通过将天山根瘤菌中的自体诱导物合成酶基因mrtI在转录水平融合lacZ构建了5’mrtI-lacZ融合表达菌株HMZ1。利用多株不同属的根瘤菌上清液对该菌株进行诱导,发现有3株豌豆根瘤菌和1株三叶草根瘤菌上清提取物能诱导mrtI基因的表达,且外源上清量越多,mrtI被诱导的程度越高,TLC的结果则显示它们可能有着相同的AI。该结果显示在相同功能的细菌间存在信号交流,为进一步研究群体感应调节在共生固氮上的作用提供了理论及实践依据。
Quorum sensing is a mechanism used by single-cell bacteria to monitor their population density and control a variety of physiological functions in a cell-density-dependent manner. We constructed an 5'mrtI-lacZ (the mrtI is the AHL production gene in M.tianshanesne) transcriptional fusion strains. We found the supematant of three strains which were got from pea and one strain which got from clover can induce the mrtI-lacZ expression. We also found the more the supernatant was the stronger the lacZ expressed. The TLC experiment showed that their AIs maybe have the same structure. This study showed the interaction between strains with same function and also paved the way of further studying the relationship between quorum sensing and symbiotic nitrogen fixation of the M. tianshanesne strains.