Budelier K A, Smith A G, Gasser C S
Plant Gene Expression, Monsanto Company, St. Louis, MO 63198.
Mol Gen Genet. 1990 Nov;224(2):183-92. doi: 10.1007/BF00271551.
We have characterized a gene, 9612, that is expressed predominantly in the styles of tomato pistils according to a tightly regulated temporal program. 9612 RNA levels were maximal in mature pistils from flowers at anthesis, with transcripts undetectable in pistils from flowers collected 5-7 days prior to anthesis. In situ localization of mRNA in tissue sections showed that expression of the gene is confined in the pistil to the outer five cell layers of the strands of transmitting tissue within the upper two-thirds of the style. The maximal levels of 9612 RNA detected in anthers and vegetative organs were more than 50-fold and 250-fold lower than the level in pistils, respectively. A homolog to the 9612 gene was detected in tobacco and was also found to be expressed predominantly in the style. The ability of the 5' flanking region of the tomato gene to appropriately regulate expression of a heterologous coding sequence was examined in transformed tomato and tobacco plants. In contrast to results with previously described regulated genes, the 9612 promoter functions correctly in the pistils of tomato plants, but fails to direct correct expression in tobacco plants. The sequence of the 9612 cDNA includes an open reading frame encoding a polypeptide of 404 amino acids with a highly hydrophobic amino-terminal region that may represent a signal peptide.
我们鉴定了一个名为9612的基因，该基因根据严格调控的时间程序，主要在番茄雌蕊的花柱中表达。9612 RNA水平在花期花朵的成熟雌蕊中最高，而在花期前5 - 7天采集的花朵的雌蕊中检测不到转录本。组织切片中mRNA的原位定位显示，该基因在雌蕊中的表达局限于花柱上三分之二处的传递组织束的外侧五个细胞层。在花药和营养器官中检测到的9612 RNA的最高水平分别比雌蕊中的水平低50倍和250倍以上。在烟草中检测到了9612基因的一个同源物，并且也发现它主要在花柱中表达。在转化的番茄和烟草植株中检测了番茄基因5'侧翼区域适当调控异源编码序列表达的能力。与先前描述的调控基因的结果相反，9612启动子在番茄植株的雌蕊中功能正常，但在烟草植株中不能指导正确的表达。9612 cDNA的序列包含一个开放阅读框，编码一个由404个氨基酸组成的多肽，其氨基末端区域具有高度疏水性，可能代表一个信号肽。
