Wheat development enhanced by hormone syndrome

• Published in: Botanical gazette (Chicago, Ill.) Ill.), 1988-09, Vol.149 (3), p.317-324
• Main Authors: Trione, E.J, Sayavedra-Soto, L.A
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chemical agents; Chlorophylls; CITOCININAS; COMPOSICION; COMPOSITION; CYTOKININE; CYTOKININS; Dwarfing; ETAPAS DE DESARROLLO DE LA PLANTA; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungi; Gibberellins; GROWTH RATE; Hormones; HOST PARASITE RELATIONSHIPS; Hyphae; INDICE DE CRECIMIENTO; Ovaries; PARASITISM; PARASITISME; PARASITISMO; PATHOGENICITY; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; PLANT DEVELOPMENTAL STAGES; Plant physiology and development; Plants; PODER PATOGENO; POUVOIR PATHOGENE; STADE DE DEVELOPPEMENT VEGETAL; TAUX DE CROISSANCE; TILLETIA; TILLETIA CARIES; TILLETIA CONTRAVERSA; TRITICUM AESTIVUM; Vegetative apparatus, growth and morphogenesis. Senescence; Wheat
• ISSN: 0006-8071; 1940-1205
• DOI: 10.1086/337721

The morphological-physiological alterations that are correlated with increased grain yields in wheat appear to characterize a beneficial hormone syndrome, i.e., increased dwarfing, tillering, seed set, and greenness. Those changes in the growth habit appear to be linked and symbolize cytokinin responses. Similar changes occur in wheat plants treated in several different ways: (1) plants carrying the Rht dwarfing genes, (2) treated with chloro-cholinechloride (CCC), and (3) infected with wheat bunt fungal pathogens. The wheat bunt fungi, Tilletia caries and T. controversa, were analyzed for cytokinins in culture and in bunt-infected ovaries. Zeatin riboside (ZR) and isopentenyl adenosine (IPA) were present in hyphal cultures of the bunt fungi as determined by high-performance liquid chromotography and enzyme-linked immunosorbent assay. The identity of these two cytokinins was established by gas chromatography-mass spectroscopy. Zeatin was detected only in hyphal culture filtrates. Five other cytokinin-like compounds that bound to cytokinin-specific antibodies were not identified chemically but were detected consistently in bunt hyphae and culture fluids. One of these unknowns was present at high levels in young bunt-infected wheat kernels. Additional circumstantial evidence that supports the probable involvement of cytokinins in the symptoms of the dwarf bunt disease include the increase in chlorophyll levels, the change in the chlorophyll a:b ratio, and the separation of host cells in the infected ovaries. Wheat plants treated exogenously with ZR, IPA, or CCC developed symptoms similar to the hormone syndrome described above.