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.
Citations
More filters
TL;DR: The adaptive formation of nitrate and nitrite reductases in Micrococcus denitrificans as well as the properties and the relation between the NO 3 − and O 2 respiratory pathways have been investigated.
65 citations
TL;DR: The physiological and biochemical mechanisms involved in the formation of the egg-shell while conserving resources lead to the emergence of unique structural properties in the eggshell, providing for the developing embryo a self-contained and precisely regulated environment.
Abstract: Publisher Summary This chapter discusses the physiological aspects of reproduction in nematodes. A general survey of the range of reproductive phenomena in the Nematoda indicates that all the main cytogenetic mechanisms observed in the animal kingdom are apparently represented in this phylum. In the pursuit of reproductive efficiency, there has been an elaboration of the reproductive systems, particularly in the parasitic members, such that greater histological and cytological differentiation has engendered precise and, perhaps, unique physiological mechanisms that ensure a successful fertilization and development of the embryo. In particular, the physiological and biochemical mechanisms involved in the formation of the egg-shell while conserving resources lead to the emergence of unique structural properties in the eggshell, providing for the developing embryo a self-contained and precisely regulated environment. The great success of nematodes as parasites is derived mainly from their ability to maintain reproductive efficiency with little morphological specialization while retaining at the same time some capability for biological variation in ontogeny.
65 citations
TL;DR: Results indicate that O. sanctum leaf extract stimulates the immunity and makes L. rohita more resistant to bacterial infection (A. hydrophila) and enhanced super oxide anion production, lysozyme activity, total immunoglobulin in plasma, serum total protein, globulin, total RBC counts, total WBC counts and haemoglobin content are demonstrated.
Abstract: A 60 days study was conducted to evaluate the efficacy of water extract of Ocimum sanctum Linn. leaf on the immune response and disease resistance of Labeo rohita fingerlings against the Aeromonas hydrophila infection. Ocimum sanctum extract was incorporated in the diets (at 0.0%, 0.05%, 0.1%, 0.2%, 0.5% and 1%) of Labeo rohita, rohu fingerlings (6.6 � 0.013 g). After 42 days blood, plasma and serum were sampled to determine super oxide anion production, lysozyme activity, total immunoglobulin in plasma, blood glucose, serum total protein, albumin, globulin, albumin:globulin ratio, WBC, RBC, haemoglobin content. Fish were challenged with A. hydrophila after 42 days and mortalities were recorded over 18 days post infection. The results demonstrate enhanced super oxide anion production, lysozyme activity, total immunoglobulin in plasma, serum total protein, globulin, total RBC counts, total WBC counts and haemoglobin content (P < 0.05) in treatments group compared with control group. Dietary O. sanctum extracts of 0.2% showed significantly (P < 0.05) higher protection relative percentage survival (RPS 40.00 � 5.773%) against A. hydrophila infection than control. These results indicate that O. sanctum leaf extract stimulates the immunity and makes L. rohita more resistant to bacterial infection (A. hydrophila).
64 citations
TL;DR: The secondary metabolites of Zanthoxylum s.l. are used to construct a putative phylogeny of the genus and its possible "key" position in the evolution of the family is speculated upon.
Abstract: Summary The biosynthetic pathways leading to the major groups of secondary metabolites isolated from the Zanthoxylum/Fagara complex are reviewed and there is shown to be a common precursor in chorismic acid. The use of the compounds as chemotaxonomic markers is discussed and they are found to support the concept of a direct link between the Rutaceae and ranalian stock. The potential value of the secondary metabolites in chemosystematic analysis within the family is also briefly discussed. The alkaloids, coumarins, flavanoids and lignans of the taxa Zanthoxylum and Fagara are examined in detail and the distribution found to support authorities who have expressed the view that these taxa are congeneric (Zanthoxylum s.l.). The chemosystematics of Zanthoxylum s.l. indicates that the genus is primitive within the family. The secondary metabolites of Zanthoxylum s.l. are used to construct a putative phylogeny of the genus and its possible "key" position in the evolution of the family is speculated upon. It is noted that the Englerian classification of Zanthoxylum s.l., and of the Rutaceae in general, appears to be unsatisfactory.
64 citations
TL;DR: Long-stalked glandular hairs of outer and inner involucral bracts of Sigesbeckia jorullensis, which are important for epizoic fruit propagation, were investigated using light and scanning electron microscopy and the essential oil secreted by the hairs was analysed.
64 citations
References
More filters
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