Effects Of Continuous Cropping On Physiological Activity Of Ginseng And Its Stress Response Mechanism

Ginseng is a traditional Chinese medicine plant with a long history,and the ginseng industry is also a characteristic pillar health industry in Jilin Province,but the ginseng industry is facing resource depletion due to the limitation of ginseng succession barrier.Given that there are few studies on the molecular mechanism of ginseng crop disorder,this study was conducted to analyze the response pattern of ginseng to crop disorder at transcriptional and metabolic levels and to explore the formation mechanism of crop disorder from the perspectives of soil science,plant physiology and ecology,and molecular biology,respectively,using potted ginseng as the research object.The aim of this study is to provide a basis for the analysis of the crop barrier in ginseng.The aim is to provide theoretical basis for breaking the continuous crop barrier of ginseng,reusing old ginseng land resources,and ensuring the sustainable and effective supply of productive land.The main findings are as follows.1.We investigated the effect of ginseng continuous cropping soil on the growth and development of normal ginseng to break the ginseng continuous cropping barrier.We systematically analyzed the effects of continuous crop soil on normal ginseng growth and development at different growth periods from three aspects,including plant tissue morphology,physiological and biochemical levels,and intra-tissue antioxidant levels,using potted ginseng samples as the control group(Control Check,CK)and ginseng samples grown in continuous crop soils as the model group(Continuous Crop obstacles,CCO).The results showed that the CCO group of ginseng had a significant impact on the growth and development of normal ginseng.The results showed that the plant height,main root length and number of fibrous roots of ginseng plants in the CCO group were significantly different(P < 0.05)compared with those in the CK group at the harvesting stage.During the fruiting and harvesting periods,catalase(CAT)activity was significantly lower and malondialdehyde(MDA)content was significantly increased(P < 0.05)in the sample tissues of the CCO group;during the harvesting period,ginseng peroxidase(POD)activity was significantly increased(P < 0.05)and superoxide dismutase(SOD)activity was significantly lower(P < 0.05)in the CCO group compared with the CK group.It shows that ginseng continuous crop soil can significantly affect both oxidative stress levels and growth and development of normal ginseng plants,and if the continuous crop problem can be cracked by soil improvement methods,it will effectively solve the bottleneck problem in the field of ginseng cultivation in Jilin Province.2.In this chapter,the old ginseng land soil and new forest land soil in different growth periods of ginseng were used as the research objects,potted tests were conducted to monitor their growth,and soil physicochemical properties and enzyme activities in different growth periods were measured to explore and study the changes of physicochemical properties and enzyme activities of ginseng continuous cropping soil in different growth periods and their patterns,which are important for improving the quality of ginseng herbs,improving the problem of ginseng continuous cropping obstacles This is of great significance for improving the quality of ginseng herbs,improving ginseng crop barriers and regulating the growth of ginseng plants.The continuous ginseng crop lowered the p H value of the inter-root soil and caused weak acidification of the inter-root soil.The alkaline nitrogen content of the soil decreased and the effective phosphorus and fast-acting potassium increased,resulting in an imbalance of nutrients in the inter-rhizosphere soil of ginseng.Acid phosphatase,soil urease,catalase and sucrase activity in ginseng inter-root soil decreased,which aggravated the deterioration of continuous ginseng inter-root soil.3.To explore the physiological and molecular mechanisms behind ginseng crop disorders,this study combined transcriptomics and metabolomics to analyze the effects of continuous crop on changes in ginseng metabolites,differential gene expression and regulation of root secretions.In this study,106 metabolites and 1175 genes were significantly altered at the metabolic and transcriptional levels in succession-cropped ginseng compared to the control group.The metabolic pattern of continuous-crop ginseng was changed,and the accumulation of various organic acids,alkaloids,flavonoids and phenolics was significantly increased in continuous-crop ginseng.There were significant differences in the expression of genes involved in phytohormone signaling,phenylpropanoid biosynthesis,and plant-pathogen interaction pathways.This study provides information on the regulation of expression of genes associated with continuous crop disorders,but also suggests that continuous crop disorders may lead to severe damage to roots by pathogens and result in slow growth of continuous cropping plants.Our results provide new insights into the response of ginseng to crop disorders,which will reveal the potential molecular mechanisms of ginseng to crop disorders.4.Given that the problem of ginseng crop disorder is a serious constraint to the development of the industry and that there are few studies on the mechanism of ginseng crop disorder,this study investigated ginseng crop disorder-related mi RNAs and their target genes.A total of 376 mi RNAs were obtained from all tissue samples.121 mi RNAs were found to be differentially expressed in ginseng.Then,the target genes of differentially expressed mi RNAs were enriched and found to be involved in phytohormone-related regulation,MAPK signaling pathway-plant,amino and nucleotide sugar metabolism and monoterpene biosynthesis,suggesting that the alteration of these related pathways may play a key role in causing ginseng crop disorder.Finally,the correlations between mi RNAs and m RNAs were integrated to construct corresponding interactions networks and discover mi RNAs that may play key roles in diseased tissues.osa-MIR818d-p3＿1ss1TA and pgi-MIR6135i-p3＿1ss11TG and pgi-MIR6140c-p5＿1ss12CT were found to be at the core of the network.These mi RNAs are presumed to play an important role in the formation of ginseng linkage disorder.In this paper,we investigated the soil environment between the roots of successive ginseng crops in different periods,and explored the response mechanisms of successive ginseng crops to successive crop disorders at the transcriptional and metabolic levels by studying the tissue morphology,physiological and biochemical levels,and intratissue antioxidant levels of successive ginseng plants in different periods,and then by means of transcriptomics and metabolomics.The findings of this paper may lay a foundation for subsequent research on ginseng crop disorders.