| Abstract Detail
Oxidative Stress Hunt, Arthur [1], Zhang, Jingxian [2], Addepalli, Balasubramanyam [3], Yun, Kil-Young [4], Artiushin, Irina [2], Rao, Suryadevara [3], Xu, Ruqiang [5], Li, Quinn [5], Falcone, Deane [4]. The Arabidopsis polyadenylation factor subunit CPSF30 is implicated in responses to oxidative stress. A common response of plants to a range of unfavorable environmental conditions is the onset of oxidative stress. To gain further insight into oxidative stress responses, Arabidopsis mutants that exhibit enhanced tolerance to oxidative stress were isolated. One such mutant, oxt6, is due to the disruption of a complex gene (At1g30460) that encodes the Arabidopsis ortholog of the 30 kD subunit of the cleavage and polyadenylation specificity factor (AtCPSF30) as well as a larger, related 65 kD protein. Expression of mRNAs encoding AtCPSF30 was able to restore wild-type growth and stress susceptibility to the oxt6 mutant. Bulk poly(A) tail length was not affected in the oxt6 mutant, indicating that global polyadenylation of mRNAs was not reduced in the mutant. However, poly(A) site selection in specific genes was different. These observations implicate AtCPSF30 in the process of poly(A) site selection. Transcriptional profiling using microarrays and single gene expression studies suggest that stress tolerance in the oxt6 mutant is due to elevated constitutive expression of a subset of genes that encode proteins containing thioredoxin- and glutaredoxin- related domains. This molecular phenotype is similar to those seen in other systems in which protein folding is altered, and provides a conceptual link between the polyadenylation “phenotype” of the mutant and the stress tolerance. Together with earlier studies showing that calmodulin regulates the activity of AtCPSF30 in vitro (Delaney et al., Plant Physiol. 140,1507-1521, 2006), these results implicate the Arabidopsis CPSF30 in the posttranscriptional control of the responses of plants to stress, and in particular to the expression of a set of genes that suffices to confer tolerance to oxidative stress.
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1 - University of Kentucky, Department of Plant and Soil Sciences, 301A Plant Science Building, Lexington, KY, 40546-0312, USA
2 - Kentucky Tobacco Research and Development Center
3 - University of Kentucky, Department of Plant and Soil Sciences
4 - University of Massachusetts Lowell, Department of Biological Sciences
5 - Miami University, Department of Botany
Keywords:
polyadenylation
posttranscriptional control
oxidative stress.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P06007
Abstract ID:322 |
