Rapid Identification of Cytokinins by an Immunological Method

Morris, Roy O.; Jameson, Paula E.; Laloue, Michel; Morris, J. Carrell

doi:10.1104/pp.95.4.1156

Cited by 17 publications

(9 citation statements)

References 23 publications

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“…The latter make use of the ability of antibodies raised against ZR or ipA to crossreact to a larger or smaller degree with other, structurally similar, cytokinins (Weiler 1980; Barthe and Stewart 1985). When antibodies against ZR or ipA were used in immunoaffinity chromatography (IAC), several cytokinins other than the immunogens were also retained (McDonald and Morris 1985;Davies et al 1986;McDonald et al 1986; Wang et al 1987; Morris et al 1991). …”

Section: Introductionmentioning

confidence: 99%

Immunoaffinity co-purification of cytokinins and analysis by high-performance liquid chromatography with ultraviolet-spectrum detection

Nicander

Ståhl

Björkman

et al. 1993

Planta

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A rapid methodology for the simultaneous analysis of a large number of cytokinins is presented. The cross-reactivity of a mixture of polyclonal antibodies against zeatin riboside and isopentenyladenosine was exploited in a protocol that can be used for immunoaffinity purification of 23 additional cytokinins. Ligands include the cytokinin bases zeatin, dihydrozeatin, isopentenyladenine, benzyl-adenine and kinetin, and their corresponding nucleoside, nucleoside-5'-monophosphate, and 9-glucoside derivatives, as well as cis-zeatin, cis-zeatin riboside, the 2-methylthiol derivatives of isopentenyladenosine and zeatin riboside, and benzyl-adenine-3-glucoside. Mixtures of cytokinins could be retained with high recoveries of all the components. Immunoaffinity purification of extracts of Arabidopsis thaliana (L.) Heynh. and Solarium tuberosum L. gave fractions clean enough, as verified by gas chromatographymass spectrometry (GC-MS), to allow analysis of endogenous cytokinins using a single high-performance liquid chromatography (HPLC) step with on-line UV-spectrum detection. The detection limit was 4-6 pmol. The procedure described forms a routine assaying technique that is faster and simpler, yet yields better qualitative and quantitative information than the commonly used procedure of immunoassaying of HPLC fractions.

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Section: Introductionmentioning

confidence: 99%

Immunoaffinity co-purification of cytokinins and analysis by high-performance liquid chromatography with ultraviolet-spectrum detection

Nicander

Ståhl

Björkman

et al. 1993

Planta

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“…cis-CK could arise from a de novo synthetic pathway or as a result of tRNA turnover in situ (Prinsen et al, 1997), and either could be due to plant metabolism or to the activity of symbiotic bacteria colonizing the shoots (Holland, 1997). Current models of de novo CK biosynthesis (Binns, 1994;Jameson, 1994, figure 9-3 Holland's (1997) hypothesis for bacterial CK synthesis, it is perhaps significant that in bacteria, which are symbionts of, or are otherwise associated with, plants (Morris et al, 1991;Upadhyaya et al, 1991;Holland and Polacco, 1994), cis-CK can be a significant component of the free CK pool. Should transfer to the tissues of the seed take place this might lead to an accumulation of cis-isomers.…”

Section: Cis-isomers Of Cytokinin Predominate In Chickpea Seedsmentioning

confidence: 99%

cis -Isomers of Cytokinins Predominate in Chickpea Seeds throughout Their Development1

Emery

Leport²,

Barton³

et al. 1998

Plant Physiology

108

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Trans-isomers of cytokinins (CK) are thought to predominate and have greater biological activity than corresponding cis-isomers in higher plants. However, this study demonstrates a system within which the predominant CK are cis-isomers. CK were measured at four developmental stages in developing chickpea (Cicer arietinum L. cultivar Kaniva) seeds by gas chromatography-mass spectrometry. Concentrations were highest at an early endospermic fluid stage and fell considerably when the cotyledons expanded. Seed tissues were the source for isolation of the first naturally occurring CK, trans-Z (Miller, 1961;Letham, 1963). Seeds have turned out to be a rich source of CK, and in the past 30 years investigators have described a range of different CK from seed tissues (van Staden et al., 1982). This may reflect their relatively high levels in seeds (van Staden et al., 1982), a status that is believed to indicate a role for CK in establishing developing seeds as strong assimilate sinks (Brenner and Cheikh, 1995). Despite a vast literature concerning the occurrence, form, and significance of CK in plant development, the nature and site(s) of their synthesis is yet to be established. In fact, Holland (1997) recently proposed that CK are not formed by plants at all but rather by bacterial symbionts that colonize plant tissues. Although there is good evidence for the transfer of CK synthesized by Rhizobium in legume nodules (Upadhyaya et al., 1991), a role for bacteria in providing CK to roots or shoot organs needs to be investigated more thoroughly. Because unequivocal evidence for a plant isopentenyl transferase is lacking, a persistent hypothesis, which has recently been reviewed (Prinsen et al., 1997), is that the free CK in plants are not synthesized de novo but are released during tRNA turnover.Z, [9R-MP]Z, and [9R]Z have an unsaturated isopentenyl side chain that can exist in the cis or trans conformation. The cis-isomer occurs when the hydroxyl group of the isopentenyl side chain is oriented toward the N-1 position of the purine ring, whereas in the trans-isomer the hydroxyl group is oriented away from the purine ring (Korszun et al., 1989; Fig. 1). The trans-isomers of [9R]Z and Z are by far the more commonly reported forms and are considered the predominant isomers in higher plants (McGaw and Burch, 1995;Prinsen et al., 1997). Systems in which the existence of cis-CK can be demonstrated unequivocally would be significant for two reasons. First, because cis-CK show much lower activity than trans-CK in bioassays (Kaminek, 1982) and their interconversion may constitute a mechanism for reducing CK bioactivity in vivo. Second, cis-CK provide evidence for the hypothesis that the free CK pool in higher plants may be at least partially derived from the breakdown of tRNA. The major criticism of this hypothesis has been the structural distinctness between tRNA-bound CK and free-pool CK (Letham and Palni, 1983;McGaw and Burch, 1995;Prinsen et al., 1997

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“…CKs are also produced by a range of various microbial pathogens, including Pseudomonas syringae (Akiyoshi et al, 1987;Morris et al, 1991) and leaf-mining insects (Engelbrecht, 1968), causing the formation of green islands, galls, growth abnormalities, and manipulation of primary carbon metabolism (Balibrea Lara et al, 2004). For several pathogens, it was shown that this CK production is essential for infection (Crespi et al, 1994;Hwang et al, 2010).…”

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confidence: 99%

Cytokinins Mediate Resistance againstPseudomonas syringaein Tobacco through Increased Antimicrobial Phytoalexin Synthesis Independent of Salicylic Acid Signaling

Großkinsky

Naseem²,

Abdelmohsen³

et al. 2011

Plant Physiology

180

169

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Cytokinins are phytohormones that are involved in various regulatory processes throughout plant development, but they are also produced by pathogens and known to modulate plant immunity. A novel transgenic approach enabling autoregulated cytokinin synthesis in response to pathogen infection showed that cytokinins mediate enhanced resistance against the virulent hemibiotrophic pathogen Pseudomonas syringae pv tabaci. This was confirmed by two additional independent transgenic approaches to increase endogenous cytokinin production and by exogenous supply of adenine-and phenylurea-derived cytokinins. The cytokinin-mediated resistance strongly correlated with an increased level of bactericidal activities and up-regulated synthesis of the two major antimicrobial phytoalexins in tobacco (Nicotiana tabacum), scopoletin and capsidiol. The key role of these phytoalexins in the underlying mechanism was functionally proven by the finding that scopoletin and capsidiol substitute in planta for the cytokinin signal: phytoalexin pretreatment increased resistance against P. syringae. In contrast to a cytokinin defense mechanism in Arabidopsis (Arabidopsis thaliana) based on salicylic acid-dependent transcriptional control, the cytokininmediated resistance in tobacco is essentially independent from salicylic acid and differs in pathogen specificity. It is also independent of jasmonate levels, reactive oxygen species, and high sugar resistance. The novel function of cytokinins in the primary defense response of solanaceous plant species is rather mediated through a high phytoalexin-pathogen ratio in the early phase of infection, which efficiently restricts pathogen growth. The implications of this mechanism for the coevolution of host plants and cytokinin-producing pathogens and the practical application in agriculture are discussed.

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Rapid Identification of Cytokinins by an Immunological Method

Cited by 17 publications

References 23 publications

Immunoaffinity co-purification of cytokinins and analysis by high-performance liquid chromatography with ultraviolet-spectrum detection

Immunoaffinity co-purification of cytokinins and analysis by high-performance liquid chromatography with ultraviolet-spectrum detection

cis -Isomers of Cytokinins Predominate in Chickpea Seeds throughout Their Development1

Cytokinins Mediate Resistance againstPseudomonas syringaein Tobacco through Increased Antimicrobial Phytoalexin Synthesis Independent of Salicylic Acid Signaling

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