Determination of cytokinins by mass spectrometry based on stable isotope dilution

Hashizume, Takeshi; Sugiyama, Tamiji; Imura, Mimiko; Cory, H. Therese; Scott, Monica; McCloskey, James A.

doi:10.1016/0003-2697(79)90631-6

Cited by 34 publications

(7 citation statements)

References 31 publications

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“…The A of the extract was measured at 663 and 645 nm. Chl content was determined as described by Arnon (1 Chemicals 2H-labeled standards used for the mass spectrometric analysis were prepared as described previously (7,19). Z3 and RZ consisted of the trans-isomer (92%) and the cis-isomer (8%).…”

Section: Chi Contentmentioning

confidence: 99%

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Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

Soejima¹,

Sugiyama²,

Ishihara³

1992

Plant Physiol.

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Changes in exudation rate and cytokinin activities in the exudates were measured in two varieties of rice (Oryza sativa L.), cv Nipponbare (a Japanese normal cultivar) and cv Akenohoshi (a highyielding cultivar). The exudation rates of Akenohoshi, the leaves of which remained green for a longer time, were higher than those of Nipponbare after the booting stage. Cytokinin activities in the exudates of Akenohoshi were higher than those of Nipponbare during the ripening period. Cytokinins in the exudates collected during the middle of the ripening stage were analyzed with mass spectrometry using deuterium-labeled standards. trans-Zeatin, trans-ribosylzeatin, and N'-isopentenyladenosine were detected as free cytokinins, and zeatin was detected in the hydrolysates of highly polar fractions ("conjugated zeatin") in the exudates of both cultivars. Conjugated zeatin was the predominant cytokinin in both cultivars. Therefore, we suggest that conjugated zeatin is an important form of cytokinin during the ripening stage. The level of each of the cytokinins in Akenohoshi was higher than that in Nipponbare. Also, we discuss the correlation between the leaf senescence and cytokinin content in root exudates.In a previous study to clarify the physiological and ecological characteristics of high-yielding rice varieties (11, 12), it was reported that the yield in Akenohoshi was about 1780 kg/ha higher than that in Nipponbare, a Japanese standard cultivar, and that Akenohoshi had a higher dry matter production capacity compared with Nipponbare. This was attributed to the maintenance of a higher net assimilation rate during the ripening period in the former. 1724 stage were 9.2 ,umol of CO2 m-2 s-' (44.6% of its maximum rate at the panicle formation stage) and 12.7 smol of CO2 m-2 S-1 (62.0%), respectively. In addition, the cause for these differences between the two cultivars was examined by measuring the active and passive water absorption abilities of the roots. The rate of exudation from the main stem and the resistance to water transport from the root surface to the leaves under intense transpiration were higher and lower in Akenohoshi than in Nipponbare, respectively. These differences between the two cultivars were especially large during the ripening stage. This fact suggests that physiological activity in the roots of Akenohoshi was higher than that in Nipponbare. It is known that a decline in the physiological activity of roots causes leaf senescence and death of the leaves at the lower positions (10), but the mechanism by which this occurs is not understood well.Cytokinins transported from the roots via the xylem are known to delay leaf senescence (6,16,18). In the exudate of rice plants, several cytokinins were identified (15). However, the constitution of cytokinins in the exudate, the level of these cytokinins, and their effects on leaf photosynthesis and senescence have been examined in only a few studies (20).In this report, we discuss the changes in the exudation rates and cytokinin activities in the exudat...

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Section: Chi Contentmentioning

confidence: 99%

“…Peak height ratios of endogenous cytokinins to the intemal standards were determined, and corrections for the unlabeled materials were made from the standard calibration curve obtained in previous studies (7). The identities of the peaks were confirmed by complete mass spectra.…”

Section: Changes In Exudation Ratementioning

confidence: 99%

Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

Soejima¹,

Sugiyama²,

Ishihara³

1992

Plant Physiol.

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“…4. The ions monitored were m/z 670 from ms 2io6A-~9~2 6 (TMS)4 and m/z 673 from ms io A-d3-(TMS)4 (12). As indicated by a blank run using the internal standard only (data not shown), the standard contains a small amount of cis-ms 2io6A-d and approximately 8% trans-ms 2io6A.…”

Section: Gc/ms Analysis Of a 2mentioning

confidence: 96%

c/s2-Methylthio-ribosylzeatin (ms²io⁶is present in the transfer RNA ofSalmonella ryphimurium, but notEscherichis coti

Buck¹,

McCloskey

Basile

et al. 1982

Nucl Acids Res

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We have identified the cis isomer of N6-(4-hydroxy-isopentenyl)-2-methylthioadenosine (ms2io6A) as a component of the tRNA of Salmonella typhimurium. This is the first report of this compound in the tRNA of any member of the enterobacteriaceae: the nucleoside was previously thought to be found exclusively in plants or plant associated bacteria. Interestingly, all E. coli strains examined were found to lack ms2io6A. Evidence is presented which suggests S. typhimurium tRNA also contains low levels of 5-carboxymethylaminomethyl-2-thiouridine (cmnm5s2U) in addition to 5-methylaminomethyl-2-thiouridine (mnm5s2U).

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“…Several types of deuterated standards have been developed recently for cytokinins containing a modified isopentenyl N6-substituent, and have been used in conjunction with scanning gas chromatography mass spectrometry, direct probe mass spectrometry, and multichannel selected ion monitoring (SIM). [4][5][6] In the present p'rper, we describe a new method for the synthesis of cytokinins labelled with four 15N atoms in the purine ring, and illustrate the use of such compounds as internal standards by the measurement by SIM of zeatin riboside in cultured tissues of Vinca rosea.…”

Section: Introductionmentioning

confidence: 99%

Quantification of cytokinins by selected ion monitoring using15N labelled internal standards

Scott

Horgan

1980

Biol. Mass Spectrom.

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A procedure has been developed for the synthesis of 6-chloropurine labelled with four * ' N atoms. This compound can be used in the synthesis of a range of labelled cytokinin bases, which can be ribosylated by an enzymatic procedure. 15N labelled zeatin riboside was synthesized and used as an internal standard in the measurement by selected ion monitoring of the levels of this cytokinin in cultured crown gall and normal tissues of Vinca rosea, which were found to contain 402 and 2.5 ng per g fresh weight respectively.

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Determination of cytokinins by mass spectrometry based on stable isotope dilution

Cited by 34 publications

References 31 publications

Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

c/s2-Methylthio-ribosylzeatin (ms²io⁶is present in the transfer RNA ofSalmonella ryphimurium, but notEscherichis coti

Quantification of cytokinins by selected ion monitoring using15N labelled internal standards

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Determination of cytokinins by mass spectrometry based on stable isotope dilution

Cited by 34 publications

References 31 publications

Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.)

c/s2-Methylthio-ribosylzeatin (ms2io6is present in the transfer RNA ofSalmonella ryphimurium, but notEscherichis coti

Quantification of cytokinins by selected ion monitoring using15N labelled internal standards

Contact Info

Product

Resources

About

c/s2-Methylthio-ribosylzeatin (ms²io⁶is present in the transfer RNA ofSalmonella ryphimurium, but notEscherichis coti