Poster abstracts
Poster number 49 submitted by Guijie Hao
Alternative Polyadenylation as a Potential Mechanism Responding to Drought Stress in Arabidopsis thaliana
Guijie Hao (Deparment of Plant and Soil Sciences), Arthur G. Hunt (Deparment of Plant and Soil Sciences)
Abstract:
mRNA polyadenylation is an important step in eukaryotic gene expression. Polyadenylation impacts gene expression through determining the coding and regulation potential of the mRNA, especially the mRNAs of genes that may be polyandenylated at more than one position. Alternative polyadenylation (APA) has potential effect to gene regulation and function. In Arabidopsis, APA may be linked with stress responses through a polyadenylation complex subunit (CPSF30) that is inhibited by calmodulin and by disulfide remodeling. Calcium signaling (through calmodulin) and disulfide remodeling (through the generation of reactive oxygen species) are typically associated with various stress responses in plants, suggestive of a possible connection.
In order to explore this, a study was done to examine the effects that an artificial drought stress (triggered by growth of plants in mannitol) has on genome-wide poly (A) site choice. We treated wild type Arabidopsis with different concentrations of mannitol, for varying lengths of time. RNA was extracted after harvesting the whole seedlings and poly (A) tag libraries were prepared and sequenced on the Illumina platform. The sequence data was analyzed to assess gene expression and alternative polyadenylation. The gene expression analysis demonstrated genes from certain GO categories are up- or down- regulated by the simulated drought stress; these categories include responses to hormone stimulus, secondary metabolism, transmembrane transport, regulation of transcription, and protein phosphorylation. Moreover, the results showed that drought stress caused significant changes in the usage of poly (A) sites that lie within 5’-UTRs; specifically, the poly (A) site profiles for a number of genes were shifted to increased usage of sites within 5’ UTRs, site that would truncate the mRNA.
These results indicate that drought stress alters poly (A) site choice for many genes, and may play negative regulatory roles for genes that possess poly (A) sites that fall within 5’-UTRs. They also suggest that APA plays an important role in the responses of Arabidopsisto drought stress. Future studies will include 3’-RACE confirmation of selected genes, and comparisons of the effects of drought stress with other abiotic and biotic stress.
References:
1.Arthur G Hunt. The Arabidopsis polyadenylation factor subunit CPSF30 as conceptual link between mRNA polyadenylation and cellular signaling. Current Opinion in Plant Biology 2014, 21:128–132
2.Lutz CS, Moreira. Alternative mRNA polyadenylation in eukaryotes: an effective regulator of gene expression. Wiley Interdiscip Rev RNA. 2011 Jan-Feb; 2(1):23-31
3.Zhang J, Addepalli B, Yun KY, Hunt AG, Xu R, Rao S, Li QQ, Falcone DL. A polyadenylation factor subunit implicated in regulating oxidative signaling in Arabidopsis thaliana. PLoS One 2008, 3:e2410
Keywords: Alternative polyadenylation, drought stress, Arabidopsis thaliana