Project description:Recently, 2-aminoxy-3-phenylpropionic acid (L-AOPP) had been demonstrated to possess an inhibitory activity against IAA biosynthesis but the molecular basis of the action was unclear. To investigate the function of L-AOPP in relation to Auxin biosynthesis, we conducted microarray analysis.
Project description:Recently, 2-aminoxy-3-phenylpropionic acid (L-AOPP) had been demonstrated to possess an inhibitory activity against IAA biosynthesis but the molecular basis of the action was unclear. To investigate the function of L-AOPP, we conducted microarray analysis using the shoot apical meristem (SAM) part of A. thaliana in addition to whole plants after the treatment of L-AOPP. We performed microarray analysis using the shoot apical meristem (SAM) part of A. thaliana (Columbia-0) to investigate function of 2-aminoxy-3-phenylpropionic acid (L-AOPP) in relation to inhibition of auxin biosynthesis. Total RNA was extracted from SAM part of 7-day-old seedlings grown on 1/2 MS medium containing L-AOPP (50 µM),L-AOPP (50 µM) + Indole-3-acetic acid (IAA 10 nM) or Dimethyl sulfoxide (DMSO 0.1%).
Project description:Recently, 2-aminoxy-3-phenylpropionic acid (L-AOPP) had been demonstrated to possess an inhibitory activity against IAA biosynthesis but the molecular basis of the action was unclear. To investigate the function of L-AOPP, we conducted microarray analysis using the shoot apical meristem (SAM) part of A. thaliana in addition to whole plants after the treatment of L-AOPP.
Project description:We found that auxin stimulates gene expression of DWF4, which encodes a rate-dertermining step in brassinosteroid biosynthesis pathways. This increased gene expressioin subsequently led to elevation of the biosynthetic flux in Arabidopsis roots. To determine the list of genes that are regulated by auxin-synthesizing brassinosteroids, we challenged Arabidopsis seedlings with either auxin only or auxin plus brassinosteroid biosynthetic inhibitor brassinazole. Keywords: Hormone treatment
Project description:This is the single cell model for analysis of hormonal crosstalk in Arabidopsis described in the article:
Modelling and experimental analysis of hormonal crosstalk in Arabidopsis.
Liu J, Mehdi S, Topping J, Tarkowski P and Lindsey K. Mol Syst Biol. 2010 Jun 8;6:373; PmID: 20531403
, DOI: 10.1038/msb.2010.26
Abstract:
An important question in plant biology is how genes influence the crosstalk between hormones to regulate growth. In this study, we model POLARIS (PLS) gene function and crosstalk between auxin, ethylene and cytokinin in Arabidopsis. Experimental evidence suggests that PLS acts on or close to the ethylene receptor ETR1, and a mathematical model describing possible PLS-ethylene pathway interactions is developed, and used to make quantitative predictions about PLS-hormone interactions. Modelling correctly predicts experimental results for the effect of the pls gene mutation on endogenous cytokinin concentration. Modelling also reveals a role for PLS in auxin biosynthesis in addition to a role in auxin transport. The model reproduces available mutants, and with new experimental data provides new insights into how PLS regulates auxin concentration, by controlling the relative contribution of auxin transport and biosynthesis and by integrating auxin, ethylene and cytokinin signalling. Modelling further reveals that a bell-shaped dose-response relationship between endogenous auxin and root length is established via PLS. This combined modelling and experimental analysis provides new insights into the integration of hormonal signals in plants.
This model was originally created using Copasi and taken from the supplementary materials of the MSB article. It uses equation 5 for the auxin biosynthesis and was altered to also contain the reactions for ACC, IAA and cytokinine import. Different from the supplementary material, the parameters for the auxin synthesis, v2, are set to k2c = 0.01 uM and k2=0.2 uM_per_sec and for the WT PLS transcription k6=0.3 . To obtain the model described in the first table of the supplementary materials, set k2c=k2=0 and k6=0.9 . For the pls and PLSox mutants, k6 should be set to 0 and 0.45, respectively.
This model originates from BioModels Database: A Database of Annotated Published Models. It is copyright (c) 2005-2010 The BioModels Team.
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To cite BioModels Database, please use Le Novère N., Bornstein B., Broicher A., Courtot M., Donizelli M., Dharuri H., Li L., Sauro H., Schilstra M., Shapiro B., Snoep J.L., Hucka M. (2006) BioModels Database: A Free, Centralized Database of Curated, Published, Quantitative Kinetic Models of Biochemical and Cellular Systems Nucleic Acids Res., 34: D689-D691.
Project description:To better understand the role of phenylpropanoid pathway perturbation in plant metabolism, Populus tremuloides cell cultures previously established from leaf mesophyll tissue were fed with methyl jasmonate, alpha-aminooxy-beta-phenylpropionic acid (AOPP), or both approximately 5 days after transfer to fresh medium. Methyl jasmonate is an elicitor that activates a suite of defense responses including phenylpropanoid metabolism. In contrast, AOPP acts as an inhibitor of phenylalanine ammonia lyase (PAL). Samples were harvested 48 hrs after initiation of the experiment. Total RNA was extracted and gene expression measured using Affymetrix poplar genome microarrays.
Project description:We used a next-generation sequencing approach, Illumina Digital Gene Expression (DGE) technology, to Genome-wide profiling of gene expression during cotton SE. As a result, 5,076 differentially expressed genes were identified during cotton SE. Expression profile and functional assignments of these genes indicated significant transcriptional complexity during this process. Transcription factor-encoding genes were found to be differentially regulated during SE. The complex pathways of auxin abundance, transport and response with differentially regulated genes revealed that the auxin-related transcripts belonged to IAA biosynthesis, indole-3-butyric acid (IBA) metabolism, IAA conjugate metabolism, auxin transport, auxin-responsive protein / indoleacetic acid-induced protein (Aux/IAA), auxin response factor (ARF), small auxin-up RNA (SAUR), Aux/IAA degradation, and other auxin-related proteins, which allow an intricate system of auxin utilization to achieve multiple purposes in SE. Quantitative real-time PCR (qRT-PCR) was performed on selected genes with different expression patterns and functional assignments were made to demonstrate the utility of RNA-Seq for gene expression profiles during cotton SE. We report here the first comprehensive analysis of transcriptome dynamics that may serve as a gene expression profile blueprint in cotton SE. Our main goal was to adapt the RNA-Seq technology to this notable development process and to analyse the gene expression profile. Complex auxin signalling pathway and transcription regulation were highlighted. Together with biochemical and histological approaches, this study provides comprehensive gene expression data sets for cotton SE that serve as an important platform resource for further functional studies in plant embryogenesis. differential gene expression analysis at 9 time-points/stages during somatic embryogenesis in cotton by deep sequencing, using Illumina GAIIx.