Structure and Function of Rhizomicrobes Recruited by Acteoside in Root Exudates of Rehmannia glutinosa / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo reveal the correlation of Rehmannia glutinosa-soil feedback process with the formation of its continuous cropping obstacles through the identification of the root exudates of R. glutinosa and analysis of the specific rhizomicrobes recruited by the root exudate. MethodThe root exudates of R. glutinosa seedlings germinated under sterilized condition and those enriched in the rhizosphere of R. glutinosa cultivated in the field were collected and analyzed using the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry（UPLC-Q-TOF-MS）. The highly abundant compounds identified in the root exudates were added into blank soil， and the soil microbial community was profiled using Illumina Miseq sequencing. The bacterial and fungal functions were predicted by PICRUSt and FUNGuild， respectively. ResultThe identification results showed that seven phenylethanoid glycosides were found in R. glutinosa root exudates， and acteoside possessed the highest abundance. In the soil enriched with acteoside， the bacterial genera such as Agromyces， Pseudomonas， Lysobacter， Sphingobium， Pseudoxanthomonas and Sphingomonas were enriched. For the fungi， the genera Neocosmospora， Plectosphaerella and Dactylonectria， and the species such as Neocosmospora rubicola， Plectosphaerella cucumerina， Dactylonectria alcacerensis and Fusarium solani showed higher abundance. The functional analysis indicated the above-mentioned bacterial genera may realize rapid proliferation by utilizing， biodegrading and transforming phenylethanoid glycosides， and some potential fungal pathogens were colonized. ConclusionThe R. glutinsoa-soil feedbacks were likely generated by the phenylethanoid glycosides in the root exudates together with the specific rhizomicrobes. The investigations of R. glutinsoa-soil feedbacks under continuous cropping system are critical to the further understanding of the underlying mechanisms related to its continuous cropping obstacles.