Abstract

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 cDNA 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.

中文摘要

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 Kb DNA 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。

Keyword: Superoxide dismutase, rice, CuZnSOD cDNA. 超氧歧化酶，基因選殖，水稻。