Linked Life Data

18270730

Source:http://linkedlifedata.com/resource/pubmed/id/18270730

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-4-16
pubmed:abstractText
Germination and seedling establishment follows a distinct pattern which is partly controlled by hormones. Roots have high levels of cytokinins. By quantifying the fluctuations in endogenous cytokinins over time, further insight may be gained into the role of cytokinins during germination and seedling establishment. Radicles were excised from sterile Pisum sativum L. seeds after 30 min and 5 h imbibition. Seedlings germinated on agar were harvested after 1, 3, 6 and 9 days. The roots were divided into the root tip, root free zone, secondary root zone and from day 6, the secondary roots. Samples were purified by various chromatographic methods and endogenous cytokinins detected by LC(+)ES-MS. Benzyladenine levels doubled after 5 h imbibition and then gradually decreased over time. Low concentrations of cis-Zeatin (cZ) type cytokinins were detected in the radicle after 30 min imbibition. After 5 h imbibition, cis-zeatin riboside-5'-monophosphate had greatly increased. The total cytokinin content of the roots increased over time with the ribotides being the predominant conjugates. From day 3 onwards, there was a gradual increase in the free bases, O-glucosides and their ribosylated forms. Mainly N ( 6 )-(2-isopentenyl)adenine (iP)-type cytokinins were detected in the root tip, whereas trans-zeatin- (tZ), dihyrozeatin- (DHZ) and iP-type cytokinins were found in the secondary roots and root zone. Cytokinin biosynthesis was only detected after day 6. Biosynthesis of iP and tZ derivatives was quite rapid, whereas biosynthesis of cZ derivatives remained at a low basal level. These fluctuations in cytokinin types and concentrations suggest the cytokinins may be synthesized from various pathways in pea roots.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
227
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1279-89
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Spatial and temporal changes in endogenous cytokinins in developing pea roots.
pubmed:affiliation
School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Scottsville, 3209, South Africa. stirk@ukzn.ac.za
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't