Koltunow A. M., Truettner J., Cox K. H., Wallroth M., Goldberg R. B.
Department of Biology, University of California, Los Angeles, California 90024-1606.
Plant Cell. 1990 Dec;2(12):1201-1224. doi: 10.1105/tpc.2.12.1201.
We studied the temporal and spatial regulation of three mRNA sequence sets that are present exclusively, or at elevated levels, in the tobacco anther. One mRNA set accumulates in the tapetum and decays as the tapetum degenerates later in anther development. The second mRNA set accumulates after the tapetal-specific mRNAs, is localized within the stomium and connective, and also decays as these cell types degenerate during anther maturation. The third mRNA sequence set persists throughout anther development and is localized within most anther tissues. A tapetal-specific gene, designated as TA29, was isolated from a tobacco genome library. Runoff transcription studies and experiments with chimeric [beta]-glucuronidase and diphtheria toxin A-chain genes showed that the TA29 gene is regulated primarily at the transcriptional level and that a 122-base pair 5[prime] region can program the tapetal-specific expression pattern. Destruction of the tapetum by the cytotoxic gene had no effect on the differentiation and/or function of surrounding sporophytic tissues but led to the production of male-sterile plants. Together, our studies show that several independent gene expression programs occur during anther development and that these programs correlate with the differentiated state of specific anther cell types.
我们研究了仅在烟草花药中存在或在其中高水平存在的三个mRNA序列集的时空调控。一个mRNA集在绒毡层中积累，并在花药发育后期随着绒毡层的退化而衰减。第二个mRNA集在绒毡层特异性mRNA之后积累，定位于药室和药隔中，并且在花药成熟期间随着这些细胞类型的退化而衰减。第三个mRNA序列集在整个花药发育过程中持续存在，并定位于大多数花药组织中。从烟草基因组文库中分离出一个绒毡层特异性基因，命名为TA29。径流转录研究以及嵌合β-葡萄糖醛酸酶和白喉毒素A链基因的实验表明，TA29基因主要在转录水平上受到调控，并且一个122个碱基对的5′区域可以编程绒毡层特异性表达模式。细胞毒性基因对绒毡层的破坏对周围孢子体组织的分化和/或功能没有影响，但导致了雄性不育植株的产生。总之，我们的研究表明，在花药发育过程中发生了几个独立的基因表达程序，并且这些程序与特定花药细胞类型的分化状态相关。
