Shoot apical meristems (SAMs), which are maintained at the tips of stems, are indeterminate structures and sources of stem cells from which all aerial organs are ultimately derived. Although mechanisms that regulate the homeostasis of the stem cells have been extensively investigated, identification of further unknown regulators should provide better understanding of the regulation. Here, we re...

In what follows we develop a mathematical model to describe the signaling and transcriptional network dynamics by which negative and positive feedback loops regulate cytokinin signaling and WUS expression. The main focus of the model is to explore several hypotheses, as to how WUS induction occurs as a function of cytokinin signaling and to understand how individual feedback loops contribute to...

Increased-branching mutants of garden pea (Pisum sativum; ramosus [rms]) and Arabidopsis (Arabidopsis thaliana; more axillary branches) were used to investigate control of cytokinin export from roots in relation to shoot branching. In particular, we tested the hypothesis that regulation of xylem sap cytokinin is dependent on a long-distance feedback signal moving from shoot to root. With the ex...

Moniliophthora perniciosa causes witches’ broom disease of cacao and inflicts symptoms suggestive hormonal imbalance. We investigated whether infection the tomato (Solanum lycopersicum) model system Micro-Tom (MT) by Solanaceae (S)-biotype perniciosa, which stem swelling hypertrophic growth axillary shoots, results from changes in host cytokinin metabolism. Inoculation an MT-transgenic line tha...

Two classes of compounds which bind to calmodulin in a calcium-dependent manner (neuroleptic drugs and local anaesthetics) were used to investigate the possible involvement of a calcium-dependent regulator protein in the action of the plant hormones cytokinins.The cytokinin-induced synthesis of betacyanin in Amaranthus tricolor seedlings was used as one test system. The calmodulin antagonists i...

Lignocellulosic biomass can be a significant source of renewable clean energy with continued improvement in biomass yield and bioconversion strategies. In higher plants, the leaf blade is the central energy convertor where solar energy and CO2 are assimilated to make the building blocks for biomass production. Here we report that introducing the leaf blade development regulator STENOFOLIA (STF)...

The current research investigated the regulation of monogalactosyldiacylglycerol (MGDG) biosynthesis, catalyzed by MGDG synthase (MGD) (UDP-galactose:1,2-diacylglycerol 3-beta-D-galactosyltransferase; EC 2.4.1.46), during chloroplast development in cucumbers (Cucumis sativus L. cv. Aonagajibai). In etiolated seedlings, white light induced a transient increase in MGD mRNA, followed by a subseque...

priming is one of the seed enhancement methods that might be resulted in increased seed performance (germination and emergence), seedling growth and plant yield under stress conditions, such as salinity, temperature and drought stress. in order to evaluate the effect of growth hormones on morphology characteristics and essential oil of basil under drought stress condition, a experiment was cond...

Cytokinins have been implicated in many developmental processes and environmental responses of plants, including leaf senescence, apical dominance, chloroplast development, anthocyanin production, and the regulation of cell division and sink/source relationships. They were identified in the pioneering work of Skoog and Miller (1957) by their ability to promote cell division in cultured cells in...

Cytokinins are a structurally diverse group of N 6 -substituted purine derivatives capable of inducing plant cell division. The discovery of cytokinins by Folke Skoog and colleagues in the 1950s initially focused on kinetin, a synthetic compound derived from autoclaved salmon sperm DNA (Miller et al., 1955). Miller, Skoog, and others subsequently found that cytokinins are naturally occurring pl...