Arabidopsis (Arabidopsis thaliana) leaf development relies on subsequent phases of cell proliferation and cell expansion. During the proliferation phase, chloroplasts need to divide extensively, and during the transition from cell proliferation to expansion, they differentiate into photosynthetically active chloroplasts, providing the plant with energy. The transcription factor GROWTH REGULATIN...

A pot experiment was conducted in the screen of the National Research Centre during two successive seasons to study the response of periwinkle plants to foliar spray with tryptophan or putrescine at the concentrations 10 M, 10 M or 10 M. The obtained data indicated that exogenous application of tryptophan or putrescine on periwinkle transplants considerably increased plant growth at successive ...

Cytokinins are phytohormones that induce cytokinesis and are essential for diverse developmental and physiological processes in plants. Cytokinins of the trans-zeatin type are mainly synthesized in root vasculature and transported to the shoot, where they regulate shoot growth. However, the mechanism of long-distance transport of cytokinin was hitherto unknown. Here, we report that the Arabidop...

The endogenous hormonal system plays a leading role in the regulation of growth and development of plants. This regulatory system responds sensitively to even slight changes in the plant environment, which is manifested in reorganization of the hormonal status. Detrimental factors lead to an imbalance in the content of different groups of phytohormones, as a rule reflected in the accumulation o...

BACKGROUND Although cytokinins have been known for decades to play important roles in the regulation of plant growth and development, our knowledge of the regulatory mechanism of endogenous content of specific cytokinins remains limited. METHODOLOGY/PRINCIPAL FINDINGS Here, we characterized two SOB five-like (SOFL) genes, AtSOFL1 and AtSOFL2, in Arabidopsis (Arabidopsis thaliana) and showed t...

Cytokinins are distributed through the vascular system and trigger responses of target cells via receptor-mediated signal transduction. Perception and transduction of the signal can occur at the plasma membrane or in the cytosol. The signal is terminated by the action of extra- or intracellular cytokinin oxidases. While radiotracer studies have been used to study transport and metabolism of cyt...

The catalytic reaction of cytokinin oxidase/dehydrogenase (EC 1.5.99.12) was studied in detail using the recombinant flavoenzyme from maize. Determination of the redox potential of the covalently linked flavin cofactor revealed a relatively high potential dictating the type of electron acceptor that can be used by the enzyme. Using 2,6-dichlorophenol indophenol, 2,3-dimethoxy-5-methyl-1,4-benzo...