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: These include headspace analyses of plant VOCs emitted by the whole organism, organs or enzymes as well as advanced on-line analysis methods for simultaneous measurements of VOC emissions with other physiological parameters.
Abstract: *Summary Plants emit volatile organic compounds (VOCs) that play important roles in their interaction with the environment and have a major impact on atmospheric chemistry. The development of static and dynamic techniques for headspace collection of volatiles in combination with gas chromatography–mass spectrometry analysis has significantly improved our understanding of the biosynthesis and ecology of plant VOCs. Advances in automated analysis of VOCs have allowed the monitoring of fast changes in VOC emissions and facilitated in vivo studies of VOC biosynthesis. This review presents an overview of methods for the analysis of plant VOCs, including their advantages and disadvantages, with a focus on the latest technical developments. It provides guidance on how to select appropriate instrumentation and protocols for biochemical, physiological and ecologically relevant applications. These include headspace analyses of plant VOCs emitted by the whole organism, organs or enzymes as well as advanced on-line analysis methods for simultaneous measurements of VOC emissions with other physiological parameters.
539 citations
479 citations
TL;DR: The role of polyols in storage of reducing power and coenzyme regulation, as well as other phyla, and endogenous metabolism, are reviewed.
Abstract: CONTENTS PAGE INTRODUCTION I. . . . . 44 FUNGI . . . . . . . . . . . 144 Occurrence and quantitative variation . . . . . I44 Metabolism and physiological role . . . . . . 148 Uptake and utilization . . . . . . . 148 Polyols as natural substrates . . . . . .I49 Polyols as storage products . . . . . . I50 Polyols in spores and spore germination . . . . I51 Intermediary metabolism and enzymology . . . . I53 The role of polyols in storage of reducing power and coenzyme regulation . . . . . . . . . . 56 The control of polyol synthesis . . . . . .I57 ALGAE . . . . . . . . . . . I57 Occurrence and quantitative variation . . . . . 157 Phaeophyta . . . . . . . . . I59 Rhodophyta . . . . . . . . .I6I Chlorophyta . . . . . . . i6I Chrysophyta and Pyrrophyta . . . . . i6i Heterotrophic growth . . . . . . . . i6I Metabolism and physiological role . . . . . . i62 Phaeophyta . . . . . . . . . i62 Other phyla . . . . . . . . .I63 LICHENS . . . . . . . . . . . I64 Occurrence and quantitative variation . . . . . I64 Metabolism and physiological role . . . . . . i66 Accumulation of polyols during photosynthesis . . . i66 Uptake . . . . . . . . . . I67 Endogenous metabolism . . . . . . . I67 HIGHER PLANTS . . . . . . . . . i68 Occurrence and quantitative variation . .. . . I68 Metabolism and physiological role I. . . . . 70 Photosynthesis and translocation . . . . . . I70 Enzymology . . . . . . . . 171 Endogenous metabolism . . . . . . I73 Heterotrophic nutrition . . . . . . . I74 DISCUSSION . . . . . . . . . . 175 Occurrence and quantitative variation . . . . . 175 Carbohydrate storage . . . . . . . . 175 Translocation . . . . . . . . . 176 Osmo-regulation . . . . . . . . . I77 Enzymology and control of synthesis . . . . . 177 Coenzyme regulation and storage of reducing power . . I78 Conclusions . . . . . . . . . I78 ACKNOWLEDGMENTS I. . . . . 78 REFERENCES . . . . . . . . . . I79
475 citations
TL;DR: Cyanidium caldarium, an alga found in acid hot springs troughout the world, has a morphology and developmental history resembling those of Chlorella, but contains C-phycocyanin and no chlorophyll other thanchlorophyll a.
Abstract: Cyanidium caldarium, an alga found in acid hot springs troughout the world, has a morphology and developmental history resembling those of Chlorella, but contains C-phycocyanin and no chlorophyll other than chlorophyll a. The reasons for considering it to be a member of the Chlorophyta are reviewed.
Cyanidium is also remarkable for its thermal and acid tolerance. It grows readily in the dark on sugar media. However, light is required for the formation of chlorophyll and phycocyanin except in occasional variant cells which can form limited amounts of these pigments in the dark. Light-grown Cyanidium carries out normal green plant photosynthesis but resembles the red and some of the blue-green algae in that chlorophyll-absorbed light is used with lower efficiency than that absorbed by phycocyanin. The possible significance of the unusual pigmentation of Cyanidium is discussed.
445 citations
TL;DR: In this paper, the authors present a review of these sensing technologies and discuss how they are used for precision agriculture and crop management, especially for specialty crops, and some of the challenges and considerations on the use of these sensors and technologies for specialty crop production are also discussed.
427 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