水稻含銅鋅超氧歧化酶之選殖與性質研究

Isolation and Characterization of a eDNA for CuZn-Superoxide Dismutase of Rice

以RT-PCR合成水稻之含銅鋅超氧歧化酶基因片段（0.3-Kb）。經序列分析證實後，以此0.3-KbDNA做為探針從水稻cDNA library篩選得到CuZnSOD之全長cDNA，其DNA及對應之amino acid序列與多種植物CuZnSOD之序列有很高之同源性。北方轉印結果顯示，熱或乾旱處理水稻幼苗後，其CuZnSOD對應之mRNA增加。南方轉印顯示水稻CuZnSOD之基因多於一個。

RT-PCR was used for the SOD-DNA amplification from rice total RNA in a two-step reaction. Using this PCR-made SOD-DNA as the probe to screen a rice λgt11 cDNA library, four putative clones of CuZnSOD were isolated. The clone having the largest insert was subcloned and sequenced. This eDNA clone had a full-length open reading frame of 459bp corresponding to 152 amino acid residues and the derived amino acid sequence from this clone matched the cytosolic CuZnSOD isozyme. Its amino acid sequence showed approximately 99 and 86% identity to rice and corn CuZnSOD sequences. Northern blot hybridization showed that the heat-shock, drought-treated rice seedlings had the enhanced transcripts of CuZnSOD. Genomic Southern analysis indicated that CuZnSODs in rice was encoded by multigenes.