著者

Patwira Boonjing Yukari Masuta Kosuke Nozawa Atsushi Kato Hidetaka Ito

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.19-00046, (Released:2020-08-03)

参考文献数

34

被引用文献数

10

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The Ty1/copia-like retrotransposon ONSEN is conserved among Brassica species, as well as in beans, including adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi), which is one of the economically important crops in Japan. ONSEN has acquired a heat-responsive element that is recognized by plant heat stress defense factors, resulting in its transcription and the production of full-length extrachromosomal DNA under conditions with elevated temperatures. DNA methylation plays an important role in regulating the activation of this transposon in plants. Therefore, chemical inhibition of DNA methyltransferases has been utilized to study the effect of DNA methylation on transposon activation. To understand the effect of DNA methylation on ONSEN activation, Arabidopsis thaliana and adzuki bean seedlings were treated with zebularine, which is known to be an effective chemical demethylation agent. The results showed that ONSEN transcription levels were upregulated in zebularine-treated plants. Extrachromosomal DNA of ONSEN also accumulated in the treated plants.

著者

Yui Hayashi Kanako Takehira Kosuke Nozawa Takamasa Suzuki Yukari Masuta Atsushi Kato Hidetaka Ito

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.95, no.4, pp.183-190, 2020-08-01 (Released:2020-10-23)

参考文献数

46

被引用文献数

3 10

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Most transposable elements (TEs) are tightly regulated by epigenetic mechanisms such as DNA methylation. RNA-directed DNA methylation (RdDM) is a major control mechanism of TE silencing in plants. We analyzed the transposition activity of a heat-responsive retrotransposon, ONSEN, in Arabidopsis thaliana. Transgenerational transposition was observed in RdDM pathway-deficient mutants upon heat stress. The transposition frequency was higher in the mutants of the upstream processes, but lower in the mutants of the downstream steps, of RdDM. The transposition frequency was not associated with the number of extrachromosomal ONSEN copies. Constitutive heterochromatin of interphase nuclei was dispersed upon heat stress. The degree of decondensation was higher in the RdDM mutants than in wild-type plants subjected to heat stress. We discuss the possible role of RdDM in the regulation of ONSEN transposition upon heat stress.

著者

Seiji Masuda Kosuke Nozawa Wataru Matsunaga Yukari Masuta Akira Kawabe Atsushi Kato Hidetaka Ito

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.91, no.6, pp.293-299, 2016-12-01 (Released:2017-05-13)

参考文献数

34

被引用文献数

4

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Natural accessions are used for studying intraspecies genetic variation in the model plant Arabidopsis thaliana in order to address fundamental questions of evolution. Transposable elements are responsible for a wide range of mutations and play significant roles in shaping a genome over evolutionary time. In the present study, we aimed to characterize ONSEN, a heat-activated long terminal repeat (LTR) retrotransposon, in natural A. thaliana accessions. Southern blot analysis demonstrated that ONSEN was present in all the studied accessions, but the copy number was diverse. Olympia-1 contained a single ONSEN copy, located in the centromere of Chromosome 3. A premature stop codon in Olympia-1 ONSEN presumably abolishes integrase activity, which in turn presumably renders the retrotransposon non-functional. Hybridization of Col-0 with Olympia-1 showed that several ONSEN copies in Col-0 were activated by heat stress and maintained their transpositional activity in the progeny.

著者

Yukari Masuta Akira Kawabe Kosuke Nozawa Ken Naito Atsushi Kato Hidetaka Ito

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

pp.17085, (Released:2018-03-24)

被引用文献数

14

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In plants, several transposable elements are conserved across species. We found a homolog of ONSEN, which is a heat-activated retrotransposon originally isolated from Arabidopsis thaliana, in Vigna. The ONSEN-like elements (VaONS) were detected in all the analyzed Japanese accessions of Vigna angularis (adzuki bean) by Southern blot analysis. However, VaONS sequences were observed to be polymorphic in the different accessions. Interestingly, extrachromosomal DNA (ecDNA) was detected in some accessions of adzuki bean, indicating the conserved heat-activation of VaONS. Furthermore, we successfully induced retrotransposition of VaONS in adzuki plant regenerated through callus. Findings of our study should provide a new tool for molecular breeding of adzuki bean.