title: Loss of Arabidopsis 5'-3' Exoribonuclease AtXRN4 Function Enhances Heat Stress Tolerance of Plants Subjected to Severe Heat Stress.
abstract: mRNA degradation plays an important role in the rapid and dynamic alteration of gene expression in response to environmental stimuli. Arabidopsis 5'-3' exoribonuclease (AtXRN4), a homolog of yeast Xrn1p, functions after a de-capping step in the degradation of uncapped RNAs. While Xrn1p-dependent degradation of mRNA is the main process of mRNA decay in yeast, information pertaining to the targets of XRN4-based degradation in plants is limited. In order to better understand the biological function of AtXRN4, the current study examined the survivability of atxrn4 mutants subjected to heat stress. The results indicated that atxrn4 mutants, compared with wild-type plants, exhibited an increased survival rate when subjected to a short-term severe heat stress. A microarray and mRNA decay assay showed that loss of AtXRN4 function caused a reduction in the degradation of heat shock factor A2 (HSFA2) and ethylene response factor 1 (ERF1) mRNA. The heat stress tolerance phenotype of atxrn4 mutants was significantly reduced or lost by mutation of HSFA2, a known key regulator of heat acclimation, thus indicating that HSFA2 is a target gene of AtXRN4-mediated mRNA degradation both under non-stress conditions and during heat acclimation. These results demonstrate that AtXRN4-mediated mRNA degradation is linked to the suppression of heat acclimation.
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan Department of Bioscience, Nagahama Institute of Bioscience and Technology, Nagahama, 526-0829 Japan.
authors.forename: Anh Hai
authors.initials: AH
authors.lastname: Nguyen
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsui
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan.
authors.forename: Maho
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Mizunashi
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nakaminami
authors.affiliation: Department of Bioscience, Nagahama Institute of Bioscience and Technology, Nagahama, 526-0829 Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Graduate School of Medicine, Kyoto University, Kyoto, 606-8501 Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Iida
authors.affiliation: Integrated Database Unit, Advanced Center for Computing and Communication (ACCC), RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Toyoda
authors.affiliation: National Key Laboratory for Plant Cell Technology, Agricultural Genetics Institute, Hanoi, Vietnam.
authors.forename: Dong Van
authors.initials: DV
authors.lastname: Nguyen
authors.affiliation: Plant Genomic Network Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan Kihara Institute for Biological Research, Yokohama City University, Yokohama, 244-0813 Japan Core Research for Evolutional Science and Technology, Japan Science and Technology, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012 Japan motoaki.seki@riken.jp.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
mesh_terms: D000064:Acclimatization; D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D005095:Exoribonucleases / Q000172:deficiency / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018869:Heat-Shock Response; D006358:Hot Temperature; D009154:Mutation / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism*; D018526:Plant Transpiration / Q000502:physiology; D020871:RNA Stability / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; C418137:Xrn1 protein, plant; D005095:Exoribonucleases
keywords: Arabidopsis; AtXRN4; Heat stress tolerance; RNA degradation