Phytohormones, their functions, synthesis and effects, are of great interest. To study them in plant tissues accurate and sensitive methods are required. In the present study we aimed at optimizing experimental conditions to separate and determine not only plant hormones but also their metabolites, by liquid chromatography coupled with a UV-VIS detector. The mixture we analyzed was composed of ...

Higher plants are exposed to a multitude of fungi and bacteria, which are present in the surrounding phyllosphere and rhizosphere and which may also grow inside the shoot and the root. Compounds, known to act as hormones in higher plants, are produced by many of these microorganisms and are often functionalized in “friendly” or “hostile” interaction with the respective host plant. A large numbe...

Activity of endogenous auxins and growth inhibitors, gibberellins and cytokinins was observed in the extracts of seedlings of Pisum sativum under NaCl stress. After 6 days of germination, when Pisum sativum seedlings were subjected to low concentration of NaCl (50 mM) or boron (10 ppm) increased the endogenous growth regulating substances. Higher concentration of NaCl (150 mM) decreased endogen...

Eclipta alba is a medicinal herb, also known as Bhringraj belonging to family Asteraceae. The plant has hepatoprotective, antimicrobial and hair growth promoting properties. The effect of various phytohormones on in-vitro callus induction and shoot regeneration in Eclipta alba from leaf explant was evaluated. The sterilized explants were inoculated on MS medium supplemented with different conce...

Two-dimensional separation of proteins newly synthesized by tobacco mesophyll protoplasts cultivated in vitro allows us to detect, reproducibly, 257 spots. The pattern is extremely stable throughout the three days of culture, the intensity of only 24 spots varying during this time. The absence of cytokinin (N(6)-benzyladenine) in the culture medium prohibits entry into S phase but does not modi...

Excised roots of Bryophyllum calycinum require for growth both auxin and cytokinin. This is demonstrated by the poor growth of 2-mm root tips in a basal medium of mineral salts, sucrose, and vitamins supplemented with either an auxin or a cytokinin, and much better growth when the basal medium is supplemented with both auxin and cytokinin. However, both substances are synthesized by the root, a...

Xylogenesis in mature root parenchyma is elicited in vitro by the concerted action of the hormones cytokinin and auxin. Decreasing the temperature delayed the initiation of xylogenesis relative to the initiation of nonxylem cell formation. Once xylem or nonxylem cell formation was initiated, its rate was not temperature-sensitive within the 10-25 degrees C range. Lowering the temperature after ...

The phytohormones auxin and cytokinin interact to regulate many plant growth and developmental processes. Elements involved in the biosynthesis, inactivation, transport, perception, and signaling of these hormones have been elucidated, revealing the variety of mechanisms by which signal output from these pathways can be regulated. Recent studies shed light on how these hormones interact with ea...

The developmental programme of the pistil is under the control of both auxin and cytokinin. Crosstalk between these factors converges on regulation of the auxin carrier PIN-FORMED 1 (PIN1). Here, we show that in the triple transcription factor mutant cytokinin response factor 2 (crf2) crf3 crf6 both pistil length and ovule number were reduced. PIN1 expression was also lower in the triple mutant...

False broomrape on tobacco (Nicotiana tabacum) can be induced by applying cytokinins to the roots, by causing an increase in the cytokinin-auxin ratio in the roots, by removing the apical and auxillary buds, or by applying extracts from tobacco with false broomrape to the roots of healthy plants. It can be prevented by treating debudded plants with auxin.