. Vertical bars indicate se . Lowercase letters a and b indicate significant differences. Expression of CmMAX1 was repressed by different phytohormones. To study the regulation of CmMAX1 by strigolactone, auxin, and cytokinin, we detected the expression
2011 ). The second messenger plays a crucial role in regulating branching through the control of two hormones: strigolactone (SL) and cytokinin (CTK). SL is a carotenoid-derived molecule that is synthesized in roots and stems and is transported from
reduction in ‘Natchez’ blackberry, suggesting its potential negative side effects on floral development ( Lin and Agehara, 2020 ). Cytokinins act as an antagonist of GA during floral transition in apple ( Malus × domestica Borkh.) by upregulating the
somatic embryo induction and plant regeneration is influenced by several factors, such as species, explant source, culture medium, and type and concentration of auxins and cytokinins ( Araujo et al. 2016 ; Araújo et al. 2021 ; Gulzar et al. 2020
Abstract
Nonmycorrhizal or mycorrhizal (Glomus fasciculatum, G. etunicatum, or Gigaspora heterogama) sour orange (Citrus aurantium L.) seedlings were fertilized with 3 phosphorus levels applied in the irrigation water. At 0 mg P/L fertility, dry weight and cytokinin production of mycorrhizal plants were more than twice those of the nonmycorrhizal plants. Concentrations of P in leaves of mycorrhizal plants also were greater than the concentrations of P in the nonmycorrhizal plants. At 50 mg P/L fertility, concentrations of P in leaves were similar whether or not plants were mycorrhizal. Dry weight and cytokinin production of the mycorrhizal plants, however, were still twice those of the nonmycorrhizal plants. At 100 mg P/L fertility, dry weight and cytokinin production did not differ between nonmycorrhizal plants and plants infected with 2 of 3 mycorrhizal fungi. In G. heterogama-infected plants, cytokinin production was greater than that of nonmycorrhizal plants despite similar dry weights and P concentrations in the leaves. Enhancement of cytokinin production seemed to be associated with mycorrhizal infection rather than with increased P uptake.
). Micropropagated shoots can be readily rooted either in vitro or ex vitro, and acclimatized to greenhouse conditions. The most important factors in successfully micropropagating A. american were cytokinin and auxin levels. Cytokinin in the medium was reported to
Soybean sprouts are one of the most-favored traditional vegetables around the world. The sprouts are usually consumed 7 to 10 days after sowing depending upon the growing conditions. High-quality sprouts should have less secondary roots, short and well-swollen hypocotyls in pure white color, and small cotyledons in hooked position. Cytokinins were reported to be effective in producing such sprouts by promoting sprout growth while inhibiting the excessive hypocotyl elongation and secondary root growth. Seeds of four soybean cultivars with different characteristics were soaked in water for 4 h and, 2 to 3 h after the imbibition, the seeds were soaked again in solutions of different cytokinins such as benzyladenine (BA), BA-riboside (BAR), BPA, 2iP, 2iP-riboside, 4-CPPU, and kinetin-riboside (KR) for 10 min. After the treatment, the sprouts were grown in a plastic tube (25 cm height × 10.5 cm diameter) a dark culture room with ample watering every 4 h. After 7 days of growth, uniform samples were taken from each treatment and the sprout characteristics were examined. Some cytokinins such as BA, BAR, 4-CPPU were highly effective in promoting the sprout growth (fresh weight) even though the hypocotyl length was markedly reduced. Other cytokinins such as 2iP, 2iPR, and KR had no effect on sprout growth. Hypocotyl diameter was markedly increased by BA and 4-CPPU treatment, thus resulting in short, strong and good quality sprouts. Cultivars responded differently to cytokinin treatment by showing different growth promotion depending upon the sprout parts. Injury-like symptoms, abnormal and twisted heads or cotyledons, appeared in cytokinin-treated sprouts at high concentrations and the symptoms were severe when the sprouts were grown at high temperatures. In all the cultivars tested, BAR appeared to be better than others in terms of sprout quality and growth promoting characteristics.
Abstract
When silver thiosulfate (STS), an antiethylene agent, was used prior to a preservative holding solution for carnations (Dianthus caryophyllus L.), there was no benefit in using the cytokinin benzyladenine (BA). If no STS or preservative was used, BA extended longevity. Most of the BA applied to the cut carnation remained localized in stem tissue. Stem, petal, gynoecium, and leaf tissue all metabolized BA. The applied BA levels increased in the gynoecium during carnation senescence, but STS prevented this increase. It is likely that STS altered the source:sink relationship between petals and gynoecium, since movement of cytokinin into the gynoecium corresponded to increased gynoecium fresh weight.
Abstract
Cytokinins were extracted from lettuce leaves (Lactuca sativa L., butterhead type), purified by cation exchange, paper and Sephadex LH-20 column chromatography and bioassayed with tobacco callus. Compounds with chromatographic mobilities corresponding to those of zeatin and zeatin riboside were detected. The inner, developing leaves of the heads contained most of the cytokinin activity.
Abstract
Sprays of a synthetic cytokinin, 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (PBA), applied to seedlings of Macadamia tetraphylla L. in the greenhouse resulted in sprouting of axillary buds, and reduced growth of the terminal shoot. Terminal removal caused lateral shoot development in more seedlings than PBA.