The role of carbonic anhydrase in photosynthesis in Arabidopsis

碳酸酐酶在拟南芥光合作用中的作用

• 批准号: 1146597
• 负责人: James Moroney
• 金额: $ 50万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1146597&HistoricalAwards=false
• 关键词: role; carbonic; anhydrase; photosynthesis; Arabidopsis

This project will investigate whether carbonic anhydrase (CA), an enzyme that catalyzes the interconversion of CO2 and HCO3-, facilitates CO2 fixation in plants that perform C3 photosynthesis. Moroney et al. (2001) Plant, Cell Environ. 24: 141 reported that Arabidopsis possesses at least 14 CA genes. Preliminary results showed that a double mutant missing two cytosolic CAs, βCA2 and βCA3, exhibited reduced growth and a reduced affinity for CO2 indicating these CAs play an integral role in CO2 fixation. The overall goal of this project is to determine the roles and importance of different CA enzymes for photosynthesis in C3 plants. The work will involve a molecular characterization of leaf CAs in Arabidopsis and a reverse genetics approach to obtain knockout Arabidopsis plants missing one or more CA isoforms. Using the knock-out plants, the physiological roles of the specific CA isoforms will be determined by measuring gas exchange, mesophyll conductance, and isotopic discrimination in whole plants. Recently, Zhu et al. (2010) Ann Rev. Plant Biol. 61: 235 pointed out that a significant limitation to CO2 fixation in C3 plants is the resistances to the diffusion of CO2 from outside mesophyll cells to chloroplasts. This research project will increase our understanding of the factors that affect CO2 fixation allowing scientists to better formulate strategies to improve CO2 delivery and crop yield particularly in the face of increasing atmospheric CO2. This project will be an important component in the education of graduate and undergraduate students. At LSU, there are many programs to foster participation of a diverse group of students in hands-on research, providing a framework for these students to go on to successful careers in industry, medicine and academics.

本项目将研究碳酸酐酶（CA），一种催化CO2和HCO 3-相互转化的酶，是否有助于进行C3光合作用的植物固定CO2。Moroney等人（2001）Plant，Cell Environ. 24：141报道了拟南芥至少拥有14个CA基因。 初步结果显示，缺失两个胞质CA（#946; CA 2和#946; CA 3）的双突变体表现出生长减少和对CO2的亲和力降低，表明这些CA在CO2固定中起着不可或缺的作用。本项目的总体目标是确定不同CA酶在C3植物光合作用中的作用和重要性。这项工作将涉及拟南芥叶CA的分子特征和反向遗传学方法，以获得敲除拟南芥植物缺失一个或多个CA亚型。使用敲除植物，将通过测量整个植物中的气体交换、叶肉传导性和同位素辨别来确定特定CA同工型的生理作用。最近，Zhu等人（2010）Ann Rev. Plant Biol.61：235指出，C3植物中CO2固定的显著限制是对CO2从叶肉细胞外部扩散到叶绿体的抗性。该研究项目将增加我们对影响CO2固定的因素的了解，使科学家能够更好地制定策略，以改善CO2的输送和作物产量，特别是在大气CO2增加的情况下。该项目将成为研究生和本科生教育的重要组成部分。 在路易斯安那州立大学，有许多计划，以促进学生在实践研究的多元化群体的参与，为这些学生提供了一个框架，继续在工业，医学和学术事业的成功。