Class 1 KNOTTED-like (KNOX) transcription factors control cell meristematic identity. An investigation was carried out to determine whether they maintain this function in peach plants and might act in leaf curliness caused by the ascomycete Taphrina deformans. KNOPE1 function was assessed by overexpression in Arabidopsis and by yeast two-hybrid assays with Arabidopsis BELL proteins. Subsequentl...

Using chromatographic, chemical, and enzymic techniques, 11 compounds capable of stimulating the division of soybean callus cells were tentatively identified in the root sap of Bougainvillea ;San Diego Red.' These cytokinin-like compounds included phosphorylated and glucosylated forms of zeatin, ribosylzeatin, and their dihydro derivatives. In addition, isopentenyl adenosine and isopentenyl ade...

Intact wheat seedlings (Triticum aestivum L.) were induced to senesce by placing them in the dark and at various stages of senescence were placed back in the light and their recoverability observed. Seedlings demonstrated complete recovery of chlorophyll, protein, and rate of photosynthesis after 2 days in the dark, but were unable to recover fully after 4 days. This suggests the onset of an ir...

The aim of this work was to evaluate phytohormone biosynthesis, siderophores production, and phosphate solubilization in three strains (E109, USDA110, and SEMIA5080) of Bradyrhizobium japonicum, most commonly used for inoculation of soybean and nonlegumes in USA, Canada, and South America. Siderophore production and phosphate solubilization were evaluated in selective culture conditions, which ...

Pea seeds were swollen in solutions with different concentrations of cytokinin benzyladenine (BA). As compared with controls, a low concentration of BA (0.05 mg/l) did not affect the growth of stems and roots of twelve-day-old seedlings but concentrations of 0.20–4.00 mg/l showed an inhibiting effect; this inhibition was proportional to the concentration of BA. In controls the ratio between the...

In vitro culture methods were used to germinate olive embryos prior to maturation. Fruit, seed and embryo development were established with consecutive sampling from 20 to 100 days after bloom. For that same period, embryo development and germination success were determined by in vitro culture trials using one-third strength MS medium with or without the addition of zeatin. For early developmen...

A simple procedure for the separation of the cis and trans isomers of zeatin and ribosylzeatin by column chromatography on a neutral polystyrene resin, Porapak Q, in aqueous ethanol solutions is reported. The method has been used to examine the stereoisomer composition of ribosylzeatin isolated from wheat germ transfer RNA. Chromatographic data for several other cytokinins are also presented.

Abstract The endogenous level of cytokinins (CKs) and auxins (Auxs) was analyzed in isolated microspores ovaries two doubled haploid (DH) lines triticale (× Triticosecale Wittm.) to better understand the mechanism microspore embryogenesis (ME)—the most efficient widely applied method producing DHs. responsiveness studied ME significantly varied. induced by pre-treating tillers with low temperat...

Strains of Escherichia coli that express two different cytokinin receptors of Arabidopsis thaliana, CRE1/AHK4 and AHK3, were used to study the relative sensitivity of these receptors to various cytokinins. Both receptors were most sensitive to the bases of the isoprenoid-type cytokinins trans-zeatin and isopentenyladenine but differed significantly in the recognition of other cytokinin compound...