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Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots. Nitrogen (N), as an important mineral element, can directly affect plant growth and development at different N levels. It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants. However, there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels. In this experiment, the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P. polyphylla var. yunnanensis infested by AMF as the test material. It was found that nitrogen addition increased the biomass, chlorophyll content, and nutrient content of above- and below-ground plant parts and increased the content of saponin content of P. polyphylla var. yunnanensis to some extent, but AMF inoculation increased the saponin content of P. polyphylla var. yunnanensis more significantly. AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway, including 3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS), squalene epoxidase 1 (SE1), and cycloartenol synthase (CAS), which is in according with the accumulation of saponin in plants. It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.

Root-knot nematode (RKN) is a soil-borne pathogen that severely damages Panax notoginseng. It has been recently shown that intercropping P. notoginseng in forests constitutes an innovative system that can promote P. notoginseng growth and suppress the spread of disease. However, there is little research on the interspecific interaction between pine trees and P. notoginseng. Here, two years of field experiments were designed to explore the effects of RKN infestation and P. notoginseng–pine tree intercropping on the growth and saponin synthesis of P. notoginseng. The results showed that RKN infestation could significantly reduce the root biomass, nutrient uptake and saponin accumulation of P. notoginseng seedlings. Interestingly, two-year-old P. notoginseng plants grew normally (specifically, root biomass, saponin synthesis, nutrient uptake and root morphology were normal) under nematode infection, while the incidence of RKN disease was decreased compared with that of seedlings before transplantation, indicating that P. notoginseng has adult-plant resistance (APR) to RKN disease. Furthermore, P. notoginseng–pine tree intercropping could significantly reduce the incidence of RKN disease and increase the biomass, nutrient uptake and saponin synthesis of P. notoginseng under mild infection, and root architecture may play a key role. Above all, P. notoginseng showed APR to RKN disease, and P. notoginseng–pine tree intercropping represents a type of interspecific facilitation that can promote the growth and quality of P. notoginseng.

Growth of the Chinese herbal medicine industry has resulted in several new pests and diseases. China is one of the world largest producers of monkshood (Aconitum carmichaelii Debx.), but an unidentified root-knot nematode has become a significant pest in the southwestern provinces of Yunnan and Sichuan. Morphological characteristics and the ribosomal DNA-internal transcribed spacer and D2-D3 region of the 28S ribosomal RNA gene sequences were used to identify the nematode as Meloidogyne hapla. Through investigation, this is the first report of M. hapla infecting monkshood in Yunnan and Sichuan Provinces.

Panax notoginseng, a traditional medicinal and edible plant, is widely used in medicine, health care, cosmetics, and other industries. Affected by the discrepancy between market supply and demand and price, the adulteration of P. notoginseng products with other plant-derived ingredients occurs at times. With the continuous development of technologies such as spectroscopy, chromatography, and DNA barcoding, the detection techniques for rapid and sensitive determination of the authenticity identification and origin of P. notoginseng have become more diversified to meet the needs of different regulatory goals and could effectively control practices that mislead consumers and promote false labeling. This review analyzes and summarizes the existing technologies for determining the authenticity and origin of P. notoginseng from these three aspects: morphological, chemical, and molecular biology methods from the literature since 2001; on this basis, the current problems and future research directions are discussed to provide a reference for the establishment of rapid and accurate methods to verify authenticity and origin to promote the further development and improvement of quality control technology systems for P. notoginseng.

To determine Calculation method of sprinkler and micro-sprinklers, computational models of sprinkler pattern radius model is established which based on hydraulic parameters of nozzle diameter, working pressure, Installation Heights, spray elevation angle, discharge coefficient, wind direction and speed, water flow regime, and water droplet motion in air, etc., as well by Newton's second law of motion, aerodynamics, and fluid mechanics principles, and by experimental verification for common sprinkler pattern radius, nozzle diameter, working pressure, spray elevation angle, Installation Heights, and wind direction and speed. The results indicate that sprinkler pattern radius with nozzle diameter, working pressure, Installation Heights, spray elevation angle, discharge coefficient, wind direction and speed, water flow regime, and droplet motion in air was in highly significant correlation, the sprinkler pattern radius Progressive decreases around the sprinkler along the sprinkler pattern radius direction, as well increases by 5.2342%~10.6278% in the downwind direction and decreases by 4.6897%~9.8623% in the headwind direction compared with no wind. The wind speed increases, then the range decreases, and the wind direction shifts, then the range shifts, so the wind direction wind speed changes then the range changes. The coefficients of determination, the consistency Index, the root mean square error, absolute error, relative error between calculated Values and Measured Values of computational models are 0.9146, 0.9205, 8.7748%, 10.4980%, 8.2524% and 8.1421%, respectively. The smaller coefficients of determination and the consistency Index of calculated Values and Measured Values of computational model under windy conditions comparing with no wind, as well the larger root error, deviation, absolute error and relative error. The calculation model in this paper has a clear principle, comprehensive influence factors, complete physical meaning, high calculation accuracy, small error, and wide applicability. This calculation model can effectively reflect the nozzle range change law. This study provides theoretical basis for determining the sprinkler hydraulic performance and provides technology support for Planning and Design of sprinkler irrigation system.

The spider mite, Tetranychus pueraricola (Ehara & Gotoh; Acari: Tetranychidae), is a serious pest in agriculture and horticulture. Application of chemical pesticides is the main mode of this pest control. Due to pesticide residues and resistance-induced resurgence of pests, there is a need to discover alternatives for spider mite management. GC16 comprises a mixture of calcium chloride (CaCl2, 45%) and lecithin (55%), which was recently found to have acaricidal properties. We evaluated the sublethal effects of GC16 on T. pueraricola using life table and enzyme [catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), carboxylesterase (CarE), glutathione S-transferases (GST), and Ca2+-ATPase (Ca2+-ATP)] activity assays. The results showed that fecundity of T. pueraricola increased at LC30 but decreased at LC50 of GC16. The intrinsic rate of increase (r) of T. pueraricola decreased under the LC30 and LC50 of GC16. GC16 concentration and exposure time significantly influenced the activities of CAT, POD, CarE, GST, and Ca2+-ATP in adult mites. Twelve hours later after the treatment, GST and Ca2+-ATP activities were significantly inhibited by LC30 but enhanced by LC50. Moreover, the demographic parameter r and enzyme activities were negatively correlated. In sum, sublethal amounts of GC16 had an adverse effect on mites, and there was a trade-off between developmental performance and physiological enzyme activity of mites under GC16 stress, and GC16 showed an acaricidal potential for T. pueraricola. This work provides guidance for the application of GC16 to control T. pueraricola.

Traditional agrosystems, where humans, crops and microbes have coevolved over long periods, can serve as models to understand the ecoevolutionary determinants of disease dynamics and help the engineering of durably resistant agrosystems. Here, we investigated the genetic and phenotypic relationship between rice (Oryza sativa) landraces and their rice blast pathogen (Pyricularia oryzae) in the traditional Yuanyang terraces of flooded rice paddies in China, where rice landraces have been grown and bred over centuries without significant disease outbreaks. Analyses of genetic subdivision revealed that indica rice plants clustered according to landrace names. Three new diverse lineages of rice blast specific to the Yuanyang terraces coexisted with lineages previously detected at the worldwide scale. Population subdivision in the pathogen population did not mirror pattern of population subdivision in the host. Measuring the pathogenicity of rice blast isolates on landraces revealed generalist life history traits. Our results suggest that the implementation of disease control strategies based on the emergence or maintenance of a generalist lifestyle in pathogens may sustainably reduce the burden of disease in crops.

A simple, green, and solvent-free pyrolysis method for the preparation of starch-based carbon dots (CDs) was developed.

Plants have powerful defence mechanisms, and extensive immune receptor repertoires, yet crop monocultures are prone to epidemic diseases. Rice is susceptible to many diseases, such as rice blast caused byMagnaporthe oryzae. Varietal resistance of rice to blast relies on intracellular nucleotide binding, leucine-rich repeat (NLR) receptors that recognize specific pathogen molecules and trigger immune responses. In the Yuanyang terraces in south-west China, rice landraces rarely show severe losses to disease whereas commercial inbred lines show pronounced field susceptibility. Here, we investigate within-landrace NLR sequence diversity of nine rice landraces and eleven modern varieties ofindica, japonicaandaususing complexity reduction techniques. We find that NLRs display high sequence diversity in landraces, consistent with balancing selection, and that balancing selection at NLRs is more pervasive in landraces than modern varieties. Notably, modern varieties lack many ancient NLR haplotypes that are retained in some landraces. Our study emphasises the value of standing genetic variation that is maintained in farmer landraces as resource to make modern crops and agroecosystems less prone to disease.

An innovative cultivation technique for Chinese medicinal herbs had been practiced in China, which led a new road for medicinal herbs production without input of chemical fertilizer and chemical pesticides. The organic practice was based on the principle of biodiversity for pest control. An example of Panax notoginseng (Burk.) F. H. Chen was chosen for explaining cultivation technology under forest. The key technologies for P. notoginseng cultivation under forest include forest land selection, land tillage, seedling breeding and transplanting, and on-farm organic management. These technologies can standardize herbs production in large-scale under forest, and the quality and safety of P. notoginseng can be effectively improved without applying chemical pesticides and chemical fertilizer in the production process.

Overaccumulation of allelochemicals in soil from trees has a negative effect on the growth of Panax notoginseng and cause root rot. Many plant secreted phenols are water-soluble substances that can be depleted by leaching. However, comprehensive understanding of the effect of leaching of phenols in Chinese fir soil on P. notoginseng root rot disease is still lacking. Soil with high level of phenols was leached with five intensities and their effect on the root rot of P. notoginseng was assessed. Then, the relationship of root rot with changes in soil chemical properties and phenol content as well as rhizospheric microorganisms was analyzed. With increasing leaching intensity, the levels of phenols in soils and the incidence of root rot decreased significantly. Decreased phenol content could alleviate root rot by modifying the soil microbial community. Network analysis showed that root rot incidence was positively correlated with the p-hydroxybenzoic acid-enriched pathogenic fungus Ilyonectria but negatively correlated with p-hydroxybenzoic acid (HA)-, ferulic acid (FA)- or vanillic acid (VA)-suppressed bacteria, including Sphingomonas, Lysobacter, Massilia and Burkholderia. Culture experiments confirmed that individual HA, FA and VA as well as a mixture of the five phenols with increasing concentrations could stimulate the growth and sporulation of I. destructans but suppress the growth and biofilm formation of bacteria (Burkholderia and Lysobacter). Moreover, Burkholderia isolates showed antagonistic activity against the growth of I. destructans. Leaching could relieve the stimulation of pathogenic fungi by phenols and reduce the pressure on phenolic-suppressed bacteria, thereby reducing the incidence of root rot disease.

The objective of the research was to investigate the digestion and fecal fermentation characteristics of the flowers of

Drought stress (DS) is one of the important abiotic stresses facing cash crops today. Drought can reduce plant growth and development, inhibit photosynthesis, and thus reduce plant yield. In this experiment, we investigated the protective mechanism of AMF on plant photosynthetic system by inoculating Paris polyphylla var. yunnanensis with a clumping mycorrhizal fungus (AMF) under drought conditions. The drought environment was maintained by weighing AM plants and non-AM plants. The relative water content (RWC) of plant leaves was measured to determine its drought effect. DS decreased the RWC of plants, but AMF was able to increase the RWC of plants. chlorophyll a fluorescence curve measurements revealed that DS increased the OKJIP curve of plants, but AMF was able to reduce this trend, indicating that AMF increased the light absorption capacity of plants. dS also caused a decrease in plant Y(I) and Y(II). ETRI and ETRII, and increased Y(NO) and Y(NA) in plants, indicating that DS caused photosystem damage in plants. For the same host, different AMFs did not help to the same extent , but all AMFs were able to help plants reduce this damage and contribute to the increase of plant photosynthesis under normal water conditions.This work was supported by the Key R & D program of Yunnan Province, China (grant no. 202103AC100003；202101AS070228)；Major special projects of the Ministry of science and technology (2021YFD1000202)；the National Nature Science Foundation of China (Grant No. 31860075)

Traditional Chinese herbal medicines are subject to heavy metal contamination. Standard detection methods are too complicated, time-consuming, and expensive for routine analysis, so low-cost methods are in high demand for rapid on-site screening. This study reports a high-sensitivity X-ray fluorescence (HS-XRF) method to determine As, Pb, and Cd residues simultaneously in herbal medicines. It couples monochromatic excitation energy dispersive X-ray fluorescence spectrometry and the fast fundamental parameters method. Each test takes only 10-30 min and costs 1/10th to 1/5th of the standard method. The detection limits, precision and accuracy were evaluated using different approaches, and application notes in practice are also proposed. This study is the first attempt to establish and evaluate HS-XRF in analyzing multiple heavy metals in herbal medicines. This rapid screening method would promote the testing efficiency and thus improve the monitoring of heavy metal contamination in herbal medicines.

Multicolor luminescent carbon dots (CDs) were successfully prepared by a solvothermal method using tannic acid (TA) and phthalaldehyde as carbon sources. The distinct optical features of these CDs are based on differences in the sizes of sp2 domains, which can be governed by the structure of phthalaldehyde.

Acidic reagents play an important role in the preparation of carbon dots (CDs). Therefore, we prepared efficient green fluorescent CDs by potassium bisulfate, acetic acid and hydrochloric acid catalysis and discussed why the acid catalyst induced a fluorescence redshift and improved the quantum yield of the CDs. Furthermore, the concentration-dependent photoluminescence behaviour of the CDs was characterized. CD/PVA composites emitting green to yellow light were obtained by exploiting the fluorescence tunability of CDs. Based on different light-emitting diode substrates, green, yellow and white light-emitting diodes with excellent performance were prepared.

The under-forest economy in the agroforestry system can improve land use efficiency, protect ecological environment, and promote arable land sustainable development. However, the effects of soil moisture in the forest and irrigation strategies on the healthy growth of intercropping crops are still incomplete. Here, considering the organic Panax notoginseng cultivated under pine forests (PPF) as the research object, we explored the effects of different soil moisture on the physiological state, yield, quality and disease occurrence of PPF. Our results suggested that 80-85% and 95-100% field capacity (FC) treatments were more conducive to increased photosynthetic rate and biomass accumulation of PPF, but 50-55% and 65-70% FC treatments were more conducive to the accumulation of saponins in PPF leaves. Notably, the root rot index of PPF was highest under 95-100% FC (19.51) treatment, significantly higher than that under 65-70% FC (8.44) and 80-85% FC (10.21) treatments. Further, the rhizosphere microorganisms of PPF under different soil moisture treatments were sequenced, and the sequencing data analysis revealed that high soil moisture (95-100% FC) could destroy the microbial diversity balance and cause the accumulation of pathogens (Fusarium oxysporum and Ilyonectria radicicola), leading to a high incidence of root rot. The incidence of PPF root rot was negatively correlated with rhizosphere microbial diversity. Overall, our results highlight that the quantitative irrigation (80-85% FC) is conducive to maintaining the balance between yield, saponin content and disease occurrence of PPF, providing a practical basis for PPF irrigation strategy and promoting the sustainable development of PPF agroforestry system.

Background: Sanqi round spot, which is caused by Mycocentrospora acerina, is a destructive disease limits the production of Panax notoginseng in Yunnan province of China. However, the disease has not been studied comprehensively. Results: In the current study, we identify M. acerina polymorphic microsatellite markers using CERVUS 3.0 and compare the genetic diversity of its isolates from P. notoginseng round spot using Simple Sequence Repeat (SSR) markers and polyacrylamide gel electrophoresis. Thirty-two SSR markers with good polymorphism were developed using MISA and CERVUS 3.0. The genetic diversity of 187 M. acerina isolates were evaluated using 14 representative SSR primers, and the polymorphic information content values of 14 sites ranged from 0.813 to 0.946, with a total of 264 alleles detected at 14 microsatellite loci. The average expected heterozygosity was 0.8967. Conclusion: 14 SSR primers of M.acerina can be used in diversity analysis and identification of M. acerina and its closely related species. Genetic diversity of M. acerina in Yunnan province does not reflect geographic specificity.

Root-knot nematodes (RKNs) are soil-borne pathogens that severely affect

Panax notoginseng is a highly valuable herb, but root rot disease severely impairs its development and decreases the yield and quality of roots. In this study, a fungal isolate (3A‐2‐2) was obtained from P. notoginseng seedlings with root rot symptoms and was identified as Plectosphaerella plurivora based on morphological characteristics and molecular analysis. The fungal isolate 3A‐2‐2 could cause root rot disease and be re‐isolated, fulfilling Koch's postulates. This is the first study to report on root rot disease caused by P. plurivora on P. notoginseng in China.

Endophytic fungi can be beneficial to plant growth. However, the molecular mechanisms underlying colonization of Acremonium spp. remain unclear. In this study, a novel endophytic Acremonium strain was isolated from the buds of Panax notoginseng and named Acremonium sp. D212. The Acremonium sp. D212 could colonize the roots of P. notoginseng, enhance the resistance of P. notoginseng to root rot disease, and promote root growth and saponin biosynthesis in P. notoginseng. Acremonium sp. D212 could secrete indole-3-acetic acid (IAA) and jasmonic acid (JA), and inoculation with the fungus increased the endogenous levels of IAA and JA in P. notoginseng. Colonization of the Acremonium sp. D212 in the roots of the rice line Nipponbare was dependent on the concentration of methyl jasmonate (MeJA) (2-15 μmol/L) and 1-naphthalenacetic acid (NAA) (10-20 μmol/L). Moreover, the roots of the JA signaling-defective coi1-18 mutant were colonized by Acremonium sp. D212 to a lesser degree than those of the wild-type Nipponbare and miR393b-overexpressing lines, and the colonization was rescued by MeJA but not by NAA. It suggests that the cross-talk between JA signaling and the auxin biosynthetic pathway plays a crucial role in the colonization of Acremonium sp. D212 in host plants.

Long-term moderately high or low temperatures can damage economically important plants. In the present study, we treated Panax notoginseng, an important traditional Chinese medicine, with temperatures of 10, 20, and 30 °C for 30 days. We then investigated P. notoginseng glycerolipidome responses to these moderate temperature stresses using an ESI/MS-MS-based lipidomic approach. Both long-term chilling (LTC, 10 °C) and long-term heat (LTH, 30 °C) decreased photo pigment levels and photosynthetic rate. LTH-induced degradation of photo pigments and glycerolipids may further cause the decline of photosynthesis and thereafter the senescence of leaves. LTC-induced photosynthesis decline is attributed to the degradation of photosynthetic pigments rather than the degradation of chloroplastidic lipids. P. notoginseng has an especially high level of lysophosphatidylglycerol, which may indicate that either P. notoginseng phospholipase A acts in a special manner on phosphatidylglycerol (PG), or that phospholipase B acts. The ratio of sulfoquinovosyldiacylglycerol (SQDG) to PG increased significantly after LTC treatment, which may indicate that SQDG partially substitutes for PG. After LTC treatment, the increase in the degree of unsaturation of plastidic lipids was less than that of extraplastidic lipids, and the increase in the unsaturation of PG was the largest among the ten lipid classes tested. These results indicate that increasing the level of unsaturated PG may play a special role in maintaining the function and stability of P. notoginseng photosystems after LTC treatment. Keywords: Extraplastidic lipids, Glycerolipidome, Long-term chilling stress, Long-term heat stress, Panax notoginseng, Plastidic lipids

Management of crop root rot disease is one of the key factors in ensuring sustainable development in agricultural production. The accumulation of autotoxins and pathogens in soil has been reported as a primary driver of root rot diseases; however, less is known about the correlation of plants, their associated pathogens and microbiome mediated by autotoxins as well as the contributions autotoxins make to the occurrence of root rot disease. Here, we integrated metabolomic, transcriptomic, and rhizosphere microbiome analyses to identify the root cell wall degradants cellobiose and d-galacturonic acid as being induced by the autotoxic ginsenoside Rg1 of Panax notoginseng, and we found that exogenous cellobiose and d-galacturonic acid in addition to Rg1 could aggravate root rot disease by modifying the rhizosphere microbiome. Microorganisms that correlated positively with root rot disease were enriched and those that correlated negatively were suppressed by exogenous cellobiose, d-galacturonic acid, and Rg1. In particular, they promoted the growth and infection of the soilborne pathogen Ilyonectria destructans by upregulating pathogenicity-related genes. Cellobiose showed the highest ability to modify the microbiome and enhance pathogenicity, followed by Rg1 and then d-galacturonic acid. Collectively, autotoxins damaged root systems to release a series of cell wall degradants, some of which modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease. IMPORTANCE The accumulation of autotoxins and pathogens in soil has been reported as a primary driver of root rot disease and one of the key factors limiting sustainable development in agricultural production. However, less is known about the correlation of plants, their associated pathogens, and the microbiome mediated by autotoxins, as well as the contributions autotoxins make to the occurrence of root rot disease. In our study, we found that autotoxins can damage root systems, thus releasing a series of cell wall degradants, and both autotoxins and the cell wall degradants they induce could aggravate root rot disease by reassembling the rhizosphere microbiome, resulting in the enrichment of pathogens and microorganisms positively related to the disease but the suppression of beneficial microorganisms. Deciphering this mechanism among plants, their associated pathogens, and the microbiome mediated by autotoxins will advance our fundamental knowledge of and ability to degrade autotoxins or employ microbiome to alleviate root rot disease in agricultural systems.