Towards biological nitrogen fixation in monocotyledonous plants - study plant genes for colonization and nitrogen fixation by Gluconacetobacter diazotrophicus

氮是各种作物获得高产的必需营养素，特别是谷类作物。土壤中有效氮的不足通常是通过使用工业肥料来提供的。氮肥是昂贵的，是种植各种作物，特别是谷类作物的最高成本。此外，作物对氮肥的吸收通常较低，常常低于50%。未使用的化肥造成重大的环境污染问题。重氮营养葡萄糖酸醋杆菌是一种自由生活在甘蔗植物细胞间隙的细菌。该细菌可以主动固定大气氮，并为甘蔗植物提供大量的氮。G.固氮菌属具有广泛的生长条件，不与植物形成特定的结构（如豆科植物中的根瘤），并且似乎不太具有物种特异性。探讨了G.在其他谷类作物中的固氮菌可能导致这些类型植物的固氮作用。本研究将利用基因组学方法研究植物基因参与G.固氮菌定殖和固氮作用。本研究将使用一种新的禾本科基因组学模式植物二穗短柄草（Brachypodium distachyon）。短柄草基因组小，物理尺寸小，生命周期短。最近，短柄草的基因组序列草图已经被披露。已经开发了大量的插入突变体。短柄草是研究固氮作用的理想植物。在谷类植物中的固氮菌。枝梗属植物在G.将研究固氮菌定殖。本研究将对大量与固氮不同方面有关的短柄草属插入突变体进行研究。固氮菌感染将对来自微阵列研究和突变体研究的数据进行汇总分析。植物基因响应G.将分析固氮菌。研究结果为G.固氮菌用于谷类作物的固氮。

Nitrogen is an essential nutrient for attaining high yields for various crops, especially cereal crops. Shortfalls in available nitrogen in soils are usually provided by use of industrial fertilizers. Nitrogen fertilizers are costly and are the highest cost to grow various crops, especially the cereal crops. In addition, nitrogen fertilizer uptake by crops is usually low, often lower than 50%. Unused fertilizers cause major environmental pollution problems. Gluconacetobacter diazotrophicus is a bacterium that freely lives in intercellular spaces of sugarcane plants. The bacterium can actively fix atmosphere nitrogen and provides significant amounts of nitrogen to sugarcane plants. G. diazotrophicus has a wide range of growth conditions, does not form specific structure with plants (like nodules in legume plants), and appears to be less species specific. Exploration of the nitrogen fixation feature of G. diazotrophicus in other cereal crops may lead to nitrogen fixation in these types of plants. This research will use genomics approaches to study plant gene involvement in G. diazotrophicus colonization and nitrogen fixation in cereal plants. A new grass genomics model plant, Brachypodium distachyon (Brachypodium) will be used in the research. Brachpodium has a small genome, small physical size and a short lifecycle. The draft genome sequence of Brachypodium has been recently revealed. A large number of insertion mutants has been developed. Brachypodium is an ideal plant for studying nitrogen fixation of G. diazotrophicus in cereal plants. Global gene expression of Branchypodium plant upon G. diazotrophicus colonization will be studied. A large number of Brachypodium insertion mutants relating to different aspects of nitrogen fixation will be investigated upon G. diazotrophicus infection. Data from microarray study and mutant study will be analyzed collectively. Plant genes responding to colonization and involving in nitrogen fixation by G. diazotrophicus will be analyzed. The information obtained from the research will be useful for use of G. diazotrophicus for nitrogen fixation in cereal crops.