Auxin-Responsive Promoters and Auxin-Induced Growth

生长素响应启动子和生长素诱导的生长

• 批准号: 9303956
• 负责人: Thomas Guilfoyle
• 金额: $ 30万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9303956&HistoricalAwards=false
• 关键词: Auxin; Responsive; Promoters; Induced; Growth

9303956 Guilfoyle The plant hormone, auxin, plays roles in cell division, extension, and differentiation. Dr. Guillfoyle has cloned a number of auxin responsive genes (GH1, GH2/4, GH3, and SAURs) from soybean, pea and Arabidopsis that are expressed in meristems, epidermal and cortical cells within elongation zones, vascular tissues, and/or developing xylem elements. Each of these gene families shows distinct tissue, organ, and developmental specific patterns of expression. The functions of the auxin responsive gene products are under investigation. The GH2/4 gene encodes a putative glutathione S- transferase. The promoters for these genes are being analyzed in transgenic plants and by particle gun bombardment of soybean and transient expression in carrot cells. Putative auxin responsive elements (AuxREs) have been identified and transcription factors that bind to the AuxREs are being cloned. The auxin responsive promoters have been used to monitor auxin regulated gene expression during tropisms, xylogenesis, rooting, flowering, and seed formation. These promoters have also been used to drive expression of auxin and cytokinin biosynthetic genes and a gene encoding an auxin conjugating enzyme in transgenic plants. The tissue and organ specific expression of these hormone modifying genes produces a number of changes in plant growth and development, as well as changes in cell fate. The transgenic plants with altered hormone levels are being used along with Arabidopsis gravitropic mutants to study alterations in expression of auxin responsive genes. Dr. Guilfoyle is proposing to 1) determine precisely what sequence elements make a gene auxin responsive; to determine if more than one type of AuxRE exists in different auxin responsive genes and to clone and analyze the transcription factors that interact with the AuxREs; 2) to use the AuxREs or auxin responsive promoters as molecular probes to study gene expression during auxin regulated growth and development; to use transgenic plants that overproduce or conjugate auxin or overproduce cytokinins as tools to study auxin regulated gene expression; 3) to gain insight into the functions of the auxin responsive gene products and their possible roles in auxin action; and 4) to take advantage of the chimeric constructs to identify auxin responsive mutants; to search for mutants in the auxin signal transduction pathway(s). The long range goals of this research are to understand how auxin regulates gene expression and how signals are transduced from the auxin receptor to events such as cell expansion, cell division, and plant development; to manipulate auxin responsive promoters, auxin responsive gene products and/or auxin or cytokinin biosynthetic genes to modify plant growth and development in beneficial ways. ***

植物激素生长素在细胞分裂、扩展和分化中起作用。Guillfoyle博士从大豆、豌豆和拟南芥中克隆了许多生长素应答基因（GH1、GH2/4、GH3和SAURs），这些基因在分生组织、表皮和皮层细胞的伸长区、维管组织和/或发育的木质部元素中表达。这些基因家族中的每一个都显示出不同的组织、器官和发育特定的表达模式。生长素反应基因产物的功能正在研究中。GH2/4基因编码一种假定的谷胱甘肽S转移酶。这些基因的启动子已在转基因植物、大豆粒子枪轰击和胡萝卜细胞中的瞬时表达中进行了分析。推测的生长素应答元件（AuxREs）已经被鉴定出来，与AuxREs结合的转录因子正在被克隆。生长素响应启动子已被用于监测生长素调控基因在向性、木质化、生根、开花和种子形成过程中的表达。这些启动子还被用于驱动转基因植物中生长素和细胞分裂素生物合成基因以及编码生长素偶联酶的基因的表达。这些激素修饰基因的组织和器官特异性表达使植物生长发育发生许多变化，也改变细胞命运。激素水平改变的转基因植物与拟南芥向地性突变体一起被用于研究生长素反应基因表达的变化。吉尔福约尔博士建议：1)精确确定哪些序列元素使一个基因对生长素产生反应；确定不同生长素应答基因中是否存在多种AuxRE，并克隆和分析与AuxRE相互作用的转录因子；2)利用AuxREs或生长素响应启动子作为分子探针，研究生长素调控生长发育过程中的基因表达；利用过量产生或结合生长素或过量产生细胞分裂素的转基因植物作为研究生长素调控基因表达的工具；3)深入了解生长素应答基因产物的功能及其在生长素作用中的可能作用；4)利用嵌合结构鉴定生长素应答突变体；寻找生长素信号转导通路中的突变体。本研究的长期目标是了解生长素如何调节基因表达，以及信号如何从生长素受体转导到细胞扩增、细胞分裂和植物发育等事件；操纵生长素响应启动子、生长素响应基因产物和/或生长素或细胞分裂素生物合成基因，以有益的方式改变植物的生长发育。＊＊＊