Abstract：
Omics are the most promising approaches to investigate microbes for which no genetic tools exist such as the nitrogen-fixing symbiotic Frankia. A proteogenomic analysis of symbiotic Frankia alni was done by comparing those proteins more and less abundant in Alnus glutinosa nodules relative to N2-fixing pure cultures with propionate as the carbon source. There were 250 proteins that were significantly overabundant in nodules at a fold change (FC) ≥ 2 threshold, and 1429 with the same characteristics in in vitro nitrogen-fixing pure culture. Nitrogenase, SuF (Fe-Su biogenesis) and hopanoid lipids synthesis determinants were the most overabundant proteins in symbiosis. Nitrogenase was found to constitute 3% of all Frankia proteins in nodules. Sod (superoxide dismutase) was overabundant, indicating a continued oxidative stress, while Kats (catalase) were not. Several transporters were overabundant including one for dicarboxylates and one for branched amino acids. The present results confirm the centrality of nitrogenase in the actinorhizal symbiosis.
摘要：
组学是研究微生物的最有前途的方法，这些微生物不存在遗传工具，例如固氮共生Frankia。通过比较Alnusglinosa结节中相对于以丙酸盐为碳源的N2固定纯培养物中的那些蛋白质或多或少丰富，对共生Frankiaalni进行了蛋白质组学分析。结节中有250种蛋白质在倍数变化（FC）≥2阈值时明显过量，和1429在体外固氮纯培养中具有相同的特征。固氮酶,SuF（Fe-Su生物发生）和类hopanoid脂质合成决定子是共生中最丰富的蛋白质。发现固氮酶占结节中所有Frankia蛋白的3％。Sod（超氧化物歧化酶）过量，表明持续的氧化应激，而Kats（过氧化氢酶）不是。几种转运蛋白过多，包括一种用于二羧酸酯和一种用于支链氨基酸。本结果证实了固氮酶在放线菌共生中的中心地位。
