Arabidopsis 2010: A New Pathway for GSH Metabolism in Plants

智力优势：植物生长和作物产量对环境中的有毒化学物质非常敏感，不仅包括土壤中的重金属和异物，还包括空气中的氧气，后者可以反应产生破坏性的氧自由基。谷胱甘肽(GSH)是一种由常见氨基酸组成的小分子，是保护动植物免受许多有毒化学物质伤害的关键，GSH-抗坏血酸循环可清除危险的氧自由基。创造对环境压力更具抵抗力的植物，从而使作物在不利条件下保持产量，需要详细了解如何控制GSH水平，包括它是如何产生的，以及它是如何分解的。虽然人们对谷胱甘肽的合成和调节了解很多，但对谷胱甘肽是如何分解的却知之甚少。这项拟南芥2010年的研究项目研究了一种新发现的酶活性，称为伽马-谷氨酰环转移酶，实验表明，该酶催化了模式植物拟南芥中大部分GSH的分解。这个项目中的实验将确定植物中负责这种酶活性的基因和蛋白质。将结合蛋白质化学和基因组学技术来鉴定拟南芥中的该基因。随后的基因实验将被用来验证分离的基因是负责GSH周转的，以及GSH周转是如何相对于合成进行调节的。所获得的信息将使旨在设计或选择具有更高潜力保护自己免受环境威胁的植物的实验成为可能。此外，由于GSH存在于所有生物体中，在GSH代谢途径中发现一个新的分支对于理解所有生物体如何在含氧环境中生存具有变革性。广泛影响：为了使研究界受益，通过该项目产生的数据和信息将通过拟南芥信息资源(TAIR：www.arabidopsis.org)提供。种子库存和任何独特的dna材料将通过abrc(http://www.biosci.ohio-state.edu/~plantbio/Facilities/abrc/abrchome.htm).提供。为了加强教育，该项目将让本科生参与研究和专业发展活动，旨在让他们接触先进的生物技术，并使他们能够在STEM学科中继续职业生涯。一名博士后研究助理将接受研究和指导方面的培训，为教师职业生涯做准备。此外，本科生将与PI和博士后助理合作开发一个线粒体模块，该模块将包含在虚拟3D细胞中，这是一个基于网络的视频环境，旨在向大学预科和初学者教授植物细胞生物学的基础知识。

Intellectual Merit:Plant growth and crop yields are very sensitive to toxic chemicals in their environment, including not only heavy metals and xenobiotics in the soil, but also oxygen in the air, which can react to produce destructive oxygen radicals. Glutathione (GSH) is a small molecule made from common amino acids that is key in protecting plants and animals from many toxic chemicals, and the GSH-ascorbate cycle detoxifies dangerous oxygen radicals. Creating plants that are more resistant to environmental stresses and therefore crops that maintain their yields under unfavorable conditions, requires detailed knowledge of how GSH levels are controlled, both through how it is made and how it is broken down. While a lot is known about GSH synthesis and regulation, very little is known about how GSH is broken down. This Arabidopsis 2010 research project investigates a newly discovered enzyme activity, termed gamma-glutamyl cyclotransferase, which experiments suggest catalyzes a majority of GSH break down in the model plant Arabidopsis thaliana. Experiments in this project will define the gene and protein that are responsible for this enzyme activity in plants. A combination of protein chemistry and genomics techniques will be employed to identify the gene in Arabidopsis. Subsequent genetic experiments will be used to verify that the isolated gene is responsible for GSH turnover and how GSH turnover is regulated relative to synthesis. Information gained will enable experiments designed to engineer or select plants with elevated potential for defending themselves from environmental threats. In addition, because GSH is found in all organisms, discovery of a new branch in the pathway of GSH metabolism is transformative with regard to understanding how all organisms survive in an oxygen containing environment.Broader Impacts:To benefit the research community, data and information generated through this project will be made available through the Arabidopsis Information Resource (TAIR: www.arabidopsis.org). Seed stocks and any unique DNA materials will be made available through ABRC (http://www.biosci.ohio-state.edu/~plantbio/Facilities/abrc/abrchome.htm). To enhance education, the project will engage undergraduate students in research and professional development activities that are designed to expose them to advanced biotechnology, and enable them to continue careers in STEM disciplines. A postdoctoral research associate will be trained in research and mentoring, in preparation for a faculty career. In addition, undergraduates will work with the PI and the postdoctoral associate to develop a module on mitochondria to be included in the "Meta!Blast" virtual 3D cell, a web-based video environment designed to teach the basics of plant cell biology to precollege and beginning college students.