נגישות
menu      
חיפוש מתקדם

Sonawane,, P.D., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Heinig, U., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Panda, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Gilboa, N.S., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Yona, M., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel;  Alkan, N., Department of Postharvest Science of Fresh Produce, Agricultural ResearchSonawane, P.D., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Heinig, U., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Panda, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Gilboa, N.S., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Yona, M., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Pradeep Kumar, S., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;  Unger, T., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Bocobza, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Pliner, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Malitsky, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Tkachev, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Meir, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Rogachev, I., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Aharoni, A., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel Organization, Volcani Center, Rishon LeZion, Israel; Unger, T., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Bocobza, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Pliner, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Malitsky, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Tkachev, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Meir, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Rogachev, I., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Aharoni, A., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel

Thousands of specialized, steroidal metabolites are found in a wide spectrum of plants. These include the steroidal glycoalkaloids (SGAs), produced primarily by most species of the genus Solanum, and metabolites belonging to the steroidal saponins class that are widespread throughout the plant kingdom. SGAs play a protective role in plants and have potent activity in mammals, including antinutritional effects in humans. The presence or absence of the double bond at the C-5,6 position (unsaturated and saturated, respectively) creates vast structural diversity within this metabolite class and determines the degree of SGA toxicity. For many years, the elimination of the double bond from unsaturated SGAs was presumed to occur through a single hydrogenation step. In contrast to this prior assumption, here, we show that the tomato GLYCOALKALOID METABOLISM25 (GAME25), a short-chain dehydrogenase/reductase, catalyzes the first of three prospective reactions required to reduce the C-5,6 double bond in dehydrotomatidine to form tomatidine. The recombinant GAME25 enzyme displayed 3β-hydroxysteroid dehydrogenase/ Δ5,4 isomerase activity not only on diverse steroidal alkaloid aglycone substrates but also on steroidal saponin aglycones. Notably, GAME25 down-regulation rerouted the entire tomato SGA repertoire toward the dehydro-SGAs branch rather than forming the typically abundant saturated α-tomatine derivatives. Overexpress-ing the tomato GAME25 in the tomato plant resulted in significant accumulation of α-tomatine in ripe fruit, while heterologous expression in cultivated eggplant generated saturated SGAs and atypical saturated steroidal saponin glycosides. This study demonstrates how a single scaffold modification of steroidal metabolites in plants results in extensive structural diversity and modulation of product toxicity. © 2018 National Academy of Sciences. All Rights Reserved.

פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Short-chain dehydrogenase/reductase governs steroidal specialized metabolites structural diversity and toxicity in the genus Solanum
115

Sonawane,, P.D., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Heinig, U., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Panda, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Gilboa, N.S., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Yona, M., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel;  Alkan, N., Department of Postharvest Science of Fresh Produce, Agricultural ResearchSonawane, P.D., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Heinig, U., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Panda, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Gilboa, N.S., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Yona, M., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Pradeep Kumar, S., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;  Unger, T., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Bocobza, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Pliner, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Malitsky, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Tkachev, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Meir, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Rogachev, I., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Aharoni, A., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel Organization, Volcani Center, Rishon LeZion, Israel; Unger, T., Structural Proteomics Unit, Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel; Bocobza, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Pliner, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Malitsky, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Tkachev, M., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Meir, S., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Rogachev, I., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel; Aharoni, A., Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel

Short-chain dehydrogenase/reductase governs steroidal specialized metabolites structural diversity and toxicity in the genus Solanum .

Thousands of specialized, steroidal metabolites are found in a wide spectrum of plants. These include the steroidal glycoalkaloids (SGAs), produced primarily by most species of the genus Solanum, and metabolites belonging to the steroidal saponins class that are widespread throughout the plant kingdom. SGAs play a protective role in plants and have potent activity in mammals, including antinutritional effects in humans. The presence or absence of the double bond at the C-5,6 position (unsaturated and saturated, respectively) creates vast structural diversity within this metabolite class and determines the degree of SGA toxicity. For many years, the elimination of the double bond from unsaturated SGAs was presumed to occur through a single hydrogenation step. In contrast to this prior assumption, here, we show that the tomato GLYCOALKALOID METABOLISM25 (GAME25), a short-chain dehydrogenase/reductase, catalyzes the first of three prospective reactions required to reduce the C-5,6 double bond in dehydrotomatidine to form tomatidine. The recombinant GAME25 enzyme displayed 3β-hydroxysteroid dehydrogenase/ Δ5,4 isomerase activity not only on diverse steroidal alkaloid aglycone substrates but also on steroidal saponin aglycones. Notably, GAME25 down-regulation rerouted the entire tomato SGA repertoire toward the dehydro-SGAs branch rather than forming the typically abundant saturated α-tomatine derivatives. Overexpress-ing the tomato GAME25 in the tomato plant resulted in significant accumulation of α-tomatine in ripe fruit, while heterologous expression in cultivated eggplant generated saturated SGAs and atypical saturated steroidal saponin glycosides. This study demonstrates how a single scaffold modification of steroidal metabolites in plants results in extensive structural diversity and modulation of product toxicity. © 2018 National Academy of Sciences. All Rights Reserved.

Scientific Publication
You may also be interested in