A genetic engineering approach to improve the carbon fixation in C3 plants by reducing the flux through the photorespiratory pathway. Consequences of the expression of novel activities in chloroplasts of A. thaliana

一种通过减少光呼吸途径通量来改善 C3 植物碳固定的基因工程方法。

• 批准号: 41426985
• 负责人: Professorin Dr. Veronica Maurino
• 金额: --
• 依托单位: Abteilung Molekulare Pflanzenphysiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/41426985?language=en
• 关键词: genetic; engineering; approach; improve; carbon

Photorespiration results from the oxygenation reaction catalysed by ribulose 1,5-bisphosphate carboxylase/oxygenase. In this reaction glycolate 2-P is produced and subsequently metabolised in the photorespiratory pathway to form glycerate 3-P. During this process, CO2 and NH4+ are released and ATP and reducing equivalents are consumed, thus making photorespiration a wasteful process. By introducing two alternative and complete glycolate catabolic cycles into C3 chloroplasts, we attempt to create an autoregulatory cycle which results in an attenuation of photorespiration and an expected improvement in the efficiency of CO2 assimilation and consequently, faster biomass production. The model plant Arabidopsis thaliana will be used to set up and characterized the novel pathways. In a further step, the new glycolate cycles will be introduced into plants with agronomical interest, like tomato or potato. On the other hand, during our previous work the introduction of single activities for each pathway in A. thaliana rendered transgenic plants with interesting and unexpected phenotypes (e.g., salt resistance, photoperiod-dependent pale green rosettes and accelerated dark-induced senescence). A thorough metabolic characterization of these transgenic plants will be performed to clarify the physiological alterations introduced with the expression of the transgenes.

光呼吸是由核酮糖1,5-二磷酸羧化酶/加氧酶催化的氧化反应产生的。在这个反应中，产生甘油酸2-P，随后在光呼吸途径中代谢形成甘油酸3-P。在这个过程中，CO2和NH4+被释放，ATP和还原性等价物被消耗，从而使光呼吸成为一个浪费的过程。通过在C3叶绿体中引入两个替代的和完整的乙醇酸分解代谢循环，我们试图创建一个自调节循环，其结果是光呼吸的衰减和二氧化碳同化效率的预期改善，从而更快的生物质生产。模式植物拟南芥将被用来建立和表征新的途径。在进一步的步骤中，新的乙醇酸循环将被引入具有农艺学意义的植物，如西红柿或土豆。另一方面，在我们之前的工作中，在拟蓝中引入每个途径的单一活性，使转基因植物具有有趣的和意想不到的表型（例如，耐盐性，依赖光周期的淡绿色莲座和加速黑暗诱导的衰老）。将对这些转基因植物进行彻底的代谢表征，以阐明转基因表达所带来的生理改变。