Root-knot Nematode Infection Research Articles

Transcriptome Analysis of Eggplant Root in Response to Root-Knot Nematode Infection

Eggplant (Solanum melongena L.), which belongs to the Solanaceae family, is an important vegetable crop. However, its production is severely threatened by root-knot nematodes (RKNs) in many countries. Solanum torvum, a wild relative of eggplant, is employed worldwide as rootstock for eggplant cultivation due to its resistance to soil-borne diseases such as RKNs. In this study, to identify the RKN defense mechanisms, the transcriptomic profiles of eggplant and Solanum torvum were compared. A total of 5360 differentially expressed genes (DEGs) were identified for the response to RKN infection. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that these DEGs are mainly involved in the processes of response to stimulus, protein phosphorylation, hormone signal transduction, and plant-pathogen interaction pathways. Many phytohormone-related genes and transcription factors (MYB, WRKY, and NAC) were differentially expressed at the four time points (ck, 7, 14, and 28 days post-infection). The abscisic acid signaling pathway might be involved in plant-nematode interactions. qRT-PCR validated the expression levels of some of the DEGs in eggplant. These findings demonstrate the nematode-induced expression profiles and provide some insights into the nematode resistance mechanism in eggplant.

The Meloidogyne incognita Nuclear Effector MiEFF1 Interacts With Arabidopsis Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenases to Promote Parasitism.

Root-knot nematodes are obligate endoparasites that maintain a biotrophic relationship with their hosts over a period of several weeks. They induce the differentiation of root cells into specialized multinucleate hypertrophied feeding cells known as giant cells. Nematode effectors synthesized in the esophageal glands and injected into the plant tissue through the syringe-like stylet play a key role in giant cell ontogenesis. The Meloidogyne incognita MiEFF1 is one of the rare effectors of phytopathogenic nematodes to have been located in vivo in feeding cells. This effector specifically targets the giant cell nuclei. We investigated the Arabidopsis functions modulated by this effector, by using a yeast two-hybrid approach to identify its host targets. We characterized a universal stress protein (USP) and cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs) as the targets of MiEFF1. We validated the interaction of MiEFF1 with these host targets in the plant cell nucleus, by bimolecular fluorescence complementation (BiFC). A functional analysis with Arabidopsis GUS reporter lines and knockout mutant lines showed that GAPCs were induced in giant cells and that their non-metabolic functions were required for root-knot nematode infection. These susceptibility factors are potentially interesting targets for the development of new root-knot nematode control strategies.

Screening for Tolerance-Resistance to Root-knot nematode Meloidogyne incognita in Grafted and Ungrafted Cucurbit Rootstocks

THE CURRENT study aimed to screen eight ungrafted and grafted cucurbit rootstocks as well as melon Hybrid London genotype against root-knot nematode infection. Ungrafted and grafted rootstocks i.e. Nun 6001, Squash No3, Super Shintosa, Flixel Fort, Ferro RZ, Coplt, Bottle gourd were classified as tolerant to M. incognita infection whereas melon genotype Hybrid London and Pakistani Loof rootstock ranked as susceptible hosts. Grafted cucurbit rootstocks i.e. Nun 6001 and Ferro RZ, gave the higher plant survival rate and growth parameters compared to ungrafted ones and the rest of rootstocks and melon genotype. Number of galls, females, and egg masses of M. incongita were significantly suppressed in ungrafted and grafted rootstocks compared to melon plant Hybrid London. All the rootstocks differed in their ability to stimulate peroxidase (PO), polyphenol oxidase (PPO) activities, and phenol content. The study revealed that grafting melon plants onto all the previous tolerant rootstocks is an effective tool that may enable the susceptible melon scion to tolerate M. incognita which leads to an increase in plant survival rate and growth parameters.

Overexpression of DUF538 from Wild Arachis Enhances Plant Resistance to Meloidogyne spp.

DUF538 proteins belong to a large group of uncharacterized protein families sharing the highly conserved Domain of Unknown Function (DUF). Attention has been given to DUF538 domain-containing proteins due to changes in their gene expression behavior and protein abundance during plant development and responses to stress. Putative roles attributed to DUF538 in plants under abiotic and biotic constraints include involvement in cell redox balance, chlorophyll breakdown and pectin degradation. Our previous transcriptome studies suggested that DUF538 is also involved in the resistance responses of wild Arachis species against the highly hazardous root-knot nematodes (RKNs). To clarify the role of the AsDUF538 gene from the wild peanut relative Arachis stenosperma in this interaction, we analyzed the effect of its overexpression on RKN infection in peanut and soybean hairy roots and Arabidopsis transgenic plants. AsDUF538 overexpression significantly reduced the infection in all three heterologous plant systems against their respective RKN counterparts. The distribution of AsDUF538 transcripts in RKN-infected Arachis roots and the effects of AsDUF538 overexpression on hormonal pathways and redox system in transgenic Arabidopsis were also evaluated. This is the first time that a DUF538 gene is functionally validated in transgenic plants and the earliest report on its role in plant defense against RKNs.

Induced systemic resistance in beet plants infected with Meloidogyne javanica

Root-knot nematode infection has a direct and negative impact on the commercial value of beet (Beta vulgaris L.) tubers. The aim of this study was to evaluate induced resistance in beet tuberous roots infected with different population levels of Meloidogyne javanica (Treub, 1885) Chitwood, 1949. Plants were inoculated with increasing inoculum levels (0, 1500, 5000, and 10 000 eggs + juveniles [J2]) and treated with different products that can potentially induce resistance: mannanoligosaccharides (MOS), citrus biomass, and acibenzolar-S-methyl (ASM). Vegetative, nematological, and enzymatic parameters were evaluated after 60 d. In general, when compared to the control (water), inducers did not promote a positive effect on tuber diameter and weight, regardless of the inoculum level. Only the weight of plants inoculated with 5000 eggs + J2 and treated with citrus biomass (40.70 g) increased compared with the control (32.38 g). The treatments did not reduce the number of galls, nematodes per root system, and nematodes per gram of root. Resistance inducers increased catalase activity (CAT) and phenylalanine ammonia-lyase (PAL) and MOS and ASM were the most effective. The highest CAT activity was for ASM and 5000 eggs + J2, resulting in 42.44% compared with the control. The MOS and ASM exhibited the highest PAL activity (0.22 and 0.15 mg trans-amino acid h-1 mg-1 protein, respectively) compared with the control (0.03 mg trans-amino acid h-1 mg-1 protein) in uninoculated plants. Results led us to conclude that inducers should not be used in isolation to control nematodes in beet. However, deformed tubers can be used in manufacturing, thus preventing food waste. In addition, new rates and application intervals should be evaluated to help control nematodes in beet plants.

Influence of Meloidogyne javanica parasitism on soybean development and chemical composition

BackgroundSoybean is a major economic crop worldwide, but its yield and quality are greatly affected by root-knot nematode infection. This study aimed to assess the effects of Meloidogyne javanica parasitism on soybean growth, yield, and quality. Soybean plants were inoculated with 0, 1000, 2000, or 4000 eggs + second-stage juveniles (J2) of M. javanica and evaluated for vegetative and nematode parameters. Grains from each treatment were analyzed for yield, proximate composition, total phenolic content, total flavonoid content, isoflavone profile, and antioxidant capacity.ResultsPlants free of nematodes had lower vegetative growth and higher yield than nematode-infected plants. The maximum estimated reproduction factor was 34.85, achieved by inoculation of 2433 eggs + J2. Moisture, fiber, and protein contents decreased with increasing inoculum levels. Lipid content increased with inoculum level until reaching 22.59 g 100 g−1 of sample. Total phenolic and flavonoid contents decreased with increasing inoculum level up to about 2000 eggs + J2 and then increased until reaching 219.20 mg gallic acid equivalents 100 g−1 of sample and 121.67 mg quercetin equivalent 100 g−1 of sample, respectively, at 4000 eggs + J2. A similar behavior was observed for antioxidant capacity determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging, superoxide radical scavenging, and ferric reducing antioxidant power assays. The highest contents of malonylgenistin (539 mmol g−1), acetylglycitin (106 mmol g−1), and genistin (87 mmol g−1) were found in grains from plants inoculated with 4000 eggs + J2.ConclusionsM. javanica inoculum level affected soybean development, grain production, yield, composition, and antioxidant capacity.

Impact of Meloidogyne incognita (nematode) infection on root tissues and cell wall composition of okra (Abelmoschus esculentus L. Moench, Malvaceae).

Root-knot nematodes are endoparasites whose mature females lodge and grow inside the root of some cultivated plants, leading to losses in productivity. Herein, we investigated if the infection of okra, Abelmoschus esculentus (Malvaceae), promoted by the root-knot nematode Meloidogyne incognita (Meloidogynidae) changes some agronomic traits of the host plant, as well as the cell wall composition of the root tissues. The okra Santa Cruz 47® cultivar was infected with a suspension of 5000 M. incognita juveniles. The inoculated and non-inoculated okra plants were then submitted to morphological analysis at the end of experiment, as well as histological (at 4, 11, 18, 39, ad 66 days after inoculation) and immunocytochemical analysis (control and 66 days after inoculation). Root-knot nematode infection reduced the dry weight of the stem system but, unexpectedly, the number and weight of fruits increased. At 11 days after inoculation, we detected the presence of giant cells that increased in number and size until the end of the experiment, at 66 days after inoculation. These cells came from the xylem parenchyma and showed intense and moderate labeling for epitopes recognized by JIM5 and JIM7. The presence of homogalacturonans (HGs) with different degrees of methyl esterification seems to be related to the injuries caused by the nematode feeding activity and to the processes of giant cell hypertrophy. In addition, the presence of HGs with high methyl-esterified groups can increase the cell wall porosity and facilitate the flux of nutrients for the root-knot nematode.

English

Root-knot nematodes (Meloidogyne spp.) are soil-borne pathogens that can cause severe damage to agricultural production. The most common approaches to prevent root-knot nematode infections are based on crop rotation with non-host plants, use of chemical insecticides, biological control methods, and use of nematode-antagonistic or trap plants. Marigolds (Tagetes erecta) are used as nematode-killing plants, but there is controversy over the mechanism through which they control root-knot nematodes. This study confirmed that marigold root-exudates are lethal to root-knot nematodes, illustrated that marigolds act as trap plants for root-knot nematodes when planted close to nematode host plants such as tomato. We investigated the rates of infection and development of nematode larvae injected into the marigold root system to evaluate whether marigolds could act as a non-host plant for root-knot nematodes. We found that aqueous solutions of marigold root-exudates showed strong lethal and inhibitory effects on sec-stage juveniles and eggs of root-knot nematodes. Marigold roots secreted substances that attracted nematodes from the surrounding environment. Furthermore, marigold root cells contained substances that had a strong inhibitory effect on the development of root-knot nematodes, resulting in diapause in nematodes, and inhibition of further infection. Herein we report a preliminary exploration of the antagonistic mechanism in marigolds for controlling the growth and development of root-knot nematodes. Our research provides basis for promoting the use of marigold for the control of nematodes as an important part of sustainable cropping strategies that rely on biological pest control. © 2021 Friends Science Publishers

Oxylipins are implicated as communication signals in tomato\u2013root-knot nematode (Meloidogyne javanica) interaction

Throughout infection, plant-parasitic nematodes activate a complex host defense response that will regulate their development and aggressiveness. Oxylipins—lipophilic signaling molecules—are part of this complex, performing a fundamental role in regulating plant development and immunity. At the same time, the sedentary root-knot nematode Meloidogyne spp. secretes numerous effectors that play key roles during invasion and migration, supporting construction and maintenance of nematodes' feeding sites. Herein, comprehensive oxylipin profiling of tomato roots, performed using LC–MS/MS, indicated strong and early responses of many oxylipins following root-knot nematode infection. To identify genes that might respond to the lipidomic defense pathway mediated through oxylipins, RNA-Seq was performed by exposing Meloidogyne javanica second-stage juveniles to tomato protoplasts and the oxylipin 9-HOT, one of the early-induced oxylipins in tomato roots upon nematode infection. A total of 7512 differentially expressed genes were identified. To target putative effectors, we sought differentially expressed genes carrying a predicted secretion signal peptide. Among these, several were homologous with known effectors in other nematode species; other unknown, potentially secreted proteins may have a role as root-knot nematode effectors that are induced by plant lipid signals. These include effectors associated with distortion of the plant immune response or manipulating signal transduction mediated by lipid signals. Other effectors are implicated in cell wall degradation or ROS detoxification at the plant–nematode interface. Being an integral part of the plant's defense response, oxylipins might be placed as important signaling molecules underlying nematode parasitism.

Effect of root-knot nematodes (meloidogyne spp) on yield of three tomato varieties in zalingei area.

This study conducted at the demonstration farm of the Faculty of Agriculture University of Zalingei during the period from April to August 2013, to evaluate the effect of Root knot nematodes on the yield of three tomatoes (Lycopersiconesculentum) varieties (Castle rock, Strain-B and Rio Grande). Six treatments were randomly arranged in a Completely Randomized Design (CRD) with four replicates. Primary survey carried out to determine the infection of Root knot nematodes on tomato fields in the area and sampling. Parameters measured included: number of leaves per plant, plant height and rating index of root galls. Data collected subjected to statistical analysis. The results showed that: Root knot nematodes found in all tomato fields surveyed in the area (10 fields). The number of leaves on treated Rio Grande variety were significantly lower compared with the number of leaves of untreated plants at (P= 0.05). The plants from the different varieties grown in treated soil showed longer plants than untreated one, throughout the six observations. The variety Strain-B was the most susceptible to the root knot nematodes among with the other two varieties.

Soybean Root-Knot Nematode: A Diagnostic Guide

Root-knot nematodes (Meloidogyne spp.) are one of the most economically important plant parasites in the world, and significantly impacts soybean production in places where they are endemic. Several species of root-knot nematode are capable of causing significant damages to soybean and have broad host ranges that include common rotational crops and weeds. Symptoms of root-knot nematode infections may be confused with other diseases, nutritional disorders, or common root features associated with legumes. The purpose of this diagnostic guide is to provide information regarding identification, isolation, storage, and other relevant aspects of this pathosystem.

Formulasi Konsorsium Bakteri Endofit untuk Menekan Infeksi Nematoda Puru Akar Meloidogyne incognita pada Tomat

The root-knot nematodes ( Meloidogyne incognita ) infection can cause a significant yield loss in tomato plants. One of the environmentally friendly efforts to control this nematode is through the application of endophytic bacteria. The application of endophytic bacteria in the form of a consortium was reported to be more effective than the application using a single isolate. This study aims to test the effectiveness of the endophytic bacteria consortium formula in suppressing M. incognita infection in tomato plants. The research stages were the selection of the consortium of endophytic bacteria as a growth promoter for tomato plants infected with M. incognita . The best performing consortium was formulated using 100 g of grass compost + 100 g vermicompost + 10 ml molasses + 1 g peptone and 50 ml distilled water. The test of bacterial cell viability in the endophytic formula was carried out for 20 weeks. The formula made was tested for its performance as a biocontrol agent against M. incognita in tomato plants. The results showed that three consortia gave the best results as growth promoters of M. incognita infected tomatoes, namely TmtN5, TmtN2, and GsgN2. The three of them survived the formula with log CFU at week 20 of 6.07 (TmtN5), 5.56 (TmtN2), and 6.11 (GsgN2). This formula can suppress the nematode population on tomato plants' roots and suppress the number of root knots in tomato plants. This study provides information that there are three consortia of endophytic bacteria (TmtN5, TmtN2, and GsgN2), which have the potential to become biological control agents for root-purulent nematodes.

The Role of Arbuscular Mycorrhizal Fungi Against Root-Knot Nematode Infections in Coffee Plants

Coffee (Coffea arabica) is one of the most important tropical crops in the world, and root-knot nematode (Meloidogyne spp.) infections are one of the main factors that negatively affect crop yields throughout the South American region. This study aimed to evaluate the role of indigenous arbuscular mycorrhizal fungi against root-knot nematode infections in coffee plants grown under different soil conditions in the Peruvian Amazon. The experimental design was a 3A × 2B × 4C factorial scheme with 24 treatments. Each experimental unit consisted of six coffee plants, with three replicates in randomized blocks, totaling 18 coffee plants per treatment. The studied factors were soil conditions (A), types of coffee propagation (B), and arbuscular mycorrhizal fungi consortia (C). The data were statistically examined by three-way analysis of variance, and the Tukey HSD test was applied for multiple comparisons of group means. Mycorrhiza-induced tolerance was confirmed against root-knot nematodes, as the severity of infection was significantly lower in mycorrhizal roots, with an average reduction of 52.5%, 38.5% and 38.3% in coffee plants inoculated with Huall-pache, Do-cat, and Mo-cat, respectively. Furthermore, the effects on plant growth and biological control vary depending on the diversity of arbuscular mycorrhizal fungi consortia, soil conditions, and type of propagation. This study therefore demonstrates that the inoculation of coffee plants with indigenous arbuscular mycorrhizal fungi prior to field establishment promotes coffee plant growth after root-knot nematode infections.

A method for evaluating root-knot nematode infection in rice using a transparent paper pouch.

The root-knot nematode (RKN) Meloidogyne incognita is one of the most economically damaging plant-parasitic nematodes. Molecular studies of the plant-RKN interaction have been vigorously carried out in dicotyledonous model plants, while the host range of M. incognita is wide including monocotyledonous plants. As M. incognita causes quality and yield losses in rice (Oryza sativa L.) cultivated in both upland and irrigated systems, we developed a method to examine the plant-RKN interaction in this model monocotyledonous crop plant. Here, we show that a transparent paper pouch could be used to evaluate nematode infection rates in rice with similar results to that of the traditional soil method. The system using a transparent paper pouch can be used to observe the spatial and temporal distribution of developing galls and can save the space of growth chamber.

SUSCEPTIBILITY AND TOLERANCE TO ROOT-KNOT NEMATODES (MELOIDOGYNE INCOGNITA) OF TELFAIRIA OCCIDENTALIS UNDER ORGANIC CONVERSION

Three cultivars of Telfairia occidentalis were assessed for their resistance or otherwise to root-knot nematodes (Meloidogyne spp.) infection on the field. Seeds were extracted from the pods of the selected cultivars and planted on moist sawdust in nursery trays to raise seedlings for transplanting. The experiment was laid out in Randomized Complete Block Design and replicated thrice. Pre-plant soil samples were taken to estimate initial nematode populations. At seven days after transplanting, eggs of Meloidogyne incognita (Mi) were extracted from 60 day-old Celosia argentea and used for inoculation of the three cultivars of T. occidentalis at approximately 5000 eggs/stand. Plants were, thereafter, observed for vine length, vine girth and number of leaves from two weeks till 8 weeks after transplanting. Final soil nematode population and root gall indices were determined at 60-66 days after inoculation. Reproduction factor was determined and used along with the gall indices to rate the cultivars for resistance or susceptibility to Mi. Results showed that cultivars NHTo-020 and NHTo-030 were susceptible to root-knot nematode which implied that plants allowed nematode reproduction and also suffered yield loss while cultivar NHTo-010 was tolerant to nematode infestation meaning that nematode reproduction took place but the plant does not suffer yield loss. There was no significant (P>0.05) difference in the mean vine length and number of leaf irrespective of the inoculum while effect on the vine girth was significantly variable. The inoculated plants gave significantly better vegetative growth than the naturally infested plants which indicated genetic variability in the cultivars.

Alterations in the phenylpropanoid pathway affect poplar ability for ectomycorrhizal colonisation and susceptibility to root-knot nematodes.

This study investigates the impact of the alteration of the monolignol biosynthesis pathway on the establishment of the in vitro interaction of poplar roots either with a mutualistic ectomycorrhizal fungus or with a pathogenic root-knot nematode. Overall, the five studied transgenic lines downregulated for caffeoyl-CoA O-methyltransferase (CCoAOMT), caffeic acid O-methyltransferase (COMT), cinnamoyl-CoA reductase (CCR), cinnamyl alcohol dehydrogenase (CAD) or both COMT and CAD displayed a lower mycorrhizal colonisation percentage, indicating a lower ability for establishing mutualistic interaction than the wild-type. The susceptibility to root-knot nematode infection was variable in the five lines, and the CAD-deficient line was found to be less susceptible than the wild-type. We discuss these phenotypic differences in the light of the large shifts in the metabolic profile and gene expression pattern occurring between roots of the CAD-deficient line and wild-type. A role of genes related to trehalose metabolism, phytohormones, and cell wall construction in the different mycorrhizal symbiosis efficiency and nematode sensitivity between these two lines is suggested. Overall, these results show that the alteration of plant metabolism caused by the repression of a single gene within phenylpropanoid pathway results in significant alterations, at the root level, in the response towards mutualistic and pathogenic associates. These changes may constrain plant fitness and biomass production, which are of economic importance for perennial industrial crops such as poplar.

Expression analysis of sweetpotato NADPH oxidase-encoding Rboh genes in response to infection with the root-knot nematode Meloidogyne incognita

Sweetpotato (Ipomoea batatas L.) is a globally important food crop that is susceptible to infestation with the root-knot nematode Meloidogyne incognita, which can cause substantial crop losses. Previous transcriptomic analysis of the roots of susceptible and resistant sweetpotato cultivars identified genes that were likely to contribute to protection against root-knot nematode. The identified genes included respiratory burst oxidase homolog (Rboh) genes, which encode NAPDH oxidase homologs in plants. In this study, the role of Rboh genes in sweetpotato defense responses during root-knot nematode infection was examined in susceptible and resistant cultivars. Comparison with Arabidopsis Rboh genes identified groups of sweetpotato genes orthologous to AtRboh B, E, F, and G. Of these, the group resembling AtrbohB contained the highest number of unigenes, nine, and these genes were highly responsive to nematode infection in sweetpotato roots. These results indicate that Rboh genes play roles in protecting sweetpotato roots against root-knot nematode infection.

The atypical E2F transcription factor DEL1 modulates growth\u2013defense tradeoffs of host plants during root-knot nematode infection

In plants, growth–defense tradeoffs are essential for optimizing plant performance and adaptation under stress conditions, such as pathogen attack. Root-knot nematodes (RKNs) cause severe economic losses in many crops worldwide, although little is known about the mechanisms that control plant growth and defense responses during nematode attack. Upon investigation of Arabidopsis thaliana infected with RKN (Meloidogyne incognita), we observed that the atypical transcription factor DP-E2F-like 1 (DEL1) repressed salicylic acid (SA) accumulation in RKN-induced galls. The DEL1-deficient Arabidopsis mutant (del1-1) exhibited excessive SA accumulation in galls and is more resistant to RKN infection. In addition, excessive lignification was observed in galls of del1-1. On the other hand, the root growth of del1-1 is reduced after RKN infection. Taken together, these findings suggest that DEL1 plays an important role in the balance between plant growth and defense responses to RKN infection by controlling SA accumulation and lignification.

Efficacy of Purpureocillium lilacinum in combination with chitosan for the control of Meloidogyne javanica

ABSTRACT The nematicidal effect of Purpureocillium lilacinum strain 251 and a formulated product containing chitosan was recorded against second stage juveniles (J2s) and eggs of Meloidogyne javanica. There was a significant gradual decrease in the number of J2s survival as the chitosan concentration increased. The survival of J2s and hatching of eggs of Meloidogyne javanica were influenced by the presence of chitosan at different concentrations. However increase of P. lilacinum concentration from 1 × 106 to 3 × 106 conidia g−1 soil did not significantly reduce J2s survival in the treated soil. There was a clear interaction effect between P. lilacinum and chitosan 14 days after inoculation of soil with J2s. This was not obvious when the incubation time was prolonged to 21 days. When the soil was inoculated with eggs, there was an interaction effect only in one experiment 14 days after inoculation. Higher level of infection of root-knot nematodes by P. lilacinum was evident after applying glucose in either sterilised or non-sterilised soil.

Expression analysis of MicroRNAs and their target genes in Cucumis metuliferus infected by the root-knot nematode Meloidogyne incognita

MicroRNAs (miRNAs) are types of transcriptional and post-transcriptional modulators of gene expression that play crucial roles in response to diverse stresses. Although significant progress on the miRNA-mediated gene regulation has been made recently in plant-nematode interactions, none has been reported on root-knot nematode (RKN, Meloidogyne spp.) infection in Cucumis metuliferus, which is a relative of cucumber with resistance to M. incognita. To gain insights into the regulatory roles of miRNAs for resistance to RKN in C. metuliferus, it is necessary to create expression profiles for miRNAs and their targets. In this study, ten miRNAs were identified from our miRNAs sequencing data of C. metuliferus for expression analysis through quantitative reverse transcription-PCR (qRT-PCR). The results showed that RKN infection had a significant effect on both miRNAs expression and their corresponding targets in either resistant or susceptible plants but with differential expression. Moreover, four out of ten selected miRNA-target pairs, miR156-SBP, miR390-ARF3, ath-miR159a-MYB104 and aly-miR827-3p-PTI, exhibited inverse expression patterns between miRNAs and their targets, which laid a foundation for investigating resistance mechanisms induced in C. metuliferus by M. incognita infection. Additionally, the possible roles of these miRNAs have been discussed during C. metuliferus-RKN interactions.