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: Transgenic plants converted supplied betaine aldehyde to glycine betaine at high rates, demonstrating that they were able to transport betaineAldehyde across both the plasma membrane and the chloroplast envelope.
Abstract: Certain higher plants synthesize and accumulate glycine betaine, a compound with osmoprotectant properties. Biosynthesis of glycine betaine proceeds via the pathway choline-->betaine aldehyde-->glycine betaine. Plants such as tobacco (Nicotiana tabacum L.) which do not accumulate glycine betaine lack the enzymes catalyzing both reactions. As a step towards engineering glycine betaine accumulation into a non-accumulator, spinach and sugar beet complementary-DNA sequences encoding the second enzyme of glycine-betaine synthesis (betaine aldehyde dehydrogenase, BADH, EC 1.2.1.8) were expressed in tobacco. Despite the absence of a typical transit peptide, BADH was targeted to the chloroplast in leaves of transgenic plants. Levels of extractable BADH were comparable to those in spinach and sugar beet, and the molecular weight, isoenzyme profile and Km for betaine aldehyde of the BADH enzymes from transgenic plants were the same as for native spinach or sugar beet BADH. Transgenic plants converted supplied betaine aldehyde to glycine betaine at high rates, demonstrating that they were able to transport betaine aldehyde across both the plasma membrane and the chloroplast envelope. The glycine betaine produced in this way was not further metabolized and reached concentrations similar to those in plants which accumulate glycine betaine naturally. Betaine aldehyde was toxic to non-transformed tobacco tissues whereas transgenic tissues were resistant due to detoxification of betaine aldehyde to glycine betaine. Betaine aldehyded ehydrogenase is therefore of interest as a potential selectable marker, as well as in the metabolic engineering of osmoprotectant biosynthesis.
160 citations
TL;DR: Colored materials in sodium dodecyl sulfate-solubilized spinach chloroplasts move to the anode on the electrophoresis with polyacrylamide gel, and are separated into three components denoted I, II and III, respectively, from the origin to theAnode.
156 citations
TL;DR: In this paper, a comparison was made between the annealing characteristics of commercial waxy, normal and amylomaize starches, where improved registration of amylopectin double helices was proposed, with optimisation of hydrogen bonding along the full length of individual helices.
154 citations
TL;DR: In this paper, a simple method involving a single extraction procedure is given for the determination of water-soluble carbohydrates (sugars + fructosans) in grasses.
Abstract: A simple method involving a single extraction procedure is given for the determination of water-soluble carbohydrates (sugars + fructosans) in grasses. Factors such as storage of grass samples and clarification, hydrolysis and storage of extracts are discussed. The method is likely to have a routine application in silage studies where a measure of fermentable carbohydrates is required.
153 citations
TL;DR: Investigation on fungal infection, moisture content, germinability and deterioration of three seeds in storage at the locality of Santiniketan, West Bengal, India, under natural condition for 1 year found that Seed moisture was maximum in the rainy season followed by a gradual decrease during longer storage.
Abstract: This paper deals with investigations on fungal infection, moisture content, germinability and deterioration of three seeds, viz., maize (starchy), groundnut (oily) and soybean (proteinaceous) in storage at the locality of Santiniketan, West Bengal, India, under natural condition for 1 year. The airspora of storage environment was trapped using culture plate method. Different species of Aspergillus (A. candidus, A. flavus, A. niger, A. terreus, and A. ruber) were dominant followed by Rhizopus, Penicillium, Curvularia, Fusarium, Alternaria, etc. Seed moisture was maximum in the rainy season followed by a gradual decrease during longer storage. A gradual decrease in field fungi with simultaneous increase in storage fungi accompanied by a reduction in germinability occurred in all seeds as storage proceeded. A gradual loss of carbohydrate (both soluble and insoluble) content in all the seeds were recorded. A loss of protein content was recorded followed by a small increase. Oil content decreased in prolonged storage with simultaneous increase in fatty acid.
153 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