Two maize genes encoding ω-3 fatty acid desaturase and their differential expression to temperature
Two maize genes encoding ω-3 fatty acid desaturase and their differential expression to temperature
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DOI：
10.1023/a:1005993408270
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发表时间：
1998-01-01
影响因子：
5.1
通讯作者：
Kusano, T
中科院分区：
文献类型：
--
作者：
Berberich, T;Harada, M;Kusano, T
我们以拟南芥FAD7基因为探针，分离了两个编码脂肪酸去饱和酶的玉米cdna及其相应基因。他们在DNA序列水平上几乎有90%的相似性。Northern分析表明，在常温和低温生长条件下，这两个基因在叶片中表达，而在根中不表达。这些转录本的总体水平在低温下升高。组织特异性表达和DNA序列数据表明，这两个基因编码可塑的omega-3脂肪酸去饱和酶。其中一个在常温下完全表达，而在5℃下不表达，而另一个则相反表达。因此，我们将它们分别命名为ZmFAD7和ZmFAD8。在其他胁迫中，高盐处理诱导ZmFAD7和ZmFAD8转录本在根系中积累，而干旱对其表达没有影响。环己亚胺诱导ZmFAD7转录物在根中积累。ZmFAD7和ZmFAD8基因组克隆由8个外显子和7个内含子组成，与拟南芥FAD7和FAD8基因相同，且6个内外显子的大小相同。并对ZmFAD7、ZmFAD8氨基酸序列和其他植物源氨基酸序列进行了系统发育分析。
We have isolated two maize cDNAs and the corresponding genes encoding fatty acid desaturase with Arabidopsis thaliana FAD7 gene as a probe. They shared almost 90% identity at DNA sequence level. Northern analysis revealed that both genes are expressed in leaves, but not in roots at normal temperature-and low temperature-growth condition. The overall level of these transcripts are elevated upon exposure to low temperature. The tissue-specific expression and DNA sequence data indicate that both genes encode plastidic omega-3 fatty acid desaturases. One of them is expressed exclusively at normal temperature but not at 5 OC, whereas the other is expressed inversely. We, therefore, termed them ZmFAD7 and ZmFAD8, respectively. Among other stresses, high-salt treatment induced the accumulation of the ZmFAD7 and ZmFAD8 transcripts in roots but drought had no effect on their expression. Cycloheximide induced the accumulation of the ZmFAD7 transcript in roots. The genomic clones of ZmFAD7 and ZmFAD8 consist of 8 exons and 7 introns as same as in the cases of A. thaliana FAD7 and FAD8 genes and the sizes of the 6 internal exons were identical among them. A phylogenetic analysis of ZmFAD7, ZmFAD8 amino acid sequences and those originated from other plant species is also presented.