Content of endogenous cytokinins in intact and transversally cut leaf blades of Bryophyllum crenatum

Slabý, K.; Šebánek, J.

doi:10.1007/bf00024859

Cited by 5 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, measurements of cytokinin levels in Bryophyllum crenatum, in which plantlet development is contingent on leaf detachment, are not consistent with the model presented here. In this species an increase of cytokinin levels in leaves after their removal from the plant has been reported (Slaby and Sebanek, 1984).…”

Section: Comparison Of Present Results With Earlier Data From Other Lmentioning

confidence: 99%

Cytokinins inhibit epiphyllous plantlet development on leaves of Bryophyllum (Kalanchoe) marnierianum

Kulka

2006

Journal of Experimental Botany

View full text Add to dashboard Cite

When leaves of Bryophyllum marnierianum are detached from the plant, plantlets develop from primordia located at their margins. Leaves excised with a piece of stem attached do not produce plantlets. Severing the major leaf veins overcomes the inhibitory effect of the attached stem, indicating that the control agent is transmitted through the vascular system. A possible mechanism is that an inhibitory substance, possibly a known plant hormone, transported from the stem to the leaf, suppresses plantlet development. A number of hormones were tested for their ability to inhibit plantlet primordium development in whole isolated leaves. Auxins had no effect, indicating that apical dominance is not involved. The cytokinins zeatin, kinetin, and benzylaminopurine (BAP) strongly inhibited plantlet development, suggesting that they may be the or a factor involved in maintenance of plantlet primordium dormancy when the leaf is attached to the plant. This hypothesis was strongly supported by the finding that treatment of leaves attached to stems with a cytokinin antagonist (purine riboside) released the primordia from inhibition. In contrast to whole leaves, plantlet primordium development on leaf explants incubated on Murashige Skoog medium containing 3% sucrose was strongly stimulated by cytokinins. A possible explanation of these observations is that in whole leaves the cytokinin signal is transduced into an inhibitory signal whereas in the isolated primordium cytokinin has a direct stimulatory effect. The inhibitory cytokinin pathway must be dominant as long as the leaf is attached to the plant. A model is proposed which could explain these findings. This study points to a novel role of cytokinins in the maintenance of foliar plantlet primordium dormancy.

show abstract

Section: Comparison Of Present Results With Earlier Data From Other Lmentioning

confidence: 99%

Cytokinins inhibit epiphyllous plantlet development on leaves of Bryophyllum (Kalanchoe) marnierianum

Kulka

2006

Journal of Experimental Botany

View full text Add to dashboard Cite

show abstract

“…46 Cotyledons of D plants were influenced by three factors: 1) after the removal of the leaves the cotyledons took over the function of the leaves, 2) cotyledons were without leaf cover and were exposed to higher irradiation than controls, 3) plants were damaged by repeated wounding.…”

mentioning

confidence: 99%

The capacity of antioxidant protection during modulated ageing of bean (Phaseolus vulgaris L.) cotyledons. 1. The antioxidant enzyme activities

Procházková

Wilhelmová

2005

Cell Biochemistry & Function

View full text Add to dashboard Cite

Reactive oxygen species are known to increase in plant senescence. We investigated the participation of antioxidative enzymes in initiation of cotyledon senescence. Senescence of bean (Phaseolus vulgaris L.) cotyledons was modulated by UV C irradiation and by the decapitation of plant apices. Senescence was accompanied by a decrease of protein content and by a decrease of photochemical efficiency. A drop in activity of antioxidative enzymes preceded the onset of senescence in control plants. In cotyledons with prolonged life span, the decrease of antioxidant activities and the markers of senescence onset appeared at a similar age as in controls. Thus we presumed that the period from senescence initiation to cotyledon abscission was extended. On the other hand, in UV C irradiated plants we did not observe actual senescence initiation, and antioxidant enzymes although elevated, did not effectively play their role. The decrease of antioxidant enzymes activity and the markers of senescence appeared at a similar age both in control and in decapitated (D) plants, so we can presume that we prolonged mainly the period from senescence onset to cotyledon abscission in D plants. In UV C irradiated plants the antioxidative enzymes were probably destroyed before the process of senescence could begin.

show abstract

The release of primordia of marginal buds onbryophyllum crenatum leaves from growth inhibition in relationship to the level of endogenous IAA

Slabý¹,

Šebánek²,

Psota³

1990

Biol Plant

View full text Add to dashboard Cite

Content of endogenous cytokinins in intact and transversally cut leaf blades of Bryophyllum crenatum

Cited by 5 publications

References 6 publications

Cytokinins inhibit epiphyllous plantlet development on leaves of Bryophyllum (Kalanchoe) marnierianum

Cytokinins inhibit epiphyllous plantlet development on leaves of Bryophyllum (Kalanchoe) marnierianum

The capacity of antioxidant protection during modulated ageing of bean (Phaseolus vulgaris L.) cotyledons. 1. The antioxidant enzyme activities

The release of primordia of marginal buds onbryophyllum crenatum leaves from growth inhibition in relationship to the level of endogenous IAA

Contact Info

Product

Resources

About