Journal Article

Effects of Conditional IPT-Dependent Cytokinin Overproduction on Root Architecture of <i>Arabidopsis</i> Seedlings

Alena Kuderová, Ivana Urbánková, Martina Válková, Jiří Malbeck, Břetislav Brzobohatý, Danka Némethová and Jan Hejátko

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 49, issue 4, pages 570-582
Published in print April 2008 | ISSN: 0032-0781
Published online April 2008 | e-ISSN: 1471-9053 | DOI: https://dx.doi.org/10.1093/pcp/pcn029
Effects of Conditional IPT-Dependent Cytokinin Overproduction on Root Architecture of Arabidopsis Seedlings

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Cytokinin (CK) has been known to inhibit primary root elongation and suggested to act as an auxin antagonist in the regulation of lateral root (LR) formation. While the role of auxin in root development has been thoroughly studied, the detailed and overall description of CK effects on root system morphology, particularly that of developing lateral root primordia (LRPs), and hence its role in organogenesis is still in progress. Here we examine the effects of conditional endogenous CK overproduction on root architecture and consider its temporal aspect during the early development of Arabidopsis thaliana. We employed the pOp/LhGR system to induce ectopic ipt overexpression with a glucocorticoid dexamethasone at designated developmental points. The transient CaMV 35S>GR>ipt transactivation greatly enhanced levels of biologically active CKs of zeatin (Z)-type and identified a distinct developmental interval during which primary root elongation is susceptible to increases in endogenous CK production. Long-term CK overproduction inhibited primary root elongation by reducing quantitative parameters of primary root meristem, disturbed a characteristic graded distribution pattern of auxin response in LRPs and impaired their development. Our findings indicate the impact of perturbed endogenous CK on the regulation of asymmetric auxin distribution during LRP development and imply that there is cross-talk between auxin and CK during organogenesis in A. thaliana.

Keywords: Arabidopsis thaliana; Auxin–cytokinin cross-talk; CaMV 35S>GR>ipt transactivation; DR5 activity; Endogenous cytokinin; Root development

Journal Article.  8597 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.