Coombs / Hall / Long Techniques in Bioproductivity and Photosynthesis

Pergamon International Library of Science, Technology, Engineering and Social Studies
2. Auflage 2014
ISBN: 978-1-4831-9080-8
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 324 Seiten

Techniques in Bioproductivity and Photosynthesis, Second Edition is a manual that provides information on the field and laboratory techniques associated with the measurement of plant productivity. The title discusses the most reliable and relevant techniques that can be applied to a wide variety of problems. The coverage of the text includes various quantitative methods, such as measurement of plant biomass and net primary production; measurement of CO2 assimilation by plants in the field and the laboratory; and measurement of oxygen and chlorophyll fluorescence. The selection also deals with photosynthetic energy conversion; assimilatory nitrate reduction; and ammonia assimilation and amino acid biosynthesis. The book will be of great interest to botanists, horticulturists, and agriculturists.

Autoren/Hrsg.

Coombs, J.

Hall, D. O.

Long, S. P.

Inhaltsverzeichnis

1;Front Cover;1
2;Techniques in Bioproductivity and Photosynthesis;4
3;Copyright Page;5
4;Table of Contents;12
5;Addresses of Contributors;7
6;PREFACE TO THE SECOND EDITION;8
7;PREFACE TO THE FIRST EDITION;10
8;INTRODUCTION;22
9;UNITS, SYMBOLS AND ABBREVIATIONS;26
10;CHAPTER 1. MEASUREMENT OF PLANT BIOMASS AND NET PRIMARY PRODUCTION;28
10.1;1.1 Introduction;28
10.2;1.2 Sampling design;29
10.3;1.3 Measurement of above-ground biomass;30
10.4;1.4 Measurement of below-ground biomass;34
10.5;1.5 Non-destructive measurement of biomass;36
10.6;1.6 Estimation of losses;39
10.7;1.7 Estimation of net primary production;42
10.8;1.8 Experimental work;43
10.9;References;45
11;CHAPTER
2. PLANT GROWTH ANALYSIS;47
11.1;2.1 Introduction;47
11.2;2.2 Basic principles;47
11.3;2.3 Components of classical growth analysis;48
11.4;2.4 Functional growth analysis;50
11.5;2.5 Experimental investigations;51
11.6;References;51
12;CHAPTER
3. PLANT MICROCLIMATE;53
12.1;3.1 General introduction;53
12.2;3.2 Radiation - solar and long wave;53
12.3;3.3 Temperature;59
12.4;3.4 Humidity;62
12.5;3.5 Wind;64
12.6;3.6 Automatic weather stations;65
12.7;3.7 Recording;65
12.8;3.8 Experimental work;66
12.9;References;66
13;CHAPTER
4. CANOPY STRUCTURE AND LIGHT INTERCEPTION;68
13.1;4.1 Introduction;68
13.2;4.2 Radiation in canopies;68
13.3;4.3 Measurement of canopy structure;72
13.4;References;76
14;CHAPTER 5. WATER RELATIONS;77
14.1;5.1 Stomatal conductance;77
14.2;5.2 Plant water status;82
14.3;5.3 Soil water status;84
14.4;5.4 Practical work on water relations;86
14.5;References and further reading;87
15;CHAPTER 6. MEASUREMENT OF CO2 ASSIMILATION BY PLANTS IN THE FIELD AND THE LABORATORY;89
15.1;6.1 Introduction;89
15.2;6.2 Infra-red gas analysis;94
15.3;6.3 14C incorporation;102
15.4;6.4 Measurement and control of gas flow;103
15.5;6.5. Chamber conditions and construction;107
15.6;6.6 Analysis of gas exchange measurements;112
15.7;6.7 Conclusion;117
15.8;6.8 Experimental work;117
15.9;References;120
16;CHAPTER
7. MEASUREMENT OF OXYGEN AND CHLOROPHYLL FLUORESCENCE;122
16.1;7.1 The oxygen electrode;122
16.2;7.2 The leaf disc electrode;125
16.3;7.3 Chlorophyll fluorescence measurement;129
16.4;References;133
17;CHAPTER
8. SHOOT MORPHOLOGY AND LEAF ANATOMY IN RELATION TO PHOTOSYNTHESIS;134
17.1;8.1 Shoot morphology and the relationship of single leaf to whole plant CO2 assimilation and canopy productivity;134
17.2;8.2 Leaf anatomy;135
17.3;8.3 Experiments;141
17.4;References;144
18;CHAPTER
9. CHLOROPLASTS AND PROTOPLASTS;145
18.1;9.1 Introduction;145
18.2;9.2 Mesophyll protoplasts from C3, C4 and CAM plants;147
18.3;9.3 Photosynthesis by isolated protoplasts;150
18.4;9.4 Chloroplast isolation from protoplasts;151
18.5;9.5 Mechanical separation of intact chloroplasts;152
18.6;9.6 Photosynthesis by isolated chloroplasts;153
18.7;9.7 Carbon assimilation by C3 chloroplasts;155
18.8;9.8 Materials;158
18.9;References;158
19;CHAPTER
10. PHOTOSYNTHETIC ENERGY CONVERSION;160
19.1;10.1 Introduction;160
19.2;10.2 Measurement of proton flux, photophosphorylation and electron transport using broken chloroplasts and a pH electrode;161
19.3;10.3 Partial electron transport reactions assayed with the O2 electrode and a conventional recording spectrophotometer;163
19.4;References;165
20;CHAPTER
11. CARBON METABOLISM;166
20.1;11.1 Introduction;166
20.2;11.2 The carbon reduction cycle;166
20.3;11.3 Photorespiration;168
20.4;11.4 C4 photosynthesis;171
20.5;11.5 CAM plants;174
20.6;11.6 Carboxylation enzymes;175
20.7;11.7 Experiments;177
20.8;References;183
21;CHAPTER
12. NITROGEN FIXATION;185
21.1;12.1 Nitrogen metabolism;185
21.2;12.2 Introduction to N-fixation;185
21.3;12.3 The genus Rhizobium;186
21.4;12.4 Measurement of N-fixation by direct means;186
21.5;12.5 Indirect assay of nitrogenase activity;187
21.6;12.6 Preparation of acetylene;189
21.7;12.7 Gas chromatography;189
21.8;12.8 Experimental schedule;190
21.9;References;191
22;CHAPTER
13. ASSIMILATORY NITRATE REDUCTION;192
22.1;13.1 Introduction;192
22.2;13.2 Enzymology;192
22.3;13.3 Relationship between nitrate reduction and photosynthesis;193
22.4;13.4 Determination of enzymatic activities;193
22.5;13.5 Other analytical procedures useful for the study of nitrate assimilation;196
22.6;13.6 Uptake of nitrate by cells of blue-green algae. Effects of ammonium and MSO;198
22.7;References;198
23;CHAPTER
14. AMMONIA ASSIMILATION AND AMINO ACID BIOSYNTHESIS;200
23.1;14.1 Ammonia assimilation;200
23.2;14.2 Transport of nitrogenous compounds;206
23.3;14.3 Biosynthesis of amino acids;208
23.4;References;214
24;CHAPTER
15. MICRO-ALGAE: LABORATORY GROWTH TECHNIQUES AND OUTDOOR BIOMASS PRODUCTION;215
24.1;15.1 Introduction;215
24.2;15.2 Growth of micro-algae: techniques and kinetics;215
24.3;15.3 Chemostat cultures;218
24.4;15.4 Synchronised cultures;218
24.5;15.5 Nutrient-limited growth;218
24.6;15.6 Analytical techniques;219
24.7;15.7 Growth, maintenance and preservation of algal cultures;221
24.8;15.8 Culture media;221
24.9;15.9 Definition of common units and terms;224
24.10;15.10 Technical problems;224
24.11;15.11 Where to obtain algal cultures;224
24.12;15.12 Algal biomass production;225
24.13;References and further reading;227
25;CHAPTER
16. ENZYMES: SEPARATION AND KINETICS;228
25.1;16.1 Introduction;228
25.2;16.2 Enzyme activity;229
25.3;16.3 Isolation of enzymes;230
25.4;16.4 Protein determination;230
25.5;16.5 Extraction of proteins;231
25.6;16.6 Protection from phenols and phenol oxidase activity;231
25.7;16.7 Crude extracts;231
25.8;16.8 Ammonium sulphate precipitation;232
25.9;16.9 Modern methods of protein purification;233
25.10;16.10 Enzyme kinetics;236
25.11;16.11 Experiments;238
25.12;16.12 The Enzyme Commission classification system;242
25.13;References;245
26;CHAPTER17. ANALYTICAL TECHNIQUES;246
26.1;17.1 Protein analysis;246
26.2;17.2 Analysis of carbon isotope discrimination ratios;247
26.3;17.3 Measurement of light absorption;248
26.4;17.4 Chlorophyll determination;250
26.5;17.5 Measurement of starch and sucrose in leaves;252
26.6;17.6 Mineral analysis of plants, soil and water;254
26.7;References;254
27;APPENDICES;256
27.1;A. Equipment for field and laboratory studies of whole plant and crop photosynthesis and productivity research;256
27.2;B. Experimental design and presentation of results;299
27.3;C. Biomass production and data;301
27.4;D. Conversion factors and approximate conversion factors;315
27.5;E. Solar radiation on the earth;317
28;INDEX;318

Leseproben

INTRODUCTION
J.M.O. SCURLOCK, S.P. LONG, D.O. HALL and J. COOMBS Photosynthesis research is stimulated not only by by curiosity but also by the belief that it may provide a means for increasing plant productivity and crop yields. This book provides an introduction to methodologies for investigation of photosynthetic limitations to plant productivity in both crops and natural vegetation. Although photosynthesis is fundamental to plant productivity, many other factors modify the magnitude of productivity attained in the field. The quantitative relationship between photosynthesis and plant productivity should be considered first of all. For any crop or stand of natural vegetation, four factors determine the net biomass gain or net productivity (Pn): the quantity of incident light (Q), the proportion of that light intercepted by green plant organs (ß), the efficiency of photosynthetic conversion of the intercepted light into biomass (e), and respiratory losses of biomass (R). The relationship between plant productivity and these factors is described by the following equation: n=Q.ß.e-R For crops the economic yield is the amount of this productivity which is partitioned into the useful or harvested portion of the crop, e.g. the grains of cereals, the trunks of timber trees or the shoots of herbage crops. The proportion of total biomass production which is invested into the harvested parts of the plant is termed the harvest index. The harvest index has been increased in many crops by improved fertilisation practices and protection against pests, so ensuring that more of productivity is available for formation of the economic yield. Genetic improvement of yields has been achieved by selection of genotypes in which a larger proportion of productivity is partitioned into the harvested component, not necessarily by selection of plants with a higher total productivity. Of course, this approach is of very limited value in crops where the bulk of the plant forms the harvestable component, e.g. forage and biomass crops. In all crops, the limit to improvement of yield through increased harvest index is set by total productivity. Further increases in yield depend upon improvements in productivity itself. In natural communities, productivity is also important, both as a measure of the potential of wild species for domestication and as a measure of the total input of energy or carbon to the ecosystem. The above equation suggests three possible means by which productivity might be increased. The amount of incident light (Q) is determined by the climate and is thus independent of the crop. However, the remaining three factors may be modified. Respiratory losses of biomass (R) in the maintenance of existing tissues and growth of new tissue, constitute an important limitation on productivity. Recent work has shown significant differences in R between genotypes of herbage grasses, suggesting a promising potential for the scientific selection of genotypes with higher productivity and maximum yield potential. The efficiency of light interception (ß) is a function of the size, structure and colour of the plant canopy. Where productivity has been increased in crops, this may usually be attributed to an increase in light interception. For example, the major effect of nitrogen fertilisation in cereal crops is an increase in leaf area and duration, resulting in improved ß over the growing season. Most inorganic fertilisers improve yields through their effect on leaf growth and duration, whilst many stress factors have the opposite effect. Thus, modifications to the efficiency of light interception have been achieved mostly through improved cultural practices. The I.R. varieties of rice provide an important exception, being the result of selection of genotypes with a canopy structure which gives improved light interception. Efficiency of energy conversion (e) is determined directly by the photosynthetic process and expresses the direct relationship between productivity and photosynthesis, e may be measured for crops and natural communities, over periods from several days to a whole season, by combining productivity measurements with integrated measurements of the light absorbed by the canopy; or for leaves, over periods of a few minutes, by gas exchange studies. There are remarkably few instances where it has been possible to raise the maximum value of e (emax) of a species in order to increase productivity. Furthermore, there are no proven instances of genetic improvement of emax under optimal conditions within a species. However, e is affected by the environment: CO2 enrichment is the one notable exception where an improvement in e has been obtained. CO2 enrichment greatly reduces photorespiration; this has resulted in increases in both productivity and economic yield for many glasshouse crops. In theory, improvement of e is the most attractive means of increasing productivity and economic yield. If this could be achieved through genetic selection, an increase in productivity would be achieved without the increased inputs of fertiliser on which many recent yield improvements have depended. Whilst improvement of emax under optimal conditions is uncertain, there is little doubt that enhancement of e under sub-optimal conditions might be achieved. Many environmental stresses are known to lead to a decrease in the efficiency of light energy conversion, at least in the short term. In particular, photoinhibitory damage to the photosynthetic mechanism produced by combination of high light and low temperature or water stress may be significant. An important area of future crop improvement would be the identification of crop genotypes in which e is less sensitive to such environmental stress. Photosynthetic energy conversion describes the whole photosynthetic process from light capture on the photosynthetic membranes to CO2 assimilation and its subsequent metabolism in the chloroplasts and elsewhere. To understand how efficiency may be improved, a fuller understanding of all levels of the photosynthetic process is required. A research approach
When dealing with the efficency of light energy conversion into biomass in higher plants, concern often centres on such questions as why a given genotype is more productive in one environment than in another, or what the limitations to productivity are for a given genotype in a given environment. A common mistake in the scientific approach to such a problem is to look at the isolated parts of the plant first, rather than to study the whole. For example, in analysing why increased salinity decreases the productivity of a crop variety, it would be better first to study the whole plant or whole canopy, rather than to look at changes in single leaf rates of CO2 assimilation, isolated ribulose bisphosphate carboxylase (RUBISCO) activity, or amounts of 14CO2 incorporated into different compounds. Even if salinity-induced changes are found, these processes may not necessarily be limiting productivity. The reduction in productivity may not have anything to do with the effect of salinity on the photosynthetic apparatus; it could equally well be an effect on leaf area or canopy structure, causing changes in the amount of light intercepted. Thus it is good practice to follow a logical sequence of steps in investigating limitations to productivity in a crop, a natural stand of plants, or a single plant. Such a logical sequence, forming a reductive analysis of limiting factors, is as follows:
A reductive analysis of factors limiting plant/crop productivity. This book is broadly based on such a “top-down” approach. The first chapters are concerned with direct measurement of whole plant productivity and its analysis, and are followed by descriptions of the determination of important factors such as light, canopy structure, water status and leaf CO2 assimilation rate. Thus the components of the above photosynthetic equation may be evaluated. Direct measurement of plant productivity by dry matter determination may then lead to a consideration of plant metabolism, since dry matter measurements represent only the difference between what has been produced and what has been lost. A deeper insight into the underlying metabolic processes can be obtained from physiological and biochemical studies of individual aspects of the photosynthetic process. These include aspects of nitrogen assimilation (also a part of the photosynthetic process) and consideration of both nitrogen and carbon metabolism. Some of the research techniques currently used for the more laboratory-based studies of photosynthesis are described in later chapters of the book; these should lead to a better understanding of how, and indeed if, photosynthetic efficiency may be improved. Further reading 1. U.N.E.P./Tycooly Publishing, Oxford Beadle, C. L., Long, S. P., Imbamba, S. K., Hall, D. O., Olembo, R. J. Photosynthesis in Relation to Plant Production in Terrestrial Environments. Natural Resources and The Environment. Vol. 18, 1985. 2. Charles-Edwards, D.A.Physiological Determinants of Crop Growth. Sydney: Academic Press, 1982. 3. Long, S. P. C4 photosynthesis at low temperatures. Plant Cell Env.. 1983; 6:345–363. 4. Osmond, C. B.,...