Melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience

Melatonin and dopamine can potentially prevent waterlogging stress in apples.The current study investigated the mechanism by which melatonin and dopamine alleviate apple waterlogging stress.This study demonstrated that melatonin and dopamine alleviated waterlogging by removing reactive oxygen species(ROS),and that the nitric oxide(NO)content and nitrate reductase(NR)activity were significantly correlated.Melatonin and dopamine were also found to recruit different candidate beneficial endophytes(melatonin:Novosphingobium,Propionivibrio,and Cellvibrio;dopamine:Hydrogenophaga,Simplicispira,Methyloversatilis,Candidatus_Kaiserbacteria,and Humicola),and these endophytes were significantly and positively correlated with plant growth.Network analyses showed that melatonin and dopamine significantly affected the endophytic bacterial and fungal communities under waterlogging stress.The metabolomic results showed that melatonin and dopamine led to waterlogging resistance by upregulating the abundance of beneficial substances such as amino acids,flavonoids,coumarins,and organic acids.In addition,melatonin and dopamine regulated the physicochemical properties of the soil,which altered the endophyte community and affected plant growth.The co-occurrence network demonstrated close and complex relationships among endophytes,metabolites,soil,and the plants.Our results demonstrate that melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience.This study provides new insights into how melatonin and dopamine alleviate stress and a theoretical basis for synergistic beneficial microbial resistance to waterlogging stress.

The Effects of Increasing Production of Endophytes Phomopsis B3 on Rice

After insufflating extended endophytes phomopsis B3 ferment diluent on seedling bed of rice, the effect of microbial inoculum on rice growth was studied. The investigation result of seedlings before transplanting seedling showed that leaf age,the number of green leaves,the number of tiller of individual plant and the weight of per 100 fresh plants in microbial inoculum treatment group increased 0.11,0.12 ,0. 03 and 2.6 g respectively compared with those of control group. 20 days after transplanting, increased tiller number in microbial inoculum treatment group was 55 500 hm^2 more than that in control group. 30 days after transplanting, tiller number in microbial inoculum treatment group was 42 000 hm^2 more than that in control group. In harvest season, the yield ,weight of I 0130 grain and seed-setting rate increased 300 kg/hm2, 0. 7 g and 0. 23% respectively compared with these in control group. The result of preliminary study demonstrated that microbial inoculum confected by endophytes phomopsis B3 could increase the number of strong seedling and yield.

Diversity Analysis of Endophytes in Wheat Infected by Powdery Mildew

Common wheat (Triticum aestivum L.) is one of the most important food crops. Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most serious diseases on wheat. In this study, the changes of endogenous bacteria in root, stem and leaf tissues of wheat infected and uninfected with powdery mildew were measured based on 16S rDNA. Integration, OTU cluster analysis, taxonomic analysis, diversity index, Shannon-Index curve, Rank-Abundance curve and PCoA analysis were carried out for each sample, and the roots, stems and leaves of different tissue parts were classified and summarized. The results showed that the infection of wheat powdery mildew had a certain effect on endophytic bacteria in stem tissue. There are also differences in the control and treatment of leaf tissue and root tissue. This indicated that endophytic bacteria were distributed differently in different parts of wheat.

Diversity of endophytes across the soil-plant continuum for Atriplex spp. in arid environments

Endophytes are hypothesized to be transferred across the soil-plant continuum, suggesting both the transfers of endophytes from environment to plant and from plant to soil. To verify this hypothesis and to assess the role of locality, we evaluated the similarity of microbial communities commonly found both in soils and endophytic communities in three arid regions, i.e. the Jornada LTER （Long Term Ecological Research） site in New Mexico, USA, and the research station of Jordan University of Science and Technology （JUST） and Khanasd research station in Badia region of Jordan. Rhizosphere and non-rhizosphere soils, leaves and seeds of Atriplex spp. were sampled. Diversity and distribution of bacteria and fungi across the soil-plant continuums were assessed by tag-encoded FLX amplicon pyrosequencing and sequence alignment. Of the total bacterial OTUs （operational taxonomic units）, 0.17% in Khanasri research station, 0.16% in research station of JUST, and 0.42% in Jornada LTER site were commonly found across all the plant and soil compartments. The same was true for fungi in two regions, i.e. 1.56% in research station of JUST and 0.86% in Jornada LTER site. However, in Khanasri research station, 12.08% of total fungi OTUs were found in at least one soil compartment and one plant compartment. Putative Arthrobacter, Sporosarcina, Cladosporium and members of Proteobacteria and Actinobacteria were found across all the soil-plant continuums. Ascomycota, mainly including Didymellaceae, Pleosporaceae and Davidiellaceae were present across all the soil-plant continuums. Microbial communities in two regions of Jordan were similar to each other, but both of them were different from the Jornada LTER site of USA. SIMPER （similarity percentage） analysis of bacterial and fungal taxa for both soil and endophyte communities revealed that dissimilarities of two bacterial genera （Arthrobacter and Sporosarcina） and two fungal genera （Cladosporium and Alternaria） are very high, so they play key roles in the soil-plant continuums. A weighed Pearson correlation analysis for the specific bacterial OTUs in the soil-plant continuums only showed high similarity between the two regions of Jordan. However, fungal groups showed higher similarities among all regions. This research supports the hypothesis of continuity of certain bacterial and fungal communities across the soil-plant continuums, and also explores the influences of plant species and geographic specificity on diversity and distribution of bacteria and fungi.

Endophytes as Producers of Peptides:An Overview About the Recently Discovered Peptides from Endophytic Microbes

An endophyte is a fungus or bacterium that lives within a plant in a symbiotic relationship.Extensive colonization of the plant tissue by endophytes creates a barrier effect,where they outcompete and prevent pathogenic organisms from taking hold.This happens by producing secondary metabolites that inhibit the growth of the competitors or pathogens.In this way they play a very important role in the plant defence mechanisms.The metabolites produced by these endophytes fall within a wide range of classes of compounds that include peptides which are the focus of this review.Peptides are increasingly being selected for drug development because they are specific for their targets and have a higher degree of interactions.There have been quite a number of endophytic peptides reported in the recent past indicating that endophytes can be used for the production of peptide based drugs.Molecular screening for NRPS,which shows peptide producing capability,has also shown that endophytes are potential producers of peptides.The presence of NRPS also offers the possibility of genetic modifications which may generate peptides with high pharmacological activities.This review,therefore,aims to show the current status of peptides isolated from endophytic bacteria and fungi in the recent decade.Endophytes as potential sources of peptides according to NRPS studies will also be discussed.

Anti‑leishmanial and Anti‑inflammatory Agents from Endophytes:A Review

Leishmaniases and chronic inflammatory diseases are the cause of millions of deaths in the world each year.The treatment of leishmaniasis is facing serious drawbacks particularly due to the limited number of effective medicines,the resistance,and the toxicity of available drugs.On the other hand,many drugs are used for the management of inflammatory disorders.However,the most commonly prescribed although efficient is highly toxic with multiples side effects.New leads compounds for the development of new anti-leishmanial and anti-inflammatory drugs are needed.Over the past decade,several studies on the potential of endophytes to produce bioactive metabolites have been reported.We are presenting in the present review the status of research from 2000 to 2019 on the anti-leishmanial and anti-inflammatory metabolites isolated from endophytes from diverse habitats.An emphasis was put on existing gaps in the literature to inspire and guide future investigations.We hope that this review will help accelerate the drug discovery against leishmaniases and inflammation-associated disorders.

Antioxidant Activity and Phytochemical Screening of Crude Endophytes Extracts of <i>Tabebuia argentea</i>Bur. &K. Sch.

The aim of this study is to investigate in vitro antioxidant activities and the phytochemical screening endophytes. Seven different endophytic fungi were isolated from different parts of the plant and their extracts subjected to know antioxidant properties and phytochemical screening. Phytochemical analysis revealed the presence of tannins, flavonoids, steroids, alkaloids, phenols and proteins from different solvents extracts of different endophytes. The antioxidant activity was evaluated by six separated methods: scavenging of free radical DPPH, FRAP, TBA, superoxide radical, FTC and iron methods. All seven different endophytes yielded almost all phytochemicals in methanol extracts which were tested. The endophytes A. niger, Penicillium sp. and Trichoderma sp. have shown potential in vitro antioxidant activities. Further work is needful to isolate the exact compound which is responsible for antioxidant activity and biophysical characterization will be done in the future.

Isolation and Identification of Fungal Endophytes from Grasses along the Oregon Coast

Fungal endophytes have been shown to improve abiotic and biotic stress response in plants. Grasses growing along the Oregon coast are exposed to harsh conditions and may harbor endophytes that enable them to survive and grow under these conditions. Endophytic fungi were isolated from thirty-four grass plants representing eight different grass species at four different locations along the Oregon coast. The ITS-1, 5.8S, and ITS-2 regions of each isolate were amplified, sequenced, and used to perform a BLAST search against the nucleotide database collection at National Center for Biotechnology Information. One-hundred-eleven different fungal isolates were classified into thirtynine genera with two isolates that did not show a match greater than 95%. These endophytes will be investigated to determine their potential for improving the adaptability of grasses and other crop plants to grow in diverse environments where they are subjected to multiple biotic and abiotic stresses.

Research Progress on Medicinal Active Components of Endophytes in Plants

Endophytes are a type of microorganisms which live in plant tissues and have no obvious disease symptoms to plants,mainly including fungi,bacteria and actinomycetes.Endophytes can produce the same or similar active substances as host plants,so they have become a hot spot in the research of natural medicinal active products in recent years.Endophytes provide abundant resources for searching medicinal active substances because of their abundant species and huge reserves.In this paper,the species,structural characteristics,separation methods and pharmacological studies of active products of endophytic fungi were reviewed,in order to provide theoretical reference for the research of medicinal active components of endophytic fungi.

Analysis on Composition and Diversity of Endophytes in Moringa oleifera

[Objectives] To explore the diversity of endophytes in Moringa oleifera,and provide a scientific basis for better protection,development and use of Moringa oleifera resources. [Methods] With Moringa oleifera stems and leaves as materials,the Illumina Mi Seq highthroughput sequencing technology was used to study the endophyte diversity. [Results] A total of 199 OTUs were measured in the samples,belonging to 12 phyla such as Proteobacteria,Actinobacteria,Acidobacteria,Gemmatimonadetes,Bacteroidetes,Chloroflexi,DeinococcusThermus,Verrucomicrobia,Candidatus Saccharibacteria and Cyanobacteria. [Conclusions]Gemmatimonas is the dominant population of endophyte in Moringa oleifera.

Antimicrobial Activity of Ulva reticulata and Its Endophytes

Seaweeds are known to exhibit various antimicrobial properties, since it harbours an enormous range of indigenous bioactive compounds. The emergence of drug resistant strains has directed to the identification of prospective metabolites from seaweed and its endophytes, thereby exploiting the properties in resisting bacterial diseases. The current study was aimed to assess the antimicrobial activity of extracts obtained from Ulva reticulate, for which metabolites of Ulva reticulata and its endophytes were extracted and assessed against human pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Bacillus subtilis. It was observed that the hexane extract of isolate VITDSJ2 was effective against all the tested pathogens but a significant inhibition was observed for Staphylococcus aureus and Escherichia coli. Further, Gas chromatography coupled with Mass spectroscopy （GC-MS） revealed the existence of phenol, 3, 5-bis （1, 1-dimethylethyl） in the crude hexane extract which is well-known to possess antibacterial activity. The effective isolate VITDSJ2 was identified to be the closest neighbour of Pseudomonas smtzeri by phenotypic and genotypic methods. The crude extracts of the seaweed Ulva reticulata was also screened for antibacterial activity and the hexane extract was effective in showing inhibition against all the tested pathogens. The compound in the crude extract of Ulva reticulata was identified as hentriacontane using GC-MS. The extracts obtained from dichloromethane did not show significant activity in comparison with the hexane extracts. Hence the metabolites of Ulva reticulata and the bacterial secondary metabolites of the endophytes could be used in the treatment of bacterial infections.

Isolation and Identification of Bacterial Endophytes from Grasses along the Oregon Coast

Bacterial endophytes have been shown to improve abiotic and biotic stress responses in plants. Plants growing under harsh conditions along the Oregon Coast could contain bacterial endophytes that improve persistence and growth of grasses in this environment. Thirty-four plants consisting of eight different species were collected along the Oregon coast from four different sites. Bacterial endophytes were isolated from root crown, stem and leaf tissues. A portion of the 16S rRNA ITS regions of each isolate was amplified, sequenced, and used to perform a BLAST search against the nucleotide database collection at National Center for Biotechnology Information. One-hundred and thirty-three different bacterial isolates, ninety-four of which were unique, representing thirty-six different taxonomic groups were found. Over 50% of the total bacteria isolates were in just five taxonomic groups. Pseudomonads were the most predominant bacteria isolated, making up 20.3% of the total isolates, followed by Curtobacterium and Microbacterium, each at 8.2%, Bacillus at 7.5% and Xanthomomas at 6%. Forty-seven percent (17 of 36) of the taxonomic groups contained only a single isolate. Fourteen bacterial isolates from five taxonomic groups, nine of which were from the genus Pseudomonas, were found to have 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, an enzyme associated with improving plant growth under stress. These newly discovered bacterial endophytes will be a valuable biological resource to develop approaches to increase the yield and adaptability of grasses and other crops grown in diverse environments and to meet the challenges associated with an unpredictable climate.

Non-mycorrhizal fungal endophytes in two orchids of Kaiga forest(Western Ghats), India

We used standard isolation protocols to explore the endophytic fungal communities in three tissue types of two dominant orchids （Bulbophyllum neilgherrense and Vanda testacea） of the Kaiga forest of the Western Ghats. We surface sterilized and assessed 90 segments of each orchid for the occurrence and diversity of endophytic fungal taxa. The 118 fungal isolates were obtained from root, bulb and leaves of B. neilgherrense, consisting of 17 anamorphic taxa （range, 10-15 taxa） with 1.3 fungal taxa per segment （range, 1.2-1.4 taxa）. Four taxa （Aspergillus flavus, A. niger, Penicillium sp. and morpho sp. 1） belonged to the core group （11.1%--32.2%）. The relative abundance of A. flavus and morpho sp. 1 was more than 10%. A total of 130 fungal isolates from roots, stems and leaves of V. testacea yielded 20 anamorphic taxa （range, 11-15 taxa） with 1.4 fungal taxa per segment （range, 1.4-1.5 taxa）. Aspergillusflavus, A. niger, A. ochraceus, Gliocladium viride, Penicillium sp. and morpho sp. 1 belonged to the core group. Relative abundance exceeded 10% for A. flavus, A. niger, and morpho sp. 1. The Simpson and Shannon diversity indices were higher in leaf than root or bulb/stem of both orchids. Jaccard＇s similarity coefficient was higher between root and leaf in both orchids （56.3%-60%） than between other pairs. Our study revealed that the endophytic fungal assemblage and diversity orB. neilgherrense and E testacea of Kaiga forest of the Western Ghats were relatively similar between orchids and their tissues.

Testing of Bacterial Endophytes from Non-Host Sources as Potential Antagonistic Agents against Tomato Wilt Pathogen <i>Ralstonia solanacearum</i>

The study was taken up with the objective of testing whether the endophytic organisms isolated from crops that are normally non-hosts to the bacterial wilt pathogen Ralstonia solanacearum possessed pathogen-antagonistic activity and to evaluate the selected isolates for the alleviation of wilt disease in the target tomato crop through horizontal movement of promising organisms. Sixteen endophytic bacteria (EB) isolated from the micropropagated cultures of grape, watermelon and papaya were tested for potential antagonistic effects against R. solanacearum tomato isolate “NH-01” through agar-well diffusion assay. Enterobacter cloacae from papaya (EB-11) displayed the maximum antagonistic effect followed by Bacillus subtilis (EB-06) and B. flexus (EB-07) from watermelon and B. pumilus (EB-02) from grape. Testing the above organisms for crop protection through seed fortification of susceptible tomato cv. Arka Vikas at sowing in R. solanacearum inoculated (Ral+) organic cocopeat showed EB-02 and EB-11 promising (33% and 32% survival, respectively, four weeks after sowing against 15% in Ral+ control). A second trial showed 37%, 28%, 21% and 55% seedling survival 6 weeks after sowing for EB-02, EB-06, EB-07 and EB-11 respectively, compared to 2.5% in non-treated control. Assessing the four endophytes for crop protection in Ral+ sick-soil through seedling fortification at transplanting indicated less disease incidence in treated sets (40%, 40%, 20% and 20% survival, respectively, six weeks after transplanting) over non-fortified control (5%). Endophytic fortification of seedlings through hypocotyl inoculation showed some systemic resistance induction upon seedling transplanting to sick soil but not with petiole fortification. Seedling growth was enhanced by the isolates EB-06 and EB-07. The study thus identifies four endophytic organisms from crops unrelated to tomato possessing potential antagonistic activity against the wilt pathogen and prospects for exploitation as biocontrol agents coupled with seedling growth promotion effects.

Antimicrobial and plant growth-promoting activities of bacterial endophytes isolated from Calotropis procera(Ait.)W.T.Aiton

Bacterial endophytes are beneficial to their hosts as they can fix nitrogen in the soil and make it available to the host.Endophytic bacteria also secrete plant growth-promoting hormones to support their host plants under normal as well as stress conditions.The current study aimed to isolate endophytic bacteria from different parts of Calotropis procera,i.e.,roots,stem and leaves of Calotropis procera(Ait.)W.T.Aiton.Plants were collected from the Lundkhwar,district Mardan.A total of 12 bacterial strains,i.e.,six from roots,three from the stem and three from the leaves were isolated.The strains were screened for their growth-promoting activity in rice plants because rice shows a quick and easy response to the bioactive compounds present in the culture filtrate(CF)of the potent endophytic strains.The rice plants were cultivated in pots containing 30 mL of 0.8%w/v water-agar medium.The pots were placed in a growth chamber,operated at 28±0.3℃ for 14 h(day);and 25±0.3℃ for 10 h(night),at 70%relative-humidity.Among the isolated strains,R1,S1,S3,L1,R5 and R6 showed visible growth promotion in rice plants.The biochemical analysis revealed that the strains were able to produce indole acetic acid(IAA)and flavonoids in higher quantities.Moreover,the strains also produced bioactive compounds that inhibited the growth of Escherichia coli and Aspergillus flavus using the well diffusion method.From the results,it was concluded that these strains can secrete potent compounds that can promote the host plant growth and inhibit the growth of pathogenic microorganisms and,therefore,can be used as bio-fertilizer and bio-control agents.

Phylogenetic analysis of Endophytes from Bitter Melon (<i>Momordica charantia</i>) in Guangdong Province

This study aims to isolate and identify taxonomic characterization of endophytic fungi from bitter melon in Guangdong province, China. A total of 1172 endophytic fungi are isolated from roots, stems, leaves, flowers, and fruits of healthy plants, and they are classified to 49 taxa based on morphological and molecular features. The results show that endophytic fungi from bitter melon plants exhibit high biodiversity. Arthrinium aureum, A. marii, A. sphaerospermum, Corynascus verrucosus, Curvularia borreriae and C. protuberate have not been recorded in any plants in China. Basidiomycetous endophytes, such as Ceratobasidium sp., and C. cornigerum, are reported in this study for the first time in bitter melon. According to the results of phylogenetic analysis, the rDNA ITS (Internal Transcribed Spacer) sequences can successfully separate species, such as F. solani, F. kyushuense, C. verrucosus, C. globosum, E. rostratum, C. brachyspora, C. verruculosus, C. affinis, P. bougainvilleicola, P. longicolla, P. glabrae, P. verruculosum, P. oxalicum, P. citrinum, P. chermesinum, P. glomerata, A. fumigatus and A. japonicas. Some isolates belonging to A. alternata, C. gloeosporioides, C. cladosporioides, C. brasiliense, C. convolutum, F. proliferatum, F. oxysporum, F. verticillioides, F. equiseti, F. camptoceras and Xylaria, however, require the analysis of others molecular markers to provide better taxonomic resolution. Molecular analyses of rDNA ITS sequences are useful for identification and classification of endophytes of bitter melon, but it is desirable to consider an integrated approach, such as molecular phylogeny, host, colony growth rate, symptoms, and shape of conidia.

Characterization of Endophytes Isolated from <i>Eclipta prostrate</i>and Roles in Regulating the Gut Microbiota of C57BL/6J Mice

Eclipta prostrata has been extensively studied for its promoting effect on human health. Previous study proved that E. prostrata possessed anti-osteoporosis function in SAMP6 mice via gut microbiota (GM). Endophytes are widespread in plants, especially in Chinese herbal medicines. However, little is known regarding the endophytes of E. prostrata. In this study, we focus on screening and identifying the endophytes from plant E. prostrata and exploring their roles in modulating GM. According to biochemical, physiological tests and 16S rDNA sequence analysis, ten endophytes were characterized in different locations of plant E. prostrata belonging to Lactococcus, Bacillus, Enterococcus, Exiguobacterium and Pantoea. The antimicrobial activity of endophytes EP01-10 was investigated via the oxford cup method. Furthermore, the acid and bile salt resistant ability of EP01-10 was detected to explore their survival ability in gastrointestinal tract. Results indicated that strains of Lactococcus, Bacillus and Exiguobacterium (EP01, 03 and 05) showed strong antimicrobial activity against Escherichia coli and Staphylococcus aureus and strains of Lactococcus, Bacillus and Enterococcus (EP01, 02, 04, 08 and 10) have the ability to survive in the gastrointestinal tract. 16S rRNA sequencing of GM in C57BL/6J mice was performed for diversity and structure analysis responded to the administration of E. prostrata extract. E. prostrata extract acted on improving the microflora diversity, particularly in increasing the abundance of Lactococcus significantly. Thus, as an endophyte, Lactococcus plays an important role in E. prostrata modulating intestinal tract. Our study suggested that endophytes of Chinese herbal medicines might be a novel target for the treatment of diseases by regulating the GM.

Plant growth-promoting characteristics of root fungal endophytes isolated from a traditional Cordillera rice landrace

This study was conducted to isolate and characterize the plant growth-promoting potential of fungal endophytes from the roots of Diket red,a traditional rice plant from the Cordillera,Northern Luzon.Eighteen morphospecies of filamentous endophytes were isolated of which twelve isolates were successfully identified to the species level.These isolates were identified as Aspergillus versicolor,Aspergillus sp.,Chaetosphaeria sp.,Cladosporium cladosporioides,Hypocrea lixii,Microascus murinus,and Trichoderma harzianum.The identified twelve isolates were selected to screen in vitro for their plant growth-promoting characteristics,and evaluated in vivo for their beneficial effects on seedling vigor and early seedling growth.Isolate PPL14 produced the highest IAA at 55.5μg ml^(-1)and M.murinus PPL10 produced the highest amount of IAA at 3.73μg IAA mg^(-1)dry mycelia wt.The seedling vigor assay and in vivo plant growth promotion bioassay indicated overall positive effects of culture filtrate(CF)application of the endophyte isolates.Rice seeds and seedlings grown in aseptic condition and treated with endophyte CFs displayed significantly enhanced levels of germination,seedling vigor,shoot,root,and total plant growth,and biomass compared to non-treated control.Other plant growth-promoting characteristics were also studied including phosphate solubilization,siderophore production,ammonia production,and catalase activity.This study supports the potential use of fungal endophytes as bio-inoculants for plant growth promotion and enhancement of nutrient assimilation of agriculturally important crops.

Arbuscular mycorrhiza and plant growth promoting endophytes facilitates accumulation of saponin under moderate drought stress

Objective: Paris polyphylla var. yunnanensis, one of the important medicinal plant resources in Yunnan,China, usually takes 6–8 years to be harvested. Therefore, it is urgent to find a method that can not only shorten its growth years, but also improve its quality. In this study, we examined the effects of a combination treatment of arbuscular mycorrhizal fungi(AMF) and plant growth-promoting endophytes(PGPE)and drought stress on the accumulation of saponins in it.Methods: P. polyphylla var. yunnanensis was infected with a mixture of AMF and PGPE under drought stress. The content of saponins, as well as morphological, physiological, and biochemical indicators, were all measured. The UGTs gene related to saponin synthesis was obtained from transcriptome data by homologous comparison, which were used for RT-PCR and phylogenetic analysis.Results: Regardless of water, AMF treatment could infect the roots of P. polyphylla var. yunnanensis, however double inoculation with AMF and PGPE(AMF + PGPE) would reduce the infection rate of AMF. Plant height, aboveground and underground fresh weight did not differ significantly between the single inoculation AMF and the double inoculation treatment under different water conditions, but the inoculation treatment significantly increased the plant height of P. polyphylla var. yunnanensis compared to the noninoculation treatment. Single inoculation with AMF considerably increased the net photosynthetic rate,stomatal conductance, and transpiration rate of P. polyphylla var. yunnanensis leaves under various water conditions, but double inoculation with AMF + PGPE greatly increased the intercellular CO2concentration and chlorophyll fluorescence parameter(Fv/Fm). Under diverse water treatments, single inoculation AMF had the highest proline content, whereas double inoculation AMF + PGPE may greatly improve the amount of abscisic acid(ABA) and indoleacetic acid(IAA) compared to normal water under moderate drought. Double inoculation AMF + PGPE treatment improved the proportion of N, P, and K in the rhizome of P. polyphylla var. yunnanensis under various water conditions. Under moderate drought stress,AMF + PGPE significantly enhanced the contents of P. polyphylla var. yunnanensis saponins I, II, VII, and total saponins as compared to normal water circumstances. Farnesyl diphosphate synthase(FPPS),Geranyl pyrophosphate synthase(GPPS), Cycloartenol synthase(CAS), and Squalene epoxidase(SE1) were the genes that were significantly up-regulated at the same time. The amount of saponins was favorably linked with the expression of CAS, GPPS, and SE1. Saponin VI content and glycosyl transferase(UGT)010922 gene expression were found to be substantially associated, as was saponin II content and UGT010935 gene expression.Conclusion: Under moderate drought, AMF + PGPE was more conducive to the increase of hormone content, nutrient absorption, and total saponin content in P. polyphylla var. yunnanensis, and AMF + PGPE could up regulate the expression of key genes and UGTs genes in one or more steroidal saponin synthesis pathways to varying degrees, thereby stimulating the synthesis and accumulation of steroidal saponins in the rhizome of P. polyphylla var. yunnanensis. The combination of AMF and PGPE inoculation, as well as adequate soil drought, reduced the buildup of saponins in P. polyphylla var. yunnanensis and increased its quality.

Determining the earliest growth stage to detect the presence of endophytes in tall fescue and perennial ryegrass seedlings using molecular markers

Background:Tall fescue(Festuca arundinacea[Schreb.],Lolium arundinaceum[Schreb.]Darbysh)and perennial ryegrass(Lolium perenne)are important cool-season forage and amenity grasses that have a mutualistic association with an endophytic fungus.Endophytes confer insect and drought resistance to plants but can produce mammalian toxins.Novel endophytes that do not produce mammalian toxins have been introduced to elite cultivars for commercial production.Seed companies need to maintain adequate levels of novel endophytes within the elite forage cultivars.Endophyte detection is performed using immunochemical and molecular techniques because of their speed and reliability.Early detection in seedlings is essential to evaluate the viability of the endophyte within seed lots.Methods:This research aimed to identify the earliest growth stage in which immunochemical and molecular methods can detect viable endophyte in seedlings of tall fescue cultivars BarOptima(e34),Texoma MaxQII(584),and Jesup MaxQ(542),as well as the perennial ryegrass cultivar Remington(NEA2).Results:Immunochemical testing detected endophytes in seedlings 14 days after germination(DAG),but the detection rate increased until 42 DAG in some cultivars tested.The molecular marker Tef1exon detected endophytes at a lower rate than the immunochemical method at 28–42 DAG.However,there was insufficient DNA to detect endophytes in 14 DAG seedlings using markers.Conclusions:We conclude that the most accurate detection of viable endophytes in seedlings was 42 DAG,at which sufficient and consistent endophyte colonization occurred.