Skip Navigation


AOBPreview originally published online on January 16, 2009
Annals of Botany 2009 103(5):807-817; doi:10.1093/aob/mcn267
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
103/5/807    most recent
mcn267v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in Ann Bot
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Dubrovsky, J. G.
Right arrow Articles by Ivanchenko, M. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dubrovsky, J. G.
Right arrow Articles by Ivanchenko, M. G.
Agricola
Right arrow Articles by Dubrovsky, J. G.
Right arrow Articles by Ivanchenko, M. G.
Related Collections
Right arrow Arabidopsis
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© The Author 2009. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

The lateral root initiation index: an integrative measure of primordium formation

J. G. Dubrovsky1,*, A. Soukup1,{dagger}, S. Napsucialy-Mendivil1, Z. Jeknic2 and M. G. Ivanchenko3

1 Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), A. P. 510-3, 62250 Cuernavaca, Morelos, Mexico
2 Department of Horticulture, ALS 4017, Oregon State University, Corvallis, OR 97331, USA
3 Department of Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, OR 97331, USA

* For correspondence. E-mail jdubrov{at}ibt.unam.mx

Received: 15 September 2008    Returned for revision: 20 October 2008    Accepted: 26 November 2008    Published electronically: 16 January 2009

Background and Aims: Lateral root initiation is an essential and continuous process in the formation of root systems; therefore, its quantitative analysis is indispensable. In this study a new measure of lateral root initiation is proposed and analysed, namely the lateral root initiation index (ILRI), which defines how many lateral roots and/or primordia are formed along a parent-root portion corresponding to 100 cortical cells in a file.

Methods: For data collection, a commonly used root clearing procedure was employed, and a new simple root clearing procedure is also proposed. The ILRI was determined as 100dl, where d is the density of lateral root initiation events (number mm–1) and l is the average fully elongated cortical cell length (mm).

Key Results: Analyses of different Arabidopsis thaliana genotypes and of a crop plant, tomato (Solanum lycopersicum), showed that ILRI is a more precise parameter than others commonly used as it normalizes root growth for variations in cell length. Lateral root primordium density varied in the A. thaliana accessions Col, Ler, Ws, and C24; however, in all accessions except Ws, ILRI was similar under the same growth conditions. The nitrogen/carbon ratio in the growth medium did not change the lateral root primordium density but did affect ILRI. The ILRI was also modified in a number of auxin-related mutants, revealing new root branching phenotypes in some of these mutants. The rate of lateral root initiation increased with Arabidopsis seedling age; however, ILRI was not changed in plants between 8 and 14 d post-germination.

Conclusions: The ILRI allows for a more precise comparison of lateral root initiation under different growth conditions, treatments, genotypes and plant species than other comparable methods.

Key words: Arabidopsis thaliana, auxin, lateral root density, lateral root initiation index, mutant phenotype, pericycle, root architecture, root branching, root primordium, Solanum lycopersicum

{dagger} Present address: Department of Plant Physiology, Faculty of Science, Charles University in Prague, Vinicna 5, 128 44 Prague 2, Czech Republic.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?

Related articles in Ann Bot:

ContentSnapshots

Ann Bot 2009 103: i. [Extract] [Full Text]  





Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.