Originally published as Genetics Published Articles Ahead of Print on September 12, 2005.

Genetics, Vol. 172, 485-498, January 2006, Copyright © 2006
doi:10.1534/genetics.105.047555

Identification of Quantitative Trait Loci That Regulate Arabidopsis Root System Size and Plasticity

Jonathan N. Fitz Gerald1,2, Melissa D. Lehti-Shiu2, Paul A. Ingram, Karen I. Deak, Theresa Biesiada and Jocelyn E. Malamy3

Molecular Genetics and Cell Biology Department, The University of Chicago, Chicago, Illinois 60637

3 Corresponding author: Room 209, Erman Biology Center, University of Chicago, 1103 E. 57th St., Chicago, IL 60637.
E-mail: jmalamy{at}bsd.uchicago.edu

Root system size (RSS) is a complex trait that is greatly influenced by environmental cues. Hence, both intrinsic developmental pathways and environmental-response pathways contribute to RSS. To assess the natural variation in both types of pathways, we examined the root systems of the closely related Arabidopsis ecotypes Landsberg erecta (Ler) and Columbia (Col) grown under mild osmotic stress conditions. We found that Ler initiates more lateral root primordia, produces lateral roots from a higher percentage of these primordia, and has an overall larger root system than Col under these conditions. Furthermore, although each of these parameters is reduced by osmotic stress in both ecotypes, Ler shows a decreased sensitivity to osmotica. To understand the genetic basis for these differences, QTL for RSS under mild osmotic stress were mapped in a Ler x Col recombinant inbred population. Two robust quantitative trait loci (QTL) were identified and confirmed in near-isogenic lines (NILs). The NILs also allowed us to define distinct physiological roles for the gene(s) at each locus. This study provides insight into the genetic and physiological complexity that determines RSS and begins to dissect the molecular basis for naturally occurring differences in morphology and developmental plasticity in the root system.




This article has been cited by other articles:


Home page
 Plant CellHome page
C. Alonso-Blanco, M. G.M. Aarts, L. Bentsink, J. J.B. Keurentjes, M. Reymond, D. Vreugdenhil, and M. Koornneef
What Has Natural Variation Taught Us about Plant Development, Physiology, and Adaptation?
PLANT CELL, July 1, 2009; 21(7): 1877 - 1896.
[Abstract] [Full Text] [PDF]

Home page
 Plant Physiol.Home page
M. J. van der Merwe, S. Osorio, T. Moritz, A. Nunes-Nesi, and A. R. Fernie
Decreased Mitochondrial Activities of Malate Dehydrogenase and Fumarase in Tomato Lead to Altered Root Growth and Architecture via Diverse Mechanisms
Plant Physiology, February 1, 2009; 149(2): 653 - 669.
[Abstract] [Full Text] [PDF]

Home page
 Plant Physiol.Home page
N. C. Collins, F. Tardieu, and R. Tuberosa
Quantitative Trait Loci and Crop Performance under Abiotic Stress: Where Do We Stand?
Plant Physiology, June 1, 2008; 147(2): 469 - 486.
[Full Text] [PDF]

Home page
 jashsHome page
A. Fita, B. Pico, A. J. Monforte, and F. Nuez
Genetics of Root System Architecture Using Near-isogenic Lines of Melon
J. Amer. Soc. Hort. Sci., May 1, 2008; 133(3): 448 - 458.
[Abstract] [Full Text] [PDF]

Home page
 J HeredHome page
O. Torjek, R. C. Meyer, M. Zehnsdorf, M. Teltow, G. Strompen, H. Witucka-Wall, A. Blacha, and T. Altmann
Construction and Analysis of 2 Reciprocal Arabidopsis Introgression Line Populations
J. Hered., February 28, 2008; (2008) esn014v1.
[Abstract] [Full Text] [PDF]

Home page
 Phil Trans R Soc BHome page
J.I.L Morison, N.R Baker, P.M Mullineaux, and W.J Davies
Improving water use in crop production
Phil Trans R Soc B, February 12, 2008; 363(1491): 639 - 658.
[Abstract] [Full Text] [PDF]