1. A genome-wide survey of HD-Zip genes in rice and analysis of drought-responsive family members
- Author
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Agalou, A., Purwantomo, S., Övernäs, E., Johannesson, H., Zhu, X., Estiati, A., Kam, R.J.de, Engström, P., Slamet-Loedin, I.H., Zhu, Z., Wang, M., Xiong, L., Meijer, A.H., Ouwerkerk, P.B.F., and TNO Kwaliteit van Leven
- Subjects
Dicotyledoneae ,Natural Disasters ,Arabidopsis ,expressed sequence tag ,Crops ,Oryza sativa ,phylogeny ,Plants (botany) ,reverse transcription polymerase chain reaction ,Transcription factors ,Homeobox ,genetics ,Elongation ,genome ,chromosome map ,Expressed Sequence Tags ,Drought ,Seed ,Reverse Transcriptase Polymerase Chain Reaction ,rice ,fungi ,article ,Genes, Homeobox ,food and beverages ,Chromosome Mapping ,Eukaryota ,Homeodomain-leucine zipper ,Genes ,disaster ,human activities ,Genome, Plant - Abstract
The homeodomain leucine zipper (HD-Zip) genes encode transcription factors that have diverse functions in plant development and have often been implicated in stress adaptation. The HD-Zip genes are the most abundant group of homeobox (HB) genes in plants and do not occur in other eukaryotes. This paper describes the complete annotation of the HD-Zip families I, II and III from rice and compares these gene families with Arabidopsis in a phylogeny reconstruction. Orthologous pairs of rice and Arabidopsis HD-Zip genes were predicted based on neighbour joining and maximum parsimony (MP) trees with support of conserved intron-exon organization. Additionally, a number of HD-Zip genes appeared to be unique to rice. Searching of EST and cDNA databases and expression analysis using RT-PCR showed that 30 out of 31 predicted rice HD-Zip genes are expressed. Most HD-Zip genes were broadly expressed in mature plants and seedlings, but others showed more organ specific patterns. Like in Arabidopsis and other dicots, a subset of the rice HD-Zip I and II genes was found to be regulated by drought stress. We identified both drought-induced and drought-repressed HD-Zip genes and demonstrate that these genes are differentially regulated in drought-sensitive versus drought-tolerant rice cultivars. The drought-repressed HD-Zip family I gene, Oshox4, was selected for promoter-GUS analysis, showing that drought-responsiveness of Oshox4 is controlled by the promoter and that Oshox4 expression is predominantly vascular-specific. Loss-of-function analysis of Oshox4 revealed no specific phenotype, but overexpression analysis suggested a role for Oshox4 in elongation and maturation processes. © 2007 The Author(s).
- Published
- 2008