著者

Reika Hasegawa Tomoki Arakawa Kenjiro Fujita Yuichiro Tanaka Zen Ookawa Shingo Sakamoto Hironori Takasaki Miho Ikeda Ayumi Yamagami Nobutaka Mitsuda Takeshi Nakano Masaru Ohme-Takagi

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.39, no.2, pp.209-214, 2022-06-25 (Released:2022-06-25)

参考文献数

51

被引用文献数

1

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Brassinosteroid (BR) is a phytohormone that acts as important regulator of plant growth. To identify novel transcription factors that may be involved in unknown mechanisms of BR signaling, we screened the chimeric repressor expressing plants (CRES-T), in which transcription factors were converted into chimeric repressors by the fusion of SRDX plant-specific repression domain, to identify those that affect the expression of BR inducible genes. Here, we identified a homeobox-leucine zipper type transcription factor, BRASSINOSTEROID-RELATED-HOMEOBOX 3 (BHB3), of which a chimeric repressor expressing plants (BHB3-sx) significantly downregulated the expression of BAS1 and SAUR-AC1 that are BR inducible genes. Interestingly, ectopic expression of BHB3 (BHB3-ox) also repressed the BR inducible genes and shorten hypocotyl that would be similar to a BR-deficient phenotype. Interestingly, both BHB3-sx and BHB3-ox showed pale green phenotype, in which the expression of genes related photosynthesis and chlorophyll contents were significantly decreased. We found that BHB3 contains three motifs similar to the conserved EAR-repression domain, suggesting that BHB3 may act as a transcriptional repressor. These results indicate that BHB3 might play an important role not only to the BR signaling but also the regulation of greenings.

著者

Reika Hasegawa Kenjiro Fujita Yuichiro Tanaka Hironori Takasaki Miho Ikeda Ayumi Yamagami Nobutaka Mitsuda Takeshi Nakano Masaru Ohme-Takagi

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.39, no.2, pp.185-189, 2022-06-25 (Released:2022-06-25)

参考文献数

27

被引用文献数

1

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The brassinosteroid (BR) phytohormone is an important regulator of plant growth. To identify novel transcription factors that regulate BR responses, we screened chimeric repressor gene silencing technology (CRES-T) plants, in which transcription factors were converted into chimeric repressors by the fusion of SRDX plant-specific repression domain, with brassinazole (Brz), an inhibitor of BR biosynthesis. We identified that a line that expressed the chimeric repressor for zinc finger homeobox transcription factor, BRASSINOSTEORID-RELATED-HOMEOBOX-2 (BHB2-sx), exhibited Brz-hypersensitive phenotype with shorter hypocotyl under dark, dwarf and round and dark green leaves similar to BR-deficient phenotype. Similar to BHB2-sx plants, bhb2 knockout mutant also exhibited Brz hypersensitive phenotype. In contrast, ectopic expression of BHB2 (BHB2-ox) showed hypocotyl elongation phenotype (BR excessive), showing decrease to Brz sensitivity. The expression of the DWF4 and CPD BR biosynthesis genes was repressed in BHB2-sx plants, whereas it was enhanced in BHB2-ox plants. The BR deficient-like phenotype of BHB2-sx plants was partially restored by treatment with brassinolide (BL), indicating that the BR deficient phenotype of BHB2-sx plant may be due to suppression of BR biosynthesis. Our results indicate that BHB2 is a positive regulator of BR response may be due to the promotion of BR biosynthesis genes.

著者

Shinya TAKAMAEDA-YAMAZAKI Hiroshi NAKATSUKA Yuichiro TANAKA Kenji KISE

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E98-D, no.12, pp.2150-2158, 2015-12-01

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Soft processors are widely used in FPGA-based embedded computing systems. For such purposes, efficiency in resource utilization is as important as high performance. This paper proposes Ultrasmall, a new soft processor architecture for FPGAs. Ultrasmall supports a subset of the MIPS-I instruction set architecture and employs an area efficient microarchitecture to reduce the use of FPGA resources. While supporting the original 32-bit ISA, Ultrasmall uses a 2-bit serial ALU for all of its operations. This approach significantly reduces the resource utilization instead of increasing the performance overheads. In addition to these device-independent optimizations, we applied several device-dependent optimizations for Xilinx Spartan-3E FPGAs using 4-input lookup tables (LUTs). Optimizations using specific primitives aggressively reduce the number of occupied slices. Our evaluation result shows that Ultrasmall occupies only 84% of the previous small soft processor. In addition to the utilized resource reduction, Ultrasmall achieves 2.9 times higher performance than the previous approach.