Effects of benzylaminopurine and irradiance on cytokinin contents, α-tubulin gene expression and cucumber cotyledon expansion

Li, Y. L.; H., Q.

doi:10.1007/s10535-007-0044-6

Cited by 5 publications

(7 citation statements)

References 27 publications

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“…However, a relationship between cytokinin and light in inducing cell division in green alga is not fully understood. It was only reported by Li and Ma (2007) that BA applications under dark conditions markedly increased the contents of endogenous cytokinins and induced a-tubulin gene expression in cucumber cotyledon. Therefore, the normal cell expansion and mitosis can contribute to cotyledon growth and development in darkness.…”

Section: Discussionmentioning

confidence: 99%

Cellular response of light/dark-grown green alga Chlorella vulgaris Beijerinck (Chlorophyceae) to exogenous adenine- and phenylurea-type cytokinins

Piotrowska

Czerpak

2009

Acta Physiol Plant

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Treatment exposed to light Chlorella vulgaris Beijerinck (Chlorophyceae) with adenine-(BA, Kin, Z) and phenylurea-type (DPU) cytokinins effects positively on alga viability by 1.5-to twofold increase in cell number, chlorophylls, carotenoids, monosaccharides and glycolate content as well as NADH-dependent hydroxypyruvate reducing enzyme activity (NADH-HPR) extensively involved in carbon metabolism. Cytokinins enhance nitrogen assimilation by stimulation of NADH-dependent glutamate dehydrogenase (NADH-GDH) aminating activity finally leading to higher protein level and its secretion as well as polypeptide accumulation in the range of molecular weight 12-195 kDa. In the dark, cytokinins mimic the regulatory effect of light upon algal cell division, metabolite content and stimulate carbon recycling for Calvin cycle reactions by enhancing of light-dependent NADH-HPR activity. The delaying of protein degradation and stimulation of their secretion to environment, triggering polypeptide accumulation and twofold higher NADH-GDH activity catalysing amino acids biosynthesis are observed in the dark-grown microalgae in response to cytokinins. Chlorella vulgaris exhibits sensitivity on cytokinins in the following order of their stimulating properties: DPU [ Z [ Kin [ BA in both light and dark conditions. Understanding of cytokinin role in lower plants under different light conditions could be a step toward the elucidation of the evolution of hormone regulation and their action at molecular level.

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Section: Discussionmentioning

confidence: 99%

Cellular response of light/dark-grown green alga Chlorella vulgaris Beijerinck (Chlorophyceae) to exogenous adenine- and phenylurea-type cytokinins

Piotrowska

Czerpak

2009

Acta Physiol Plant

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“…However, Kudoyarova et al (2007) recently observed decrease in CK content in tomato leaf tissue up to 46 % during water stress but no changes in xylem sap CK content. Treatment of cucumber cotyledons with CK benzyladenine (BA; 20 μM) increased content of endogenous CKs (Li and Ma 2007). In bean plants, pre-treatment with BA ameliorated effects of water stress on gas exchange parameters (Pospíšilová and Baťková 2004) and BA application also improved recovery of drought stressed bean plants after rehydration (Rulcová and Pospíšilová 2001).…”

Section: Introductionmentioning

confidence: 99%

The impact of trans-zeatin O-glucosyltransferase gene over-expression in tobacco on pigment content and gas exchange

Haisel¹,

Vaňoková²,

Synková³

et al. 2008

Biologia plant.

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The responses of tobacco plants over-expressing trans-zeatin O-glucosyltransferase gene under constitutive or senescence-inducible promoter (35S:ZOG1 and SAG12:ZOG1) and of wild type (WT) plants to water stress and subsequent rehydration were compared. In plants sufficiently supplied with water, both transgenics have higher net photosynthetic rate (P N ) in upper and middle leaves and higher stomatal conductance (g s ) in middle leaves than WT. Water use efficiency (WUE = P N /E) was higher in both transgenics than in WT. During prolonged water stress, both P N and E declined to a similar extent in both transgenics and WT plants. However, 7 d after rehydration P N in SAG:ZOG (upper and middle leaves) and 35S:ZOG (upper leaves) was higher than that in WT plants. Increased content of endogenous CKs in 35S:ZOG plants did not prevent their response to ABA application and the results obtained did not support concept of CK antagonism of ABA-induced stomatal closure. The chlorophyll (Chl) a+b content was mostly higher in both transgenics than in WT. During water stress and subsequent rehydration it remained unchanged in upper leaves, decreased slightly in middle leaves only of WT, while rapidly in lower leaves. Total degradation of Chl, carotenoids and xanthophyll cycle pigments (XCP) was found under severe water stress in lower leaves. Carotenoid and XCP contents in middle and upper leaves mostly increased during development of water stress and decreased after rehydration. While β-carotene content was mostly higher in WT, neoxanthin content was higher in transgenics especially in 35S:ZOG under severe stress and after rehydration. The higher content of XCP and degree of their deepoxidation were usually found in upper and middle leaves than in lower leaves with exception of SAG:ZOG plants during mild water stress.

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“…51 During the life cycle of eukaryotic cells, microtubules are capable of performing various tasks which may relate to cell expansion and cell division. 52,53 Li & Ma 54 found that light enhanced the cucumber (Cucumis sativa L.) cotyledon expansion as compared with dark and benzylaminopurine (BAP) further enhanced the expansion of cotyledons. In cucumber cotyledon expansion, BAP treatment markedly increased the contents of endogenous cytokinins and induced α-tubulin gene expression.…”

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confidence: 99%

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

Kataria¹,

Kn²

2018

HIJ

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The negative effect on plant responses are expected due to increased amounts of ultraviolet-B (UV-B) radiation reaching on the Earth's surface by stratospheric ozone depletion. Cytokinins (CKs) are essential phytohormones in plant growth and development. Perusal of relevant literature reveals that CKs mitigate the oxidative damage caused by abiotic stresses like salt, drought, high temperature and heavy metal due to their antioxidant effects. However, very few reports are available on the interaction of CKs with UV-B stress on the expansion growth of the cucumber cotyledons. CKs induced the expansion growth of the excised cucumber cotyledons in the darkness. CKs induced expansion growth of cucumber cotyledons in darkness was inhibited by supplemental UV-B. UV-B radiation enhanced the level of oxyradicals like superoxide and hydroxide radicals in the excised cucumber cotyledons, which was evident by EPR spectroscopy. CKs like Zeatin, TDZ, BAP and FAP reduced the level of oxyradicals produced in the dark grown cucumber cotyledons, while promoting the expansion growth of the cotyledons. Production of oxyradical in UV-B exposed cotyledons showed that these oxyradicals might partially account for inhibition of expansion growth. Since considerable amount of oxyradicals were quenched by CKs at higher concentrations (10 and 20 µg/ml) it partially restores the inhibition of expansion growth caused by UV-B stress. It indicates that overproduction of oxyradicals by UV-B could not be entirely responsible for the inhibition of CKs induced expansion growth of cotyledons; which might be caused by some other physiological changes caused by UV-B irradiation in addition to the production of oxyradicals. UV-B is also known to inactivate protein inhibitor of peroxidase in cucumber cotyledons. This may reduce the antioxidants defence and enhance the damaging effects of oxyradicals for the growth of cotyledons.

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Effects of benzylaminopurine and irradiance on cytokinin contents, α-tubulin gene expression and cucumber cotyledon expansion

Cited by 5 publications

References 27 publications

Cellular response of light/dark-grown green alga Chlorella vulgaris Beijerinck (Chlorophyceae) to exogenous adenine- and phenylurea-type cytokinins

Cellular response of light/dark-grown green alga Chlorella vulgaris Beijerinck (Chlorophyceae) to exogenous adenine- and phenylurea-type cytokinins

The impact of trans-zeatin O-glucosyltransferase gene over-expression in tobacco on pigment content and gas exchange

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

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