联合固氮菌的合成生物学研究进展

Advances in synthetic biology of associated nitrogen-fixation bacteria

摘要:

氮素是作物生长过程中最重要的元素，氮素缺乏将会严重影响作物生长。随着人类对粮食的需求量增加，化学氮肥的施用量越来越多。生物固氮在全球氮素循环中有着重要的作用，60%的氮来源于生物固氮。因此，生物固氮，尤其是能够在作物中定殖的联合固氮菌，最有可能代替氮肥成为粮食作物的主要氮源。长期以来，如何提高生物固氮效率以及在作物中实现生物固氮是生物学家的重要研究方向。合成生物学的出现和发展为能够生物固氮的研究带了新的机遇，有望缓解粮食作物对化学氮肥的大量需求。本文概述了固氮菌的种类、联合固氮菌中固氮基因岛的组成以及转录调控机理，阐述了合成生物学在生物固氮领域中的研究现状，对未来的联合固氮菌合成生物学的发展方向作出了展望。

Abstract:

Nitrogen is an essential element of life, and is one of the major nutrients limiting plant growth. To meet the increased food production demand in agriculture, chemical nitrogen requirements increase from year to year. Biological nitrogen fixation (BNF) plays an important role in agriculture. More than 60% of the fixed N on earth results from BNF. Associative nitrogen-fixing bacterium in major cereal crops is considered as one alternative in reducing the use of chemical nitrogen fertilizer. There has been a goal to increase biological nitrogen fixation and engineering such associations in non-legume crops to reduce the use of chemically derived fertilizer. The use of synthetic biology tools to boost biological nitrogen fixation has been considered as one of the best strategies to increase crop yield to face population growth and general agronomic crop demand. This review discusses the nitrogen fixation microorganisms, nitrogen-fixation island genes in associative nitrogen-fixing bacterium and nitrogen-fixing mechanisms. This review also elaborates on current research efforts involved in nitrogen fixation using synthetic biology tools. Moreover, this review also proposes new and emerging strategies to improve the nitrogenase activity and future perspectives in this research field.