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

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.

Research progress on application of biochar in cultivation of agriculture and Chinese materia medica / 中国中药杂志

Biochar is a kind of solid material with high aromatization and rich in carbon, which is formed by pyrolysis of biomass at high temperature(250-700 ℃) under anoxic or hypoxic conditions. It has the characteristics of large specific surface area and rich pores. In recent years, as a good soil conditioner, biochar has gradually improved its advantages in improving soil rhizosphere micro ecological environment, promoting plant growth and development, and enhancing plant resistance, etc. It has been proved that biochar can affect the growth and development of plants by improving soil physical and chemical properties, adjusting microbial community structure, participating in the metabolic process in plants, and inducing plants to enhance resistance. This paper summarized the research progress of biochar application in agriculture and introduced the ecological effects and mechanism of biochar on plant seed germination, seedling growth, crop yield and stress resistance. Combined with the characteristics of Chinese materia medica, this paper expounds the application potential of biochar in improving the content of secondary metabolites of Chinese materia medica and alleviating continuous cropping obstacles of Chinese materia medica, etc. In the future, it is necessary to strengthen the research of biochar in the biosynthesis of secondary metabolites, allelopathy and heavy metal stress of medicinal plants, so as to provide reference for the application of biochar in the cultivation of Chinese materia medica.

Production and quality control of original herbal materials of Danhong Injection / 中国中药杂志

Cardiovascular and cerebrovascular diseases are the leading cause of death for residents in China. Danhong Injection(DHI) decoction piece is prepared from Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, with the function of promoting the blood circulation, removing the blood stasis, relaxing the sinews and dredging the collaterals. In recent years, about 100 million bottles of DHI have been sold. Consequently, its safety and effectiveness are very important to a large number of patients. Raw materials are the source and foundation for production of traditional Chinese medicine injections. In this article, we reviewed the identification of Salviae Miltiorrhizae Radix et Rhizoma and Carthami Flos, resource distribution, cultivation, quality control, and detection of xenobiotic pollutants, in order to guide the production of high-quality, stable, and pollution-free raw materials. This will be a benefit in ensuring the safety and effectiveness of DHI and reducing the incidence of adverse reactions from the raw materials. By comparing the similarities and differences between the quality standards of Salviae Miltiorrhizae Radix et Rhizoma, Carthami Flos and DHI, we provided some comments for improving the quality standards and post-marketing reevaluation of DHI, and provided some theoretical supports for the production of high-quality herbal raw materials.

Advances in molecular identification and functional genes of Rehmannia glutinosa / 中草药

Rehmannia glutinosa is one of the most common bulk medicinal materials in China and it has a long history of medicinal use. In recent years, with the development of molecular biology, especially for the emergence of high-throughput sequencing technology, it not only provides new ways to identify R. glutinosa quickly, and reveal the genetic diversity and relationship of R. glutinosa, but also lays the vital foundation for explaining the mechanism on metabolism, root tuber growth, stress response and continuous cropping obstacles of R. glutinosa. The present paper reviews the recent study progress in molecular biology research of R. glutinosa from molecular systematics, molecular identification and functional genes, and puts forward three research prospects in order to provide a reference for further study on molecular biology of R. glutinosa.

Research progress in microorganism changes of rhizospheric soil and root endogenous and ecology during continuous cropping of Panax notoginseng / 中草药

Panax notoginseng is one of the most important traditional Chinese medicinal herbs, and it is mainly distributed in Yunnan and Guangxi Provinces and only can be planted in a very narrow geographical environment. Its yield is significantly limited by continuous cropping obstacles in the cultivation process, which has seriously affected the application and development of P. notoginseng. The dynamic patterns of root and soil rhizosphere microbial community response were main reasons for the continuous cropping obstacle. In this paper, the dynamic changes of the root and rhizosphere systems, pathogenic microorganisms and symbiotic microorganisms in the formation of P. notoginseng continuous cropping obstacles were analyzed, and the progress in this field was summarized. Two methods for studying soil and root microorganism of continuous cropping process are proposed: 1. The dynamic analysis of microorganism in the rhizosphere and root of P. notoginseng must be completed with the method of pure-culture and culture-independent; 2. Quantitative analysis of main pathogenic microorganisms of P. notoginseng. It will provide theoretical basis for overcoming continuous cropping obstacles in plant of P. notoginseng.

Research progress of relationship between continuous cropping obstacles and microRNAs in Rehmannia glutinosa / 中国中药杂志

The efficacy of Rehmannia glutinosa which as a large quantity of traditional Chinese medicine is significant. However, the land must be given up after one season of R. glutinosa cultivation or replanted after a period of 8-10 years because of the severe continuous cropping obstacles. MicroRNAs is a class of endogenous non-coding small RNAs, which participate in regulation of physiological activities by target mRNA cleavage or translational repression in plants. In recent years,studies on the role of miRNAs in plants have made significant progresses,especially in medicinal plants．MiRNAs from some different medicinal plant species have been identified with regulatory effects．When plants are exposed to environmental stress, miRNAs act on stress-related genes and initiate stress-resistance mechanisms in the body against adverse factors. R. glutinosa is also a kind of environmental stress. It is conducive to deciphering the molecular mechanism of continuous cropping obstacles for us by researching miRNAs. This article reviews the production of miRNAs, mechanism, research approaches and characteristics of resisting the environmental stresses in plants, the development trends and future prospect of R. glutinosa miRNAs research.

DNA marker-assisted selection of medicinal plants (Ⅰ) .Breeding research of disease-resistant cultivars of Panax notoginseng / 中国中药杂志

DNA marker-assisted selection of medicinal plants is based on the DNA polymorphism, selects the DNA sequences related to the phenotypes such as high yields, superior quality, stress-resistance and so on according to the technologies of molecular hybridization, polymerase chain reaction and high-throughput sequencing, and assists the breeding of new cultivars. This study bred the first disease-resistant cultivar of notoginseng "Miaoxiang Kangqi 1" using the technology of DNA marker-assisted selection of medicinal plants and systematic breeding. The disease-resistant cultivar of notoginseng contained 12 special SNPs based on the analysis of Restriction-site Associated DNA Sequencing (RAD-Seq). Among the SNP (record_519688) was related to the root rot-resistant characteristics, which indicated this SNP could serve as genetic markers of disease-resistant cultivars and assist the systematic breeding. Compared to the conventional cultivated cultivars, the incidence rate of root-rot and rust-rot in notoginseng seedlings decreased by 83.6% and 71.8%, respectively. The incidence rate of root-rot respectively declined by 43.6% and 62.9% in notoginseng cultivation for 2 and 3 years compared with those of the conventional cultivated cultivars. Additionally, the potential disease-resistant groups were screened based on the relative SNP, and this model enlarged the target groups and advanced the breeding efficiency. DNA marker-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry.

Changes of diversity and composition of fungal communities in rhizosphere of Panax ginseng / 中国中药杂志

Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles.

A semimicroquality evaluation method on Panax notoginseng and its application in analysis of continuous cropping obstacles research samples / 中国中药杂志

Panax notoginseng is a commonly used traditional Chinese medicine with blood activating effect while has continuous cropping obstacle problem in planting process. In present study, a semimicroextraction method with water-saturated n-butanol on 0.1 g notoginseng sample was established with good repeatability (RSD<2.5%) and 9.6%-20.6% higher extraction efficiency of seven saponins than the conventional method. A total of 16 characteristic peaks were identified by LC-MS-IT-TOF, including eight 20(S)-protopanaxatriol (PPT) type saponins and eight 20(S)-protopanaxadiol (PPD) type saponins. The established method was utilized to evaluate the quality of notoginseng samples cultivated by manual intervened methods to overcome continuous cropping obstacles.As a result, HPLC fingerprint similarity, content of Fa and ratio of notoginsenoside K and notoginsenoside Fa (N-K/Fa) were found out to be as valuatable markers of the quality of samples in continuous cropping obstacle research, of which N-K/Fa could also be applied to the analysis of notoginseng samples with different growth years.Notoginseng samples with continuous cropping obstacle had HPLC fingerprint similarity lower than 0.87, in consistent with normal sample, and had significant lower content of notoginsenoside Fa and significant higher N-K/Fa (2.35-4.74) than normal group (0.45-1.33). All samples in the first group with manual intervention showed high similarity with normal group (>0.87), similar content of common peaks and N-K/Fa (0.42-2.06). The content of notoginsenoside K in the second group with manual intervention was higher than normal group. All samples except two displayed similarity higher than 0.87 and possessed content of 16 saponins close to normal group. The result showed that notoginseng samples with continuous cropping obstacle had lower quality than normal sample. And manual intervened methods could improve their quality in different levels.The method established in this study was simple, fast and accurate, and the markers may provide new guides for quality control in continuous cropping obstacle research of notoginseng.