In order to elucidate the role of maleic hydrazide (MH, 1,2-dihydro-3,6-pyridazinedione; coline salt) in increasing ̄ower bud formation on the Japanese pear, the effect of MH on cytokinin contents in the lateral buds of Japanese pear shoots were investigated. Foliar application of MH at 2600 mg lÿ1 increased zeatin, zeatinriboside, and isopentenyladenine levels in lateral buds though isopenteny...

A continuous growth apparatus was used to measure the effect of cytokinin on auxin-induced elongation. The soybean hypocotyl segments elicited a bi-phasic response to auxin that appeared to be two overlapping responses. The first response, which began 12 min after auxin addition, was not inhibited by cytokinin, even after long preincubation in cytokinin, but the second response to auxin, which ...

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...

Plant hormones regulate many aspects of plant growth and development. Both auxin and cytokinin have been known for a long time to act either synergistically or antagonistically to control several significant developmental processes, such as the formation and maintenance of meristem. Over the past few years, exciting progress has been made to reveal the molecular mechanisms underlying the auxin-...

Sinapis alba is a long-day (LD) plant that can be induced to flower by a single LD. A number of changes normally occurring in the meristem of plants subjected to the LD can be produced in short day by a single application of a cytokinin to the apical bud. However, flower buds are not produced indicating that evocation by the cytokinin is only partial. In this work, the cytokinin content of root...

We have recently identified cytokinin as an important xylem-carried signal involved in the photosynthetic acclimation of plants to light gradients in dense canopies. Lower leaves become shaded in a dense canopy and consequently have reduced transpiration rates. our measurements have shown that this results in a reduced delivery of cytokinins carried in the transpiration stream to shaded leaves,...

Cytokinins are important signals that participate in different plant processes, and are well known for their strong influence in plant development. With the years, knowledge has been built about their effects, chemical nature, metabolism, and signaling mechanisms. However, one aspect about cytokinins that has been lagging behind is cytokinin transport. Recent reports are providing more informat...

BACKGROUND AND AIMS The typical rootless linear shoots of aquatic carnivorous plants exhibit clear, steep polarity associated with very rapid apical shoot growth. The aim of this study was to determine how auxin and cytokinin contents are related to polarity and shoot growth in such plants. METHODS The main auxin and cytokinin metabolites in separated shoot segments and turions of two carnivo...

SHORT-ROOT (SHR) is a key regulator of root growth and development in Arabidopsis (Arabidopsis thaliana). Made in the stele, the SHR protein moves into an adjacent cell layer, where it specifies endodermal cell fate; it is also essential for apical meristem maintenance, ground tissue patterning, vascular differentiation, and lateral root formation. Much has been learned about the mechanism by w...

Leaves originate from stem cells located at the shoot apical meristem. The meristem is shielded from the environment by older leaves, and leaf initiation is considered to be an autonomous process that does not depend on environmental cues. Here we show that light acts as a morphogenic signal that controls leaf initiation and stabilizes leaf positioning. Leaf initiation in tomato shoot apices ce...