RÉSUMÉ
Linseed, also known as flax is an important oilseed crop with many potential uses in paint, textile, food and pharmaceutical industries. Susceptibility to bud fly (Dasyneura lini Barnes) infestation is a serious biotic concern leading to severe yield penalty in linseed. Protease inhibitors (PIs) are potential candidates that activate during the insect-pest attack and modulate the resistance. In the present study, we explored the PI candidates in the linseed genome and a total of 100 LuPI genes were identified and grouped into five distinct subgroups. The analysis of cis-acting elements revealed that almost all LuPI promoters contain several regulatory elementary related to growth and development, hormonal regulation and stress responses. Across the subfamilies of PIs, the specific domains are consistently found conserved in all protein sequences. The tissue-specific in-silico expression pattern via RNA-seq revealed that all the genes were regulated during different stress. The expression through qRT-PCR of 15 genes revealed the significant up-regulation of LuPI-24, LuPI-40, LuPI-49, LuPI-53, and LuPI-63 upon bud fly infestation in resistant genotype EC0099001 and resistant check variety Neela. This study establishes a foundation resource for comprehending the structural, functional, and evolutionary dimensions of protease inhibitors in linseed.
Sujet(s)
Diptera , Lin , Régulation de l'expression des gènes végétaux , Inhibiteurs de protéases , Lin/génétique , Lin/métabolisme , Animaux , Diptera/génétique , Inhibiteurs de protéases/pharmacologie , Inhibiteurs de protéases/métabolisme , Cartes d'interactions protéiques , Protéines végétales/génétique , Protéines végétales/métabolisme , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Régions promotrices (génétique) , Séquences d'acides nucléiques régulatrices , Famille multigénique , PhylogenèseRÉSUMÉ
Striga hermonthica (Sh) and S. asiatica (Sa) are major parasitic weeds limiting cereal crop production and productivity in sub-Saharan Africa (SSA). Under severe infestation, Striga causes yield losses of up to 100%. Breeding for Striga-resistant maize varieties is the most effective and economical approach to controlling the parasite. Well-characterized and genetically differentiated maize germplasm is vital to developing inbred lines, hybrids, and synthetic varieties with Striga resistance and desirable product profiles. The objective of this study was to determine the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties germplasm using phenotypic traits and single nucleotide polymorphism (SNP) markers to select Striga-resistant and complementary genotypes for breeding. The test genotypes were phenotyped with Sh and Sa infestations using a 13x10 alpha lattice design with two replications. Agro-morphological traits and Striga-resistance damage parameters were recorded under a controlled environment. Further, high-density Diversity Array Technology Sequencing-derived SNP markers were used to profile the test genotypes. Significant phenotypic differences (P<0.001) were detected among the assessed genotypes for the assessed traits. The SNP markers revealed mean gene diversity and polymorphic information content of 0.34 and 0.44, respectively, supporting the phenotypic variation of the test genotypes. Higher significant variation was recorded within populations (85%) than between populations using the analysis of molecular variance. The Structure analysis allocated the test genotypes into eight major clusters (K = 8) in concordance with the principal coordinate analysis (PCoA). The following genetically distant inbred lines were selected, displaying good agronomic performance and Sa and Sh resistance: CML540, TZISTR25, TZISTR1248, CLHP0303, TZISTR1174, TZSTRI113, TZDEEI50, TZSTRI115, CML539, TZISTR1015, CZL99017, CML451, CML566, CLHP0343 and CML440. Genetically diverse and complementary lines were selected among the tropical and sub-tropical maize populations that will facilitate the breeding of maize varieties with Striga resistance and market-preferred traits.
Sujet(s)
Polymorphisme de nucléotide simple , Striga , Zea mays , Zea mays/génétique , Zea mays/parasitologie , Striga/physiologie , Striga/génétique , Variation génétique , Phénotype , Génotype , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Résistance à la maladie/génétique , Amélioration des plantes , Mauvaises herbes/génétique , Climat tropical , Marqueurs génétiquesRÉSUMÉ
The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies.
Sujet(s)
Hevea , Phylogenèse , Phytophthora , Maladies des plantes , Inde , Phytophthora/génétique , Phytophthora/classification , Maladies des plantes/microbiologie , Maladies des plantes/parasitologie , Hevea/microbiologie , Hevea/parasitologie , Typage par séquençage multilocus , Feuilles de plante/microbiologie , Feuilles de plante/parasitologie , Analyse de séquence d'ADN , Virulence , Espaceur de l'ADN ribosomique/génétique , Prévalence , Analyse de regroupements , Fongicides industriels/pharmacologie , Alanine/analogues et dérivésRÉSUMÉ
The whitefly, a polyphagous insect pest feeding on nearly 1328 plant species, is a major threat to global cotton production and incurs up to 50% yield losses in cotton production in Pakistan. We investigated whether increased aspartate in phloem sap imparts whitefly toxicity and protects cotton plants from intense damage. The enzymatic step for aspartate production is carried through aspartate aminotransferase (AAT). In this study, we constitutively overexpressed the Oryza sativa cytoplasmic AAT (OsAAT2) under the CaMV35S promoter in Gossypium hirsutum cv. CIM-482. Real-time PCR analysis of the AAT transcripts revealed a 2.85- to 31.7-fold increase in mRNA levels between the different cotton lines. A substantial increase in the free-amino acid content of the major N-assimilation and transport amino acids (aspartate, glutamate, asparagine, and glutamine) was seen in the phloem sap of the transgenic cotton lines. The bioassay revealed that the two transgenic cotton lines with the highest free aspartate content in the phloem sap exhibited 97 and 94% mortality in the adult whitefly population and a 98 and 96% decline in subsequent nymph populations, respectively. There was also a significant change in the physiological behaviour of the transgenic cotton lines, with an increased net assimilation (A), gaseous exchange (Gs) and rate of transpiration (E). Improved morphological characteristics like plant height, total number of bolls and fiber yield were recorded in transgenic cotton lines. The AAT gene shows promise in mitigating whitefly infestations and enhancing the overall health and yield of cotton plants.
Sujet(s)
Acide aspartique , Gossypium , Hemiptera , Végétaux génétiquement modifiés , Gossypium/génétique , Gossypium/métabolisme , Gossypium/parasitologie , Animaux , Hemiptera/physiologie , Végétaux génétiquement modifiés/génétique , Acide aspartique/métabolisme , Oryza/génétique , Oryza/parasitologie , Oryza/métabolisme , Aspartate aminotransferases/métabolisme , Aspartate aminotransferases/génétique , Phloème/métabolisme , Phloème/génétique , Maladies des plantes/parasitologie , Maladies des plantes/génétiqueRÉSUMÉ
Plant pathogens are constantly under selection pressure for host resistance adaptation. Soybean cyst nematode (SCN, Heterodera glycines) is a major pest of soybean primarily managed through resistant cultivars; however, SCN populations have evolved virulence in response to selection pressures driven by repeated monoculture of the same genetic resistance. Resistance to SCN is mediated by multiple epistatic interactions between Rhg (for resistance to H. glycines) genes. However, the identity of SCN virulence genes that confer the ability to overcome resistance remains unknown. To identify candidate genomic regions showing signatures of selection for increased virulence, we conducted whole genome resequencing of pooled individuals (Pool-Seq) from two pairs of SCN populations adapted on soybeans with Peking-type (rhg1-a, rhg2, and Rhg4) resistance. Population differentiation and principal component analysis-based approaches identified approximately 0.72-0.79 million SNPs, the frequency of which showed potential selection signatures across multiple genomic regions. Chromosomes 3 and 6 between population pairs showed the greatest density of outlier SNPs with high population differentiation. Conducting multiple outlier detection tests to identify overlapping SNPs resulted in a total of 966 significantly differentiated SNPs, of which 285 exon SNPs were mapped to 97 genes. Of these, six genes encoded members of known stylet-secreted effector protein families potentially involved in host defence modulation including venom-allergen-like, annexin, glutathione synthetase, SPRYSEC, chitinase, and CLE effector proteins. Further functional analysis of identified candidate genes will provide new insights into the genetic mechanisms by which SCN overcomes soybean resistance and inform the development of molecular markers for rapidly screening the virulence profile of an SCN-infested field.
Sujet(s)
Résistance à la maladie , Glycine max , Maladies des plantes , Polymorphisme de nucléotide simple , Tylenchoidea , Animaux , Glycine max/génétique , Glycine max/parasitologie , Polymorphisme de nucléotide simple/génétique , Virulence/génétique , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Résistance à la maladie/génétique , Tylenchoidea/génétique , Tylenchoidea/pathogénicité , Sélection génétique , Génétique des populations , Séquençage du génome entierRÉSUMÉ
Wheat plants infested by Russian wheat aphids (RWA) induce a cascade of defense responses, including the hypersensitive responses (HR) and induction of pathogenesis-related (PR) proteins, such as ß-1,3-glucanase and peroxidase (POD). This study aims to characterize the physicochemical properties of cell wall-associated POD and ß-1,3-glucanase and determine their synergism on the cell wall modification during RWASA2-wheat interaction. The susceptible Tugela, moderately resistant Tugela-Dn1, and resistant Tugela-Dn5 cultivars were pregerminated and planted under greenhouse conditions, fertilized 14 days after planting, and irrigated every 3 days. The plants were infested with 20 parthenogenetic individuals of the same RWASA2 clone at the 3-leaf stage, and leaves were harvested at 1 to 14 days post-infestation. The Intercellular wash fluid (IWF) was extracted using vacuum filtration and stored at -20 °C. Leaf residues were crushed into powder and used for cell wall components. POD activity and characterization were determined using 5 mM guaiacol substrate and H2O2, monitoring change in absorbance at 470 nm. ß-1,3-glucanase activity, pH, and temperature optimum conditions were demonstrated by measuring the total reducing sugars in the hydrolysate with DNS reagent using ß-1,3-glucan and ß-1,3-1,4-glucan substrates, measuring the absorbance at 540 nm, and using glucose standard curve. The pH optimum was determined between pH 4 to 9, temperature optimum between 25 and 50 °C, and thermal stability between 30 °C and 70 °C. ß-1,3-glucanase substrate specificity was determined at 25 °C and 40 °C using curdlan and barley ß-1,3-1,4-glucan substrates. Additionally, the ß-1,3-glucanase mode of action was determined using laminaribiose to laminaripentaose. The oligosaccharide hydrolysis product patterns were qualitatively analyzed with thin-layer chromatography (TLC) and quantitatively analyzed with HPLC. The method presented in this study demonstrates a robust approach for infesting wheat with RWA, extracting peroxidase and ß-1,3-glucanase from the cell wall region and their comprehensive biochemical characterization.
Sujet(s)
Aphides , Paroi cellulaire , Triticum , Triticum/composition chimique , Paroi cellulaire/composition chimique , Paroi cellulaire/métabolisme , Animaux , Glucan 1,3-beta-glucosidase/métabolisme , Glucan 1,3-beta-glucosidase/composition chimique , Myeloperoxidase/composition chimique , Myeloperoxidase/métabolisme , Maladies des plantes/parasitologieRÉSUMÉ
BACKGROUND: Root-lesion nematodes (RLN) are the most economically important pathogenic nematodes attacking maize. Significant economic losses due to lesion nematodes have been reported in maize producing countries in the world. METHODS AND RESULTS: This study was conducted to determine the distribution and identity of root-lesion nematodes (Pratylenchus spp.) (Tylenchida: Hoplolaimidae) in maize (Zea mays L.) (Poales: Poaceae) fields of the Black Sea region of Türkiye. For this purpose, 39 locations were surveyed and soil samples were taken from 17 regional provinces. Nematodes were extracted using the modified Baerman funnel technique. The species were identified based on sequences of the Internal Transcribed Spacer (ITS) region of ribosomal DNA, as well as morphological characters and morphometrics. In addition, species identifications were confirmed using species-specific primers in the D3 expansion region of 26 S rDNA. At the end of the study, 51.3% of the maize production areas sampled in the region were infected with root-lesion nematode species. Pratylenchus agilis, P. mediterraneus, P. neglectus, P. penetrans, P. thornei, and P. vulnus were identified, and were present in 25%, 5%, 25%, 10%, 15%, and 20% of samples, respectively. To our knowledge, this is the first report of P. agilis in Türkiye. CONCLUSION: The present study concluded that the molecular analysis of Pratylenchus sequences based on the ITS and D3 region of ribosomal RNA genes allowed the identification of six root lesion nematode species. This study is of great importance in terms of adding additional species to the root-lesion nematode fauna in Turkey and will provide data for future research on the management of these nematodes.
Sujet(s)
Phylogenèse , Maladies des plantes , Racines de plante , Tylenchida , Zea mays , Animaux , Zea mays/parasitologie , Zea mays/génétique , Racines de plante/parasitologie , Racines de plante/génétique , Tylenchida/génétique , Tylenchida/pathogénicité , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Espaceur de l'ADN ribosomique/génétique , Turquie , ADN ribosomique/génétique , ADN des helminthes/génétiqueRÉSUMÉ
KEY MESSAGE: This study provided a non-destructive detection method with Vis-NIR hyperspectral imaging combining with physio-biochemical parameters in Helianthus annuus in response to Orobanche cumana infection that took insights into the monitoring of sunflower weed. Sunflower broomrape (Orobanche cumana Wallr.) is an obligate weed that attaches to the host roots of sunflower (Helianthus annuus L.) leading to a significant reduction in yield worldwide. The emergence of O. cumana shoots after its underground life-cycle causes irreversible damage to the crop. In this study, a fast visual, non-invasive and precise method for monitoring changes in spectral characteristics using visible and near-infrared (Vis-NIR) hyperspectral imaging (HSI) was developed. By combining the bands sensitive to antioxidant enzymes (SOD, GR), non-antioxidant enzymes (GSH, GSH + GSSG), MDA, ROS (O2-, OH-), PAL, and PPO activities obtained from the host leaves, we sought to establish an accurate means of assessing these changes and conducted imaging acquisition using hyperspectral cameras from both infested and non-infested sunflower cultivars, followed by physio-biochemical parameters measurement as well as analyzed the expression of defense related genes. Extreme learning machine (ELM) and convolutional neural network (CNN) models using 3-band images were built to classify infected or non-infected plants in three sunflower cultivars, achieving accuracies of 95.83% and 95.83% for the discrimination of infestation as well as 97.92% and 95.83% of varieties, respectively, indicating the potential of multi-spectral imaging systems for early detection of O. cumana in weed management.
Sujet(s)
Helianthus , Imagerie hyperspectrale , Orobanche , Helianthus/parasitologie , Orobanche/physiologie , Imagerie hyperspectrale/méthodes , Spectroscopie proche infrarouge/méthodes , Feuilles de plante/parasitologie , Feuilles de plante/métabolisme , Maladies des plantes/parasitologie , Antioxydants/métabolisme , Mauvaises herbes , Interactions hôte-parasiteRÉSUMÉ
The genus Phytophthora contains more than 100 plant pathogenic species that parasitize a wide range of plants, including economically important fruits, vegetables, cereals, and forest trees, causing significant losses. Global agriculture is seriously threatened by fungicide resistance in Phytophthora species, which makes it imperative to fully comprehend the mechanisms, frequency, and non-chemical management techniques related to resistance mutations. The mechanisms behind fungicide resistance, such as target-site mutations, efflux pump overexpression, overexpression of target genes and metabolic detoxification routes for fungicides routinely used against Phytophthora species, are thoroughly examined in this review. Additionally, it assesses the frequency of resistance mutations in various Phytophthora species and geographical areas, emphasizing the rise of strains that are resistant to multiple drugs. The effectiveness of non-chemical management techniques, including biological control, host resistance, integrated pest management plans, and cultural practices, in reducing fungicide resistance is also thoroughly evaluated. The study provides important insights for future research and the development of sustainable disease management strategies to counter fungicide resistance in Phytophthora species by synthesizing current information and identifying knowledge gaps.
Sujet(s)
Résistance des champignons aux médicaments , Fongicides industriels , Phytophthora , Maladies des plantes , Phytophthora/effets des médicaments et des substances chimiques , Phytophthora/génétique , Fongicides industriels/pharmacologie , Maladies des plantes/microbiologie , Maladies des plantes/prévention et contrôle , Maladies des plantes/parasitologie , Résistance des champignons aux médicaments/génétique , Mutation , AgricultureRÉSUMÉ
Research interest in the mechanisms enabling plant-parasitic nematodes to adjust their physiological performance and cope with changing temperatures has intensified in light of global warming. Here, we show that geographically distinct populations of the root-knot nematode Meloidogyne incognita, which is prevalent in the three main pepper-growing regions in Israel-Carmel Valley (Carmel), Jordan Valley (JV), and Arava Rift (Arava)-possess persistent differences in their thermal acclimation capacity, which affect pre- and postembryonic development. The optimal temperature for embryonic growth completion was 25°C for the Carmel population; 25 and 30°C for the JV population; and 30°C for the Arava population. Cumulative hatching percentages showed variations among populations; relative to hatching at 25°C, the Carmel population experienced hatching reduction at the higher studied temperatures 30 and 33°C, while the JV and Arava populations exhibited an increase in hatching at 30 and 33°C, respectively. Juvenile survival indicates that at the lowest temperature (20°C), the Carmel population gained the highest survival rates throughout the experimental duration, while at the same duration at 33°C, the Arava population gained the highest survival rate. Infective juveniles of the Carmel population demonstrated increased penetration of tomato roots at 25°C compared to the JV and Arava populations. Inversely, at 33°C, increased penetration was observed for the Arava compared to the Carmel and JV populations. Altogether, the Arava population's performance at 33°C might incur distinct fitness costs, resulting in consistent attenuation compared to the Carmel population at 25°C. Precisely defining a population's thermal acclimation response might provide essential information for models that predict the impact of future climate change on these populations.
Sujet(s)
Acclimatation , Température , Tylenchoidea , Animaux , Tylenchoidea/physiologie , Maladies des plantes/parasitologie , Capsicum/parasitologie , Israël , Développement embryonnaireRÉSUMÉ
The yield of pearl millet, a resilient cereal crop crucial for African food security, is severely impacted by the root parasitic weed Striga hermonthica, which requires host-released hormones, called strigolactones (SLs), for seed germination. Herein, we identify four SLs present in the Striga-susceptible line SOSAT-C88-P10 (P10) but absent in the resistant 29Aw (Aw). We generate chromosome-scale genome assemblies, including four gapless chromosomes for each line. The Striga-resistant Aw lacks a 0.7 Mb genome segment containing two putative CARLACTONOIC ACID METHYLTRANSFERASE1 (CLAMT1) genes, which may contribute to SL biosynthesis. Functional assays show that P10CLAMT1b produces the SL-biosynthesis intermediate methyl carlactonoate (MeCLA) and that MeCLA is the precursor of P10-specific SLs. Screening a diverse pearl millet panel confirms the pivotal role of the CLAMT1 section for SL diversity and Striga susceptibility. Our results reveal a reason for Striga susceptibility in pearl millet and pave the way for generating resistant lines through marker-assisted breeding or direct genetic modification.
Sujet(s)
Génome végétal , Lactones , Pennisetum , Striga , Striga/génétique , Lactones/métabolisme , Pennisetum/génétique , Pennisetum/métabolisme , Protéines végétales/génétique , Protéines végétales/métabolisme , Chromosomes de plante/génétique , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Methyltransferases/métabolisme , Methyltransferases/génétique , Mauvaises herbes/génétique , Mauvaises herbes/métabolisme , Résistance à la maladie/génétique , Facteur de croissance végétal/métabolismeRÉSUMÉ
WRKY transcription factors (TFs) can participate in plant biological stress responses and play important roles. SlWRKY80 was found to be differentially expressed in the Mi-1- and Mi-3-resistant tomato lines by RNA-seq and may serve as a key node for disease resistance regulation. This study used RNAi to determine whether SlWRKY80 silencing could influence the sensitivity of 'M82' (mi-1/mi-1)-susceptible lines to M. incognita. Further overexpression of this gene revealed a significant increase in tomato disease resistance, ranging from highly susceptible to susceptible, combined with the identification of growth (plant height, stem diameter, and leaf area) and physiological (soluble sugars and proteins; root activity) indicators, clarifying the role of SlWRKY80 as a positive regulatory factor in tomato defense against M. incognita. Based on this phenomenon, a preliminary exploration of its metabolic signals revealed that SlWRKY80 stimulates different degrees of signaling, such as salicylic acid (SA), jasmonic acid (JA), and ethylene (ETH), and may synergistically regulate reactive oxygen species (ROS) accumulation and scavenging enzyme activity, hindering the formation of feeding sites and ultimately leading to the reduction of root gall growth. To our knowledge, SlWRKY80 has an extremely high utilization value for improving tomato resistance to root-knot nematodes and breeding.
Sujet(s)
Résistance à la maladie , Régulation de l'expression des gènes végétaux , Maladies des plantes , Protéines végétales , Solanum lycopersicum , Facteurs de transcription , Tylenchoidea , Solanum lycopersicum/parasitologie , Solanum lycopersicum/génétique , Solanum lycopersicum/métabolisme , Solanum lycopersicum/croissance et développement , Tylenchoidea/physiologie , Tylenchoidea/pathogénicité , Animaux , Maladies des plantes/parasitologie , Maladies des plantes/génétique , Protéines végétales/génétique , Protéines végétales/métabolisme , Résistance à la maladie/génétique , Facteurs de transcription/métabolisme , Facteurs de transcription/génétique , Cyclopentanes/métabolisme , Oxylipines/métabolisme , Espèces réactives de l'oxygène/métabolisme , Acide salicylique/métabolisme , Racines de plante/parasitologie , Racines de plante/génétique , Racines de plante/métabolismeRÉSUMÉ
Cytokinins (CKs) are a group of phytohormones that are involved in plant growth, development, and disease resistance. The isopentenyl transferase (IPT) and cytokinin oxidase/dehydrogenase (CKX) families comprise key enzymes controlling CK biosynthesis and degradation. However, an integrated analysis of these two gene families in radish has not yet been explored. In this study, 13 RsIPT and 12 RsCKX genes were identified and characterized, most of which had four copies in Brassica napus and two copies in radish and other diploid Brassica species. Promoter analysis indicated that the genes contained at least one phytohormone or defense and stress responsiveness cis-acting element. RsIPTs and RsCKXs were expanded through segmental duplication. Moreover, strong purifying selection drove the evolution of the two gene families. The expression of the RsIPT and RsCKX genes distinctly showed diversity in different tissues and developmental stages of the root. Expression profiling showed that RsCKX1-1/1-2/1-3 was significantly upregulated in club-resistant materials during primary infection, suggesting their vital function in clubroot resistance. The interaction network of CKX proteins with similar 3D structures also reflected the important role of RsCKX genes in disease resistance. This study provides a foundation for further functional study on the IPT and CKX genes for clubroot resistance improvement in Raphanus.
Sujet(s)
Résistance à la maladie , Régulation de l'expression des gènes végétaux , Famille multigénique , Oxidoreductases , Maladies des plantes , Protéines végétales , Raphanus , Raphanus/génétique , Résistance à la maladie/génétique , Protéines végétales/génétique , Protéines végétales/métabolisme , Oxidoreductases/génétique , Oxidoreductases/métabolisme , Maladies des plantes/génétique , Maladies des plantes/parasitologie , Alkyl et aryl transferases/génétique , Alkyl et aryl transferases/métabolisme , Phylogenèse , Racines de plante/génétique , Racines de plante/métabolisme , Régions promotrices (génétique) , Analyse de profil d'expression de gènesRÉSUMÉ
Tetranychus urticae is an important pest that causes severe damage to a wide variety of plants and crops, leading to a substantial productivity loss. Previous research has been focused on plant defence response to T. urticae to improve plant resistance. However, plant growth, development and reproduction throughout the infestation process have not been previously studied. Through physiological, biochemical, transcriptomic and hormonomic evaluation, we uncover the molecular mechanisms directing the defence-growth trade-off established in Arabidopsis upon T. urticae infestation. Upon mite attack, plants suffer an adaptation process characterized by a temporal separation between the defence and growth responses. Jasmonic and salicylic acids regulate the main defence responses in combination with auxin and abscisic acid. However, while the reduction of both auxin signalling and gibberellin, cytokinin and brassinosteroid biosynthesis lead to initial growth arrest, increasing levels of growth hormones at later stages enables growth restart. These alterations lead to a plant developmental delay that impacts both seed production and longevity. We demonstrate that coordinated trade-offs determine plant adaptation and survival, revealing mite infestation has a long-lasting effect negatively impacting seed viability. This study provides additional tools to design pest management strategies that improve resistance without penalty in plant fitness.
Sujet(s)
Arabidopsis , Facteur de croissance végétal , Tetranychidae , Animaux , Facteur de croissance végétal/métabolisme , Arabidopsis/physiologie , Arabidopsis/parasitologie , Arabidopsis/génétique , Tetranychidae/physiologie , Régulation de l'expression des gènes végétaux , Acides indolacétiques/métabolisme , Cyclopentanes/métabolisme , Acide salicylique/métabolisme , Maladies des plantes/parasitologie , Oxylipines/métabolisme , Cytokinine/métabolisme , Acide abscissique/métabolismeRÉSUMÉ
Root-knot nematodes (RKNs) are a global menace to agricultural crop production. The role of root-associated microbes (RAMs) in plant protection against RKN infection remains unclear. Here we observe that cucumber (highly susceptible to Meloidogyne incognita) exhibits a consistently lower susceptibility to M. incognita in the presence of native RAMs in three distinct soils. Nematode infection alters the assembly of bacterial RAMs along the life cycle of M. incognita. Particularly, the loss of bacterial diversity of RAMs exacerbates plant susceptibility to M. incognita. A diverse range of native bacterial strains isolated from M. incognita-infected roots has nematode-antagonistic activity. Increasing the number of native bacterial strains causes decreasing nematode infection, which is lowest when six or more bacterial strains are present. Multiple simplified synthetic communities consisting of six bacterial strains show pronounced inhibitory effects on M. incognita infection in plants. These inhibitory effects are underpinned via multiple mechanisms including direct inhibition of infection, secretion of anti-nematode substances, and regulation of plant defense responses. This study highlights the role of native bacterial RAMs in plant resistance against RKNs and provides a useful insight into the development of a sustainable way to protect susceptible plants.
Sujet(s)
Cucumis sativus , Maladies des plantes , Racines de plante , Tylenchoidea , Animaux , Racines de plante/parasitologie , Racines de plante/microbiologie , Maladies des plantes/parasitologie , Maladies des plantes/microbiologie , Maladies des plantes/prévention et contrôle , Tylenchoidea/physiologie , Cucumis sativus/parasitologie , Cucumis sativus/microbiologie , Microbiologie du sol , Bactéries , Résistance à la maladie , Consortiums microbiensRÉSUMÉ
The sustainable management of large amounts of fly ash (FA) is a concern for researchers, and we aim to determine the FA application in plant development and nematicidal activity in the current study. A pot study is therefore performed to assess the effects of adding different, FA-concentrations to soil (w/w) on the infection of chickpea plants with the root-knot nematode Meloidogyne incognita. Sequence characteristic amplified region (SCAR) and internal transcribed spacer (ITS) region-based-markers were used to molecularly confirm M. incognita. With better plant growth and chickpea yield performance, FA enhanced the nutritious components of the soil. When compared with untreated, uninoculated control (UUC) plants, the inoculation of M. incognita dramatically reduced chickpea plant growth, yield biomass, and metabolism. The findings showed that the potential of FA to lessen the root-knot nematode illness in respect of galls, egg-masses, and reproductive attributes may be used to explain the mitigating effect of FA. Fascinatingly, compared with the untreated, inoculated control (UIC) plants, the FA treatment, primarily at 20%, considerably (p ≤ 0.05) boosted plant growth, yield biomass, and pigment content. Additionally, when the amounts of FA rose, the activity of antioxidants like superoxide dismutase-SOD, catalase-CAT, and peroxidase-POX as well as osmo-protectants like proline gradually increased. Therefore, our findings imply that 20% FA can be successfully applied as a potential strategy to increase biomass yield and plant growth while simultaneously reducing M. incognita infection in chickpea plants.
Sujet(s)
Cicer , Cendre de charbon , Tylenchoidea , Animaux , Tylenchoidea/physiologie , Racines de plante/parasitologie , Sol/composition chimique , Sol/parasitologie , Maladies des plantes/parasitologie , Maladies des plantes/prévention et contrôleRÉSUMÉ
This study investigates the efficacy of Trichoderma spp. and Bacillus spp., as well as their gamma radiation-induced mutants, as potential biological control agents against Meloidogyne javanica (Mj) in tomato plants. The research encompasses in vitro assays, greenhouse trials, and molecular identification methodologies to comprehensively evaluate the biocontrol potential of these agents. In vitro assessments reveal significant nematicidal activity, with Bacillus spp. demonstrating notable effectiveness in inhibiting nematode egg hatching (16-45%) and inducing second-stage juvenile (J2) mortality (30-46%). Greenhouse trials further confirm the efficacy of mutant isolates, particularly when combined with chitosan, in reducing nematode-induced damage to tomato plants. The combination of mutant isolates with chitosan reduces the reproduction factor (RF) of root-knot nematodes by 94%. By optimizing soil infection conditions with nematodes and modifying the application of the effective compound, the RF of nematodes decreases by 65-76%. Molecular identification identifies B. velezensis and T. harzianum as promising candidates, exhibiting significant nematicidal activity. Overall, the study underscores the potential of combined biocontrol approaches for nematode management in agricultural settings. However, further research is essential to evaluate practical applications and long-term efficacy. These findings contribute to the development of sustainable alternatives to chemical nematicides, with potential implications for agricultural practices and crop protection strategies.
Sujet(s)
Bacillus , Rayons gamma , Lutte biologique contre les nuisibles , Maladies des plantes , Solanum lycopersicum , Tylenchoidea , Animaux , Tylenchoidea/physiologie , Bacillus/génétique , Bacillus/physiologie , Solanum lycopersicum/parasitologie , Solanum lycopersicum/microbiologie , Maladies des plantes/parasitologie , Maladies des plantes/prévention et contrôle , Maladies des plantes/microbiologie , Lutte biologique contre les nuisibles/méthodes , Mutation , Hypocreales/génétique , Antihelminthiques antinématodes/pharmacologie , Agents de lutte biologique/pharmacologie , Chitosane/pharmacologieRÉSUMÉ
The cotton leaf hopper is a major pest in cotton, causing a hopper burn in leaves. In this study, a comparative proteomic analysis of NDLH2010 (Resistant) and LRA5166 (Susceptible), infected with leaf hopper, was employed using a nano LC-MS/MS approach. A total of 1402 proteins varied significantly between leaf hopper-infected and control plants. The resistant and susceptible genotypes had differentially expressed proteins (DEPs) of 743 and 659, respectively. Functional annotation of DEPs revealed that the DEPs were primarily associated with stress response, hormone synthesis, photosynthesis, cell wall, and secondary metabolites. Notably, DEPs such as polyphenol oxidase, carboxypeptidase, heat shock proteins, protein BTR1-like isoform X2, chaperone protein ClpB1, and ß glucosidase factors associated with environmental stress response were also detected. Quantitative real-time PCR (qRT-PCR) analysis confirmed a positive correlation between protein abundances and transcripts for all genes. Collectively, this study provides the molecular mechanisms associated with cotton defense responses against leaf hopper. SIGNIFICANCE STATEMENT: Cotton, a natural fiber, assumes a pivotal role as a raw material for textile industries, thereby bearing significant importance in the global economy. The cotton production sector is considerably affected by both biotic and abiotic stresses. The cotton leaf hopper (Amrasca biguttula biguttula (Ishida)) stands as a polyphagous insect, emerging as a dominant sap-feeding pest of the cotton crop. The continuous onslaught of sap-feeding insects on cotton plants has a detrimental impact, with leaf hoppers potentially causing yield reductions of up to 50%. Therefore, comprehending the molecular interplay between cotton and leaf hopper, elucidated at the proteome level, holds promise for more effective pest management strategies. This approach holds the potential to offer insights that contribute to the development of leaf hopper-resistant cotton varieties.
Sujet(s)
Gossypium , Protéines végétales , Protéomique , Gossypium/métabolisme , Gossypium/génétique , Gossypium/parasitologie , Animaux , Protéomique/méthodes , Protéines végétales/métabolisme , Protéines végétales/génétique , Génotype , Maladies des plantes/parasitologie , Feuilles de plante/métabolisme , Feuilles de plante/parasitologie , Régulation de l'expression des gènes végétaux , Protéome/métabolismeRÉSUMÉ
Plant-parasitic nematodes constrain global food security. During parasitism, they secrete effectors into the host plant from two types of pharyngeal gland cells. These effectors elicit profound changes in host biology to suppress immunity and establish a unique feeding organ from which the nematode draws nutrition. Despite the importance of effectors in nematode parasitism, there has been no comprehensive identification and characterisation of the effector repertoire of any plant-parasitic nematode. To address this, we advance techniques for gland cell isolation and transcriptional analysis to define a stringent annotation of putative effectors for the cyst nematode Heterodera schachtii at three key life-stages. We define 717 effector gene loci: 269 "known" high-confidence homologs of plant-parasitic nematode effectors, and 448 "novel" effectors with high gland cell expression. In doing so we define the most comprehensive "effectorome" of a plant-parasitic nematode to date. Using this effector definition, we provide the first systems-level understanding of the origin, deployment and evolution of a plant-parasitic nematode effectorome. The robust identification of the effector repertoire of a plant-parasitic nematode will underpin our understanding of nematode pathology, and hence, inform strategies for crop protection.
Sujet(s)
Interactions hôte-parasite , Maladies des plantes , Animaux , Maladies des plantes/parasitologie , Tylenchoidea/génétique , Plantes/parasitologie , Protéines d'helminthes/génétique , Protéines d'helminthes/métabolisme , Nematoda/génétiqueRÉSUMÉ
Sorghum (Sorghum bicolor), the fifth most important cereal crop globally, serves as a staple food, animal feed, and a bioenergy source. Paclobutrazol-Resistance (PRE) genes play a pivotal role in the response to environmental stress, yet the understanding of their involvement in pest resistance remains limited. In the present study, a total of seven SbPRE genes were found within the sorghum BTx623 genome. Subsequently, their genomic location was studied, and they were distributed on four chromosomes. An analysis of cis-acting elements in SbPRE promoters revealed that various elements were associated with hormones and stress responses. Expression pattern analysis showed differentially tissue-specific expression profiles among SbPRE genes. The expression of some SbPRE genes can be induced by abiotic stress and aphid treatments. Furthermore, through phytohormones and transgenic analyses, we demonstrated that SbPRE4 improves sorghum resistance to aphids by accumulating jasmonic acids (JAs) in transgenic Arabidopsis, giving insights into the molecular and biological function of atypical basic helix-loop-helix (bHLH) transcription factors in sorghum pest resistance.