Abstract
Eukaryotes usually have three polyA removal activities. It is not well known that they have distinct functions or not. In plants, disruption mutation of polyA specific ribonuclease causes lethality, indicating its importance in plant systems. However, its physiological role has not been elucidated. By analyzing the ABA hypersensitive germination2 mutants, we showed that the reduction of polyA specific ribonuclease activity causes multiple effects on the plant physiology including dwarf phenotype, higher accumulation of endogenous ABA in seeds and stressed plants, and constitutive activation of the SA response pathway. These results suggest that PARN is deeply involved in stress response. To address the molecular basis for AtPARN in hormone response, we are trying to identify the target genes by microarray experiments, or genetic approaches, eg. isolating suppressor mutants for ahg2-1. In this symposium, the results summarized and physiological role of PARN in plants will be discussed.
