碩士 / 國立臺南大學 / 生物科技學系碩士班 / 106 / Diethyl phthalate (DEP) is one of the common plasticizer pollutants in the aquatic environment, but there are few reports analyzing DEP effects on the physiology of microalgae, which are important oxygen producers and food source in the ecosystem. The aims of this study are to investigate the physiological responses induced by DEP treatment using the model alga Chlamydomonas reinhardtii, and to utilize the genetic tool of Chlamydomonas to explore the genes that affect the tolerance of DEP. The results showed that, under the treatment of 0.8mM DEP, the growth of the cc-4533 reference strain was inhibited, the ROS was accumulated, and the MDA content caused by oxidative damage was increased. Under the treatment of DEP, the activity of antioxidant enzymes such as SOD, CAT, and APX was increased, and their mRNA transcripts were also increased. The CAT protein level did not change after DEP treatment. Characterization of an insertionaltive mutant m-0231 found that it was more sensitive to DEP treatment comparing to cc-4533 cells but showed no growth defect in the culture without DEP. The m-0231 mutant was also more sensitive to another plasticizer DBP than cc-4533, but there was no observed difference when both strains were treated with hydrogen peroxides or the glutamine synthetase inhibitor MSO, indicating that m-0231 responds to the plasticizer specifically. Similar physiological responses under DEP treatment were observed in both the m-0231 mutant and cc-4533 strain: growth inhibition, ROS accumulation, increased activities of Mn-SOD and APX, and unchanged CAT protein levels. However, the CAT activity was decreased in the m-0231 mutant while it was increased in cc-4533 under the same DEP concentration. Using RESDA PCR and inverse PCR, the flanking chromosomal sequence of the exogenous DNA inserted site in the m-0231 mutant was obtained, but flanking sequences from two sides were mapped to different chromosomes, suggesting that its genome was not simply disrupted by a simple insertion. The gene that was affected in the m-0231 mutant remains to be further investigatied.
| Identifer | oai:union.ndltd.org:TW/106NTNT0111005 |
| Date | January 2018 |
| Creators | Chen, Yi-Ting, 陳以庭 |
| Contributors | Tsao, Che-Chia, 曹哲嘉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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