Biologists ask how the growth, development and behaviour of organisms happen, how these processes are co-ordinated and how they are regulated by the environment. Today the questions are phrased in terms of the genes involved, their structure and the control of their expression. Mutations (recognised by a change in phenotype) label genes and can be used to study gene structure, gene function and the organisation of the genome. This is "Genetics". Study of phenotypes down to the level of the enzymes and structural proteins coded for by genes is "Biochemistry". It is self evident that only by studying phenotype ("Biochemistry") can we do "Ge netics" and that "Genetics" (perturbation of the phenotype) is the key to understanding the "Biochemistry". There can surely be no better argu ments for a more holistic approach to biology than the massive output of knowledge from microbial "Biochemical Genetics" and the more recent revelations from "Molecular Genetic" studies of development in Droso phila.

Inhalt
1 Gibberellin Mutants.- I. Introduction.- II. Selection and Identification of Mutants.- III. GA Synthesis.- IV. Internode Length.- V. Seed Dormancy.- VI. Flowering and Senescence.- VII. Site of Action of GA Mutants.- VIII. Conclusions.- IX. References.- 2 Genetic Aspects of Abscisic Acid.- I. Introduction.- II. ABA-Deficient Mutants.- III. Mutants Affecting ABA Sensitivity.- IV. Genetic Differences in ABA Accumulation.- V. Conclusions.- VI. References.- 3 Mutants as Tools for the Elucidation of Photosynthetic Processes.- I. Introduction.- II. Two Genomes Code for the Structural and Regulatory Elements of the Photosynthetic Apparatus.- III. Identification of Thylakoid Membrane Proteins and Their Functions.- IV. From Phenotype to Gene Structure.- V. Conclusions.- VI. References.- 4 Maize Alcohol Dehydrogenase: A Molecular Perspective.- I. Introduction.- II. Genetics and Expression of ADH Enzymes in Maize.- III. Isolation of Adh Genes.- IV. Structure of Plant Adh Genes.- V. Three-Dimensional Structure of ADH Enzymes.- VI. Genetic Change Around and Within Adh Genes of Maize.- VII. Approaches to the Mechanism of Adh Gene Regulation.- VIII. In Vivo Expression of Adh.- IX. Conclusions.- X. References.- 5 The Molecular Genetics of Higher Plant Nitrate Assimilation.- I. Introduction.- II. The Nitrate Assimilation Pathway.- III. Genetics of Nitrate Assimilation.- IV. Applied Aspects.- V. References.- 6 Plant Genetic Approaches to Symbiotic Nodulation and Nitrogen Fixation in Legumes.- I. Introduction.- II. A General Description of Legume Nodule Ontogeny.- III. The Parasponia-Bradyrhizobium Symbiosis.- IV. Biochemical and Molecular Analysis of Plant Functions.- V. Gene-for-Gene Aspects of Nodulation.- VI. Existing Plant Variation in Symbiotic Nitrogen Fixation.- VII Existing Single Locus Variation for Nodulation-Nitrogen Fixation.- VIII. Induced Mutation in Symbiotic Characters.- IX. Conclusions.- X. References.- 7 Endosperm Proteins.- I. Introduction.- II. Origin and Development of the Endosperm.- III. Classification of the Major Endosperm Proteins.- IV. Biochemical Complexity and Genetic Variation of Endosperm Proteins.- V. Gene Mutations.- VI. Chromosome Mutations.- VII. Conclusions.- VIII. References.- 8 Molecular Approaches to Plant and Pathogen Genes.- I. Introduction.- II. A Molecular Approach to Gene-for-Gene Resistance.- III. The Role of Toxins in Plant Disease.- IV. Conclusions.- V. References.- 9 Gametophytic Gene Expression.- I. Introduction.- II. Overlap Between Sporophytic and Gametophytic Genotypes.- III. Gametophytic Gene Expression and the Angiosperms.- IV. The Influence of Haploid Genotype on Pollen Size.- V. Time of Gene Expression in Pollen.- VI. Methods of Haploid Selection.- VII. Gametophytic Gene Expression and the Style.- VIII. Gene Expression in the Megagametophyte.- IX. Conclusions.- X. References.- 10 Auxotroph Isolation In Vitro.- I. Introduction.- II. Mutagenesis.- III. Methods of Selection.- IV. Phenotypes.- V. Fusion and Transformation.- VI. Conclusions and Future Prospects.- VII. References.