Modern methods of plant analysis
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.
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01 Jan 2006
TL;DR: An ancestral reaction center of Photosystem I and II (RCI/II) type of photosynthesis arose in which a membrane-spanning helix (MSH) protein bound two molecules of chlorophyll/bacteriochlorophyll in a special pair and had a Chl/quinone primary acceptor.
Abstract: Summary Photosynthesis evolved very early on the Earth, but after respiration, and probably after the metabolic processes for methanogenesis and sulfur oxidation This occurred in ancestors of anoxygenic photosynthetic bacteria An ancestral reaction center of Photosystem I and II (RCI/II) type of photosynthesis arose in which a fi ve membrane-spanning helix (MSH) protein bound two molecules of chlorophyll (Chl)/bacteriochlorophyll (BChl) in a special pair and had a Chl/quinone primary acceptor, and this protein fused, early on, with a six MSH antenna protein Logic suggests that the earliest photopigments were protoporphyrin IX, followed by Mg protochlorophyllide a, followed by Chl/BChl It is not clear whether Chl or BChl came fi rst The evolution of the modern RCI type occurred later but it is not clear under what selection pressure it arose, possibly when ferric salts and sulfur compounds became more available in the Proterozoic Eon
37 citations
TL;DR: Preliminary data suggest that only the non-alcoholic fraction of red wine protects DNA from oxidative damage but this effect cannot be explained solely by plasma catechin.
Abstract: Moderate intake of wine is associated with reduced risk of cardiovascular disease and possibly cancer however it remains unclear whether the potential health benefits of wine intake are due to alcohol or the non-alcoholic fraction of wine. We therefore tested the hypothesis that the non-alcoholic fraction of wine protects against genome damage induced by oxidative stress in a crossover intervention study involving six young adult males aged 21-26 years. The participants adhered to a low plant phenolic compound diet for 48 h prior to consuming 300 mL of complete red wine, de-alcoholized red wine or ethanol on separate occasions 1 week apart. Blood samples were collected 0.5, 1.0 and 2.0 h after beverage consumption. Baseline and radiation-induced genome damage was measured using the cytokinesis-block micronucleus assay and total plasma catechin concentration was measured. Consumption of de-alcoholized red wine significantly decreased the gamma radiation-induced DNA damage at 1 and 2 h post-consumption by 20%. In contrast alcohol tended to increase radiation-induced genome damage and complete wine protected against radiation-induced genome damage relative to alcohol. The observed effects were only weakly correlated with the concentration of total plasma catechin (R=-0.23). These preliminary data suggest that only the non-alcoholic fraction of red wine protects DNA from oxidative damage but this effect cannot be explained solely by plasma catechin.
37 citations
Journal Article•
TL;DR: In this article, two field experiment was carried out in the Experimental Farm of the Desert Research Center at Ras Sudr, South Sinai Governorate, during the two successive summer seasons of 2008 and 2009 to study the effect of the combinations between two cowpea cultivars, i.e., Kafr El-Shekh and Cream 7 with three saline irrigation water treatments, and four levels of humic acid application (0, 2, 4, 4 and 6 kg/fed).
Abstract: Two field experiment was carried out in the Experimental Farm of the Desert Research Center at Ras Sudr, South Sinai Governorate, during the two successive summer seasons of 2008 and 2009 to study the effect of the combinations between two cowpea cultivars, i.e. Kafr El- Shekh and Cream 7 with three saline irrigation water treatments, i.e., (3500, 4500 and 5500 ppm) and four levels of humic acid application (0, 2, 4 and 6 kg/ fed.) on growth, yield and its components, also chemical compositions of leaves and seeds of cowpea plants. Results revealed that: 1.Kafr El-Shekh cultivar surpassed than cream 7 cultivar in plant fresh weight, total pods yield, N, P, K uptake in addition to K/Na and Ca/Na ratio. Also, N, P, K, protein and carbohydrate content in cowpea seeds tissues. 2. The lowest values of plant growth, total pods yield N, P, K uptake and K/Na, Ca/Na ratio. Also, N, P, K, protein and carbohydrate content in cowpea seeds tissues were observed by the highest salinity level (5500 ppm). But this level significantly increased Na, Ca and Cl uptake by plant leaves, in addition to Cl and proline content in seeds tissues. 3. The effect of humic acid on the vegetative growth of cowpea plant i.e. plant height, number of branches, fresh weight, leaf area/ plant, total pods yield, N, P, K uptake and K/Na, Ca/Na ratio. Also N, P, K, protein and carbohydrate content in cowpea seeds showed significant increase with increasing the rate of humic acid application from 0, 3, 4.5 up to 6 kg/fed. 4. The interaction between cultivars and water salinity with humic acid application showed no statistical differences in both seasons.
37 citations
TL;DR: Oleic and linoleic acids were confirmed to be the most variable components of almond oil chemical composition among genotypes and could be incorporated into an almond breeding program aiming at an increase in kernel quality.
Abstract: The protein and oil content and the fatty acid profile of the kernels of selected almond genotypes from four different Moroccan regions were determined in order to evaluate the kernel quality of the plant material of these different regions. The ranges of oil content (48.7–64.5 % of kernel DW), oleic (61.8–80.2 % of total oil), linoleic (11.4–27.0 %), palmitic (5.6–7.7 %), stearic (1.3–3.1 %), and palmitoleic (0.4–0.9 %) acid percentages agreed with previous results of other almond genotypes, but the protein content (14.1–35.1 % of kernel DW) showed that some genotypes had higher values than any previously recorded in almond. Some genotypes from mountainous regions showed kernels with very high oil content as well as high and consistent oleic and linoleic ratio, establishing a possible differentiation according to the geographical origin. These differences may allow establishing a geographical denomination for almond products. In terms of genetic diversity, oleic and linoleic acids were confirmed to be the most variable components of almond oil chemical composition among genotypes. Additionally, the genotypes with extreme favorable values, such as high protein content, could be incorporated into an almond breeding program aiming at an increase in kernel quality.
37 citations
TL;DR: Die Xylemsäfte von Acer pseudoplatanus und Betula pubescens enthalten vor dem Austreiben der Knospen im Frühjahr Cytokinine und Gibberellin-ähnliche Stoffe stammen entweder aus den Wurzeln oder aus dem Xylemparenchym.
Abstract: Die Xylemsafte vonAcer pseudoplatanus undBetula pubescens enthalten vor dem Austreiben der Knospen im Fruhjahr Cytokinine und Gibberellin-ahnliche Stoffe. Diese stammen entweder aus den Wurzeln oder aus dem Xylemparenchym.
37 citations
References
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01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.
2 citations
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
1 citations