Prediction of transcriptional regulatory elements for plant hormone responses based on microarray data

<p>Abstract</p> <p>Background</p> <p>Phytohormones organize plant development and environmental adaptation through cell-to-cell signal transduction, and their action involves transcriptional activation. Recent international efforts to establish and maintain public databases of <it>Arabidopsis </it>microarray data have enabled the utilization of this data in the analysis of various phytohormone responses, providing genome-wide identification of promoters targeted by phytohormones.</p> <p>Results</p> <p>We utilized such microarray data for prediction of <it>cis</it>-regulatory elements with an octamer-based approach. Our test prediction of a drought-responsive RD29A promoter with the aid of microarray data for response to drought, ABA and overexpression of DREB1A, a key regulator of cold and drought response, provided reasonable results that fit with the experimentally identified regulatory elements. With this succession, we expanded the prediction to various phytohormone responses, including those for abscisic acid, auxin, cytokinin, ethylene, brassinosteroid, jasmonic acid, and salicylic acid, as well as for hydrogen peroxide, drought and DREB1A overexpression. Totally 622 promoters that are activated by phytohormones were subjected to the prediction. In addition, we have assigned putative functions to 53 octamers of the Regulatory Element Group (REG) that have been extracted as position-dependent <it>cis</it>-regulatory elements with the aid of their feature of preferential appearance in the promoter region.</p> <p>Conclusions</p> <p>Our prediction of <it>Arabidopsis cis</it>-regulatory elements for phytohormone responses provides guidance for experimental analysis of promoters to reveal the basis of the transcriptional network of phytohormone responses.</p

Identifying the target genes of SUPPRESSOR OF GAMMA RESPONSE 1, a master transcription factor controlling DNA damage response in Arabidopsis

In mammalian cells, the transcription factor p53 plays a crucial role in transmitting DNA damage signals to maintain genome integrity. However, in plants, orthologous genes for p53 and checkpoint proteins are absent. Instead, the plant-specific transcription factor SUPPRESSOR OF GAMMA RADIATION 1 (SOG1) controls most of the genes induced by gamma irradiation and promotes DNA repair, cell cycle arrest, and stem cell death. Thus far, the genes directly controlled by SOG1 remain largely unknown, limiting the understanding of DNA damage signaling in plants. Here, we conducted a microarray analysis and chromatin immunoprecipitation (ChIP)-sequencing, and identified 146 Arabidopsis genes as direct targets of SOG1. By using the ChIP-sequencing data, we extracted the palindromic motif [CTT(N)7AAG] as a consensus SOG1-binding sequence, which mediates target gene induction in response to DNA damage. Furthermore, DNA damage-triggered phosphorylation of SOG1 is required for efficient binding to SOG1-binding sequence. Comparison between SOG1 and p53 target genes showed that both transcription factors control genes responsible for cell cycle regulation, such as CDK inhibitors, and DNA repair proteins, whereas SOG1 preferentially targets genes involved in homologous recombination. We also found that defense-related genes were enriched in the SOG1 target genes. Consistent with this, SOG1 is required for resistance against the hemi-biotrophic fungus Colletotrichum higginsianum, suggesting that SOG1 has a unique function in controlling immune response. This article is protected by copyright. All rights reserved

Superplasticity of rapidly solidified 7475 aluminium alloys

55.00; Translated from Japanese (J. Jpn. Soc. Technol. Plast. 1986 v. 27(302) p. 415-421)SIGLEAvailable from British Library Document Supply Centre- DSC:9022.0602(BISI-NF-Trans--122)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Superplasticity of rapidly solidified 7475 aluminium alloys

55.00; Translated from Japanese (J. Jpn. Soc. Technol. Plast. 1986 v. 27(302) p. 415-421)SIGLEAvailable from British Library Document Supply Centre- DSC:9022.0602(BISI-NF-Trans--122)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo