Characterization of structural and regulatory genes of rice nitrite reductase.

以硝酸盐诱导的水稻幼苗为材料，在lambdagt 11噬菌体载体上构建了叶片和根系cDNA文库。从每个文库中克隆出两种不同类型的亚硝酸盐还原酶（NiR） cDNA并进行测序。其中一组DNA序列有一个与分离的近红外蛋白序列匹配的开放阅读框，而另一组cDNA克隆在前一组克隆的阅读框中有一个93 bp的额外序列。该插入序列在真核mRNA中具有5′和3′剪接的一致序列。以水稻基因组DNA为模板，采用PCR技术证实该插入序列存在于水稻核基因组DNA中。水稻近红外基因的完整测序可能为阐明这种不寻常的中间序列在近红外cDNA中存在的生理意义提供线索。

Leaf and root cDNA libraries were constructed in lambdagt 11 phage vector from nitrate-induced greening rice seedlings. Two different types of nitrite reductase (NiR) cDNA from each library were cloned and sequenced. DNA sequence of one group had an open reading frame matched with the isolated NiR protein sequence, while cDNA clone from the other had an addtional sequence of 93 bp in the reading frame of the former clone. The insertion sequence has consensus sequence of 5' and 3' splice junction in eukaryotic mRNA. This inserted DNA sequence was confirmed to exist in rice nuclear genomic DNA by PCR technique using the genomic DNA as a template. Complete sequencing of the rice NiR gene may provide a clue to elucidating physiological significance of this unusual presence of an intervening sequence in NiR cDNA.