Comai L, Matsudaira K L, Heupel R C, Dietrich R A, Harada J J
Department of Botany, University of California, Davis, California 95616.
Plant Physiol. 1992 Jan;98(1):53-61. doi: 10.1104/pp.98.1.53.
To study gene regulation during the transition from late embryogeny to germination, we have analyzed the expression of a gene encoding the glyoxylate cycle enzyme malate synthase in transgenic tomato (Lycopersicon esculentum) plants. We have shown that although there are at least four classes of malate synthase genes in Brassica napus L., one gene is expressed at a high level during both late embryogeny and postgermination. Analyses of transgenic tomato plants containing the expressed B. napus gene along with 4.7 and 1.0 kilobase pairs of 5' and 3' flanking sequences, respectively, confirmed that a single gene is expressed at both stages of development. Furthermore, localization studies have shown that mRNA encoded by the B. napus gene is distributed throughout the tissues of a mature embryo but is not detected in the vascular cylinder of a seedling. We conclude that the sequences required to qualitatively regulate the gene correctly over the plant life cycle are present within the transferred gene and/or flanking regions. Moreover, the malate synthase gene is regulated differently during late embryogeny and postgermination in the developing vascular cylinder.
为了研究从胚胎发育后期到种子萌发过程中的基因调控，我们分析了编码乙醛酸循环酶苹果酸合酶的基因在转基因番茄（Lycopersicon esculentum）植株中的表达情况。我们已经表明，尽管甘蓝型油菜（Brassica napus L.）中至少有四类苹果酸合酶基因，但其中一个基因在胚胎发育后期和种子萌发后均高水平表达。对分别含有4.7千碱基对的5'侧翼序列和1.0千碱基对的3'侧翼序列以及表达的甘蓝型油菜基因的转基因番茄植株进行分析，证实了单个基因在两个发育阶段均有表达。此外，定位研究表明，甘蓝型油菜基因编码的mRNA分布于成熟胚的所有组织中，但在幼苗的维管束中未检测到。我们得出结论，在植物生命周期中对该基因进行定性调控所需的序列存在于转移基因和/或侧翼区域内。此外，苹果酸合酶基因在发育中的维管束的胚胎发育后期和种子萌发后受到不同的调控。
