Effect of Kinetin on the Transcription Activity of Chromatin from Cucumber Cotyledons

Waliszewska-Wojtkowiak, Barbara; Schneider, J.; Szweykowska, A.

doi:10.1016/s0015-3796(85)80051-2

Cited by 8 publications

(3 citation statements)

References 12 publications

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“…Spermine also exerts an effect on the activity of nucleus-associated casein kinase (Datta et al 1987, Klimczak et al 1992. As was shown earlier, chromatin from kinetin-treated cucumber cotyledons exhibited higher activity (Waliszewska- Wojtkowiak et al 1985) and it was accompanied by changes in the population of translatable mRNA (Legocka 1987). The higher level of spermine bound to chromatin in kinetin-treated cotyledons in relation to the above data may suggest the involvement of polyamines (putrescine and spermine) in cytokinin-controlled gene expression.…”

Section: Treatmentmentioning

confidence: 62%

Role of polyamines in the cytokinin-dependent physiological processes II. Modulation of polyamine levels during cytokinin-stimulated expansion of cucumber cotyledons

Legocka

Żarnowska

2000

Acta Physiol Plant

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The cucumber cotyledon expansion test was used as a model system to study a possible relationship between cytokinin and polyamines. When kinetin was applied to excised cotyledons incubated in the dark it caused a marked increase in the activity of arginine decarboxylase. As a result of ADC action, putrescine content also rose markedly, whereas the level of spermidine and spermine decreased. However, inhibition of putrescine biosynthesis with D-arginine did not affect cytokinin promotion growth. Applied alone, putrescine had no significant effect on growth. These results indicate that the large increase in putrescine content that derives from cytokinin treatment cotyledons is not essential for cytokinin-induced expansion of cotyle-dons. Addition of K and Ca ions to the cotyledons incubated with cytokinin caused a marked reduction in the putrescine level and ADC activity.The higher level of putrescine (35 %) and spermine (62 %) bound to chromatin and the large increase (174 %) in spermidine content bound to ribosomes which derive from cytokinintreated cotyledons in relation to literature data can indicate that these polyamines may play an important role in gene expression during cytokinin-stimulated expansion of cucumber cotyledons.The inhibition of cytokinin effect, viz. enlargement of the cotyledons by inhibitors of spermidine biosynthesis, additionally suggessted a possible involvement of polyamines in cytokinin action.List of abbreviations: ADC -arginine decarboxylase: DCHA -dicyclohexylamine; MGBG -methylglyoxal bis-(quanylhydrazone); PAs -polyamines; Put -putrescine; SAM -S-adenosylmethionine; Spd -spermidine; Spm -spermine; TLC -thin layer chromatography.

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Section: Treatmentmentioning

confidence: 62%

Role of polyamines in the cytokinin-dependent physiological processes II. Modulation of polyamine levels during cytokinin-stimulated expansion of cucumber cotyledons

Legocka

Żarnowska

2000

Acta Physiol Plant

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“…The molecular mechanisms by which cytokinins mediate cell growth and division are still unknown. However, it has been reported that cytokinins may increase the accessibility of the DNA template, activate RNA polymerases, affect the polyadenylation and the secondary structure of mRNA, and stimulate the formation and activity of polyribosomes . Given the prominent role of cytokinins in the control of cell division, an interesting question was whether these hormones interact with the known regulatory proteins of the cell cycle.…”

Section: Introductionmentioning

confidence: 99%

Cytokinin-Derived Cyclin-Dependent Kinase Inhibitors: Synthesis and cdc2 Inhibitory Activity of Olomoucine and Related Compounds

et al. 1997

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Cyclin-dependent kinases (cdk) have recently raised considerable interest in view of their essential role in the regulation of the cell division cycle. The structure-activity relationships of cdk inhibition showed that the 1, 3; and 7 positions of the purine ring must remain free, probably for a direct interaction, in which it behaves as a hydrogen bond acceptor. Olomoucine (6-(benzylamino)-2-[(2-hydroxyethyl)amino]-9-methylpurine, OC), roscovitine (6-(benzylamino)-2(R)-[[1-(hydroxymethyl)propyl]amino]-9-isopropylpur ine), and other N6,2,9-trisubstituted adenines were found to exert a strong inhibitory effect on the p34cdc2/cyclin B kinase. Removal or change of the side chain at position 2 or the hydrophobic group at position 9 dramatically decreased the inhibitory activity of olomoucine or roscovitine. Inhibition of cdk with OC and related compounds clearly arrests cell proliferation of many tumor cell lines at G1/S and G2/M transitions and also triggers apoptosis in the target tumor cells in vitro and in vivo. Thus, from a pharmacological point of view, OC may represent a model compound for a new class of antimitotic and antitumor drugs.

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“…The known molecular mechanisms of CKs (zeatin, 2-iP and BAP) rely on the twocomponent CK signaling [22][23][24][25], cell cycle regulation [26], direct binding with type-B RRs [27], RNA, proteins, ribosomal proteins, and polyribosomes synthesis [28][29][30][31][32][33][34]. Furthermore, CKs are inhibitors of senescence by downregulating several transcription factors (TFs) [35] involved in several types of stress (drought, osmotic, salt, temperature, and oxidative) and crosstalk during plant stress with ABA and jasmonic acid.…”

Section: Discussionmentioning

confidence: 99%

The Cytokinins BAP and 2-iP Modulate Different Molecular Mechanisms on Shoot Proliferation and Root Development in Lemongrass (Cymbopogon citratus)

Cárdenas-Aquino,

Camas-Reyes,

Valencia-Lozano

et al. 2023

Plants

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The known activities of cytokinins (CKs) are promoting shoot multiplication, root growth inhibition, and delaying senescence. 6-Benzylaminopurine (BAP) has been the most effective CK to induce shoot proliferation in cereal and grasses. Previously, we reported that in lemongrass (Cymbopogon citratus) micropropagation, BAP 10 µM induces high shoot proliferation, while the natural CK 6-(γ,γ-Dimethylallylamino)purine (2-iP) 10 µM shows less pronounced effects and developed rooting. To understand the molecular mechanisms involved, we perform a protein–protein interaction (PPI) network based on the genes of Brachypodium distachyon involved in shoot proliferation/repression, cell cycle, stem cell maintenance, auxin response factors, and CK signaling to analyze the molecular mechanisms in BAP versus 2-iP plants. A different pattern of gene expression was observed between BAP- versus 2-iP-treated plants. In shoots derived from BAP, we found upregulated genes that have already been demonstrated to be involved in de novo shoot proliferation development in several plant species; CK receptors (AHK3, ARR1), stem cell maintenance (STM, REV and CLV3), cell cycle regulation (CDKA-CYCD3 complex), as well as the auxin response factor (ARF5) and CK metabolism (CKX1). In contrast, in the 2-iP culture medium, there was an upregulation of genes involved in shoot repression (BRC1, MAX3), ARR4, a type A-response regulator (RR), and auxin metabolism (SHY2).

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Effect of Kinetin on the Transcription Activity of Chromatin from Cucumber Cotyledons

Cited by 8 publications

References 12 publications

Role of polyamines in the cytokinin-dependent physiological processes II. Modulation of polyamine levels during cytokinin-stimulated expansion of cucumber cotyledons

Role of polyamines in the cytokinin-dependent physiological processes II. Modulation of polyamine levels during cytokinin-stimulated expansion of cucumber cotyledons

Cytokinin-Derived Cyclin-Dependent Kinase Inhibitors: Synthesis and cdc2 Inhibitory Activity of Olomoucine and Related Compounds

The Cytokinins BAP and 2-iP Modulate Different Molecular Mechanisms on Shoot Proliferation and Root Development in Lemongrass (Cymbopogon citratus)

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