At the 6th International Conference on Plant Growth Substances, held in Carleton University, Ottawa in 1968, it was decided that the 7th should be held in Czecho slovakia, following an invitation by Dr. Kutacek. Historical events intervened and in 1969 another venue was sought. An offer from the Academy of Science in Canberra was accepted by the steering committee. This left rather less time than is desirable to organize an international meeting of this nature and it was with surprise and great relief that the Organizing Committee in Canberra welcomed the arrival of 183 delegates, including a relatively large overseas contingent, to the meeting in December, 1970. The aim of these Conferences is, of course, to provide a forum for discussion of new work and recent trends, both in the lecture sessions and in conversation. Although many of those who initiated these meetings (e.g. Skoog, Went, Blackman, Bennet-Clark) were absent from the Canberra conference - some have retired -it was good to see present so many of the new generation of research workers in this field.

Section 1 Cell Extension: Models, Membranes and Wall Properties

Macromolecule synthesis and wall extensibility in relation to the mechanism of auxin-induced cell elongation
On the biophysical control of growth rate in Avena coleoptiles sections
Auxin-induced changes in cell wall properties and growth of Avena coleoptiles and green pea epicotyls
Measurements of water potential and hormone transport associated with the growth of cucumber hypocotyls
Promotion of plant and insect hormone action by membrane matrixmatching lipids
Gibberellin and membrane permeability
Section 2 Rapid Action of Auxins
Rapid growth responses in the Avena coleoptile: a comparison of the action of hydrogen ions, CO2 and auxin
Cell elongation and auxin action in lupin hypocotyls
Initial kinetics of auxin-induced cell elongation in coleoptiles
Kinetic studies on the auxin effect and the influence of cycloheximide and blue light
Effects of IAA and cyanide on the growth and respiration of coleoptile Sections from Triticum
Section 3 Biosynthesis of Auxins
Pathways of auxin biosynthesis in the shoots of higher plants
Enzymic oxidation of indole-3-ethanol
The control of growth by the synthesis of IAA and its conjugation
Metabolism of indole-3-acetaldehyde. IV. Electron acceptor studies and physiological significance of the aldehyde oxidase of Avena Coleoptiles
Electrophoretic isolation and growth activity of indole-3-acetic acid oxidation products
Conversion of 3-indole acetaldoxime to glucobrassicin and sulphoglucobrassicin by woad (Isatis tinctoria L.)
Isolation and characterization of indole derivatives in clubroots of Chinese cabbage
Section 4 Biosynthesis of gibberellins
Gibberellin biosynthesis and its regulation
Recent advances in the metabolism of gibberellins
The biosynthesis of gibberellin precursors in a cell-free system from Cucurbita Pepo
A polar gibberellin from apricot seed
Dwarfing genes in rice and their relation to gibberellin biosynthesis
Gibberellins in immature seed of moonflower (Caionyction acuieatum)
Section 5 Hormones and Nucleic Acids
Cytokinin-induced changes in transfer RNA species
Effect of growth substances on rapidly synthesized RNA in sterile tobacco tissue
Auxin in sRNA fraction of mung bean hypocotyl
ABA- and kinetin-induced changes in cell homogenates, chromatinbound RNA polymerase and RNA composition
The temporal separation of transcription and translation and its control in cotton embryogenesis and germination
DNA synthesis and hormonal growth response in non-meristematic tissues
Section 6 Hormones and Isoenzymes
Auxin, macromolecular repressors and the development of isoperoxidases in cultured tobacco pith
Isozymes of cellulase in the abscission zone of Phaseolus vulgaris
Section 7 Binding of Hormones to cell Constituents
Auxin-reactive proteins
On the significance of cytokinin binding to plant ribosomes
Binding of indoleacetic acid to isolated pea nuclei
Modification of enzyme activity, conformation and size by indoleacetic acid
Section 8 Inhibitors
Biochemical aspects of the action of abscisic acid
The biosynthesis and degradation of abscisic acid
The accumulation of abscisic acid in plants during wilting and under other stress conditions
Chemistry and biological action of podolactones and other inhibitors of plant growth
Occurrence of substances in dwarf peas interfering with responses of the same plants to gibberellins
Plant growth inhibitors in the bulbs of Lycoris radiata Herb
Morphactin-like activity of benzilate esters in Arabidopsis thaliana
Chemistry and physiology of rooting inhibitors in adult tissue of Eucalyptus grandis
Studies with plant growth inhibitors
Section 9 Gibberellins: The Cereal Aleurone Layer
Control of ?-amylase synthesis in isolated barley aleurone layers by gibberellic acid, abscisic acid and ethylene
Cytochemical localization of gibberellic acid-induced enzymes in the barley aleurone layer
Effect of gibberellin A3 on in vivo and in vitro induction of ?-amylase isozymes
Effect of gibberellic acid on ribonucleic acid synthesis in barley aleurone
Effect of gibberellic acid on the tRNA methylase activity of barley aleurone cells
Stages during the induction of ?-amylase in barley aleurone layers. I. The timing of sensitivity to Actinomycin D
Stages during the induction of ?-amylase in barley aleurone layers. II. Some properties of the pre- and post-transcription stages
The effect of gibberellic acid on the metabolism of soluble nucleotides in aleurone tissue isolated from wheat grain
The isolated aleurone layer
Section 10 Gibberellins: Other Systems
Metabolic changes in internodes of dwarf pea plants treated with gibberellic acid
Gibberellin metabolism in the roots of Phaseolus coccineus Seedlings
Stimulation of the levels of gibberellin-like substances by the growth retardants CCC and AMO 1618
DNA analysis of auxin-treated Jerusalem artichoke tuber tissue as a screen for the evaluation of substances influencing cell division
Promotion by CCC of growth in Jerusalem artichoke tissue
Gibberellin, a primary determinant in the expression of apical dominance, apical control and geotropic movement of conifer Shoots
Section 11 Cytokinins
Active forms of the cytokinins
Use of structural analogues in the study of cytokinin action
Uptake of cytokinins by Acer pseudopiatanus cells: enzymes of the deaminase type as possible regulators of the cytokinin level inside the cell
Cytokinins in bleeding sap of the grape vine
Medium and tissue sugar concentrations during cytokinin-controlled growth of tobacco callus tissues
Section 12 Ethylene
Studies on the action of ethylene in physiological processes of plant cells
Functions of naturally-produced ethylene in abscission, dehiscence and Seed germination
Biosynthesis of ethylene in fruit tissues
The measurement of ethylene from plant tissues and its relation to auxin effect
Auxin and ethylene in adventitious root formation in Phaseoius aureus (Roxb.)
Ethylene and the growth of plant cells: role of peroxidase and hydroxyproline-rich proteins
Trauma-induced ethylene production by citrus flowers, fruit and wood
Thoughts on the role of ethylene in plant growth and development
Section 13 Hormones in Relation to Senescence
On the nature of senescence in oat leaves
Hormonal regulation of leaf senescence in intact plants
Further studies on hormone-regulated senescence in Rumex leaf tissue
Kinetin treatment and protein synthesis in detached wheat leaves
Effects of senescence and hormone treatment on the ?-1, 3-glucan hydrolase in Nicotiana glutinosa leaves
Ethylene production and biochemical changes in detached leaves of Nymphoides indica
Increase in ABA-like growth inhibitors and decrease in gibberellinlike substances during ripening and senescence in citrus fruits
Effects of ABA and kinetin on ultrastructure of senescing wheat leaves
Section 14 Growth and Morphogenesis
The role of basal and apical factors in the co-ordination of growth in the stems of white clover (Trifolium repens L.)
Studies in leaf unrolling in barley
The effects of growth regulators on RNA metabolism during the unrolling of barley leaf segments
Auxin-induced growth of tuber tissue of Jerusalem artichoke. VII. Effect of cyclic 3', 5'-adenosine monophosphate on the auxininduced cell expansion growth
Evidence for the presence of biological activity of a chorionic gonadotropin-like plant growth substance (phytotropin)
Partial and complete growth promoting systems for cultured carrot expiants: synergistic and inhibitory interactions
Multiple interactions between media, growth factors, and the environment of carrot cultures: effects on growth and morphogenesis
Control of morphogenesis in plant tissue cultures by hormones and nitrogen compounds
Section 15 Transport and Tropisms
Experiments on the mechanism of hormone-directed transport
The movement of plant hormones: auxins, gibberellins and cytokines
Tropic stimuli and the kinetics of basipolar-transport of auxin
The source and transport of growth regulators responsible for the geotropic response Of Zea mays roots
Asymmetric "acid"growth" response following gravistimulus
The role of auxin in thigmotropism
Participation of the Golgi apparatus in geotropism
Section 16 Hormones and Flowering
Hormonal regulation of plant flowering in different photoperiodic groups
The use of aphids in the search for the hormonal factors controlling flowering
Hormonal control of flowering in Citrus and some other woody perennials
Some growth substances associated with bud failure of peach
The flowering process - a new theory
The promotion of ripening in cereal crops by peduncle injection of aqueous solutions of nucleotides
Section 17 Application of Glows to Hormone Studies
A system for the characterisation of plant growth substances based upon the direct coupling of a gas chromatogram, a mass spectrometer and a small computer - recent examples of its application
Identification of cytokinins by gas-liquid chromatography and gas liquid chromatography-mass spectrometry
Index to Authors
Index to Organisms
Index to Subjects.