著者

Kotoko Fukui Kouhei Ohnishi Yasufumi Hikichi Akinori Kiba

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.40, no.1, pp.87-92, 2023-03-25 (Released:2023-03-25)

参考文献数

36

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Phospholipid signaling plays an important role in plant immune responses. Here, we isolated two phospholipase C4 (PLC4) orthologs in the Nicotiana benthamiana genome, designated as N. benthamiana PLC4-1 and PLC4-2 (NbPLC4-1 and NbPLC4-2). We created NbPLC4-1- and NbPLC4-2- silenced plants. Induction of the hypersensitive response (HR), including HR cell death and bacterial population reduction, was accelerated in both NbPLC4-1- and NbPLC4-2-silenced plants challenged with N. benthamiana-incompatible Ralstonia solanacearum 8107. The NbPLC4-1- and NbPLC4-2-silenced plants also showed enhanced expression of Nbhin1, a HR marker gene. Expressions of genes for salicylic acid (SA) and jasmonic acid (JA) signaling were drastically increased in NbPLC4-1- and NbPLC4-2-silenced plants by R. solanacearum inoculation. In addition, NbPLC4-1 and NbPLC4-2 silencing triggered reactive oxygen species (ROS) hyper-production. These results suggest that NbPLC4s are closely associated with JA, SA, and ROS signaling and act as negative regulators of the HR in N. benthamiana.

著者

Maho Watanabe Kouhei Ohnishi Yasufumi Hikichi Akinori Kiba

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

pp.22.1121a, (Released:2023-01-23)

参考文献数

34

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Target of rapamycin (TOR) regulates essential processes associated with plant growth, development, and cell death by modulating metabolic activities and translation in response to environmental signals. The ATP-competitive TOR inhibitor AZD8055 suppressed the hypersensitive response (HR) cell death in Nicotiana benthamiana infected with the incompatible Ralstonia solanacearum. The induced expression of the HR marker gene hin1 was also inhibited by the AZD8055 treatment. To further clarify the mechanisms underlying TOR-regulated HR cell death, we focused on TOR-related ErbB3-binding protein 1 (EBP1) in N. benthamiana (NbEBP1). We found four EBP1 orthologs in the N. benthamiana genome. The expression levels of all four EBP1 orthologs in N. benthamiana were up-regulated by the R. solanacearum infection. The silencing of the four NbEBP1 orthologs suppressed the induction of HR cell death, hin1 expression, and the production of reactive oxygen species. These results suggest that the TOR signaling pathway helps regulate HR cell death along with reactive oxygen species-related signaling in N. benthamiana.

著者

Shuhei Shimmyo Kazuaki Yuki Kouhei Ohnishi

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.5, no.4, pp.360-369, 2016-07-01 (Released:2016-07-01)

参考文献数

19

被引用文献数

2 3

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This paper discusses the suppression of torque ripples in motor drives. Current ripples caused by pulse-width modulation with frequencies of 10-100kHz can be reduced by using high-frequency switching. On the other hand, current ripples caused by dead-times with 6kth-order ripples of fundamental frequencies increase with the switching frequency. Therefore, there is a trade-off relationship between the two ripples. To compensate for dead-times, feedforward compensation is widely used. However, effective compensation cannot be achieved if the feedforward compensation values contain modeling errors. This paper therefore reveals that the robustness of the output torque against compensation errors can be improved by using multilevel inverters. The proposed method is validated through simulations and experimental results.

著者

Shuhei Shimmyo Katsutoku Takeuchi Norio Takahashi Makoto Matsushita Kouhei Ohnishi

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.5, no.2, pp.69-77, 2016-03-01 (Released:2016-03-01)

参考文献数

18

被引用文献数

4 7

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This paper discusses the suppression of torque ripple using multi-level inverters in motor drives. Because it is possible to improve the output waveforms using multi-level inverters, it is also possible to improve the control performance of motors. In this paper, the multi-level inverters achieve precise motion control, and a theoretical distortion index for multi-level motor drives that takes the control sensitivity into account is proposed. By calculating the distortion index, the optimal equivalent carrier frequency that can minimize torque ripple can be obtained. The validity of the proposed method is confirmed by our experimental results.

著者

Shuhei Tagami Kouhei Ohnishi Yasufumi Hikichi Akinori Kiba

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.38, no.3, pp.373-378, 2021-09-25 (Released:2021-09-25)

参考文献数

33

被引用文献数

3

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Phosphatidic acid plays an important role in Nicotiana benthamiana immune responses against phytopathogenic bacteria. We analyzed the contributions of endoplasmic reticulum-derived chloroplast phospholipids, including phosphatidic acid, to the resistance of N. benthamiana against Ralstonia solanacearum. Here, we focused on trigalactosyldiacylglycerol 3 (TGD3) protein as a candidate required for phosphatidic acid signaling. On the basis of Arabidopsis thaliana TGD3 sequences, we identified two putative TGD3 orthologs in the N. benthamiana genome, NbTGD3-1 and NbTGD3-2. To address the role of TGD3s in plant defense responses, we created double NbTGD3-silenced plants using virus-induced gene silencing. The NbTGD3-silenced plants showed a moderately reduced growth phenotype. Bacterial growth and the appearance of bacterial wilt disease were accelerated in NbTGD3-silenced plants, compared with control plants, challenged with R. solanacearum. The NbTGD3-silenced plants showed reduced both expression of allene oxide synthase that encoded jasmonic acid biosynthetic enzyme and NbPR-4, a marker gene for jasmonic acid signaling, after inoculation with R. solanacearum. Thus, NbTGD3-mediated endoplasmic reticulum—chloroplast lipid transport might be required for jasmonic acid signaling-mediated basal disease resistance in N. benthamiana.