Genetics of microenvironmental canalization in Arabidopsis thaliana

Megan C. Hall; Ian Dworkin; Mark C. Ungerer; Michael Purugganan

doi:10.1073/pnas.0701936104

Edited by Douglas J. Futuyma, State University of New York, Stony Brook, NY, and approved July 16, 2007 (received for review March 2, 2007)

Abstract

Canalization is a fundamental feature of many developmental systems, yet the genetic basis for this property remains elusive. We examine the genetic basis of microenvironmental canalization in the model plant Arabidopsis thaliana, focusing on differential developmental stability between genotypes in one fitness and four quantitative morphological traits. We measured developmental stability in genetically identical replicates of two populations of recombinant inbred (RI) lines and one population of geographically widespread accessions of A. thaliana grown in two different photoperiod-controlled environments. We were able to map quantitative trait loci associated with developmental stability. We also identified a candidate gene, ERECTA, that may contribute to microenvironmental canalization in rosette leaf number under long-day photoperiods, and analysis of mutant lines indicates that the er-105 allele results in increased canalization for this trait. ERECTA, which encodes a signaling protein, appears to act as an ecological amplifier by transducing developmental noise (e.g., microenvironmental variation) into phenotypic differentiation. We also measured genotypic selection on four plant architecture traits and find evidence for selection for both increased and decreased canalization at various traits.

Footnotes

^¶To whom correspondence should be addressed at:
Department of Biology, New York University, Room 1009, Silver Main Building, 100 Washington Square East, New York, NY 10003.
E-mail: mp132{at}nyu.edu
Author contributions: M.C.H. and M.P. designed research; M.C.H. and M.C.U. performed research; M.C.H. and I.D. analyzed data; and M.C.H., I.D., and M.P. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0701936104/DC1.
Abbreviations:
ER,
ERECTA;
LS,
Levene's statistic;
MCIM,
multitrait composite interval mapping;
QTL,
quantitative trait locus;
RI,
recombinant inbred.
© 2007 by The National Academy of Sciences of the USA