Meloidogyne Incognita Research Articles

Local and systemic transcriptome and spliceome reprogramming induced by the root-knot nematode Meloidogyne incognita in tomato.

Root-knot nematodes (Meloidogyne spp.) are widely spread root parasites that infect thousands of vascular plant species. These highly polyphagous nematodes engage in sophisticated interactions with host plants that results in the formation of knot-like structures known as galls whose ontogeny remains largely unknown. Here, we determined transcriptome changes and alternative splicing variants induced by Megalaima incognita in galls and neighboring root cells at two distinct infective stages. M. incognita induced substantial transcriptome changes in tomato roots both locally in galls and systemically in neighboring cells. A considerable parallel regulation of gene expression in galls and neighboring cells were detected, indicative of effective intercellular communications exemplified by suppression of basal defense responses particularly during the early stage of infection. The transcriptome analysis also revealed that M. incognita exerts a tight control over the cell cycle process as a whole that results in an increase of ploidy levels in the feeding sites and accelerated mitotic activity of the gall cells. Alternative splicing analysis indicated that M. incognita significantly modulates pre-mRNA splicing as a total of 9064 differentially spliced events from 2898 genes were identified where intron retention and exon skipping events were largely suppressed. Furthermore, a number of differentially spliced events were functionally validated using transgenic hairy root system and found to impact gall formation and nematode egg mass production. Together, our data provide unprecedented insights into the transcriptome and spliceome reprogramming induced by M. incognita in tomato with respect to gall ontogeny and nematode parasitism.

Integrated Analysis of the lncRNA-miRNA-mRNA Expression Profiles in Response to Meloidogyne incognita in Radish (Raphanus sativus L.)

Radish is an important root vegetable that is widely grown in Asia. The root-knot nematode (RKN) Meloidogyne incognita seriously affects the growth and development of radish root and causes poor appearance quality. However, the molecular mechanism of radish response to RKNs remains poorly understood. In this study, a total of 220 lncRNAs, 1144 mRNAs, 20 miRNAs and 153 proteins were differential expressed between the RKN-infected and WT samples. Correlation analysis of all DEPs compared with all DGEs showed that 8 mRNAs-DEPs showed a changed abundance. The results showed that 18 DEmiRNAs have 167 target DEGs in 220 miRNA-target modules and 29 DElncRNAs were predicted as putative targets of 16 DEmiRNAs in 37 miRNA-target modules. In all, 6 DGEs in the ABA pathway and 2 DGEs in the JA pathway were identified under RKN infection, respectively. The four regulatory networks of lncRNA-miRNA-mRNA were constructed in response to RKN infection. qRT-PCR analysis found that the expression pattern of 6 DElncRNAs, 6 DEmRNAs, 6 DEmiRNAs and 6 DEPs were consistent with sequencing results. These results provide a theoretical basis for studying the molecular mechanism of radish in response to M. incognita and breeding resistant varieties to this nematode.

Pathogenicity of Root-knot Nematode, Meloidogyne incognita on Tuberose (Polianthes tuberosa L.)

A pot experiment was carried out in the net house of Department of Nematology, Assam Agricultural University, Jorhat, to study the pathogenicity of root-knot nematode, Meloidogyne incognita, on tuberose. The study found that as the inoculum level of M. incognita increased from 10 to 10,000 second-stage juveniles (J2) per pot (containing 1 kg of sterilized soil), all plant growth parameters of tuberose decreased progressively. At the highest inoculum level, the plants became severely stunted, chlorotic, and produced very few bulblets. It was noted that at the highest inoculum level, the root systems were significantly reduced, with larger and mostly coalescent galls. The treatments with no nematode (check and associated check) were free from galls and eggmasses. An initial inoculum level of 100 J2 of M.incognita per kg of soil caused significant reduction in all growth parameters and proved to be pathogenic to the tuberose plants. The number of galls and eggmasses increased gradually in the plants with an initial inoculum level of 10 to 1000 J2 of M.incognita per kg of soil, but it declined at highest inoculum level of 10,000 J2 per kg of soil. The experiment also recorded the variation in nematode population in the soil as well as their reproductive rates. These findings can be used to develop effective, targeted methods for minimizing the damage caused by root-knot nematode in tuberose crops.

IN SILICO STUDIES OF IDENTIFIED COMPOUNDS FROM ETHANOLIC EXTRACT OF CELOSIA TRIGYNA AGAINST NEMATODE (Meloidogyne incognita)

Plant-parasitic nematodes (PPNs) have been found to be a major cause of considerable economic burden on the horticultural crops industry. Celosia genus have been renown to purpose antimicrobial activity. This study tends to swing the antimicrobial activity of one species of this genus i.e. Celosia trigyna against root-knot nematodes employing molecular docking methods. The identification of compounds in the leaf extract with the potential to inhibit Meloidogyne incognita was carried out in silico. Liquid Chromatography Mass Spectrometry (LCMS) was employed for analysis of the ethanolic leaf extract of this plant, it revealed the presence of cis-9-tetradecanoic acid, vitexin-glucoside, 6”-O-deoxyhexoside, gallic acid, malic acid, sinapic acid, 3-feruloylquinic acid in the extract. Site-directed multiligand docking of the identified compounds was performed on protein 2MIF of Meloidogyne incognita and employing Bifenazate and Boscalid as positive controls. The binding affinity of 3-feruloylquinic (– 4.2 kcal/mol) was significantly higher than the positive control compounds i.e. Bifenazate and Boscalid (– 4.0 kcal/mol and – 3.9 kcal/mol). The interactions of this molecule with the amino acids of the protein showed that the mechanism of its inhibitory action is similar to that of the cocrystallized ligand. This result validates that the antimicrobial activity of the ethanolic extract of the leaves of C. trigyna could be employed against root-knot nematodes for sustainable agriculture.

Botanicals as Phyto-nematicides Against Root-knot Disease Caused by the Root-knot Nematode (Meloidogyne incognita) via Promoting growth, Yield, and Biochemical Performance of Cabbage Crop

Botanicals as Phyto-nematicides Against Root-knot Disease Caused by the Root-knot Nematode (Meloidogyne incognita) via Promoting growth, Yield, and Biochemical Performance of Cabbage Crop

Draft genome sequence of Bacillus thuringiensis strain V-AB8.18, a novel isolate with potential nematicidal activity.

We report the draft genome of Bacillus thuringiensis strain V-AB8.18, comprising 308 contigs totaling 6,182,614 bp, with 35% G + C content. It contains 6,151 putative protein-coding genes, including App6 and Cry5-like crystal proteins, exhibiting 99% pairwise identity to nematicidal proteins App6Aa2 and Cry5Ba2, active against Meloidogyne incognita and Meloidogyne hapla.

Bacillus, Pseudomonas and Serratia control Meloidogyne incognita (Rhabditida: Meloidogynidae) and promote the growth of tomato plants

Plant-parasitic nematodes cause significant losses in agriculture worldwide. Among these parasites, the root-knot nematode (Meloidogyne spp.) stands out. Consequently, control methods are being developed to combat this pest. Among these methods is biological control, the main agents of which are bacteria. This study aimed to evaluate the impact of 102 bacterial isolates on the mortality of Meloidogyne incognita J2 juveniles, hypothesizing that certain isolates could effectively control the nematode and promote tomato plant growth. Five experiments were conducted to test this hypothesis. First, the effect of the 102 bacterial isolates on J2 mortality was assessed under laboratory conditions. Second, five isolates (Bacillus cereus IBCBb130, Bacillus cereus IBCBb116, Pseudomonas aeruginosa IBCBb122, Bacillus proteolyticus IBCBb136, and Serratia sp. IBCBb118), which showed >68% J2 mortality, were evaluated over 72 h. Third, these isolates were tested at seven different concentrations. Fourth, their efficacy in controlling M. incognita on tomato plants was assessed in a greenhouse setting. Fifth, their potential to promote tomato plant growth without nematode inoculation was evaluated. The results revealed that the 102 bacterial isolates caused mortality ranging from 2 to 79.57% for M. incognita J2. At a 10% dilution, five isolates (B. cereus IBCBb130, P. aeruginosa IBCBb122, B. cereus IBCBb116, B. proteolyticus IBCBb136, and Serratia sp. IBCBb118) maintained mortality rates above 68%. Among these strains, B. cereus IBCBb130 and P. aeruginosa IBCBb122 were particularly effective, with B. cereus IBCBb130 showing high mortality rates under laboratory conditions and P. aeruginosa IBCBb122 significantly reducing nematode populations in greenhouse pots. Additionally, Serratia sp. IBCBb118 demonstrated notable potential for promoting tomato plant growth. In conclusion, specific bacterial isolates exhibit strong potential for the biocontrol of M. incognita and enhancement of tomato plant growth, suggesting a viable alternative to chemical nematicides. These findings provide insight into the development of sustainable agricultural practices through targeted manipulation of the soil microbiota. Future research should explore the underlying mechanisms of these interactions and their long-term effects on crop yield and soil health.

Multistress‐tolerant Pseudomonas aeruginosa SSVP3 uses multiple strategies to control Meloidogyne incognita in tomato

AbstractTomato is the most important horticultural crop, and India is its second largest producer; however, the plant‐pathogenic nematode Meloidogyne incognita is a serious pest of tomato, causing detrimental losses in its production. This study is focused on the use of multistress‐tolerant Pseudomonas aeruginosa SSVP3 to control this devastating nematode and attempts to decipher the roles of its metabolites and volatile organic compounds (VOCs) during this interaction. The supernatant of P. aeruginosa SSVP3 caused 58% mortality in M. incognita J2 juveniles. The major nematicidal metabolites, identified using liquid chromatography‐mass spectrometry, were pyocyanin, pyoluteorin, pyochelin, benthocyanin and phenazines. The VOCs secreted by P. aeruginosa SSVP3, which were identified via gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) in a mixture, caused 98% mortality in M. incognita J2 juveniles. In a pot experiment, seedling root treatment with P. aeruginosa SSVP3 activated the induced systemic response in tomato plants to M. incognita by increasing the activity of defence and antioxidant enzymes as well as the proline and phenolic contents. The malondialdehyde content in P. aeruginosa SSVP3‐treated plants decreased as compared to those in the other treatment groups. The number of galls formed and the number of endoparasitic stages of M. incognita in the untreated nematode control plants were much greater (19 and 35) than those in the P. aeruginosa SSVP3‐treated (0.33 and 1) and chemically treated groups (0.67 and 1.33). These results indicate that P. aeruginosa and its secreted metabolites and VOCs have a high potential for controlling nematodes.

Correction: Nematicidal potency of silver nanoparticles and extracts from Borreria verticillata (L.) G. Mey against Meloidogyne incognita on tomato plants

Correction: Nematicidal potency of silver nanoparticles and extracts from Borreria verticillata (L.) G. Mey against Meloidogyne incognita on tomato plants

Exploring the nematicidal mechanisms and control efficiencies of oxalic acid producing Aspergillus tubingensis WF01 against root-knot nematodes.

Root-knot nematodes (RKN; Meloidogyne spp.) are among the highly prevalent and significantly detrimental pathogens that cause severe economic and yield losses in crops. Currently, control of RKN primarily relies on the application of chemical nematicides but it has environmental and public health concerns, which open new doors for alternative methods in the form of biological control. In this study, we investigated the nematicidal and attractive activities of an endophytic strain WF01 against Meloidogyne incognita in concentration-dependent experiments. The active nematicidal metabolite was extracted in the WF01 crude extract through the Sephadex column, and its structure was identified by nuclear magnetic resonance and mass spectrometry data. The strain WF01 was identified as Aspergillus tubingensis based on morphological and molecular characteristics. The nematicidal and attractive metabolite of A. tubingensis WF01 was identified as oxalic acid (OA), which showed solid nematicidal activity against M. incognita, having LC50 of 27.48 μg ml-1. The Nsy-1 of AWC and Odr-7 of AWA were the primary neuron genes for Caenorhabditis elegans to detect OA. Under greenhouse, WF01 broth and 200 μg ml-1 OA could effectively suppress the disease caused by M. incognita on tomatoes respectively with control efficiency (CE) of 62.5% and 70.83%, and promote plant growth. In the field, WF01-WP and 8% OA-WP formulations showed moderate CEs of 51.25%-61.47% against RKN in tomato and tobacco. The combined application of WF01 and OA resulted in excellent CEs of 66.83% and 69.34% toward RKN in tomato and tobacco, respectively. Furthermore, the application of WF01 broth or OA significantly suppressed the infection of J2s in tomatoes by upregulating the expression levels of the genes (PAL, C4H, HCT, and F5H) related to lignin synthesis, and strengthened root lignification. Altogether, our results demonstrated that A. tubingensis WF01 exhibited multiple weapons to control RKN mediated by producing OA to lure and kill RKN in a concentration-dependent manner and strengthen root lignification. This fungus could serve as an environmental bio-nematicide for managing the diseases caused by RKN.

Biocontrol potential of endophytic fungi against phytopathogenic nematodes on potato (Solanum tuberosum L.)

Root-knot nematodes (RKNs) are a vital pest that causes significant yield losses and economic damage to potato plants. The use of chemical pesticides to control these nematodes has led to environmental concerns and the development of resistance in the nematode populations. Endophytic fungi offer an eco-friendly alternative to control these pests and produce secondary metabolites that have nematicidal activity against RKNs. The objective of this study is to assess the efficacy of Aspergillus flavus (ON146363), an entophyte fungus isolated from Trigonella foenum-graecum seeds, against Meloidogyne incognita in filtered culture broth using GC–MS analysis. Among them, various nematicidal secondary metabolites were produced: Gadoleic acid, Oleic acid di-ethanolamide, Oleic acid, and Palmitic acid. In addition, biochemical compounds such as Gallic acid, Catechin, Protocatechuic acid, Esculatin, Vanillic acid, Pyrocatechol, Coumarine, Cinnamic acid, 4, 3-indol butyl acetic acid and Naphthyl acetic acid by HPLC. The fungus was identified through morphological and molecular analysis, including ITS 1–4 regions of ribosomal DNA. In vitro experiments showed that culture filtrate of A. flavus had a variable effect on reducing the number of egg hatchings and larval mortality, with higher concentrations showing greater efficacy than Abamectin. The fungus inhibited the development and multiplication of M. incognita in potato plants, reducing the number of galls and eggs by 90% and 89%, respectively. A. flavus increased the activity of defense-related enzymes Chitinas, Catalyse, and Peroxidase after 15, 45, and 60 days. Leaching of the concentrated culture significantly reduced the second juveniles’ stage to 97% /250 g soil and decreased the penetration of nematodes into the roots. A. flavus cultural filtrates via soil spraying improved seedling growth and reduced nematode propagation, resulting in systemic resistance to nematode infection. Therefore, A. flavus can be an effective biological control agent for root-knot nematodes in potato plants. This approach provides a sustainable solution for farmers and minimizes the environmental impact.

Effect of Silybum marianum (L.) Gaertn. Leaf and Seed Extracts Prepared Using Different Solvents on Root-Knot Nematode

Objective: The nematicidal effect of milk thistle leaves and seeds prepared with different solvents on Meloidogyne incognita was investigated. Materials and Methods: Acetone, ethanol and distilled water were used. The in vitro was carried out in 6 cm petri dishes. The extractions were studied with 500 and 1000 μg/ml (ppm). The in vitro and pot experiments designed random plots with 5 replications for each extraction, solvent and concentration. Four hundred second stage juvenile larvae (J2) were used as inoculum and dead individuals were counted after 48 hours. Five days after transplantation, nematode inoculation was carried out with 500 J2 per pot. After 24 hours, 30 ml of the solution was applied to the soil at 1000 ppm concentration. The experiment was terminated for 50 days. Then, gall and egg mass counts were made. Results: In vitro, the mortality rate at 1000 ppm was found to be similar in acetone (78.0%) and ethanol (80.8%) solvents in leaf extraction, while the highest was detected in ethanol (94.0%) in the seed extract. In distilled water solvent, 68.0% mortality was determined in the leaf extract and 62.2% mortality in the seed extract. There was no statistically significant difference between the leaf and seed extracts in number of galls and egg masses. No statistical difference could be determined between the solvents in the number of egg masses in seed extraction. While the number of galls in the leaf extract was found to be higher than in acetone (8.8 unit/root) and ethanol (8.0 unit/root) in distilled water (18.0 unit/root) and the difference between them was found to be significant, no statistically significant difference in the number of egg mass between the solvents. Conclusion: It was observed that all solvents of the leaf and seed extract suppressed galls and egg masses by more than 80% compared to the control.

Design, Synthesis, Nematicidal Evaluation, and Molecular Docking Study of Pyrano[3,2-c]pyridones against Meloidogyne incognita.

Root-knot nematodes pose a serious threat to crops by affecting production and quality. Over a period of time, substantial work has been done toward the development of effective and environmentally benign nematicidal compounds. However, due to the inefficiencies of previously reported synthetics in achieving the target of safe, selective, and effective treatment, it is necessary to develop new efficacious and safer nematicidal agents considering human health and environment on top priority. This work aims to highlight the efficient and convenient l-proline catalyzed synthesis of pyrano[3,2-c]pyridone and their use as potential nematicidal agents. In vitro results of larval mortality and egg hatching inhibition revealed maximum nematicidal activity against Meloidogyne incognita from compounds 15b, 15m, and 15w with LC50 values of 28.8, 46.8, and 49.18 μg/mL at 48 h, respectively. Under similar conditions, pyrano[3,2-c]pyridones derivatives 15b (LC50 = 28.8 μg/mL) was found at par with LC50 (26.92 μg/mL) of commercial nematicide carbofuran. The in vitro results were further validated with in silico studies with the most active compound 15b nematicidal within the binding to the pocket of acetylcholine esterase (AChE). In docking, binding free energy values for compound 15b were found to be -6.90 kcal/mol. Results indicated that pyrano[3,2-c]pyridone derivatives have the potential to control M. incognita.

A QTL on Maize Chromosome 5 is Associated with Root-Knot Nematode Resistance.

This study provides the first report of a quantitative trait locus (QTL) in maize (Zea mays) for resistance to the southern root-knot nematode (SRKN) (Meloidogyne incognita). The SRKN can feed on the roots of maize in the U.S. Southern Coastal Plain region and can cause yield losses of 30% or greater in heavily infested fields. Increases in SRKN density in the soil may reduce the yield for subsequently planted susceptible crops. The use of maize hybrids with resistance to SRKN could prevent an increase in SRKN density, yet no genetic regions have been identified that confer host resistance. In this study, a B73 (susceptible) x Ky21 (resistant) S5 recombinant inbred line (RIL) population was phenotyped for total number of eggs (TE) and root weight. This population has been previously genotyped using single nucleotide polymorphisms (SNPs). By utilizing the SNP data with the phenotype data, a single QTL was identified on chromosome 5 that explained 15% of the phenotypic variation (PV) for the number of eggs and 11% of the PV for the number of eggs per g of root (EGR). Plants that were homozygous for the Ky21 allele for the most associated marker PZA03172.3 had fewer eggs and fewer EGR than the plants that were homozygous or heterozygous for the B73 allele. Thus, the first QTL for SRKN resistance in maize has been identified and could be incorporated into maize hybrids.

First report of the nematode‐trapping fungus Arthrobotrys thaumasia in Türkiye and its biocontrol potential against Meloidogyne incognita

AbstractRoot‐knot nematodes, particularly, Meloidogyne incognita, are among the most destructive endoparasitic nematodes, infecting a diverse range of plant hosts. Nematode‐trapping fungi are known for their potential application as biological control agents against plant parasitic nematodes. In the present study, the nematode‐trapping fungus Arthrobotrys thaumasia was isolated from the rhizosphere soil of tomato plants in the West Mediterranean Region of Türkiye. Two hundred and twenty‐three tomato plant rhizosphere soil samples yielded six nematode‐trapping fungal isolates, giving an occurrence frequency of 2.69%. Using morphology and molecular marker sequences (ITS and β‐tubulin loci), the species of the fungi was confirmed to be A. thaumasia. In vitro, A. thaumasia reduced second‐stage juveniles of M. incognita by 77.5% (isolate I‐Y4‐2) and 72.5% (isolate B‐G5‐1). This is the first report on the isolation and characterization of the nematode‐trapping fungus A. thaumasia from Türkiye. Two isolates of A. thaumasia (I‐Y4‐2 and B‐G5‐1) appear to be promising biological control agents that may be utilized for controlling M. incognita‐caused root‐knot diseases.

The root-knot nematode effector MiEFF12 targets the host ER quality control system to suppress immune responses and allow parasitism.

Root-knot nematodes (RKNs) are microscopic parasitic worms able to infest the roots of thousands of plant species, causing massive crop yield losses worldwide. They evade the plant's immune system and manipulate plant cell physiology and metabolism to transform a few root cells into giant cells, which serve as feeding sites for the nematode. RKN parasitism is facilitated by the secretion in planta of effector molecules, mostly proteins that hijack host cellular processes. We describe here a conserved RKN-specific effector, effector 12 (EFF12), that is synthesized exclusively in the oesophageal glands of the nematode, and we demonstrate its function in parasitism. In the plant, MiEFF12 localizes to the endoplasmic reticulum (ER). A combination of RNA-sequencing analysis and immunity-suppression bioassays revealed the contribution of MiEFF12 to the modulation of host immunity. Yeast two-hybrid, split luciferase and co-immunoprecipitation approaches identified an essential component of the ER quality control system, the Solanum lycopersicum plant bap-like (PBL), and basic leucine zipper 60 (BZIP60) proteins as host targets of MiEFF12. Finally, silencing the PBL genes in Nicotiana benthamiana decreased susceptibility to Meloidogyne incognita infection. Our results suggest that EFF12 manipulates PBL function to modify plant immune responses to allow parasitism.

Management of root knot nematode Meloidogyne incognita using black soldier fly frass in soybean [Glycine max (L.)

Glycine max (L.) is a leguminous crop used by humans and livestock; it is an alternative protein source that offers almost the same quality as animal protein. Currently, its productivity has been affected by Meloidogyne incognita, which threatens food quality and security in Sub-Saharan Africa by 25-70%. Research has been conducted to extract the knowledge and inputs that will be effective in solving nematode problems, as the available methods are inefficient, inaccessible, and expensive. This study aimed to use BSFF in managing M. incognita in Soybean cultivation. The study was conducted in Mwanza-Tanzania, where seven treatments following a CRD design were inoculated with 1000 J2 of M. incognita and replicated six times. Results showed that BSFF from Hermetia illucens has the potential to minimize the effect of M. incognita in soybean, where the number of galls was reduced from 104 in 0.0 kg BSFF/inoculated to 3 in 1.0 kg BSFF/inoculated, followed by 6.33, 23.67, 51.51 and 52.50 galls in 0.75 kg BSFF/inoculated, 0.5 kg BSFF/inoculated, 50mL chitosan /inoculated, and 0.25 kg BSFF/inoculated, respectively. Also, symptoms such as chlorosis were reduced from nine leaves in 0.0 kg BSFF/inoculated to zero in 1.0 kg BSFF. Therefore, the study found that BSFF is a sustainable way to minimize the effect of M. incognita and maximize the performance of soybean production, as it offers soil management benefits, and enhances social and economic welfare by reducing the use of harmful, expensive chemicals that interfere human health and economy.

Volatile organic compounds released from entomopathogenic nematode-infected insect cadavers for the biocontrol of Meloidogyne incognita.

Root-knot nematodes (RKNs), Meloidogyne spp., are one of the most destructive polyphagous plant-parasitic nematodes. They pose a serious threat to global food security and are difficult to control. Entomopathogenic nematodes (EPNs) show promise in controlling RKNs. However, it remains unclear whether the volatile organic compounds (VOCs) emitted from EPN-infected cadavers can control RKNs. We investigated the fumigation activity of VOCs released from cadavers infected by five different species of EPNs on RKNs in Petri dishes, and found that VOCs released from Steinernema feltiae (SN strain) and S. carpocapsae (All strain) infected cadavers had a significant lethal effect on second-stage juveniles (J2s) of Meloidogyne incognita. The VOCs released from the cadavers infected with S. feltiae were analyzed using SPME-GC/MS. Dimethyl disulfide (DMDS), tetradecane, pentadecane, and butylated hydroxytoluene (BHT), were selected for a validation experiment with pure compounds. The DMDS compound had significant nematicidal activity and repelled J2s. DMDS also inhibited egg hatching and the invasion of tomato roots by J2s. In a pot experiment, the addition of S. feltiae-infected cadavers and cadavers wrapped with a 400-mesh nylon net also significantly reduced the population of RKNs in tomato roots after 7 days. The number of root knots and eggs was reduced by 58% and 74.34%, respectively, compared to the control. These results suggested that the VOCs emitted by the EPN-infected cadavers affected various developmental stages of M. incognita and thus have the potential to be used in controlling RKNs through multiple methods. © 2024 Society of Chemical Industry.

Native Arbuscular Mycorrhizal Fungi Promote Plukenetia volubilis Growth and Decrease the Infection Levels of Meloidogyne incognita.

The use of arbuscular mycorrhizal fungi (AMF) offers promising benefits to agriculture in the Amazon regions, where soils are characteristically acidic and nutrient-poor. The purpose of this research was to investigate the potential effects of two recently described species of AMF (Nanoglomus plukenetiae and Rhizoglomus variabile) native to the Peruvian Amazon for improving the plant growth of Plukenetia volubilis (inka nut or sacha inchi) and protecting the roots against soil pathogens. Two assays were simultaneously conducted under greenhouse conditions in Peru. The first focused on evaluating the biofertilizer effect of AMF inoculation, while the second examined the bioprotective effect against the root knot nematode, Meloidogyne incognita. Overall, the results showed that AMF inoculation of P. volubilis seedlings positively improved their development, particularly their biomass, height, and the leaf nutrient contents. When seedlings were exposed to M. incognita, plant growth was also noticeably higher for AMF-inoculated plants than those without AMF inoculation. Nematode reproduction was significantly suppressed by the presence of AMF, in particular R. variabile, and especially when inoculated prior to nematode exposure. The dual AMF inoculation did not necessarily lead to improved crop growth but notably improved P and K leaf contents. The findings provide strong justification for the development of products based on AMF as agro-inputs to catalyze nutrient use and uptake and protect crops against pests and diseases, especially those that are locally adapted to local crops and cropping conditions.

High-resolution transcriptome datasets during embryogenesis of plant-parasitic nematodes

Understanding the transcriptional regulatory characteristics throughout the embryogenesis of plant-parasitic nematodes is crucial for elucidating their developmental processes’ uniqueness. However, a challenge arises due to the lack of suitable technical methods for synchronizing the age of plant-parasitic nematodes embryo, it is difficult to collect detailed transcriptome data at each stage of embryonic development. Here, we recorded the 11 embryonic developmental time-points of endophytic nematode Meloidogyne incognita (isolated from Wuhan, China), Heterodera glycines (isolated from Wuhan, China), and Ditylenchus destructor (isolated from Jinan, China) species, and constructed transcriptome datasets of single embryos of these three species utilizing low-input smart-seq2 technology. The datasets encompassed 11 complete embryonic development stages, including Zygote, 2-cell, 4-cell, 8-cell, 24–44 cell, 64–78 cell, Comma, 1.5-fold, 2-fold, Moving, and L1, each stage generated four to five replicates, resulting in a total of 162 high-resolution transcriptome libraries. This high-resolution cross-species dataset serves as a crucial resource for comprehending the embryonic developmental properties of plant-parasitic nematodes and for identifying functional regulatory genes during embryogenesis.