Two Cytochrome P450 Monooxygenases Catalyze Early Hydroxylation Steps in the Potato Steroid Glycoalkaloid Biosynthetic Pathway.
α-Solanine and α-chaconine, steroidal glycoalkaloids (SGAs) found in potato (Solanum tuberosum), are among the best-known secondary metabolites in food crops. At low concentrations in potato tubers, SGAs are distasteful; however, at high concentrations, SGAs are harmful to humans and animals. Here, we show that POTATO GLYCOALKALOID BIOSYNTHESIS1 (PGA1) and PGA2, two genes that encode cytochrome P450 monooxygenases (CYP72A208 and CYP72A188), are involved in the SGA biosynthetic pathway, respectively. The knockdown plants of either PGA1 or PGA2 contained very little SGA, yet vegetative growth and tuber production were not affected. Analyzing metabolites that accumulated in the plants and produced by in vitro enzyme assays revealed that PGA1 and PGA2 catalyzed the 26- and 22-hydroxylation steps, respectively, in the SGA biosynthetic pathway. The PGA-knockdown plants had two unique phenotypic characteristics: The plants were sterile and tubers of these knockdown plants did not sprout during storage. Functional analyses of PGA1 and PGA2 have provided clues for controlling both potato glycoalkaloid biosynthesis and tuber sprouting, two traits that can significantly impact potato breeding and the industry.
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.) naoyuki.umemoto@riken.jp.
Naoyuki
0000-0001-5507-0848
N
Umemoto
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Masaru
M
Nakayasu
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Kiyoshi
K
Ohyama
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Mari
0000-0002-5009-0409
M
Yotsu-Yamashita
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Masaharu
0000-0002-4321-0644
M
Mizutani
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Hikaru
0000-0002-6426-0368
H
Seki
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Kazuki
K
Saito
Central Laboratories for Key Technologies, Kirin Co., Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan (N.U.); RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan (N.U., K.O., K.S.); Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan (M.N., M.M.); Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan (K.O.); Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi 981-8555, Japan (M.Y.-Y.); Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan (H.S., T.M.); and Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260-8675, Japan (K.S.).
Toshiya
0000-0003-1058-2473
T
Muranaka
D053898:Biosynthetic Pathways; D001947:Breeding; D018556:Crops, Agricultural; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D006900:Hydroxylation; D010641:Phenotype; D010840:Phytosterols / Q000737:chemistry / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D035281:Plant Tubers / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D012992:Solanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D011198:Solanum tuberosum / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D010840:Phytosterols; D010940:Plant Proteins; C514919:alpha-solanine; D012992:Solanine; C011860:alpha-chaconine; D003577:Cytochrome P-450 Enzyme System