Quorum sensing (QS) is a well-known, cell density dependent regulatory process in bacterial communities. It is mediated by auto-induced synthesis of diffusible signal molecules once a critical cell density is reached. In Gram-negative bacteria, N-acyl-homoserine lactones (AHLs) are QS-signal molecules involved in, for e.g. biofilm formation, activation of virulence genes of pathogens, and induction of degradative enzyme activities. However, QS was not much characterized as being important for regulating beneficial interactions of plant growth promoting rhizobacteria (PGPR). In this article, we examine the involvement of QS-AHLs in the improvement of plant development and health. AHLs of Gluconacetobacter diazotrophicus were shown to improve growth of rice under water stress conditions. The AHLs of Rhizobium radiobacter, an endofungal bacterium of the PGP-fungus Serendipita indica, stimulated endophytic root colonization, improved growth and yields, and induced priming for pathogen resistance in wheat. Furthermore, the addition of AHL-compounds to plant seeds resulted in priming for better growth yields in winter wheat and enhanced resistance towards leaf rust in barley. Therefore, AHL signaling compounds and QS-AHL-producing rhizobacteria should be considered as promising candidates to be implemented in sustainable systems for consistent stimulation of plant growth and health.

群体感应（QS）是细菌群落中众所周知的细胞密度依赖性调节过程。一旦达到临界细胞密度，它就由可扩散信号分子的自动诱导合成介导。在革兰氏阴性细菌中，N-酰基-高丝氨酸内酯（AHL）是QS信号分子，参与例如生物膜的形成，病原体的毒力基因的激活以及降解酶活性的诱导。然而，QS并没有被认为对调节促进植物生长的根际细菌（PGPR）的有益相互作用很重要。在本文中，我们研究了QS-AHL在改善植物发育和健康方面的作用。葡萄糖醋杆菌重氮营养菌的AHL被证明可以改善水分胁迫条件下的水稻生长。的信号分子根瘤菌放射形中，PGP-真菌的细菌endofungal Serendipita籼稻，刺激内生根定殖，改善的生长和产量，以及用于在小麦病原体抗性诱导的引发。此外，向植物种子中添加AHL化合物可引发引发，以提高冬小麦的生长产量并增强大麦对叶锈病的抵抗力。因此，应将AHL信号化合物和产生QS-AHL的根瘤菌视为在可持续系统中实施的有希望的候选物，以持续刺激植物生长和健康。