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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TL;DR: A high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole -3-butyric acid (IBA), abscisic acid (ABA), gibberellic Acid (GA), zeatin (Z), N(6)-benzyladenine (BA) and 2,4-dichlorophenoxy
185 citations
Cites methods from "Modern methods of plant analysis"
...Traditionlly, enzyme- or radioimmunoassay (ELISA, RIA) were utilized n field of the phytohormone analysis [10,11]....
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TL;DR: Because cytochrome f is confined to chloroplasts, it would appear advantageous that the starting material should be isolated chloroplast or their fragments freed by washing from cytoplasmic proteins, soluble chloroplast proteins, vacuolar acids, and phenolics.
Abstract: Publisher Summary The first cytochrome to be described in the chloroplasts was cytochrome f , which has been shown to be of the c type. It is recommended that the chloroplasts be obtained in the intact state from the leaf. This is best accomplished by a very short grinding or blending of the leaf material—this and all subsequent processes are to be carried out below 5 ° . The leaf material is preferably freed from the main leaf veins and kept in a turgid condition. By using sucrose or other neutral carbohydrates to adjust the osmotic pressure, rather than salt, the chloroplast preparation can be obtained substantially free from other cytoplasmic organelles—this may be checked by suitable microscopic examination. In spite of the universal occurrence of cytochrome f in higher-plant chloroplasts the only highly purified soluble preparations to be described have been obtained from leaves of curled parsley. Because cytochrome f is confined to chloroplasts, it would appear advantageous that the starting material should be isolated chloroplasts or their fragments freed by washing from cytoplasmic proteins, soluble chloroplast proteins, vacuolar acids, and phenolics. Ammoniacal ethanol, however, extracts insignificant amounts of the cytochrome from such material. The chapter describes the procedure for the purification of the extracted cytochrome.
184 citations
TL;DR: In this article, the pericarp of unripe and ripe tomatoes was extracted from the pericle of the tomato and the wall material was sequentially extracted with cyclohexane-trans-1,2-diaminetetra-acetate (CDTA) at 20", 0.05 M Na,CO, at lo, 0.5, 1 and 4 M KOH at 20" to leave the cc-cellulose residue, which contained a significant amount of pectic material.
184 citations
TL;DR: It is proposed that the increased cross-linking of cell wall proteins via beta1,6-glucan to chitin represents a cell wall repair mechanism in yeast, which is activated in response to cell wall weakening.
Abstract: The yeast cell wall contains beta1,3-glucanase-extractable and beta1,3-glucanase-resistant mannoproteins. The beta1,3-glucanase-extractable proteins are retained in the cell wall by attachment to a beta1,6-glucan moiety, which in its turn is linked to beta1,3-glucan (J. C. Kapteyn, R. C. Montijn, E. Vink, J. De La Cruz, A. Llobell, J. E. Douwes, H. Shimoi, P. N. Lipke, and F. M. Klis, Glycobiology 6:337-345, 1996). The beta1,3-glucanase-resistant protein fraction could be largely released by exochitinase treatment and contained the same set of beta1,6-glucosylated proteins, including Cwp1p, as the B1,3-glucanase-extractable fraction. Chitin was linked to the proteins in the beta1,3-glucanase-resistant fraction through a beta1,6-glucan moiety. In wild-type cell walls, the beta1,3-glucanase-resistant protein fraction represented only 1 to 2% of the covalently linked cell wall proteins, whereas in cell walls of fks1 and gas1 deletion strains, which contain much less beta1,3-glucan but more chitin, beta1,3-glucanase-resistant proteins represented about 40% of the total. We propose that the increased cross-linking of cell wall proteins via beta1,6-glucan to chitin represents a cell wall repair mechanism in yeast, which is activated in response to cell wall weakening.
183 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