Transgenic study of parallelism in plant morphological evolution.
Developmental constraint is indicated when one finds that similar genetic mechanisms are responsible for independent origins of the same derived phenotype. We studied three independent origins of rosette flowering within the mustard family and attempted to evaluate the extent to which the same mechanisms were involved in each transition from the ancestral phenotype, inflorescence flowering. We used transformation to move a candidate gene, LFY, and its cis-regulatory sequences from rosette-flowering species into an inflorescence-flowering recipient, Arabidopsis thaliana, in place of its endogenous LFY gene. The transgenic phenotypes of experimental and control lines (containing an A. thaliana LFY transgene) and the expression driven by the cis-regulatory sequences show that changes at the LFY locus might have contributed to the evolution of rosette flowering in two of the three lineages. In the third case, changes upstream of LFY are implicated. Our data suggest that changes in a single developmental regulatory program were involved in multiple origins of the same derived trait but that the specific genetic changes were different in each case.
Yoon
Ho-Sung
HS
Department of Botany, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706, USA.
Baum
David A
DA
D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D017931:DNA Primers; D005966:Glucuronidase / Q000235:genetics; D007438:Introns; D008969:Molecular Sequence Data; D010641:Phenotype; D030821:Plants, Genetically Modified / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
D029681:Arabidopsis Proteins; D017931:DNA Primers; C074747:LFY protein, Arabidopsis; D014157:Transcription Factors; D005966:Glucuronidase