Cyclic Dipeptides Mediating Quorum Sensing and Their Biological Effects in <i>Hypsizygus Marmoreus</i>

• Published in: Biomolecules
• Main Authors: Shu-Jing Sun, Yun-Chao Liu, Cai-Hong Weng, Shi-Wei Sun, Fan Li, Hui Li, Hu Zhu
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Subjects: <i>serratia odorifera</i>; quorum sensing; diketopiperazines; <i>hypsizygus marmoreus</i>; growth and development
• Online Access: https://www.mdpi.com/2218-273X/10/2/298

A novel quorum sensing (QS) system was discovered in <i>Serratia odorifera</i>, the symbiotic bacterium of <i>Hypsizygus marmoreus</i>. This system uses cyclo(Pro-Phe), cyclo(Pro-Tyr), cyclo(Pro-Val), cyclo(Pro-Leu), cyclo(Tyr-Leu), and cyclo(Tyr-Ile) as autoinducers. This discovery is the first attempt to characterize cyclic dipeptides as QS signaling molecules in <i>S. odorifera</i> and improves the classical QS theory. Significantly, <i>except for</i> cyclo(Tyr-Leu), these QS autoinducers can increase the transcription level of lignin-degrading enzyme genes of <i>H. marmoreus</i>. The cyclo(Pro-Phe) can increase the activity of extracellular laccase (1.32-fold) and manganese peroxidase (<i>20%</i>), which may explain why QS potentially regulates the hyphal growth, primordium formation, and fruit body development of <i>H. marmoreus</i>. Furthermore, it was demonstrated that the cyclo(Tyr-Ile) biosynthesis in <i>S. odorifera</i> was catalyzed by the nonribosomal peptide synthetase (NRPS). This study supports exploring the growth and development of <i>H. marmoreus</i> promoted by its symbiotic bacteria at QS signal transduction level.