Chromatin Potentiation and ABA Activation of Phaseolin Transcription

该项目的长期目标是获得对高等生物中基因控制机制的新见解。基因启动子包含的信息指明了基因将在哪些组织中表达、表达多少以及何时表达。这里研究的基因，phases，编码豆类种子的营养蛋白phaseolin。相启动子可以被转化（移动）到实验室实验植物拟南芥的基因组中，在拟南芥中，与豆类一样，它在种子形成（胚胎发生）期间活跃，但在其他地方不活跃。先前的研究表明，如果拟南芥在叶片和其他营养组织中表达的可诱导启动子的控制下，额外（超）转化一种特殊的“B3”型转录因子（PvALF），则可以在叶片中检测到由相启动子驱动的报告物质的存在。其他先前的研究表明，阶段启动子的非表达（沉默）形式受到其组织成一个称为核小体的单位的保护。因此，在超转化的拟南芥叶组织中，PvALF的控制表达改变了抑制性核小体结构，允许研究沉默期启动子变得活跃时发生的变化。PvALF因子的修饰将使我们了解它的哪些部分是刺激核小体重塑所必需的。同时，可以使用特异性抗体研究核小体组蛋白（碱性蛋白）成分的化学状态，以深入了解其重塑过程中的变化。该项目将为研究生和本科生提供培训机会，并在农业生物技术方面具有潜在的应用前景。

The long-term goal of this project is to gain new insight to mechanisms by which genes are controlled in higher organisms. Gene promoters contain information specifying the tissues in which the gene will be expressed, how much will be expressed and when it will be expressed. The gene studied here, phas, encodes the nutritional protein, phaseolin, of bean seeds. The phas promoter can be transformed (moved) into the genome of the laboratory experimental plant Arabidopsis where, as in bean, it is active during seed formation (embryogenesis) but nowhere else. Previous work has demonstrated that, if Arabidopsis is additionally (super-) transformed with a special "B3" type of transcription factor (PvALF) under the control of an inducible promoter that allows expression in leaves and other vegetative tissues, the presence of reporter substances driven by the phas promoter can be detected in leaves. Other previous studies showed that the non-expressing (silent) form of the phas promoter is protected by its organization into a unit known as a nucleosome. Thus, the controlled expression of PvALF in supertransformed Arabidopsis leaf tissues alters the repressive nucleosome structure, allowing investigation of the changes taking place as the silent phas promoter becomes active. Modification of the PvALF factor will permit an understanding of what parts of it are necessary for stimulation of the nucleosome remodeling. Simultaneously, analysis of the chemical status of the histone (basic protein) component of the nucleosome can be studied using specific antibodies to gain insight to the changes involved in its remodeling. The project will provide training opportunities to graduate and undergraduate students and has potential applications in agricultural biotechnology.