Nematode Growth Research Articles

WOX11-mediated cell size control in Arabidopsis attenuates growth and fecundity of endoparasitic cyst nematodes.

Cyst nematodes establish permanent feeding structures called syncytia inside the host root vasculature, disrupting the flow of water and minerals. In response, plants form WOX11-mediated adventitious lateral roots at nematode infection sites. WOX11 adventitious lateral rooting modulates tolerance to nematode infections; however, whether this also benefits nematode parasitism remains unknown. Here, we report on bioassays using a 35S::WOX11-SRDX transcriptional repressor mutant to investigate whether WOX11 adventitious lateral rooting promotes syncytium development and thereby female growth and fecundity. Moreover, we chemically inhibited cellulose biosynthesis to verify if WOX11 directly modulates cell wall plasticity in syncytia. Finally, we performed histochemical analyses to test if WOX11 mediates syncytial cell wall plasticity via reactive oxygen species (ROS). Repression of WOX11-mediated transcription specifically enhanced the radial expansion of syncytial elements, increasing both syncytium size and female offspring. The enhanced syncytial hypertrophy observed in the 35S::WOX11-SRDX mutant could be phenocopied by chemical inhibition of cellulose biosynthesis and was associated with elevated levels of ROS at nematode infection sites. We, therefore, conclude that WOX11 restricts radial expansion of nematode-feeding structures and female growth and fecundity, likely by modulating ROS-mediated cell wall plasticity mechanisms. Remarkably, this novel role of WOX11 in plant cell size control is distinct from WOX11 adventitious lateral rooting underlying disease tolerance.

Impact of Bioagents on Growth and Yield Parameters of Root-knot Nematode Infested Mulberry Plants

Mulberry (Morus alba L.) is a vital crop for sericulture and its productivity is crucial for the industry's sustainability. This study investigated the influence of bioagents viz., Purpureocillium lilacinum, Trichoderma harzianum, Trichoderma viride, Pochonia clamydosporia and Pseudomonas fluorescens, alongside control treatments including carbofuran 3G and neem cake on growth and yield parameters in severely root-knot nematode infested mulberry plants. The treatments involved are generally recommended to manage root-knot nematode infestation. The results revealed that T. viride @ 5 kg/ha significantly improved plant growth, leaf area and leaf yield leading to enhanced productivity. The findings of this study underscore the potential of bioagents in fostering environmentally sustainable and economically viable sericulture. Aims: The study aims to assess the impact of bioagents on growth and yield parameters of root-knot nematode, Meloidogyne incognita infested mulberry plants. Study Design: The data collected from the experimental field were analyzed statistically by using one-way RCBD. Place and Duration of Study: The experiment was carried out in the root-knot nematode infested mulberry garden in Kalyapura Village, Shidlaghatta Taluk, Chikkaballapura District, Eastern Dry Zone (Zone-5) of Karnataka, India between January to September 2022, covering three harvests. Methodology: The treatments were incorporated near the root zone of mulberry plants within a week after pruning as per the recommendations. The observations were recorded once before the imposition of the treatments (initial) and during the first (60 DAT) and second (120 DAT) shoot harvests in mulberry after imposing the treatments. Results: Among the bioagents Trichoderma viride showed better results for shoot height (120.00 cm), number of leaves per plant (511.75), leaf area (102.10 cm2) and leaf yield per plant (528.38 g) during the second harvest i.e., 120 DAT. The minimum leaf yield per plant was recorded in the untreated check (216.43 g). Conclusion: Incorporating T. viride @ 5 kg/ha mixed with 5 tons FYM near the root zone of mulberry infested with RKN showed promising results in promoting plant growth and yield.

HLH-30/TFEB mediates sexual dimorphism in immunity in Caenorhabditis elegans

ABSTRACT Sexual dimorphism affects various biological functions, including immune responses. However, the mechanisms by which sex alters immunity remain largely unknown. Using Caenorhabditis elegans as a model species, we showed that males exhibit enhanced immunity against various pathogenic bacteria through the upregulation of HLH-30 (Helix Loop Helix 30/TFEB (transcription factor EB)), a transcription factor crucial for macroautophagy/autophagy. Compared with hermaphroditic C. elegans, males displayed increased activity of HLH-30/TFEB, which contributed to enhanced antibacterial immunity. atg-2 (AuTophaGy (yeast Atg homolog) 2) upregulated by HLH-30/TFEB mediated increased immunity in male C. elegans. Thus, the males appear to be equipped with enhanced HLH-30/TFEB-mediated autophagy, which increases pathogen resistance, and this may functionally prolong mate-searching ability with reduced risk of infection. Abbreviations: atg-2: AuTophaGy (yeast Atg homolog) 2; FUDR: 5-fluoro-2’-deoxyuridine; GSEA: gene set enrichment analysis; HLH-30: Helix Loop Helix 30; LC3: microtubule associated protein 1 light chain 3; NGM: nematode growth media; RNA-seq: RNA sequencing; SEM: standard error of the mean; TFEB: transcription factor EB; WT: wild-type

New wild-type isolates of the nematode genera <i>Oscheius, Alloionema</i>, and a different rhabditid genus (Nematoda: Rhabditida) found in forests of Vietnam

In this report, we describe the isolation and determination of four new free-living nematode (FLN) strains of three species in different nematode genera (Oscheius, Alloionema, and another rhabditid genus) from Cat Tien and Cuc Phuong National Parks, Vietnam using the isolation protocol for Caenorhabditis nematodes. Of the four strains, three strains were similar to the previous determinants and one strain may be a new rhabditid species that was first found in Vietnam. They can grow well on the E. coli OP50 – seeded media (New Cheap Media No. 18 (NcM18) and Nematode Growth Media (NGM)). Compared with the isolation of the Caenorhabditis nematodes in the same scenario, the frequencies of finding these three genera were low because of the inappropriate isolation method employed by the Caenorhabditis nematodes. This data supports knowledge of the FLN diversity and implies that FLNs that stay uncovered in forestry ecosystems should be uncovered using different isolation methods for the nematode order Rhabditida, i.e. entomopathogenic nematodes (EPNs), helminths, and the superfamily Rhabditidae.

Use of Viscous medium to study anthelmintic drug action in Caenorhabditis elegans

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity.

Pristionchus seladoniae n. sp. (Diplogastridae) isolated from a eusocial soil-dwelling bee, Halictus (Seladonia) aerarius, in Nagano, Japan

Summary A new species of Pristionchus was isolated from a soil-dwelling bee, Halictus (Seladonia) aerarius, collected from Sugadaira, Nagano, Japan. The nematode was successfully cultured on nematode growth medium agar previously inoculated with the Escherichia coli strain OP50; however, it did not propagate well. Typologically, the new species is similar to other Pristionchus belonging to the maupasi, pacificus and lheritieri groups in the stomatal structure of stenostomatous form. However, the species is characterised by the relatively short, conical tail of the female and the arrangement of male genital papillae in which the second- and third-paired papillae are almost at the same level and one of these two are directed laterally. Phylogenetically, the nematode belongs to the maupasi group, the ‘American clade’ within the genus, and is separable from the other species in the group. Biologically, the species has several interesting characters: it is seemingly native to Japan, regardless of its phylogenetic group; it is in tight and specific phoretic association with a eusocial bee; it lacks a eurystomatous form (or this form occurs rarely) under cultured conditions; and it shows characteristic clumping behaviour on culture media. The new species is taxonomically described herein as Pristionchus seladoniae n. sp.

Evaluation of the Efficiency of some Nanoparticles and Chemical Nematicides in Controlling Root-Knot Nematodes Meloidogyne Incognita (on Eggplant)

Objectives: This study was carried out to investigate the effectiveness of some nanoparticles in inhibiting the growth of the root knot nematode. Methods: This study was carried out to investigate the effectiveness of aluminum oxide Alo-NPs and silver Ag-NPs, and chemical nematicides (Velum prime and Furadan granules), in inhibiting the growth of the root knot nematode (Meloidogyne incognita) on two different types of eggplant cultivars, Barcelona and Thuraya. Results: The result obtained indicated that chemical nematicides and nanoparticles were highly effective in lowering the nematode invasion level expressed as number of knots per root and a gall index based on a 0-5 scale. Velum prime at concentrations of 300 and 400 ppm was the most effective and gave 0.67 and 0.17 knots/root average on both eggplant cultivars, respectively. In addition, the ALO-NPs treatment reduced infection to 1.17 knots/root compared to initial infection of 37.33 knots/root. The use of Ag-NPs at the concentration of 4000 ppm reduced infection to a low average of 2.83 knots/root for both eggplant varieties. All treatments average reduced the gall index to 0.95 (cv. Barcelona) and 1.20 (cv. Thuraya) compared to 3.33 and 4.00 for the infected non-treated controls, respectively. Conclusions: Nanoparticles have a role in controlling root-knot galls as alternatives to chemical pesticides that are dangerous to the environment and humans, and reducing the number of galls on the plant indicates the inhibition of eggs and second stage juveniles (J2).

Aggregate composition directly affects the characteristics of soil microbial and nematode communities in a chronosequence of Chinese fir plantations

AbstractMaintaining soil biological diversity is an effective approach in facilitating Chinese fir plantations' sustainable development. However, dynamic characteristics of soil microbial and nematode communities during Chinese fir planting remain unclear, particularly on the aggregate scales, which are the main sites of soil biological activity. Therefore, the research aims to explore how stand age (3, 9, 17, and 26 years) of Chinese fir plantations affects soil microbial biomass (including bacteria, fungi, and actinomycetes, based on the phospholipid fatty acid method), nematode abundances (including bacterivores, fungivores, plant parasites, and omnivores‐predators, based on the modified Baermann funnel method), and their diversity within aggregates of differing sizes (>2, 2–1, 1–0.25, and <0.25 mm). According to the findings, both aggregate size and stand age were major factors affecting soil microbes and nematodes in Chinese fir plantations. Specifically, soil microbial biomass (mainly bacteria), nematode abundances (except fungivores), and their diversity peaked within large macro‐aggregates (>2 mm), and the ranking order for stand ages was 17 > 9 ≈ 3 > 26 years. As the main fractions of soil aggregates in Chinese fir plantations, large macro‐aggregates had suitable internal environments for soil microbial propagation and nematode growth and mainly accumulated at 17 years, which caused the prosperity of soil microbes and nematodes at this stand age. Moreover, the partial least squares path model demonstrated that the influence of stand age on soil microbes and nematodes was indirect; but rather, the aggregate composition played a direct role in shaping their communities. Therefore, in order to maintain soil biological diversity, large macro‐aggregates should be protected during the growth of Chinese fir, especially at the late stage (from 17 to 26 years). Overall, these results could provide valuable insights into Chinese fir plantations' sustainable development.

Nematicidal Activity of 20-Deoxyingenol-3-angelate from Euphorbia peplus Latex Through Protein Kinase C Isotype TPA-1.

The latex of Euphorbia peplus and its major component 20-deoxyingenol-3-angelate (DI3A) displayed significant nematicidal activity against Caenorhabditis elegans and Panagrellus redivivus. DI3A treatment inhibited the growth and development of nematodes and caused significantly negative effects on locomotion behavior, reproduction, and accumulation of reactive oxygen species. Transcriptome analysis indicated that differential expression genes in DI3A-treated C. elegans were mainly associated with the metabolism, growth, and development process, which were further confirmed by RT-qPCR experiments. The expression level of TPA-1 gene encoding a protein kinase C isotype was obviously upregulated by DI3A treatment, and knockdown of TPA-1 by RNAi technology in the nematode could relieve the growth-inhibitory effect of DI3A. Metabolic analysis indicated that DI3A was hardly metabolized by C. elegans, but a glycosylated indole derivative was specifically accumulated likely due to the activation of detoxification. Overall, our findings suggested that DI3A from E. peplus latex exerted a potent nematicidal effect through the gene TPA-1, which provides a potential target for the control of nematodes and also suggests the potential application value of E. peplus latex and DI3A as botanical nematicides.

Reducing the metabolic burden of rRNA synthesis promotes healthy longevity in Caenorhabditis elegans

Ribosome biogenesis is initiated by RNA polymerase I (Pol I)-mediated synthesis of pre-ribosomal RNA (pre-rRNA). Pol I activity was previously linked to longevity, but the underlying mechanisms were not studied beyond effects on nucleolar structure and protein translation. Here we use multi-omics and functional tests to show that curtailment of Pol I activity remodels the lipidome and preserves mitochondrial function to promote longevity in Caenorhabditis elegans. Reduced pre-rRNA synthesis improves energy homeostasis and metabolic plasticity also in human primary cells. Conversely, the enhancement of pre-rRNA synthesis boosts growth and neuromuscular performance of young nematodes at the cost of accelerated metabolic decline, mitochondrial stress and premature aging. Moreover, restriction of Pol I activity extends lifespan more potently than direct repression of protein synthesis, and confers geroprotection even when initiated late in life, showcasing this intervention as an effective longevity and metabolic health treatment not limited by aging.

Effect of sunflower oil nanoemulsions on the growth and lifespan extension of the Caenorhabditis elegans

Caenorhabditis elegans has been used as a central model system for broad-spectrum research studies across diverse modern biological domains. A study was conducted to evaluate the potential of sunflower oil-based nanoemulsions for lifespan enhancement in stressed C. elegans worms, that had been fed on nematode growth media (NGM) seeded with two strains of pathogenic bacteria (Salmonella enterica serovar Typhimurium and Staphylococcus aureus). Nanoemulsions were fabricated using HI-CAP® 100 modified food starch, and their stability was tested under different processing conditions (temperature, pH, ionic strength) over a period of 5 months. Lifespan assay results demonstrated that sunflower-oil-based nanoemulsions with droplet size 170.2±9.3 nm, significantly facilitated the growth of C. elegans under stress conditions and increased the lifespan of the worms from the previously recorded 11 days to 26 days in the current research study.

Polyethylene glycol as an improved barrier to prevent fleeing in C. elegans.

Caenorhabditis elegans studies can be constrained by worms escaping standard solid nematode growth medium (NGM) plates. When worms are in search of food or are avoiding pathogens, chemicals, and environmental stressors, they often exhibit a behavior known as "fleeing". Palmitic acid (PA) is sometimes used as a barrier "fence" to reduce fleeing under limited food and oxygen conditions. Here, we evaluate the efficacy of palmitic acid, polyethylene glycol (PEG) and copper as potential barriers to reduce fleeing under various environmental conditions. Our results indicate that PA and PEG each reduce fasted flee rate and do not obviously alter overall health and lifespan of the worms, while copper blunts worm growth and development. We also find that PEG is a more optimal tool than PA since it is more effective in fasted conditions, reduces flee rate in a pathogenic environment, and does not alter worm size.

Sitagliptin Extends Lifespan of Caenorhabditis elegans by Inhibiting Insulin/Insulin-Like Signaling and Activating Dietary Restriction-Like Signaling Pathways

Introduction: The discovery of longevity molecules that delay aging and prolong lifespan has always been a dream of humanity. Sitagliptin phosphate (SIT), an oral dipeptidyl peptidase-4 (DPP-4) inhibitor, is an oral drug commonly used in the treatment of type 2 diabetes (T2D). In addition to being antidiabetic, previous studies have reported that SIT has shown potential to improve health. However, whether SIT plays a role in the amelioration of aging and the underlying molecular mechanism remain undetermined. Methods: Caenorhabditis elegans (C. elegans) was used as a model of aging. Lifespan assays were performed with adult-stage worms on nematode growth medium plates containing FUdR with or without the specific concentration of SIT. The period of fast body movement, body bending rates, and pharyngeal pumping rates were recorded to assess the healthspan of C. elegans. Gene expression was confirmed by GFP fluorescence signal of transgenic worms and qPCR. In addition, the intracellular reactive oxygen species levels were measured using a free radical sensor H2DCF-DA. Results: We found that SIT significantly extended lifespan and healthspan of C. elegans. Mechanistically, we found that several age-related pathways and genes were involved in SIT-induced lifespan extension. The transcription factors DAF-16/FOXO, SKN-1/NRF2, and HSF-1 played important roles in SIT-induced longevity. Moreover, our findings illustrated that SIT-induced survival benefits by inhibiting the insulin/insulin-like signaling pathway and activating the dietary restriction-related and mitochondrial function-related signaling pathways. Conclusion: Our work may provide a theoretical basis for the development of anti-T2D drugs as antiaging drugs, especially for the treatment of age-related disease in diabetic patients.

Steinernema yirgalemense inoculum size and timing impact on the population dynamics of in vitro liquid culture shake flask production

Summary Optimising the in vitro liquid mass production process for entomopathogenic nematodes (EPN) is a critical step in the development of a cost-effective EPN biopesticide product. Recording the nematode population and growth dynamics in an Erlenmeyer shake flask environment is essential to gaining a better understanding of which factors may influence the final yield. Although infective juvenile (IJ) inoculum concentration has previously been studied, no consensus yet exists as to whether it influences the final yield. This study sought to determine the impact of IJ inoculum concentration and timing on the recovery, growth and yield of the South African EPN isolate of Steinernema yirgalemense in shake flasks. The results indicated that the IJ inoculum concentration positively affects the final IJ yield of 2.88 × 155 IJ ml−1. Moreover, at higher IJ inoculum concentrations, a higher number of reproductive females and males are produced, when recovery percentages were similar. The lowest IJ inoculum concentration treatment was also the only treatment to show signs of an unwanted second generation in the final yield. The IJ inoculation timing trials confirmed that once the bacterium, Xenorhabdus indica, has ended the exponential growth phase and entered the stationary phase, it is ideal to then inoculate the IJ. However, it was found that the S. yirgalemense can be inoculated into the X. indica bacteria solution after 36 h of growth, instead of after 44-48 h. These trials demonstrated the need for further optimisation to produce consistent yields of the highly pathogenic South African EPN isolate of S. yirgalemense.

Effects of temperature for optimizing production and storage of Steinernema rarum in a novel biphasic process, and efficacy of the nematode against Sphenophorus levis

Entomopathogenic nematodes have been mass produced in vitro in a monoxenic system using two different approaches: the sponge (polyurethane) process soaked in symbiotic bacterial culture, and by liquid fermentation conducted in submerged bacterial culture. Another approach to produce nematodes under in vitro conditions is the biphasic process, which starts with liquid culture and ends with solid culture. This study was aimed at testing and optimizing a biphasic process for production of Steinernema rarum, as well as testing the efficacy of the produced nematode against the sugarcane billbug Sphenophorus levis. The process was accomplished by the initial growth of nematodes in liquid culture followed by inoculation on flaked phenolic sponges soaked with liquid medium and pre-inoculated with the symbiotic bacteria. The study consisted of three treatments represented by the three temperatures (15 °C, 25 °C, 35 °C) and evaluation at 0, 15, 30, 60, 90 and 120 days after storage at the specified temperatures. Two tests in sugarcane fields were conducted to assess the efficiency of S. rarum against S. levis. The nematode inoculated in the sponge flakes continued to reproduce after the 21 days of incubation at 21 °C, reaching a peak of infective juvenile (IJ) yield by 30 days after the bags were transferred to storage conditions, regardless of the temperature at which they were stored. The nematode reached yields above 200,000 IJs/ml of culture in the treatments of 15 °C and 25 °C, which did not significantly differ from each other nor from the temperature of 35 °C that generated 180,000 IJs/ml. The temperature of 15 °C maintained nematode viability above 80% for up to 60 days after storage, differing significantly from the temperatures of 25 °C and 35 °C, which also differed among themselves and showed a drop in nematode viability to <22% after 30 days of storage. Steinernema rarum produced by the biphasic process provided >60% and >80% control of S. levis at 29 and 37 days post application in sugarcane fields, demonstrating that the rate of 108 IJs/ha should be recommended since it did not differed from the higher rate (109 IJs/ha) tested. We conclude that the phenolic sponge biphasic system is a highly efficient approach for producing entomopathogenic nematodes; moreover, the process is advantageous relative to other systems because the sponge acts as a medium for both production and storage, and the sponge-nematode mixture can be directly applied to the field without any extraction or harvest steps.

Cadmium alters whole animal ionome and promotes the re-distribution of iron in intestinal cells of Caenorhabditis elegans.

The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans.

Preliminary study on the E-liquid and aerosol on the neurobehavior of C. elegans

E-cigarettes, also known as electronic nicotine delivery systems (ENDS), are mainly used among adolescents and young adults. Similar to traditional cigarettes, different concentrations of nicotine are also added to E-cigarette's liquid (E-liquid), but due to the supplementation of chemicals such as propylene glycol (PG), vegetable glycerin (VG) and flavors, it is difficult to determine the risk after using E-cigarettes. And given to the specificity of the aerosol particle composition and atomization process of E-cigarettes, it is necessary to assess the neurotoxic effects of long-term E-cigarettes use. In this study, two commercial nicotine-containing (5%) and nicotine-free E-liquids were diluted to investigate the neurobehavioral changes and addictive tendencies of developing C. elegans after sub-chronic exposure to E-liquid. The results showed that sub-chronic exposure of E-liquid could lead to impaired growth and development of nematodes, abnormal general neuromotor behavior and advanced learning and memory behavior, and nicotine-containing E-liquid could also lead to increased addiction tendency of nematodes. Although the damage effect of nicotine free E-liquid is smaller than that of the nicotine-containing group, its toxic effect cannot be ignored. Further analysis of the neurotoxicity mechanism found that redox imbalance-mediated mitochondrial stress and aging may be important causes of E-liquid-induced biological damage. The biosafety of e-cigarette aerosols was also included in the assessment. The study found that the heated atomization process did not alter the E-liquid components, and E-cigarette aerosols still have the effect of interfering with the growth and development of nematodes and neurobehavior, and its addictive nature is also of concern. This study can provide new ideas for future studies on the neurotoxic effects and safety assessment of the E-cigarettes, and provide theoretical reference for the study on the injury mechanism of E-cigarettes.

Zexie decoction reduce glucose-dependent lipid accumulation and oxidative stress in Caenorhabditis elegans

BackgroundObesity has become a global public health problem. Zexie decoction (ZXT) is a classic formula from Synopsis of the Golden Chamber. However, the long-term effect of ZXT in lipid accumulation remain unclear. PurposeThis study aims to investigate the effect of ZXT on aging, lipid metabolism and oxidative stress. MethodsDifferent concentration of ZXT was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or the high glucose nematode growth media (GNGM). The lifespan, heat stress resistance, lipid accumulation and related mRNA expression of the worms were examined. Oil Red staining and triglyceride were used to evaluated the lipid accumulation. Nhr-49, fat-5/fat-7, fat-5/fat-6 or skn-1 knockout mutants were used to clarify the effect on lipid metabolism of ZXT. GFP-binding mutants were used to observe the changes in protein expression. ResultsZXT improved the survival rate of C. elegans in lifespan test and heat stress test. ZXT also reduced lipid accumulation in C. elegans and significantly changed the expression of fatty acid synthesis related genes and lipid metabolism related genes. In addition, ZXT-treated C. elegans showed a higher expression of anti-oxidative protein, and reduced the expression of oxidative stress and mitochondrial dysfunction marker. However, when skn-1 was knockdown, ZXT no longer had the effect of maintaining the mitochondria membrane potential and lipid lowering but still effectively decreased the O2·− induced by high glucose. ConclusionsZXT reduced fat accumulation by regulating lipid metabolism via multiple targets and enhanced stress resistance by its antioxidant effect in C. elegans.

Fungal Endophytes: A Potential Application in Integrated Plant Health Management

Fungal endophytes are asymptomatic inhabitants of plant tissues in most plant species, providing tissue-specific protection from disease and reducing crop yield losses by 30 to 50% annually. They can increase plant fitness by inhibiting biotic and abiotic stressors, promote plant growth and development, and reduce crop yield losses. Endophytes enhance plant resistance to fungal pathogens by strengthening cell walls, increasing photosynthesis and promoting plant defense responses. They produce antibacterial and antifungal compounds that protect plants against bacterial pathogens, such as javanicin, which is effective against Bacillus species and Escherichia coli. Endophytic fungi can produce broad-spectrum antimicrobial compounds, some of which can be used as biocontrol agents for phytopathogenic bacteria. They also reduce viral diseases by increasing plant defenses or preventing viruses from spreading. Plant-parasitic nematodes attack plant roots and stems, creating wounds through which secondary opportunistic fungal, bacterial, or viral pathogens can enter. Fungi can inhibit nematode growth and spread by producing nematocidal compounds, parasitizing nematode larvae, or using hyphal loops for nematode capture. Endophytic fungi are a rich source of novel natural compounds, have a high level of biodiversity, and may produce pharmaceutical-significant compounds. Further molecular research is necessary to facilitate the recognition of endophytes carrying host genes.

Efektivitas Esktrak Akar Kenikir (Cosmos caudatus Kunth) dan Pepaya (Carica papaya L) dalam Menekan Terbentuknya Puru Akar Nematoda pada Tanaman Seledri (Apium graveolensL)

This study aims to test the effectiveness of root extracts of kenikir and papaya plants in suppressing the rate of root-knots formation, as well as the number of root-knots formed on celery plants. The method used was a factorial experiment in a randomized block design with two factors, namely the type of antagonist plant root and the dosage, with five replications. The results showed that the treatment of papaya root extract (Carica papaya L.) had a significant effect on all parameters, but the HSD test was only significantly different on the number of root knots. The highest average number of root knots in control plants was 67.2 (A1B0), and the lowest was 4.6 (A1B5). The treatment of kenikir root extract (Cosmos caudatus Kunth.) significantly affected all parameters, but the HSD test was only significantly different on plant height and number of root knots. The average plant height in the control was 31.4 cm (A2B0), and in the treatment 40.6 cm (A2B5). The highest average number of root knoots was 50.8 (A2B0), and the lowest was 1.0 (A2B5). Carpain secondary metabolites in papaya root extract, and phenylpropanoids in kenikir root extract played a role in suppressing the growth of root-knot nematodes. Coniferyl alcohol in kenikir root extract is thought to play a role in increasing the height of celery plants. Kenikir root extract was better than papaya root extract in suppressing the growth of root-knot nematodes.