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Circadian clocks are believed to confer an advantage to plants, but the nature of that advantage has been unknown. We show that a substantial photosynthetic advantage is conferred by correct matching of the circadian clock period with that of the external light-dark cycle. In wild type and in long- and short-circadian period mutants of Arabidopsis thaliana,(More)
The phytochrome family of red/far-red (R/FR)-responsive photoreceptors plays a key role throughout the life cycle of plants . Arabidopsis has five phytochromes, phyA-phyE, among which phyA and phyB play the most predominant functions . Light-regulated nuclear accumulation of the phytochromes is an important regulatory step of this pathway, but to this date(More)
Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches' Broom (AY-WB) readily(More)
Many physiological and biochemical processes in plants exhibit endogenous rhythms with a period of about 24 h. Endogenous oscillators called circadian clocks regulate these rhythms. The circadian clocks are synchronized to the periodic environmental changes (e.g. day/night cycles) by specific stimuli; among these, the most important is the light.(More)
BACKGROUND At the core of the eukaryotic circadian network, clock genes/proteins form multiple transcriptional/translational negative-feedback loops and generate a basic approximately 24 hr oscillation, which provides daily regulation for a wide range of processes. This temporal organization enhances the fitness of the organism only if it corresponds to the(More)
Alcoholism is a heritable disease that afflicts about 8% of the adult population. Its development and symptoms, such as craving, loss of control, physical dependence, and tolerance, have been linked to changes in mesolimbic, mesocortical neurotransmitter systems utilizing biogenic amines, GABA, and glutamate. Identification of genes predisposing to(More)
The phytochrome photoreceptors and the circadian clock control many of the same developmental processes, in all organs and throughout the growth of Arabidopsis plants. Phytochrome A (phyA) provides light input signals to entrain the circadian clock. The clock is known to rhythmically regulate its light input pathway, so we tested rhythmic regulation of(More)
A significant increase in the expression and activity of tissue transglutaminase (tTG), one of the effector elements of apoptosis, was observed during involution of thymus elicited by treatment with either anti-CD3 antibody or dexamethasone or by irradiation. The blood plasma concentration of epsilon(gamma-glutamyl)lysine isodipeptide, the end-product of(More)
Retinoic acids are morphogenic signaling molecules that are derived from vitamin A and involved in a variety of tissue functions. Two groups of their nuclear receptors have been identified: retinoic acid receptors (RARs) and retinoic acid X receptors (RXRs). All-trans retinoic acid is the high affinity ligand for RARs, and 9-cis retinoic acid also binds to(More)
The plant circadian clock promotes daily rhythms in the activity of many processes. These rhythms are synchronized to the diurnal day/night cycle by environmental cues such as light and temperature. Output pathways link the clock to particular biological processes, ensuring that they peak in activity at the appropriate times of day or night. Recently,(More)