Cushman J C, Meiners M S, Bohnert H J
Department of Biochemistry, University of Arizona, Tucson 85721.
Plant Mol Biol. 1993 Feb;21(3):561-6. doi: 10.1007/BF00028814.
The 5' flanking region of a salt-stress-inducible, CAM-specific phosphoenolpyruvate carboxylase (PEPC) gene from the facultative halophyte Mesembryanthemum crystallinum, was fused to the beta-glucuronidase (GUS) reporter gene and introduced into Nicotiana tabacum SR1. The Ppc1 promoter displayed high levels of expression in transgenic tobacco quantitatively and qualitatively similar to a full-length 35S CaMV-GUS construct. Histochemical assays revealed that the full-length Ppc1-GUS fusions expressed GUS activity in all tissues except in root tips. While tobacco is capable of utilizing the Ppc1 cis-acting regulatory regions from M. crystallinum to yield high levels of constitutive expression, this glycophyte fails to direct a stress-inducible pattern of gene expression typical of this promoter in its native, facultative halophytic host.
将兼性盐生植物冰叶日中花中一个盐胁迫诱导型、景天酸代谢（CAM）特异性磷酸烯醇式丙酮酸羧化酶（PEPC）基因的5'侧翼区域，与β-葡萄糖醛酸酶（GUS）报告基因融合，并导入烟草SR1中。Ppc1启动子在转基因烟草中表现出高水平的表达，在定量和定性方面与全长35S CaMV - GUS构建体相似。组织化学分析表明，全长Ppc1 - GUS融合体在除根尖外的所有组织中都表达GUS活性。虽然烟草能够利用来自冰叶日中花的Ppc1顺式作用调控区域产生高水平的组成型表达，但这种甜土植物无法在其天然的兼性盐生宿主中指导该启动子典型的胁迫诱导型基因表达模式。
