Hungarian Academy of Sciences, Szeged, Hungary.
Mol Plant Microbe Interact. 2011 Nov;24(11):1300-9. doi: 10.1094/MPMI-06-11-0152.
Symbiosomes are organelle-like structures in the cytoplasm of legume nodule cells which are composed of the special, nitrogen-fixing forms of rhizobia called bacteroids, the peribacteroid space and the enveloping peribacteroid membrane of plant origin. The formation of these symbiosomes requires a complex and coordinated interaction between the two partners during all stages of nodule development as any failure in the differentiation of either symbiotic partner, the bacterium or the plant cell prevents the subsequent transcriptional and developmental steps resulting in early senescence of the nodules. Certain legume hosts impose irreversible terminal differentiation onto bacteria. In the inverted repeat-lacking clade (IRLC) of legumes, host dominance is achieved by nodule-specific cysteine-rich peptides that resemble defensin-like antimicrobial peptides, the known effector molecules of animal and plant innate immunity. This article provides an overview on the bacteroid and symbiosome development including the terminal differentiation of bacteria in IRLC legumes as well as the bacterial and plant genes and proteins participating in these processes.
共生体是豆科植物根瘤细胞细胞质中的细胞器样结构，由称为类菌体的特殊固氮形式的根瘤菌、类菌体周质空间和植物来源的包被类菌体膜组成。这些共生体的形成需要两个合作伙伴在整个结瘤发育阶段进行复杂而协调的相互作用，因为任何一方的分化失败，无论是细菌还是植物细胞，都会阻止随后的转录和发育步骤，导致结瘤的早期衰老。某些豆科植物宿主会对细菌进行不可逆的终末分化。在缺乏反向重复的豆科植物（IRLC）中，宿主优势是通过类似于防御素样抗菌肽的结瘤特异性富含半胱氨酸的肽实现的，这些肽是动物和植物先天免疫的已知效应分子。本文概述了类菌体和共生体的发育，包括 IRLC 豆科植物中细菌的终末分化，以及参与这些过程的细菌和植物基因和蛋白质。
