Transcription profiling of wheat near-isogenic lines in response to aluminium stress to identify genes and pathways associated with aluminum stress and tolerance

ABSTRACT: Two winter wheat cultivars possessing a high tolerance to Al (Triticum aestivum L. cv. Atlas66 and the near isogenic line OK91G106, named Century-T in this work [59]) and two winter wheat cultivars with low tolerance to Al (T. aestivum L. cv. Bounty and the near isogenic line OK91G108, named Century-S in this work [59]) were grown as previously described, and treated under conditions where Al remains mostly under the Al3+ form [10]. To reduce pH variations and ensure that Al speciation was stable throughout the experiment, at least 100 ml of solution was used for each plant. The root growth inhibition (RGI) is expressed as 100 × [1- (root growth of Al-treated seedling divided by the root growth of control seedlings)]. Root tips (5-10 mm) were isolated after 24 hours of exposure to Al and frozen on dry ice. Total RNA was isolated from the root tips (5 mm long) of 50 plants collected from the various genotypes using the RNeasy Plant Mini Kit (Qiagen). The RNA quality was assessed on agarose gels and with the Bioanalyzer 2100 (Agilent). Microarray profiling was performed according to Affymetrix protocols at the Functional Genomics Platform of the McGill University and Génome Québec Innovation Centre using the Affymetrix GeneChip Wheat Genome Array. Plants of the different lines were treated with Al concentrations resulting in 50% RGI: 50 ?M for the tolerant cultivars Atlas66 and Century-T and 5 ?M for the sensitive cultivars Bounty and Century-S. Three biological replicates were used and the results were analyzed using the Robust Multiarray Analysis (RMA version 0.2) freeware. Atlas66 and Bounty plants not exposed to Al were used as control for all the other conditions. Genes showing a differential expression greater than two-fold (RMA differential expression of log2 ? 1) between the Atlas66 and Bounty controls were excluded from the reference set as these may represent cultivar dependent differences in basal expression levels that could bias the analysis. Overall, this excluded 1.26% of the genes on the microarray (773 of 55,052) demonstrating that most genes are expressed at a similar level between the two cultivars. The microarray headings are the following : For each array headings: The first term represents the cultivar: A = Atlas66; B = Bounty, 106 = Century-T, 108 = Century-S. The second twerm represents the Al concentration: 0 = no aluminum 5 = 5 ?M aluminum and 50 = 50 ?M aluminum. The last term represents the sample replicate number S1, S2 or S3.

ORGANISM(S): Triticum aestivum

SUBMITTER: Mario Houde 

PROVIDER: E-TABM-454 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress