05 and 103.9 ± 3.87 vs. 38.9 ± 0.10 and 40 ± 6.56, respectively). Diurnal variations in these physiological phenomena were closely associated (P < 0.05) with ambient temperature changes. As compared with the unshaded group, providing an asbestos shed reduced (P < 0.05) RT and RR in the hyperthermic animals during the day (39.9 ± 0.07 and 94.7 ± 3.75 vs. 40.1 ± 0.08 and 113.1 ± 4.74, respectively), but it increased (P < 0.05) these parameters during summer nights (39.5 ± 0.05 and 82.4 ± 0.95 vs. 39.2 ± 0.07 and 71.6 ± 2.41, respectively). It also increased (P < 0.05) packed cell volume 1 h after morning drinking (35 ± 0.97 vs. 33.2 ± 0.60); reduced (P < 0.05) plasma glucose (43.3 ± 5.88 vs. 53.2 ± 6.31); caused hypocalcemia (10.9 ± 0.35 vs. 11.5 +- 0.43; P < 0.05) and hypophosphatemia (3.9 ±0.35 vs. 4.6 ± 0.34; P < 0.05) as a result of hyperthermia. Monthly variations in all parameters studied were higher (P < 0.01) during early summer. It is concluded that providing an asbestos shed for growing Barki rams under Egyptian summer conditions will not protect the animals from hyperthermia by day and night, as it interferes with extra body heat dissipation to the surroundings during summer nights. Although the unshaded animals were more hyperthermic during summer days, they tended to be normal during the night.     

Über den Einfluß der Manganernährung auf den Vitamin-C-Gehalt von Pflanzenblättern

Summary The influence of manganese on the vitamin-C content of some culture plants grown in water cultures was examined. Ascorbic acid (AS) and dehydroascorbic acid (DAS) were determined by Tillmanns method. The AS-content shows an increase due to manganese nutrition but there is no influence on the total vitamin-C content (AS + DAS).

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Die vorliegenden Untersuchungen wurden im Rahmen einer großen Arbeit³ durchgeführt.     

Different effects of chlormequat on chlorophyll,protein and yield in cotton grown under varying water regimes

Summary Cotton plants grown under water stress conditions showed significant decreases in yield, though only slight decreases in protein N as well as in chlorophyll content were detected. Chlormequat (CCC) application minimized the decreases in yield and caused significant increases in both protein N and chlorophyll contents. It is concluded that changes induced by CCC in cotton yield are independent from those occurred in chlorophyll and protein N contents.