Microarray analyses of gene expression during adventitious root development in Pinus contorta.
In order to investigate the gene expression pattern during adventitious root development, RNA of Pinus contorta hypocotyls, pulse-treated with the auxin indole-3-butyric acid and harvested at distinct developmental time points of root development, was hybridized to microarrays containing 2,178 cDNAs from Pinus taeda. Over the period of observation of root development, the transcript levels of 220 genes changed significantly. During the root initiation phase, genes involved in cell replication and cell wall weakening and a transcript encoding a PINHEAD/ZWILLE-like protein were up-regulated, while genes related to auxin transport, photosynthesis, and cell wall synthesis were down-regulated. In addition, there were changes in transcript abundance of genes related to water stress. During the root meristem formation phase the transcript abundances of genes involved in auxin transport, auxin responsive transcription, and cell wall synthesis, and of a gene encoding a B-box zinc finger-like protein, increased, while those encoding proteins involved in cell wall weakening decreased. Changes of transcript abundance of genes related to water stress during the root meristem formation and root formation phase indicate that the plant roots had become functional in water transport. Simultaneously, genes involved in auxin transport were up-regulated, while genes related to cell wall modification were down-regulated. Finally, during the root elongation phase down-regulation of transcripts encoding proteins involved in cell replication and stress occurred. Based on the observed changes in transcript abundances, we suggest hypotheses about the relative importance of various physiological processes during the auxin-induced development of roots in P. contorta.
Brinker
Monika
M
Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden. mbrinker@gmx.de
van Zyl
Leonel
L
Liu
Wenbin
W
Craig
Deborah
D
Sederoff
Ronald R
RR
Clapham
David H
DH
von Arnold
Sara
S
D002455:Cell Division; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D028223:Pinus / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development; D016133:Polymerase Chain Reaction
D010940:Plant Proteins