NASCArrays Information at The BAR

Welcome to NASCArrays information at the BAR. This page hosts meta-information from the NASCArrays service (2002-2013). This information was parsed from text files available on the NASCArrays site. NASCArrays data is on iPlant server. To download experiment data from iPlant, please click on the experiment number. To download the CEL files, please click on the ftp link.

Experiment:84
Title:Carbohydrate- and redox-regulation of gene expression in a TPT mutant
Date:2003-10-27
Description:The triose-phosphate/phosphate translocator (TPT) of the chloroplast inner envelope membrane mediates the counter-exchange of stromal triose phosphates derived from CO2 fixation with cytosolic phosphate, thus providing the cytosol with precursors for sucrose synthesis. We have isolated an Arabidopsis mutant (tpt-1) in which the gene encoding TPT is disrupted by a T-DNA insertion. During growth in low light tpt-1 plants are phenotypically normal, but in high light photosynthesis is inhibited and growth is retarded relative to wildtype. This mutant compensates for the absence of TPT by diverting photosynthate into starch which is hydrolysed and exported from the chloroplast as glucose that is subsequently phosphorylated by hexokinase. In low light the capacity of the pathway of starch synthesis is sufficient to accommodate the normal rate of CO2 fixation, but in high light it is unable to match the potential rate of CO2 fixation. Consequently, in high light-grown plants there are measurable effects on the redoxstate of several components. Thus, the tpt-1 mutation influences the carbohydrate status within the cell, alters the form in which carbon is received by the cytosol, and changes the redox signals that are important in photosynthetic acclimation.Method: Plants will be grown in a 8h light:16h dark regime at both 400 and 100 ┬Ámol PAR m-2 s-1. Total RNA will be extracted from pools of individual illuminated leaves from at least eight plants at growth stage 3.70. Leaves will be harvested 2 h into the photoperiod to maximise differences between plant lines in the expression of genes of photosynthesis and carbohydrate metabolism. We anticipate that expression of many genes will be affected by the absence of TPT and by changes in light intensity. However, by comparing differences in transcript levels between wildtype and TPT mutant grown in high light with the differences that occur in plants grown in low light we will discriminate between genes whose expression is affected by changes in the pattern of carbohydrate metabolism and those influenced by redox poise of the thylakoid photochemical components. These comparisons will also highlight genes affected by recently identified regulatory interactions between sugar-sensing and redox-sensing. A genome-wide expression study will establish the extent to which gene expression is altered by the absence of TPT in leaves, and will provide the basis for more detailed analysis of a selected range of transcripts whose levels of expression differ between plant lines.
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Slide Information:
Slide IDSlide NameGenetic BackgroundTissueStock CodeCel File
Walters_A-01_WL1_Rep1_ATH1707unshaded mature rosette leaves N1601Walters_A-01_WL1_Rep1_ATH1.cel
Walters_A-02_WL2_Rep2_ATH1708unshaded mature rosette leaves N1601Walters_A-02_WL2_Rep2_ATH1.cel
Walters_A-03_WL3_Rep3_ATH1709unshaded mature rosette leaves N1601Walters_A-03_WL3_Rep3_ATH1.cel
Walters_A-04_WH1_Rep1_ATH1710unshaded mature rosette leaves N1601Walters_A-04_WH1_Rep1_ATH1.cel
Walters_A-05_WH2_Rep2_ATH1711unshaded mature rosette leaves N1601Walters_A-05_WH2_Rep2_ATH1.cel
Walters_A-06_WH3_Rep3_ATH1712unshaded mature rosette leaves N1601Walters_A-06_WH3_Rep3_ATH1.cel
Walters_A-07_ML1_Rep1_ATH1713Ws-2unshaded mature rosette leaves Walters_A-07_ML1_Rep1_ATH1.cel
Walters_A-08_ML2_Rep2_ATH1714Ws-2unshaded mature rosette leaves Walters_A-08_ML2_Rep2_ATH1.cel
Walters_A-09_ML3_Rep3_ATH1715Ws-2unshaded mature rosette leaves Walters_A-09_ML3_Rep3_ATH1.cel
Walters_A-10_MH1_Rep1_ATH1749Ws-2unshaded mature rosette leaves Walters_A-10_MH1_Rep1_ATH1.cel
Walters_A-11_MH2_Rep2_ATH1750Ws-2unshaded mature rosette leaves Walters_A-11_MH2_Rep2_ATH1.cel
Walters_A-12_MH3_Rep3_ATH1751Ws-2unshaded mature rosette leaves Walters_A-12_MH3_Rep3_ATH1.cel