Related history and laboratory work which lead to isolation of oligosaccharins, a new class of regulatory molecules found in plant cell walls. These substances function in growth, development, reproduction, and defense. Mixtures of oligosaccharins and other hormones can stimulate growth of an undifferentiated callus, roots, vegetative…

Explains the mechanisms and describes the processes that underlie gravitropism in roots. Reviews experimental efforts and investigative results that explored the causes of root behavior. (ML)

Discusses the biochemical mechanisms related to photosynthesis. Describes a water-oxidizing clock generating a molecule of oxygen with every four ticks. Lists four references. (YP)

Elucidates strategies for applying microbiological techniques to traditional agricultural practices. Discusses the manipulation of microorganisms that live with plants and also the problems involved in the introduction of new genes into crop plants by recombinant DNA methods. (CS)