title: Conservation and divergence of light-regulated genome expression patterns during seedling development in rice and Arabidopsis.
abstract: Genome-wide 70-mer oligonucleotide microarrays of rice (Oryza sativa) and Arabidopsis thaliana were used to profile genome expression changes during light-regulated seedling development. We estimate that the expression of approximately 20% of the genome in both rice and Arabidopsis seedlings is regulated by white light. Qualitatively similar expression profiles from seedlings grown under different light qualities were observed in both species; however, a quantitatively weaker effect on genome expression was observed in rice. Most metabolic pathways exhibited qualitatively similar light regulation in both species with a few species-specific differences. Global comparison of expression profiles between rice and Arabidopsis reciprocal best-matched gene pairs revealed a higher correlation of genome expression patterns in constant light than in darkness, suggesting that the genome expression profile of photomorphogenesis is more conserved. Transcription factor gene expression under constant light exposure was poorly conserved between the two species, implying a faster-evolving rate of transcription factor gene expression in light-grown plants. Organ-specific expression profiles during seedling photomorphogenesis provide genome-level evidence for divergent light effects in different higher plant organs. Finally, overrepresentation of specific promoter motifs in root- and leaf-specific light-regulated genes in both species suggests that these cis-elements are important for gene expression responses to light.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Conecticut 06520-8014, USA.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Jiao
authors.forename: Ligeng
authors.initials: L
authors.lastname: Ma
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Strickland
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D018744:DNA, Plant; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D018745:Genome, Plant; D008027:Light; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D036226:Seedlings / Q000235:genetics*; D013045:Species Specificity
chemical_list: D018744:DNA, Plant