CAREER: Genetic Engineering Approaches for the in Vivo Study of Plant Metabolism of Selenium and Other Oxyanions

职业：硒和其他氧离子植物代谢体内研究的基因工程方法

• 批准号: 9982432
• 负责人: Elizabeth Pilon-Smits
• 金额: $ 46.63万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9982432&HistoricalAwards=false
• 关键词: CAREER; Genetic; Engineering; Approaches; Vivo

Selenium (Se) and sulfur metabolism in plants are thought to make use of the same enzymes. Previous studies by this investigator have shown that overexpression of ATP sulfurylase (involved in sulfate reduction) promotes selenate reduction and leads to accumulation of organic selenium. The goals of this project are to pinpoint more enzymes that are rate-controlling for Se fluxes in plants, and to clarify any involvement of the sulfate assimilation enzymes in uptake and reduction of the related elements tellurium, molybdenum, and tungsten. Selenocysteine appears to be a control point for Se allocation into proteins (toxic), into volatile forms, or into various accumulated forms. By overexpression of two enzymes, two different Se "sinks" will be created: one as low-toxic, insoluble elemental Se, the other as low-toxic volatile Se. The effects of these new Se sinks on the Se fluxes in the plant will be tested by measuring the forms of Se accumulated by the transgenic plants, and by measuring their Se tolerance, accumulation and volatilization. To study the effect of simultaneous overexpression of two enzymes in the pathway, different transgenics will be crossed and the Se fluxes in the double-transgenics studied. The other objective of this project is to test the hypothesis that the sulfate assimilation pathway is also involved in uptake and reduction of tellurate, molybdate, and tungstate. To this end, available transgenic Indian mustard plants (Brassica juncea) that overexpress enzymes involved in uptake and reduction of sulfate/selenate will be analyzed for tolerance and accumulation of tellurium, molybdenum and tungsten, and for the accumulated forms of these elements. The new information generated by these studies may be employed for the genetic manipulation of plants with altered metabolic properties, e.g. with enhanced or reduced trace element accumulation. This is of significance since these elements are of environmental and/or medical importance, as pollutants, micronutrients, etc. An essential part of this CAREER project will be the development of a graduate course on environmental cleanup using plants (phytoremediation) and a senior-level plant physiology course. These courses will be designed to make optimal use of multimedia and on-line resources.

硒（Se）和硫在植物中的代谢被认为是利用相同的酶。该研究者先前的研究表明，ATP硫酸化酶（参与硫酸盐还原）的过度表达促进了硒酸盐还原，并导致有机硒的积累。本项目的目标是查明更多的酶，是速率控制硒通量在植物中，并澄清任何参与的硫酸盐同化酶的吸收和减少相关元素碲，钼，钨。硒半胱氨酸似乎是硒分配到蛋白质（有毒），挥发性形式，或各种积累形式的控制点。 通过两种酶的过度表达，将产生两种不同的Se“汇”：一种是低毒的不溶性元素Se，另一种是低毒的挥发性Se。这些新的硒汇对植物中硒通量的影响将通过测定转基因植物积累的硒的形式，并通过测定它们的硒耐受性、积累和挥发来测试。为了研究两种酶在该途径中同时过表达的效果，将交叉不同的转基因，并研究双转基因中的Se通量。本项目的另一个目的是检验硫酸盐同化途径也参与碲酸盐、碲酸盐和钨酸盐的吸收和还原的假设。为此，将分析过量表达参与吸收和还原硫酸盐/硒酸盐的酶的可用转基因印度芥菜植物（芥菜）的碲、钼和钨的耐受性和积累，以及这些元素的积累形式。这些研究所产生的新信息可用于改变代谢特性的植物的遗传操作，例如增强或减少微量元素积累。这是重要的，因为这些元素是环境和/或医疗的重要性，作为污染物，微量营养素等，这个职业生涯项目的一个重要组成部分将是一个研究生课程的开发环境清理使用植物（植物修复）和高级植物生理学课程。这些课程的设计将充分利用多媒体和联机资源。