English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Endogenous cytokinin-active ribonucleosides were isolated from the rRNA and tRNA of pea epicotyls (Pisum sativum L., var Alaska) and of wheat germ (Triticum aestivum). The RNA preparations were analyzed for cytokinins by enzymic hydrolysis, ethyl acetate extraction, and Sephadex LH-20 fractionation in several solvents. Tentative identification of the cytokinins was based on cochromatography with synthetic cytokinin standards in several systems and on activity in the tobacco bioassay. Both the rRNA and tRNA from 10 day old pea epicotyls contained ribosylzeatin, isopentenyladenosine, and 2-methylthioribosylzeatin. The latter compound was the most active fraction in the pea rRNA, but was the least active fraction in the tRNA, where isopentenyladenosine activity was predominant. The 2-methylthioribosylzeatin from pea rRNA was identified by gas chromatography-mass spectrometry. Wheat germ rRNA contained cis and trans ribosylzeatin and 2-methylthioribosylzeatin. The tRNA contained isopentenyladenosine in addition. The specific cytokinin activity (activity per A(260) unit) of the tRNA was over forty times that of the rRNA. Significant contamination of the rRNA preparations by cytokinin-containing tRNA is considered unlikely on the basis of quantitative differences in the cytokinin content of the rRNA and tRNA preparations, electrophoretic analysis of rRNA purity and cytokinin analysis of fractionated oligonucleotide digests.

Endogenous Cytokinins in the Ribosomal RNA of Higher Plants