Influence of osmotic stress on starch content and starch-metabolizing enzymes in sweet potato callus culture

• Main Authors: Zhang, Ai Ting, 張愛渟
• Other Authors: Su, Zhong Qing
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/78441667635326833501

碩士 === 國立臺灣大學 === 農業化學研究所 === 83 === Sweet potato callus cultured on media containing 3% sucrose supplemented with 0.1,0.2,0.4 and 0.6 M of mannitol were used for studying the influence of osmotic strees on starch metabolism. By analyzing the starch and protein contents and the activities of starch - metabolizing enzymes, the mechanism of starch metabolism was elucidated. The sweet potato callus cultured on medium containing 0.4 M mannitol contained less water and had less growth rate while the starch and protein contents increased sharply . Of the enzymes analyzed,starch phosphorylase in starch accumulating callus is higher than that of no starch accumulating callus. And the starch phosphorylase level is positively correlated with starch level , indicating that starch phosphorylase may play an important role in starch biosynthesis . Of other enzymes such as sucrose synthase,invertase,ADPG pyrophosphorylase also increased , but their increases were not so high as starch phophorylase . These results suggest that cells tend to take up more metabolizable saccharides which are converted into polysaccharides such as starch under inhibiting osmotic strees conditions.