Improved Characterization of Nod Factors and Genetically Based Variation in LysM Receptor Domains Identify Amino Acids Expendable for Nod Factor Recognition in Lotus spp.
Improved Characterization of Nod Factors and Genetically Based Variation in LysM Receptor Domains Identify Amino Acids Expendable for Nod Factor Recognition in Lotus spp.
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DOI：
10.1094/mpmi-23-1-0058
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发表时间：
2010-01-01
影响因子：
3.5
通讯作者：
Radutoiu, Simona
中科院分区：
文献类型：
--
作者：
Bek, Anita S.;Sauer, Jorgen;Radutoiu, Simona
功能性结节的形成是一个复杂的过程，取决于所有发育阶段宿主与微共生体的相容性。本报告使用百脉根和L. pedunculatus，接种中根瘤菌loti或慢生根瘤菌sp.（莲花），研究结瘤因子结构和结瘤因子受体（NFR）的根瘤菌识别，感染线程的进展，和根瘤细胞内的细菌持久性的作用。一个关键的贡献是使用800兆赫核磁共振光谱和超高效液相色谱耦合四极杆飞行时间质谱法的Nod因子分析。在非还原端的结瘤因子装饰在慢生根瘤菌和M. loti和L. pedunculatus和L.结果发现，不同的氨基酸组成。使用嵌合和野生型受体的遗传转化实验表明，这两种受体变体识别结构不同的结瘤因子，但后来的共生表型保持不变。这些结果突出了固氮共生过程中额外的检查点的重要性，并定义了几个氨基酸的LysM结构域作为消耗感知的两个差异氨甲酰化的Nod因子。
Formation of functional nodules is a complex process depending on host-microsymbiont compatibility in all developmental stages. This report uses the contrasting symbiotic phenotypes of Lotus japonicus and L. pedunculatus, inoculated with Mesorhizobium loti or the Bradyrhizobium sp. (Lotus), to investigate the role of Nod factor structure and Nod factor receptors (NFR) for rhizobial recognition, infection thread progression, and bacterial persistence within nodule cells. A key contribution was the use of 800 MHz nuclear magnetic resonance spectroscopy and ultrahigh-performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry for Nod factor analysis. The Nod factor decorations at the nonreducing end differ between Bradyrhizobium sp. (Lotus) and M. loti, and the NFR1/NFR5 extracellular regions of L. pedunculatus and L. japonicus were found to vary in amino acid composition. Genetic transformation experiments using chimeric and wild-type receptors showed that both receptor variants recognize the structurally different Nod factors but the later symbiotic phenotype remained unchanged. These results highlight the importance of additional checkpoints during nitrogen-fixing symbiosis and define several amino acids in the LysM domains as expendable for perception of the two differentially carbamoylated Nod factors.