SRA

Panax ginseng C.A. Meyer is a precious Chinese herbal medicine belonging to the Araliaceae family. Because ginseng is extremely taboo, it seriously restricts the sustainable development of the ginseng industry. The allelopathic effect of triterpenoid saponins is one of the important incentives for continuous cropping disorders. However, there are few studies on the mechanism of allelopathic autotoxicity of triterpenoid ginsenosides. Therefore, this study took ginseng hairy roots as the research object, exogenously added ginsenoside Ro to regulate the growth of hairy roots, and measured the changes in its physiological and saponin content. It was found that ginseng hairy roots grew significantly under Ro-0.5 mg/L stress. Inhibition, the specificity of root tip cell injury was obvious, promoted the accumulation of endogenous hormones IAA and SA, and inhibited the accumulation of ABA and JA. The accumulation of ginsenosides was significantly inhibited (except Rg3) under Ro-0.5 mg/L stress. The mRNA analysis of the Ro-0.5 mg/L group and CK group showed that the differentially expressed genes were mostly concentrated in the hormone signal transduction pathway. The genes ARF7 and EFM were up-regulated, and XTH23 and ZOX1 were down-regulated, which can be used as important candidates for hormone-responsive continuous cropping disorders. Gene. 74 differentially expressed miRNAs were identified based on miRNA sequencing, of which 22 were up-regulated and 52 were down-regulated. The target genes of ptc-miR156k_L+1, mtr-miR156b-5p, gma-miR156a_R+1, and mtr-miR156e were all TRINITY_DN14567_c0_g4, TRINITY_DN14567_c0_g4 is a gene in the plant hormone signal transduction pathway, and the four miRNAs are all negatively correlated with mRNA, indicating that ptc-miR156k_L+1, mtr-miR156b-5p, gma-miR156a_R+1, and mtr-miR156e are very likely involved in ginseng Response to continuous cropping disorders and regulation of ginsenoside synthesis. Our findings will provide a useful platform for unraveling the continuous cropping barrier of ginseng and new insights into the genetic engineering of plant stress responses. Overall design: From the perspective of plant physiology, ecology, and molecular biology, this study took the hairy roots of ginseng with relatively controllable experimental conditions as the research object, added ginsenoside Ro exogenously to simulate the phenomenon of continuous cropping obstacles, and dynamically detected the morphological changes. The damage degree of tip cells was measured, the contents of ginsenosides and endogenous hormones in hairy roots were measured, the response law of ginsenoside biosynthesis to ginsenoside Ro stress was explored, and the response law of ginsenoside-induced allelopathic damage to ginseng endogenous substances accumulation was revealed. Combined with mRNA and miRNA sequencing technologies, comprehensively analyze the toxic mechanism of ginseng's allelopathic interference at the transcriptional and post-transcriptional levels after ginsenoside Ro allelopathic stress. Only the transcriptome sequencing results are used in this study.