title: Sm-Like Protein-Mediated RNA Metabolism Is Required for Heat Stress Tolerance in Arabidopsis.
abstract: Sm-like proteins play multiple functions in RNA metabolism, which is essential for biological processes such as stress responses in eukaryotes. The Arabidopsis thaliana sad1 mutant has a mutation of sm-like protein 5 (LSM5) and shows impaired drought and salt stress tolerances. The lsm5/sad1 mutant also showed hypersensitivity to heat stress. GFP-fused LSM5/SAD1 was localized in the nucleus under optimal growth conditions. After heat stress treatment, GFP-fused LSM5/SAD1 fluorescence was also observed as small cytoplasmic dots, in addition to nuclear localization. Whole genome transcriptome analysis revealed that many genes in Arabidopsis were drastically changed in response to heat stress. More heat-responsive genes were highly expressed in lsm5/sad1 mutant at both 2 and 6 h after heat stress treatment. Additionally, intron-retained and capped transcripts accumulated in the lsm5/sad1 mutant after heat stress treatment. In this study, we also identified non-Arabidopsis Genome Initiative transcripts that were expressed from unannotated regions. Most of these transcripts were antisense transcripts, and many capped non-AGI transcripts accumulated in the lsm5/sad1 mutant during heat stress treatment. These results indicated that LSM5/SAD1 functions to degrade aberrant transcripts through appropriate mRNA splicing and decapping, and precise RNA metabolic machinery is required for heat stress tolerance.
authors: Arid Land Research Center, Tottori UniversityHamasaka, Japan; RIKEN Center for Sustainable Resource ScienceYokohama, Japan; PRESTO, Japan Science and Technology AgencyKawaguchi, Japan.
authors: Masanori
authors: M
authors: Okamoto
authors: RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors: Akihiro
authors: A
authors: Matsui
authors: RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors: Maho
authors: M
authors: Tanaka
authors: RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors: Taeko
authors: T
authors: Morosawa
authors: RIKEN Center for Sustainable Resource Science Yokohama, Japan.
authors: Junko
authors: J
authors: Ishida
authors: Graduate School of Medicine, Kyoto University Kyoto, Japan.
authors: Kei
authors: K
authors: Iida
authors: RIKEN Center for Integrative Medical Sciences Yokohama, Japan.
authors: Yoshiki
authors: Y
authors: Mochizuki
authors: RIKEN Advanced Center for Computing and Communication Wako, Japan.
authors: Tetsuro
authors: T
authors: Toyoda
authors: RIKEN Center for Sustainable Resource ScienceYokohama, Japan; Kihara Institute for Biological Research, Yokohama City UniversityYokohama, Japan; CREST, Japan Science and Technology AgencyKawaguchi, Japan.
authors: Motoaki
authors: M
authors: Seki
keywords: Arabidopsis; RNA metabolism; Sm-like protein; aberrant transcriptions; antisense RNA; arid region; heat stress; non-coding RNA