Khoudi H, Vézina L P, Mercier J, Castonguay Y, Allard G, Laberge S
Department de Phytologie, Université Laval, Sainte-Foy, Québec, Canada.
Gene. 1997 Sep 15;197(1-2):343-51. doi: 10.1016/s0378-1119(97)00282-5.
A genomic clone of RbcS was isolated from an alfalfa (Medicago sativa L. cv. Apica) genomic library and characterized. Although this clone has structural features similar to a functional gene, the second exon is interrupted by a stop codon and thus is not fully translatable in the plant. Sequence analysis of the 5' and 3' noncoding regions of RbcSK-1A showed a high sequence homology to the flanking sequences of the RbcS-3A gene from pea. The regions of homology contain many important cis-regulatory elements shown to be essential for regulation of the RbcS-3A gene in pea. The promoter of this alfalfa rubisco clone was used in a translational fusion to test its ability to control the expression of the GUS reporter gene in an homologous nuclear background. High levels of GUS enzyme activity were recorded. These strong levels are comparable to some exceptionally high levels produced in other studies following the use of photosynthesis gene promoters in fusions with the GUS reporter gene.
从紫花苜蓿（Medicago sativa L. cv. Apica）基因组文库中分离并鉴定了RbcS的一个基因组克隆。尽管该克隆具有与功能基因相似的结构特征，但第二个外显子被一个终止密码子打断，因此在植物中不能完全翻译。对RbcSK - 1A的5'和3'非编码区的序列分析表明，其与豌豆RbcS - 3A基因的侧翼序列具有高度的序列同源性。同源区域包含许多重要的顺式调控元件，这些元件已被证明对豌豆中RbcS - 3A基因的调控至关重要。该紫花苜蓿核酮糖二磷酸羧化酶克隆的启动子用于翻译融合，以测试其在同源核背景下控制GUS报告基因表达的能力。记录到了高水平的GUS酶活性。这些高水平与其他研究中在将光合作用基因启动子与GUS报告基因融合后产生的一些异常高水平相当。
