title: A transcriptional repressor of the ERF family confers drought tolerance to rice and regulates genes preferentially located on chromosome 11.
abstract: Plant-specific ethylene response factors (ERFs) play important roles in abiotic and biotic stress responses in plants. Using a transgenic approach, we identified two rice ERF genes, OsERF4a and OsERF10a, which conferred drought stress tolerance. In particular, OsERF4a contains a conserved ERF-associated amphiphilic repression (EAR) motif in its C-terminal region that has been shown to function as a transcriptional repression domain. Expression profiling of transgenic rice plants over-expressing OsERF4a using either a constitutively active or an ABA-inducible promoter identified 45 down-regulated and 79 up-regulated genes in common. The increased stress tolerance by over-expression of the EAR domain-containing protein OsERF4a could result from suppression of a repressor of the defense response. Expression of the putative silent information regulator 2 (Sir2) repressor protein was repressed, and expression of several stress-response genes were induced by OsERF4a over-expression. The Sir2 and 7 out of 9 genes that were down-regulated by OsERF4a over-expression were induced by high salinity and drought treatments in non-transgenic control plants. Genes that were down- and up-regulated by OsERF4a over-expression were highly biased toward chromosome 11. Rice chromosome 11 has several large clusters of disease-resistance and defense-response genes. Taken together, our results suggest that OsERF4a is a positive regulator of shoot growth and water-stress tolerance in rice during early growth stages. We propose that OsERF4a could work by suppressing a repressor of the defense responses and/or by controlling the expression of a large number of genes located on chromosome 11.
authors.affiliation: Division of Bioscience and Bioinformatics, Myongji University, Yongin 449-728, Korea.
authors.forename: Joungsu
authors.initials: J
authors.lastname: Joo
authors.forename: Hae Jong
authors.initials: HJ
authors.lastname: Choi
authors.forename: Youn Hab
authors.initials: YH
authors.lastname: Lee
authors.forename: Yeon-Ki
authors.initials: YK
authors.lastname: Kim
authors.forename: Sang Ik
authors.initials: SI
authors.lastname: Song
mesh_terms: D032461:Chromosomes, Plant; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D005810:Multigene Family; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D010940:Plant Proteins; D012097:Repressor Proteins