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Effetto di derivati ureidicidi neosisntesi in radicazione avventizia ed embriogenesi somatica
No full textRiassunto
Alcuni derivati simmetrici dell’urea, pur privi di qualsiasi attività ormono-simile per se, sono in grado di stimolare specifici processi fisiologici, quali radicazione avventizia ed embriogenesi somatica. In entrambi questi processi, la presenza di regolatori di crescita (auxine e/o citochinine) in opportune combinazioni di concentrazioni, può regolare la cascata di traduzione del segnale in modo da riprogrammare l’espressione di determinati geni, portando ad una stimolazione della radicazione avventizia o dell’embriogenesi somatica. Questi derivati ureidici grazie ad un meccanismo ancora sconosciuto, possono essere considerati composti coadiuvanti l’azione dei regolatori di crescita che giocano un ruolo fondamentale nella determinazione di entrambi i processi.
Abstract
Some symmetric urea derivatives can act either as adventitious rooting adjuvants or as somatic embryogenensis adjuvants. These physiological processes are under the control of growth regulators, auxins and cytokinins mostly, that affect the transcript level of genes involved in both the processes. The symmetric urea derivatives do not show any biological activity per se, rather it seems that they magnify the response to the growth regulator stimulus of naturally competent-to-root or -to-form-somatic-embryos cell niches. Their mode of action is still unknown
Influenza di diverse auxine sulla rigenerazione da callo in pomodoro (Solanum lycopersicon L.)
No full text
Effects of diphenylurea derivatives on adventitious rooting
No full textAdventitious root formation is a key step in vegetative propagation of plants, one of the most efficient methods to multiply plants in vivo or in vitro. Endogenous auxin (namely indole 3 acetic acid, IAA) has been established as natural inducer of root formation, and its capacity to induce roots when exogenously applied has also been rapidly recognised. However, in the case of woody plants there is often a physiological inability to produce adventitious roots even after external supplementation of auxins, either natural or synthetic. Despite the huge commercial interest and the large number of attempts, auxin alone has proved to be not sufficient to induce root formation in so called difficult to root species. Different strategies have therefore been implemented with a view to improving adventitious rooting: treatment with any kind of plant growth regulators; supplementation of non hormonal compounds such as polyamines, phenolic compounds, thiol compounds; use of Agrobacterium rhizogenes as root inducing bacterium. Considering broad interest in the area of nonhormonal
bioactive compound supplementation, in this chapter we
summarize the effects of some diphenylurea derivatives as “rooting adjuvants”, since they markedly enhance rooting when applied alone or in combination with auxins
Effects of Chromium (VI) on two freshwater plants, Lemna minor and Pistia stratiotes 2Biochemical and physiological observations
No full textEffect of polIII dependent elements on CAT reporter gene transcription in Nicotiana tabacum protoplasts
No full textUrea derivatives on the move: cytokinin-like activity and adventitious rooting enhancement depend on chemical structure
No full textUrea derivatives are synthetic compounds, some of which have proved to be positive regulators of cell division and differentiation. N-phenyl-N'-(2-chloro-4-pyridyl)urea (forchlorofenuron, CPPU) and N-phenyl-N'-(1,2,3-thiadiazol-5-yl)urea (thidiazuron, TDZ), well known urea cytokinin representatives, are extensively used in in vitro plant morphogenesis studies, as they show cytokinin-like activity often exceeding that of adenine compounds. In recent years, renewed interest in structure-activity relationship studies allowed identification of new urea cytokinins and other urea derivatives that specifically enhance adventitious root formation. In this review, we report the research history of urea derivatives, new insights into their biological activity, and recent progress on their mode of action
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