Phylogeny and Molecular Evolution of Leguminosae: Nodulation and Nodulin Gene Families

豆科的系统发育和分子进化：结​​瘤和结瘤蛋白基因家族

• 批准号: 9420215
• 负责人: Jeffrey Doyle
• 金额: $ 16.5万
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9420215&HistoricalAwards=false
• 关键词: Phylogeny; Molecular; Evolution; Leguminosae; Nodulation

9420215 Doyle The ability to use atmospheric nitrogen, rather than more complex organic compounds, as a source of nitrogen is a hallmark of the legume family (Leguminosae, the "beans") and a major cause of its great economic and ecological importance. Nitrogen fixation is accomplished biochemically in partnership with soil bacteria ("rhizobia") which are housed in complex organs termed nodules, usually found on the roots of legumes. Among the novel features of nodules are a suite of proteins ("nodulins") produced by the plant predominantly or exclusively in that organ. The origins of many of the genes encoding many of these proteins are unknown; suggestions have included horizontal transfer, gene duplication, or simply recruitment of existing genes for novel purposes. Phylogenetic and taxonomic considerations suggest that nodulation originated more than once within the legume family of plants, yet the biochemical and structural complexity of the nodule might argue for a single origin followed by many independent losses of the ability to nodulate. Dr. Jeff Doyle of Cornell University is studying the origins of genes encoding nodulin proteins in order to test ideas about the number of evolutionary shifts in nitrogen fixation. Research focuses on glutamine synthetase, a protein with an important role in nitrogen transport, encoded by a gene family that has been studied in several crop legumes (soybean, alfalfa, garden bean) but has yet to be studied in legumes more phylogenetically distant from these. The major taxonomic focus is on legumes of the nodulating genus Chamaecrista and its non-nodulating close relative, Senna. Insights into the origins of nodulation in hitherto unstudied legumes should shed light on common mechanisms of gene evolution in this important plant physiological process. ??

9420215 Doyle 使用大气中的氮而不是更复杂的有机化合物作为氮源的能力是豆科植物（Leguminosae，“豆类”）的标志，也是其具有巨大经济和生态重要性的主要原因。 固氮作用是通过与土壤细菌（“根瘤菌”）合作以生物化学方式完成的，土壤细菌位于称为根瘤的复杂器官中，通常存在于豆科植物的根部。 根瘤的新特征之一是植物主要或专门在该器官中产生的一套蛋白质（“结节素”）。 许多编码这些蛋白质的基因的起源尚不清楚。建议包括水平转移、基因复制或简单地招募现有基因用于新目的。 系统发育和分类学的考虑表明，结瘤在豆科植物中不止一次起源，但结瘤的生化和结构复杂性可能支持单一起源，随后许多独立的结瘤能力丧失。 康奈尔大学的杰夫·多伊尔博士正在研究编码结节蛋白的基因的起源，以测试有关固氮进化转变次数的想法。 研究重点是谷氨酰胺合成酶，这是一种在氮转运中发挥重要作用的蛋白质，由一个基因家族编码，该基因家族已在多种豆类作物（大豆、苜蓿、菜豆）中进行了研究，但尚未在系统发育上与这些作物较远的豆类中进行研究。 主要分类学重点是结瘤属 Chamaecrista 及其非结瘤近亲番泻叶属的豆科植物。 对迄今为止尚未研究的豆科植物结瘤起源的深入了解应该有助于揭示这一重要植物生理过程中基因进化的常见机制。 ??