A Preliminary Study On Nutritional Physiology And Molecular Mechanism Of Triterpenoid Production In Suspension Cells Of Betula Platyphylla Suk. Induced By Fungal Elicitor

In the thesis, endophytic fungus isolated from birch bark was used as elicitor to induce triterpenoids accumulation in birch (Betula platyphylla Suk.) suspension culture. First, the role of soluble sugar, soluble protein, sucrose, glucose, C/N and amino acid were studied in triterpenoid synthesis of birch cells induced by fungul elicitor. Second, the differential proteins were studied in triterpenoid synthesis of birch cells induced by fungul elicitor. The results were as follows:1. Nutrient physiology of triterpenoid production in birch cells induced by fungal elicitorThe result showed that the dry weight and triterpene production of birch cells were decreasing with the extension of fungal treatment time. Among of them, triterpene content and production were the highest after1d fungal induction, they were21.98mg·g-1and123.82g·L-1, respectively, about2times of the control. Soluble sugar content, glucose content and C/N were the highest after1d fungal induction, the increasing rates were146.93%4,84.54%and906.96%, respectively. The content of soluble protein and sucrose were on the lowest after Id fungal induction, the reducing rates were75.48%and18.62%, respectively. The fungal elicitor had no effect on the fructose content. In addition to histidine, lysine and cystine, the content of amino acids were increased induced by fungal elicitor. The correlation analysis showed that total soluble sugar, glucose levels, C/N, glutamic acid and histidine content and triterpene content was significant. It is reasoned that fungal elicitors induced the synthesis of triterpenes may be related to the change concentration of C/N, glutamic acid and histidine.2. Comparative proteomics in birch cells induced by fungal elicitor50and51protein spots were detected on6h and24h after fungal elicitor treatment, respectively. Only22protein spots were identified successfully. These proteins were mainly involved in cell wall formation and degradation, protein translation, energy and metabolism, plant defense reactions, redox, other proteins and unknown proteins.