15 research outputs found
Long-term feeding of whey protein hydrolysates increases skeletal muscle glycogen levels and improves exercise performance in mice
Post-exercise carbohydrate plus whey protein hydrolysates supplementation increases skeletal muscle glycogen level in rats
Elucidation of the indole-3-acetic acid biosynthetis pathway via indole-3-pyruvic acid in Enterobacter cloacae
報告番号: 乙11687 ; 学位授与年月日: 1994-03-14 ; 学位の種別: 論文博士 ; 学位の種類: 博士(理学) ; 学位記番号: 第11687号 ; 研究科・専攻: 理学系研究
Cholic Acid, a Bile Acid Elicitor of Hypersensitive Cell Death, Pathogenesis-Related Protein Synthesis, and Phytoalexin Accumulation in Rice
When plants interact with certain pathogens, they protect themselves by generating various defense responses. These defense responses are induced by molecules called elicitors. Since long ago, composts fermented by animal feces have been used as a fertilizer in plant cultivation, and recently, have been known to provide suppression of plant disease. Therefore, we hypothesized that the compounds from animal feces may function as elicitors of plant defense responses. As a result of examination of our hypothesis, an elicitor of rice defense responses was isolated from human feces, and its structure was identified as cholic acid (CA), a primary bile acid in animals. Treatment of rice (Oryza sativa) leaves with CA induced the accumulation of antimicrobial compounds (phytoalexins), hypersensitive cell death, pathogenesis-related (PR) protein synthesis, and increased resistance to subsequent infection by virulent pathogens. CA induced these defense responses more rapidly than did fungal cerebroside, a sphingolipid elicitor isolated from the rice pathogenic fungus Magnaporthe grisea. Furthermore, fungal cerebroside induced both types of rice phytoalexins, phytocassanes and momilactones, whereas CA mainly induced phytocassanes, but not momilactones. In the structure-activity relationship analysis, the hydroxyl groups at C-7 and C-12, and the carboxyl group at C-24 of CA contributed to the elicitor activity. These results indicate that CA is specifically recognized by rice and is a different type of elicitor from fungal cerebroside. This report demonstrated that bile acid induced defense responses in plants