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: One monoclonal antibody, G26-6-B2, is guard-cell-specific and does not react with mesophyll-cell protoplasts of the same species, probably a differentiation-specific plasma-membrane protein.
Abstract: Monoclonal antibodies were raised against the plasma membrane of Vicia faba L. guard cells by immunizing either with total membranes from purified guard-cell protoplasts or with sealed, predominantly right-side-out plasma-membrane vesicles prepared from abaxial epidermes of V. faba by aqueous two-phase partitioning. Hybridoma screening was performed by enzyme-linked immunosorbent assay using polystyrene-adsorbed plasma-membrane vesicles as solid phase and by indirect immunofluorescence analysis using unfixed, immobilized protoplasts in a microvolume Terasaki assay. A range of monoclonal antibodies was characterized and is reported here. One monoclonal antibody, G26-6-B2, is guard-cell-specific and does not react with mesophyll-cell protoplasts of the same species. It binds to a periodate-resistant but trypsin-labile epitope, probably a differentiation-specific plasma-membrane protein.
20 citations
18 Nov 1987
TL;DR: In this paper, it was shown that plant hormones are, as a rule, present at very low levels in most plant tissues, whereas most plant secondary metabolites are present at high levels.
Abstract: From information presented in previous chapters it will be clear to readers that plant hormones are, as a rule, present at very low levels in most plant tissues. Whilst relatively high levels of some hormones are found in immature seeds of certain species (e.g., GAs in developing pea seeds (10)) even these levels are low when compared with the levels of most plant secondary metabolites. Thus while many alkaloids, terpenoids and phenolics may be present at levels of mgs. per gm. dry weight of plant material, plant hormones are usually present at several hundred to several thousand fold lower levels. It is not suprising therefore that knowlege of the chemical identity of plant hormones has been limited by the techniques available for their isolation in a pure state and by the sensitivity of the spectroscopic techniques required to elucidate their chemical structure.
20 citations
TL;DR: Environmental auxin was detected in samples of substrata supporting bryophytes in a variety of locations in both Britain and Malaya and the importance of this environmental auxin for the induction of rhizoids in liverworts and for roots of higher plants is discussed.
Abstract: Summary
Auxin was detected in samples of substrata supporting bryophytes in a variety of locations in both Britain and Malaya. Activity occurred on chromatograms at zones corresponding to the Rf of indole acetic acid. The range of concentrations found, 0.4–10.4 μg/1, probably represents a two- to five-fold underestimate due to losses during extraction and purification. The amounts of auxin in samples of soil on which bryophytes were not growing were within the same range. The importance of this environmental auxin for the induction of rhizoids in liverworts and for roots of higher plants is discussed.
20 citations
15 Jun 2015
TL;DR: A field experiment was carried out at Agronomy Farm of Patuakhali Science and Technology University, Dumki, Patiakhali, from December 2011 to March 2012, to study the effects of nutrient foliar spray on soybean growth, yield and protein content as discussed by the authors.
Abstract: A field experiment was carried out at Agronomy Farm of Patuakhali Science and Technology University, Dumki, Patuakhali, from December 2011 to March 2012, to study the effects of nutrient foliar spray on soybean growth, yield and protein content. Soybean variety Shohag was used as the test crop. N, NPK, NPKS and NPKMg were sprayed and applied in the soil at vegetative and pod filling stages. Soil fertilizations were done as recommended dose, and no soil and foliar fertilization were considered as control. Plants were sprayed at the rate of 100 mg/L of water corresponding to each nutrient. The experimental design was a split plot with three replications. Result indicated that nutrient foliar spray, either singly or in combination, enhanced the growth and yield of the soybean as well as protein content in soybean seed, at the two growth stages compared to soil fertilization. However, spraying nutrients during pod filling stage was better than vegetative spraying stage in all characters studied. The highest amount of protein content in soybean seed and grain yield were obtained by spraying NPKMg. Bangladesh Agron. J. 2014, 17(1): 67-72
20 citations
TL;DR: A model is presented for the biosynthesis of the enzyme in vivo, involving conjugation of the apoprotein with FAD in the cytoplasm, followed by transport of the preholoreductase across the chloroplast envelope to reach its final destiny in the thylakoid membrane.
Abstract: Biosynthesis of ferredoxin-NADP+ reductase in higher plants was investigated in relation with the mechanism of formation of the holoenzyme. The putative precursor of the flavoprotein, obtained after cell-free translation on a wheat germ extract primed with poly(A)-rich mRNA, was able to spontaneously bind free FAD, rendering a functional prereductase. The newly synthesized preholoenzyme showed diaphorase and cytochrome c reductase activities, an apparent molecular mass of 45 kDa, and contained FAD as the only flavin cofactor. It gave a positive reaction towards antisera against mature ferredoxin-NADP+ reductase. On the other hand, intracellular distribution of flavin-synthesizing enzymes indicates that FAD formation occurs in the cytoplasm; that is, in the same compartment as the site of reductase synthesis. On the basis of the preceding data a model is presented for the biosynthesis of the enzyme in vivo, involving conjugation of the apoprotein with FAD in the cytoplasm, followed by transport of the preholoreductase across the chloroplast envelope to reach its final destiny in the thylakoid membrane.
20 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