Influence of calcium and calcium and calmodulin antagonists on the cytokinin-induced amaranthin accumulation inAmaranthus tricolor

Vallon, Ulrike; Graf, Josef A.; Kull, Ulrich

doi:10.1007/bf02025276

Cited by 7 publications

(4 citation statements)

References 31 publications

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“…Cytokinin-dependent dose-responses show at least two examples of optimum curves. The concentration-dependent effects of kinetin and kinetin-riboside on amaranthine accumulation were inhibited by excess of cytokinin (Vallon et al, 1989). Similar dose-response was described for cytokinin action on indoleacetic acid oxidase in tobacco callus tissues (Lee, 1971).…”

Section: Discussionmentioning

confidence: 56%

Regulation of resistance and susceptibility in wheat–powdery mildew pathosystem with exogenous cytokinins

Бабоша

2009

Journal of Plant Physiology

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Section: Discussionmentioning

confidence: 56%

Regulation of resistance and susceptibility in wheat–powdery mildew pathosystem with exogenous cytokinins

Бабоша

2009

Journal of Plant Physiology

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“…The susceptibility of wild-type plants was increased after treatment with low concentrations of the cytokinin BA (<1 µM) and decreased with higher concentrations (>10 µm). This bell-shaped response is reminiscent of other physiological responses regulated by cytokinin, such as shoot initiation in vitro [38] , [39] and the induction of ethylene biosynthesis [40] . In particular, this finding is similar to the effect of exogenous cytokinin on the response of wheat to powdery mildew ( Erysiphe graminis ), in which a complex dose response curve of pathogen growth was obtained in response to exogenous zeatin [20] .…”

Section: Discussionmentioning

confidence: 90%

Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity

et al. 2012

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Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens.

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“…Indole acetic acid in growth medium stimulated colonization of a resistant tobacco callus by Phytophthora parasitica, but development of the fungus sharply decreased when the phytohormone was outside the optimal range (Haberlach et al, 1978). Other examples of such doseresponses are the effect of kinetin and kinetin-riboside on amaranthine accumulation (Vallon et al, 1989), and cytokinin action on indole acetic acid oxidase in tobacco callus tissues (Lee, 1971).…”

Section: Introductionmentioning

confidence: 99%

Effect of some immunomodulators and zeatin on susceptibility of wheat to powdery mildew

Бабоша¹

2019

Turk J Bot

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The effects of zeatin, salicylic acid, and plant oligoadenylates on susceptibility of wheat seedlings to powdery mildew and the shape of dose-response curves for immunomodulation were studied. Salicylic acid and zeatin produced complex dose-responses with upregulation or downregulation of plant susceptibility. Under different experimental conditions, the dose-response curve for zeatin varied in shape from a curve with a maximum to a curve with a minimum of susceptibility to powdery mildew. More complicated curves with a resistance region framed with regions of increased susceptibility were also found. Plant oligoadenylates inhibited the development of powdery mildew at optimal concentrations. The increasing concentrations of salicylic acid and plant oligoadenylates, when combined with zeatin, led to a gradual change in the shape of the zeatin concentration curve. Treatment with salicylic acid and plant oligoadenylates in these experiments may simulate plant responses under biotic and abiotic stresses. Thus, exogenous zeatin was applied to model changes in the phytohormone metabolism. The complex multiphase nature of dose-response is proposed to cause a kind of random-number generator that produces variability in the physiological and immunological status of plants in natural conditions. Variation in susceptibility of individual plants may be crucial for the survival of infected plants and the stabilization of plant-pathogen interactions.

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Influence of calcium and calcium and calmodulin antagonists on the cytokinin-induced amaranthin accumulation inAmaranthus tricolor

Cited by 7 publications

References 31 publications

Regulation of resistance and susceptibility in wheat–powdery mildew pathosystem with exogenous cytokinins

Regulation of resistance and susceptibility in wheat–powdery mildew pathosystem with exogenous cytokinins

Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity

Effect of some immunomodulators and zeatin on susceptibility of wheat to powdery mildew

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