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。

基本信息

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

项目摘要

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.

光呼吸是由核糖1,5-双磷酸羧化酶/加氧酶催化的氧合反应引起的。在此反应中，产生乙二醇2-P，然后在光呼吸途径中代谢，形成甘油酸3-P。在此过程中，释放二氧化碳和NH4+，并且消耗了ATP和减少等价物，从而使光呼吸成为浪费的过程。通过将两个替代性和完整的乙醇酸分解代谢循环引入C3叶绿体中，我们试图创建一个自动调节周期，从而导致光刺激的衰减和二氧化碳同化效率的预期提高，从而使生物量更快。模型植物拟南芥将用于建立并表征新的途径。进一步的一步，新的乙醇酸循环将被引入具有农艺兴趣的植物，例如番茄或马铃薯。另一方面，在我们先前的工作中，塔利亚纳（A. thaliana）中每种途径的单个活动引入了具有有趣且意外的表型的转基因植物（例如，盐耐药性，光周期依赖性的淡绿色玫瑰花结和加速的黑暗诱发衰老）。将对这些转基因植物进行彻底的代谢表征，以阐明转基因表达引入的生理改变。