Goldman M H, Pezzotti M, Seurinck J, Mariani C
Plant Genetic Systems NV, Gent, Belgium.
Plant Cell. 1992 Sep;4(9):1041-51. doi: 10.1105/tpc.4.9.1041.
We have sought to identify pistil-specific genes that can be used as molecular markers to study pistil development. For this purpose, a cDNA library was constructed from poly(A)+ RNA extracted from tobacco stigmas and styles at different developmental stages. Differential screening of this library led to the isolation of cDNA clones that correspond to genes preferentially or specifically expressed in the pistil. Seven of these cDNA clones encode proteins containing repetitions of the pentapeptide Ser-Pro4, which is a typical motif found in extensins. Unlike extensin genes, the extensin-like genes described here are not induced under stress conditions. RNA gel blot hybridizations demonstrated the organ-specific expression of the extensin-like genes and their temporal regulation during pistil development. After pollination, the transcript levels of the pistil-specific extensin-like genes change relative to levels in unpollinated pistils. In situ hybridization experiments showed that at least one of these pistil-specific genes is specifically expressed in cells of the transmitting tissue. The possible roles of the extensin-like proteins in pistils are discussed.
我们试图鉴定可作为分子标记用于研究雌蕊发育的雌蕊特异性基因。为此，从不同发育阶段的烟草柱头和花柱中提取的聚腺苷酸加尾RNA构建了一个cDNA文库。对该文库进行差异筛选，分离出了与在雌蕊中优先或特异性表达的基因相对应的cDNA克隆。其中七个cDNA克隆编码含有五肽Ser-Pro4重复序列的蛋白质，这是伸展蛋白中发现的典型基序。与伸展蛋白基因不同，本文所述的类伸展蛋白基因在胁迫条件下不会被诱导。RNA凝胶印迹杂交证明了类伸展蛋白基因的器官特异性表达及其在雌蕊发育过程中的时间调控。授粉后，雌蕊特异性类伸展蛋白基因的转录水平相对于未授粉雌蕊中的水平发生变化。原位杂交实验表明，这些雌蕊特异性基因中至少有一个在传递组织的细胞中特异性表达。文中讨论了类伸展蛋白在雌蕊中的可能作用。
