著者

大西 利幸 小埜 栄一郎

出版者

一般社団法人 日本家政学会

雑誌

日本家政学会誌 (ISSN:09135227)

巻号頁・発行日

vol.67, no.4, pp.238-242, 2016 (Released:2016-04-16)

参考文献数

6

著者

大西 利幸

出版者

一般社団法人 植物化学調節学会

雑誌

植物の生長調節 (ISSN:13465406)

巻号頁・発行日

vol.50, no.1, pp.28-39, 2015-05-29 (Released:2017-09-29)

参考文献数

60

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Plants biosynthesize an excess of bioactive phytochemicals (primary metabolites and specialized metabolites) that have primary functions in photosynthesis, respiration, growth and development and specialized functions in ecological interactions and defense against plant pathogens and herbivores.Cytochrome P450 monooxygenases (P450s) play crucial roles in terpenoids biosynthesis and metabolism. 1)BR campestanol-independent pathway Recent molecular genetic studies for BR-deficient mutants of Arabidopsis, rice, tomato and garden pea have identified several P450 genes (CYP85A, 90A, 90B, 90C, 90D, 724B) so far.We, here, present that functional characterization of P450 enzymes involved in brassinosteroids biosynthesis led to the elucidation of the novel BR short-cut route (named campestanol-independent pathway). 2)CYP720 family in conifer chemical defense Recent gene discovery and phylogenetic cluster analysis for conifer P450s revealed that the CYP720 subfamily consists of over 30 P450s. Here, we report new results from the biochemical characterization of CYP720B4.In vitro assay results show that this P450 catalyze three oxidation steps at the C-18 position of abietine to form abietic acid, and also oxidize other diterpenoid olefins to the corresponding resin acids.

著者

大西 利幸

出版者

一般社団法人 植物化学調節学会

雑誌

植物の生長調節 (ISSN:13465406)

巻号頁・発行日

vol.52, no.2, pp.99-105, 2017 (Released:2018-01-12)

参考文献数

34

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Plants have the ability to synthesize and emit a diversity of volatile organic compounds (VOCs) that may act as aroma and flavor molecules in response to insect herbivores, mechanical wounding, and attraction of pollinators. Plants also have the capacity to accumulate the VOCs into plant itself. Several plant species morphologically develop specialized glandular trichomes to store VOCs which are released in response to tissue damage for chemical defense such as inhibiting microbial growth or deterring herbivores. Glycosylation is another machinery for safely storing VOCs into normal cells. Tea plant (Camellia sinensis) stores VOCs with glycosylation in tea leaves, mainly conjugated to β-primeverosides, the most abundant form of aroma diglycosides in C. sinensis. Here, we introduced two UDP-glycosyltransferases (UGTs) from C. sinensis, UGT85K11 (CsGT1) and UGT94P1 (CsGT2), converting VOCs into β-primeverosides by sequential glucosylation and xylosylation, respectively. This information can be used to preserve tea aroma better during the manufacturing process and to investigate the mechanism of plant chemical defenses.

著者

大西 利幸

出版者

静岡大学

雑誌

研究活動スタート支援

巻号頁・発行日

2009

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本研究ではイリドイド化合物の一つであるオレウロペインを化学防御物質前駆体と考え、環境ストレスに対する樹木の化学防御機構の解明を目的として防御活性化酵素の機能解析を行った。その結果、オリーブ実からオレウロペイン糖加水分解酵素(β-グルコシダーゼ)の精製し、そのペプチド配列から設計したジェネレートプライマーを用いて、オリーブから全長cDNA配列の取得に成功した。