title: Oligouridylate Binding Protein 1b Plays an Integral Role in Plant Heat Stress Tolerance.
abstract: Stress granules (SGs), which are formed in the plant cytoplasm under stress conditions, are transient dynamic sites (particles) for mRNA storage. SGs are actively involved in protecting mRNAs from degradation. Oligouridylate binding protein 1b (UBP1b) is a component of SGs. The formation of microscopically visible cytoplasmic foci, referred to as UBP1b SG, was induced by heat treatment in UBP1b-overexpressing Arabidopsis plants (UBP1b-ox). A detailed understanding of the function of UBP1b, however, is still not clear. UBP1b-ox plants displayed increased heat tolerance, relative to control plants, while ubp1b mutants were more sensitive to heat stress than control plants. Microarray analysis identified 117 genes whose expression was heat-inducible and higher in the UBP1b-ox plants. RNA decay analysis was performed using cordycepin, a transcriptional inhibitor. In order to determine if those genes serve as targets of UBP1b, the rate of RNA degradation of a DnaJ heat shock protein and a stress-associated protein (AtSAP3) in UBP1b-ox plants was slower than in control plants; indicating that the mRNAs of these genes were protected within the UBP1b SG granule. Collectively, these data demonstrate that UBP1b plays an integral role in heat stress tolerance in plants.
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource ScienceYokohama, Japan; Kihara Institute for Biological Research, Yokohama City UniversityYokohama, Japan.
authors.forename: Cam Chau
authors.initials: CC
authors.lastname: Nguyen
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nakaminami
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsui
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource ScienceYokohama, Japan; Kihara Institute for Biological Research, Yokohama City UniversityYokohama, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Synthetic Genomics Research Group, Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kurihara
authors.affiliation: Mass Spectrometry and Microscopy Unit, RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Toyooka
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors.forename: Maho
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource ScienceYokohama, Japan; Kihara Institute for Biological Research, Yokohama City UniversityYokohama, Japan; Core Research for Evolutional Science and Technology, Japan Science and TechnologyKawaguchi, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
keywords: RNA stability; UBP1b; UBP1b stress granule; heat stress tolerance