RRC ID 32172
著者 Sawai S, Ohyama K, Yasumoto S, Seki H, Sakuma T, Yamamoto T, Takebayashi Y, Kojima M, Sakakibara H, Aoki T, Muranaka T, Saito K, Umemoto N.
タイトル Sterol side chain reductase 2 is a key enzyme in the biosynthesis of cholesterol, the common precursor of toxic steroidal glycoalkaloids in potato.
ジャーナル Plant Cell
Abstract Potatoes (Solanum tuberosum) contain α-solanine and α-chaconine, two well-known toxic steroidal glycoalkaloids (SGAs). Sprouts and green tubers accumulate especially high levels of SGAs. Although SGAs were proposed to be biosynthesized from cholesterol, the biosynthetic pathway for plant cholesterol is poorly understood. Here, we identify sterol side chain reductase 2 (SSR2) from potato as a key enzyme in the biosynthesis of cholesterol and related SGAs. Using in vitro enzyme activity assays, we determined that potato SSR2 (St SSR2) reduces desmosterol and cycloartenol to cholesterol and cycloartanol, respectively. These reduction steps are branch points in the biosynthetic pathways between C-24 alkylsterols and cholesterol in potato. Similar enzymatic results were also obtained from tomato SSR2. St SSR2-silenced potatoes or St SSR2-disrupted potato generated by targeted genome editing had significantly lower levels of cholesterol and SGAs without affecting plant growth. Our results suggest that St SSR2 is a promising target gene for breeding potatoes with low SGA levels.
巻・号 26(9)
ページ 3763-74
公開日 2014-9-1
DOI 10.1105/tpc.114.130096
PII tpc.114.130096
PMID 25217510
PMC PMC4213163
MeSH Alkaloids / chemistry Alkaloids / metabolism* Biosynthetic Pathways* Cholesterol / analogs & derivatives Cholesterol / biosynthesis* Cholesterol / chemistry Enzyme Assays Gene Silencing Genes, Plant Molecular Sequence Data Oxidoreductases / metabolism Phylogeny Phytosterols / biosynthesis Phytosterols / chemistry RNA Editing Solanum lycopersicum / genetics Solanum tuberosum / enzymology* Solanum tuberosum / genetics Tetraploidy
IF 9.618
引用数 89
WOS 分野 PLANT SCIENCES BIOCHEMISTRY & MOLECULAR BIOLOGY CELL BIOLOGY
リソース情報
トマト TOMJPF00001