DNA microarray analysis of plastid gene expression in an Arabidopsis mutant deficient in a plastid transcription factor sigma, SIG2.
The plastid genome of higher plants contains more than one hundred genes for photosynthesis, gene expression, and other processes. Plastid transcription is done by two types of RNA polymerase, PEP and NEP. PEP is a eubacteria-type RNA polymerase that is essential for chloroplast development. In Arabidopsis thaliana, six sigma factors (SIG1-6) are encoded by the nuclear genome, and postulated to determine the transcription specificity of PEP. In this study, we constructed a DNA microarray for all of the plastid protein-coding genes, and analyzed the effects of the sig2 lesion on the global plastid gene expression. Of the 79 plastid protein genes, it was found that only the psaJ transcript was decreased in the mutant, whereas transcripts of 47 genes were rather increased. Since many of the up-regulated genes are under the control of NEP, it was suggested that the NEP activity was increased in the sig2-1 mutant.
Nagashima
Akitomo
A
Laboratory of Molecular Genetics, Department of Molecular Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan.
Hanaoka
Mitsumasa
M
Motohashi
Reiko
R
Seki
Motoaki
M
Shinozaki
Kazuo
K
Kanamaru
Kengo
K
Takahashi
Hideo
H
Tanaka
Kan
K
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D018087:Plastids / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D015854:Up-Regulation
C413368:Sig2 sigma factor; D012808:Sigma Factor; D014157:Transcription Factors