Poster: Late and Moved Abstracts
Abs #
1022: Microarray analysis of drought responsive genes in barley
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Presenter: |
Rodriguez, Edmundo M, edmundo.rodriguez@ucr.edu |
Authors | Rodriguez, Edmundo M (A) Jan, Svensson T (A) Close, Timothy J (A) | | Affiliations: |
(A): University of California, Riverside
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Plant gene expression during water stress has been often studied, but mostly using osmotic shock or rapid dehydration treatments. However, drought usually involves a gradual development of water deficit. In this study, we performed global gene expression profiling of barley seedlings exposed to drought stress in soil. Crown tissue was collected at soil water content values ranging from 95 % to 7% over a treatment period of 21 days. During this treatment, leaf relative water content gradually declined from a well-watered level of 95 % to a water-deficit level of 45 %. RNA was extracted from samples taken throughout the stress treatment and expression profiling was performed using the Affymetrix “Barley1” GeneChip (Close et al. 2004). A total of 15,844 probe sets of 22,800 on the array were called “present” in all three replicates for at least one treatment point. Among these, 39% had significantly different expression values between treatment points. However, only 700 probe sets detected transcripts increasing at least three-fold and only 770 detected three-fold down-regulated transcripts. Annotation of barley probe sets using closely related genes of rice and Arabidopsis allowed us to take advantage of gene ontology tools available for these model plants. Barley drought-induced genes had a significant over-representation of three biological process categories: embryonic development, response to stress and carbohydrate metabolism. Promoter analysis of closely related rice genes revealed the presence of known water stress response cis elements such as DRE, ABRE, MYC and MYB, and apparently novel drought responsive elements that have significantly over-representation in putative promoter sequences of rice genes related to barley drought-induced genes.
