阿拉伯芥錳超氧岐化酶基因 (At3g56350) 的功能分析

Functional Analysis of an Annotated Manganese Superoxide Dismutase Gene (At3g56350) in Arabidopsis

何立安(HARIYANTO)

指導教授 ： 靳宗洛

國立臺灣大學/生命科學院/植物科學研究所/碩士(2020年)

https://doi.org/10.6342/NTU202000517

摘要

超氧岐化酶(SOD)可調節過量產生的活性氧(ROS)，以緩解其在植物中的毒性。到目前為止，已在阿拉伯芥發現七個SOD的基因。這些基因分別是錳超氧岐化酶1 (MSD1) ，鐵超氧岐化酶1, 2, 3 (FeSOD1, FeSOD2, FeSOD3)，銅鋅超氧岐化酶1. 2, 3 (Cu/ZnSOD1, Cu/ZnSOD2, Cu/ZnSOD3)。這些SOD同功異構酶坐落在細胞的不同位置中。MnSOD1在粒線體基質，Cu/ZnSOD1在細胞質，Cu/ZnSOD3在過氧化體，而Cu/ZnSOD2，FeSOD1，FeSOD2，FeSOD3皆在葉綠體。現在根據SOD活性膠的結果指出MnSOD2是阿拉伯芥新發現的SOD。MnSOD2坐落於粒線體，其大小為26.89 kDa。相較於MnSOD1 (25.44 kDa)，MnSOD2有更高的分子量。MnSOD2的表現量不受非生物性逆境或是生物性逆境影響。值得注意的是，相較於MnSOD1，其在種子的表現量特別高。根據原態膠體電泳SOD活性試驗，顯示出msd2種子的胚失去了MnSOD的活性。這結果表明，MnSOD1和MnSOD2在種子發育階段的表達具有組織差異。

關鍵字

超氧岐化酶 ； 錳超氧岐化酶2 ； 活性氧

並列摘要

The over-excessive production of reactive oxygen species (ROS) has to be regulated by superoxide dismutase (SOD) in order to alleviate its toxicity level in plants. Up to date, there are seven genes of SODs in Arabidopsis thaliana which has been characterized. Those are manganese superoxide dismutase 1 (MnSOD1), iron superoxide dismutase 1, 2, and 3 (FeSOD1, FeSOD2, and FeSOD3), and copper/zinc superoxide dismutase 1, 2, and 3 (Cu/ZnSOD1, Cu/ZnSOD2, and Cu/ZnSOD3). These SODs isoenzyme differ in their subcellular localization. MnSOD1 is in the mitochondria matrix, Cu/ZnSOD1 is located in the cytosol, Cu/ZnSOD3 can be found in the peroxisome, and Cu/ZnSOD2, FeSOD1, FeSOD2, and FeSOD3 are in the chloroplast. The current result based on the SOD activity gel revealed that MnSOD2 was a novel type of SOD in Arabidopsis thaliana. MnSOD2 was localized in the mitochondria with an approximate protein mass of 26.89 kDa. MnSOD2 owned higher molecular mass compared to the MnSOD1 (25.44 kDa). The expression level of MnSOD2 was not affected by both abiotic and/or biotic stresses condition. Notably, it had the highest expression level specifically in seeds compared to the MSD1. Based on the SOD activity gel, it showed the embryo of MSD2-mutant seeds lost its MnSOD activity. The results highlighted MnSOD1 and MnSOD2 district expression activity in seed development stages.

並列關鍵字

SOD ； MSD2 ； ROS

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