Rutin Alleviates Ethephon-Induced Leaf Senescence via Multiple Diverse Mechanisms in Sweet Potato

• Main Authors: Yu-Fang Chen, 陳郁方
• Other Authors: Hsien-Jung, Chen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/3t75kg

碩士 === 國立中山大學 === 生物科學系研究所 === 107 === Rutin is a member of plant secondary metabolite flavonols, which belong to flavonoids of phenolics, It is mainly found in common wheat, olive, apple, Polygonaceae, Fabaceae, and citrus. Rutin is a strong antioxidant. Its contents positively correlate with the antioxidant capacity and relate to leaf senescent level in plants. Ethylene affects leaf senescence in sweet potato. Therefore, ethephon, an ethylene-releasing compound, promotes leaf senescence and changes of senescence-associated markers, including promotion of morphological leaf yellowing/browning, reduction of chlorophyll content, decrease of and Fv/Fm value, and elevation of H2O2/NO/MDA amounts. Ethephon-mediated leaf senescence and changes of senescence-associated markers were attenuated in the presence of rutin. Additionally in the aspect of early (within the first 6 h) signal molecules, ethephon-mediated signal molecule generation such as increase of NADPH oxidase activity, elevation of NO content, enhancement of calmodulin SPCAM amount, and rise of mitogen-activated protein kinase amount/phosphorylation level was repressed by exogenous rutin. In the late stage (72 h) of antioxidant enzymes and senescence-associated genes, ethephon-mediated (1) reduction of catalase/ascorbate peroxidase/superoxide dismutase total activities and in-gel activity staining, and (2) decrease of calmodulin SPCAM/catalase SPCAT1/ascorbate peroxidase SPAPX protein amounts were also inhibited by exogenous rutin. Results of higher antioxidant enzymatic activity/protein amount were found. Ethephon-enhanced senescence-associated cysteine protease SPCP1 expression was inhibited and remained a lower level by exogenous rutin. Based on these data, rutin alleviates ethephon-induced leaf senescence possibly by multiple diverse mechanisms in sweet potato.