ABSTRACT
Root development and its response to environmental changes is crucial for whole plant adaptation. These responses include changes in transcript levels. Here, we show that the alternative polyadenylation (APA) of mRNA is important for root development and responses. Mutations in FIP1, a component of polyadenylation machinery, affects plant development, cell division and elongation, and response to different abiotic stresses. Salt treatment increases the amount of poly(A) site usage within the coding region and 5' untranslated regions (5'-UTRs), and the lack of FIP1 activity reduces the poly(A) site usage within these non-canonical sites. Gene ontology analyses of transcripts displaying APA in response to salt show an enrichment in ABA signaling, and in the response to stresses such as salt or cadmium (Cd), among others. Root growth assays show that fip1-2 is more tolerant to salt but is hypersensitive to ABA or Cd. Our data indicate that FIP1-mediated alternative polyadenylation is important for plant development and stress responses.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Plant Roots/metabolism , Polyadenylation/genetics , Salt Stress/genetics , mRNA Cleavage and Polyadenylation Factors/metabolism , 5' Untranslated Regions , Abscisic Acid/metabolism , Alleles , Arabidopsis/drug effects , Arabidopsis/growth & development , Arabidopsis Proteins/genetics , Cadmium/toxicity , Cell Division/genetics , Gene Expression Regulation, Plant/genetics , Mutation , Phenotype , Plant Roots/cytology , Plant Roots/drug effects , Plant Roots/genetics , Polyadenylation/drug effects , Protein Biosynthesis/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , mRNA Cleavage and Polyadenylation Factors/geneticsABSTRACT
CDK-cyclin complexes are the universal drivers of cell cycle transitions. Progression through G(1) and transition to S-phase, thereby initiating genome duplication, requires the concerted action of cyclin-dependent kinase (CDK)-cyclin complexes on specific targets. These targets belong to at least two major regulatory networks: the retinoblastoma-related (RBR)/E2F pathway and complexes that are responsible for the initiation of DNA replication. The G(1) phase is central to the integration of signals that regulate both the exit from the cell division cycle to differentiation and the reactivation of cell proliferation. Cellular factors that are involved in these pathways play a role in regulating cell size and number, and organogenesis. As a consequence, they are also involved in determining plant architecture.
