Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

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Long-term growth under elevated CO2 differentially suppresses biotic stress genes in non-acclimated versus cold-acclimated winter wheat

ABSTRACT: This study compared the photosynthetic performance and the global gene expression of the winter hardy wheat Triticum aestivum cv Norstar grown under non-acclimated (NA) or cold-acclimated (CA) condition at either ambient CO2 or elevated CO2 (EC). CA Norstar maintained comparable light saturated and CO2 saturated rates of photosynthesis but lower quantum requirements for photosystem II and non photochemical quenching relative to NA plants even at EC. Neither NA nor CA plants were sensitive to feedback inhibition of photosynthesis at EC. Global gene expression using microarray combined with bioinformatics analysis revealed that genes affected by EC were 3 times higher in NA (1022 genes) compared to CA (372 genes) Norstar. The most striking effect was the down-regulation of genes involved in the plant defense responses in NA Norstar. In contrast, cold acclimation reversed this down regulation due to the cold induction of genes involved in plant pathogenesis resistance, and cellular and chloroplast protection. These results suggest that EC have less impact on plant performance and productivity in cold adapted winter hardy plants in the northern climates compared to warmer environments. Selection for cereal cultivars with constitutively higher expression of biotic stress defense genes may be necessary under EC during the warm growth period and in warmer climates. Twelve replicate pots with 3 plants per pot were grown at either NA or CA conditions at either ambient or EC. To minimize any possible chamber effects, the 12 replicate pots at each growth condition were distributed between two growth chambers. A total of 3 biological replicates for each condition were used for microarray analyses. Each biological replicate sample was obtained by pooling three whole fully expanded 3rd leaves from different plants harvested randomly. The different biological samples of Norstar winter wheat leaves were ground in dry ice to fine powder and total RNA was extracted with trizol (Invitrogen, Burlington, ON, CA). Total RNA was cleaned using RNeasy plant mini kit (Qiagen) and integrity was determined on agarose gel and on a bioanalyser (Agilent 2100). Synthesized cDNAs were transcribed to cRNAs with the 3M-bM-^@M-^YIVT labelling kit (Santa Clara, CA, USA) and hybridized to the Affymetrix wheat genome array (Santa Clara, Ca, USA) at the McGill University and GM-CM-)nome QuM-CM-)bec Innovation Centre (Montreal, Qc, CA). The experimental design consisted of three biological replicates for each of the four growth conditions, 1: Non-acclimated (NA) at ambient CO2 (AC) (NAAC); 2: Cold-acclimated (CA) at ambient CO2 (AC) (CAAC); 3: Non-acclimated (NA) at elevated CO2 (EC) (NAEC); 4: Cold-acclimated (CA) at elevated CO2 (EC) (CAEC). Thus, a total of 3 biological samples from each of the 4 growth conditions described above were used for hybridizations.

ORGANISM(S): Triticum aestivum

SUBMITTER: Khalil kane

PROVIDER: E-GEOD-48620 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Long-term growth under elevated CO2 differentially suppresses biotic stress genes in non-acclimated versus cold-acclimated winter wheat

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