Whitelaw Catherine A, Lyssenko Nicholas N, Chen Liwei, Zhou Dingbo, Mattoo Autar K, Tucker Mark L
Soybean Genomics Improvement Laboratory, United States Department of Agriculture, Building 006, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA.
Plant Physiol. 2002 Mar;128(3):978-87. doi: 10.1104/pp.010782.
Stable transformation of tomato (Lycopersicon esculentum cv Ailsa Craig) plants with a construct containing the antisense sequence for the receiver domain and 3'-untranslated portion of the tomato ethylene receptor (LeETR1) under the control of an enhanced cauliflower mosaic virus 35S promoter resulted in some expected and unexpected phenotypes. In addition to reduced LeETR1 transcript levels, the two most consistently observed phenotypes in the transgenic lines were delayed abscission and reduced plant size. Fruit coloration and softening were essentially unaffected, and all the seedlings from first generation seed displayed a normal triple response to ethylene. Two independent lines with a single copy of the transgene and reduced LeETR1 transcript accumulation were selected for detailed phenotypic analysis of second generation (R1) plants. Delayed abscission, shorter internode length, and reduced auxin movement all correlated with the presence of the transgene and the degree of reduced LeETR1 transcript accumulation. No significant differences were noted for fruit coloration or fruit softening on R1 plants and all seedlings from R1 and R2 seed displayed a normal triple response. LeETR2 transcript accumulation was only slightly reduced in the R1 plants compared with azygous plants, and LeETR3 (NR) transcript levels appeared to be unaffected by the transgene. We propose that ethylene signal transduction occurs through parallel paths that partially intersect to regulate shared ethylene responses.
用一个构建体对番茄（Lycopersicon esculentum cv Ailsa Craig）植株进行稳定转化，该构建体包含在增强型花椰菜花叶病毒35S启动子控制下的番茄乙烯受体（LeETR1）受体结构域和3'-非翻译区的反义序列，结果产生了一些预期和意外的表型。除了LeETR1转录水平降低外，转基因系中最常观察到的两种表型是脱落延迟和植株大小减小。果实着色和软化基本未受影响，第一代种子的所有幼苗对乙烯都表现出正常的三重反应。选择两个具有单个转基因拷贝且LeETR1转录积累减少的独立株系，对第二代（R1）植株进行详细的表型分析。脱落延迟、节间长度缩短和生长素移动减少均与转基因的存在以及LeETR1转录积累减少的程度相关。R1植株的果实着色或果实软化未观察到显著差异，R1和R2种子的所有幼苗对乙烯都表现出正常的三重反应。与非转基因植株相比，R1植株中LeETR2转录积累仅略有降低，而LeETR3（NR）转录水平似乎不受转基因影响。我们提出乙烯信号转导通过部分相交以调节共享乙烯反应的平行途径发生。
