Transcript profiling of local and adjacent leaf responses in barley following inoculation with Pseudomonas syringae

Transcriptional changes were monitored in the barley cultivar Golden Promise 24 hours post inoculation (hpi) with the bacteria Pseudomonas syringae pv. tomato DC3000 avrRpm1 (PstavrRpm1) using the Affymetrix Barley genome array GeneChip. Seedlings of Golden Promise were grown to growth stage 12-13 (Zadoks et al., 1974) before inoculating with either PstavrRpm1 or water (for the mock inoculation control) by infiltration. Plants were grown under a 18 C / 16 h light period; 12 C / 8 h dark period, with artificial lighting (100 mol m-2 s-1) and a relative humidity of 75 85 %. Leaf samples from three seedlings were collected 24 hpi for RNA extraction and transcriptomics analysis from the area infiltrated (local) and from the area next to the infiltrated region (adjacent) from three biological replicates. Leaf tissue was ground under liquid nitrogen and total RNA extracted using the RNeasy miniprep kit (Qiagen), following the manufacturers instructions. RNA was DNase treated using Turbo DNase (Ambion) according to the manufacturer instructions. RNA integrity was confirmed using the Agilent 2100 Bioanalyzer (Agilent). The two cycle-target labeling method was used following the Affymetrix protocol. Affymetrix GeneChip processing, including RNA quality control, microarray hybridisation and data acquisition was performed through contract research services by Cogenics (North Carolina, U.S.A.). A total of twelve hybridisations were performed. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Ellen Colebrook. The equivalent experiment is BB92 at PLEXdb.]

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Colebrook EH, Creissen G, McGrann GR, Dreos R, Lamb C, Boyd LA