Improved Disease Resistance Research Articles

Physicochemical and Structural Validation of Myxovirus Resistance 1 (Mx1) Protein of Three Strains of the Nigerian Indigenous (<i>Gallus Gallus domesticus</i>) and Exotic Chickens

This research was conducted on three strains of Nigerian Indigenous (<i>gallus gallus domesticus</i>) and Noiler (exotic) chickens. It examined the physicochemical and structural validation of Myxovirus resistance 1 (Mx1) protein on the three strains of Nigerian indigenous (naked neck, frizzle feather, normal feather) and noiler (exotic) chickens and also the prediction of the Physicochemical Analysis of protein. Nucleotide sequence were retrieved from National Center for Bio-Technology Information (NCBI) database and subjected to multiple sequence alignment, prediction of the physicochemical analysis of protein was done in the ProtParam web server. Modeling of 3D structural validation, Swiss modeling and Statistical analysis were all carried out. Software was used to align the sequences to find any Single Nucleotide Polymorphism (SNPS). The result of physicochemical analysis showed that the properties of the Mx1 protein fell within accepted threshold and predicted that the proteins were generally related. To validate the structure obtained from modeling, the obtained PDB files were ran on the Pro-check validation server and obtained Errat and Ramachandran plots. The study elucidates the unique features and potential functional implications of Mx1 protein across different strains of Nigerian indigenous and exotic chickens. This knowledge can inform the development of strategies to improve disease resistance in local chicken populations through selective breeding or genetic manipulation. Comparing the Mx1 protein among different strains of Nigerian indigenous chickens can reveal evolutionary adaptations and provide valuable information for understanding the molecular basis of immune defense mechanisms in poultry. Understanding the physicochemical properties and structural dynamics of Mx1 protein contributes to the broader understanding of innate immune responses in indigenous chicken breeds, offering insights into their disease resistance and adaptation mechanisms.

Pangenome Data Analysis Reveals Characteristics of Resistance Gene Analogs Associated with Sclerotinia sclerotiorum Resistance in Sunflower

The sunflower, an important oilseed crop and food source across the world, is susceptible to several pathogens, which cause severe losses in sunflower production. The utilization of genetic resistance is the most economical, effective measure to prevent infectious diseases. Based on the sunflower pangenome, in this study, we explored the variability of resistance gene analogs (RGAs) within the species. According to a comparative analysis of RGA candidates in the sunflower pangenome using the RGAugury pipeline, a total of 1344 RGAs were identified, comprising 1107 conserved, 199 varied, and 38 rare RGAs. We also identified RGAs associated with resistance against Sclerotinia sclerotiorum (S. sclerotiorum) in sunflower at the quantitative trait locus (QTL). A total of 61 RGAs were found to be located at four quantitative trait loci (QTLs). Through a detailed expression analysis of RGAs in one susceptible and two tolerant sunflower inbred lines (ILs) across various time points post inoculation, we discovered that 348 RGAs exhibited differential expression in response to Sclerotinia head rot (SHR), with 17 of these differentially expressed RGAs being situated within the QTL regions. In addition, 15 RGA candidates had gene introgression. Our data provide a better understanding of RGAs, which facilitate genomics-based improvements in disease resistance in sunflower.

Identification of resistant sources against collar rot disease in groundnut (Arachis hypogaea) incited by Aspergillus niger

Collar rot disease incited by Aspergillus niger van Tiegham is one of the major constraint to groundnut (Arachis hypogaea L.) production in India. This fungus is ubiquitous, soil inhabitant causing severe reduction in seed germination. Infected seeds appear surrounded by black conidia and post-emergence infection occurs on collar region of plants leading to mortality of emerged seedlings at the seedling stage. Therefore, present study was carried out during rainy (kharif) seasons of 2022 and 2023 at Regional Research Station (CCS Haryana Agricultural University, Hisar, Haryana), Bawal, Haryana to identify the strategy of disease management by identification of new resistant lines which will be useful to develop introgression lines using marker-assisted backcrossing approach to improve disease resistance against soil-borne pathogens in popular groundnut varieties. A total of 245 groundnut genotypes were screened under natural epiphytotic field conditions in randomized block design (RBD) with three replications for their resistance against collar rot disease The results of the investigation indicated that 65 genotypes displayed resistant reactions among which ICGV-6285, GC-131-1, ICGV-06319, ICGV-02038, GC-100, GC-98, ICGV-02038, ICGV-7403, ICGV-7214, TG-37A and GC-133 exhibited the lowest collar rot incidence while, rest of the genotypes displayed moderately resistant, susceptible and highly susceptible reaction. Thus, these resistant genotypes could be utilized in the hybridization programme to develop high yielding groundnut variety with inbuilt resistance against collar rot of groundnut.

Effects of Arnebia benthamii Extract on Growth Performance, Immunological Parameters and Disease Resistance against Flexibacter columnare in Spotted Snakehead Channa punctata (Bloch)

Herbal immunostimulants are known to improve disease resistance in fish by enhancing specific and non-specific defensive mechanisms. The present study was conducted to evaluate the effects of Arnebia benthamii extract (AE) on growth rate, immune status, and disease resistance towards Flexibacter columnare in spotted snakehead Channa punctata. Each experimental group of healthy C. punctata was fed on one of the four experimental diets viz. basal diet (without any AE supplementation), AE10 (supplemented with 10 mg AE/kg basal diet), AE20 (supplemented with 20 mg AE/kg basal diet) and AE40 (supplemented with 40 mg AE/kg basal diet) for 42 days. When the concentration of Arnebia benthamii was raised from 0 to 40 mg/kg, the weight gain (WG) and specific growth rate (SGR) were considerably enhanced. The lysozyme activity, C3, C4, and serum globulin levels were also significantly increased in all Arnebia benthamii supplemented groups. IgM concentration in fish fed on AE40 diet was significantly higher than in fish fed on basal diet. All A. benthamii treatment groups exhibited significantly higher survival rates after being challenged with F. columnare. These findings showed that supplementing diet of C. punctata with A. benthamii improved growth, immunological response, and disease resistance against F. columnare, with the greatest benefits in fish fed on AE40 diet for 42 days.

Investigation of the Effects of Heavy Metals (Copper, Cobalt, Manganese, Selenium, and Zinc) on Fish Immune Systems – An Overview

Abstract Aquaculture, as a strategic and developmental industry, plays an important role in ensuring food security and economic stability within countries. This crucial sector faces various influences, including infectious and nutritional diseases. Certain minerals function as essential nutrients, playing a main role in processes across all aquatic animals when present in appropriate dietary proportions. Studies showed that some heavy metals serve as a catalyst for various biological functions, including the maintenance of colloidal systems, acid-base balance, bone formation, and the regulation of fundamental natural elements such as vitamins, hormones, and minerals. Fish acquire essential elements crucial for their well-being through both diet and water sources. Adequate levels of essential elements, such as iron, zinc, copper, cobalt, manganese, and selenium, in the diet contribute to enhanced growth, increased survival rates, improved disease resistance, and heightened specific immunity in fish. When incorporated in appropriate quantities, these elements play a pivotal role in disease prevention, fostering the production of high-quality fish, minimizing economic losses, and solidifying aquaculture as a robust and profitable industry. This article aims to delve into the immunological effects induced by metal elements, specifically copper (Cu), cobalt (Co), manganese (Mn), zinc (Zn), and selenium (Se), in diverse fish species. The objective is to underscore the significance of this exploration, paving the way for the development of more potent immune supplements in the future. These supplements have the potential to improve growth, fortify immune responses, and enhance resilience against diseases in various fish species.

High-density genetic map construction and QTL mapping to identify genes for blight defense- and yield-related traits in sesame (Sesamum indicum L.).

Sesame (Sesamum indicum L.) is an important oilseed crop widely cultivated in subtropical and tropical areas. Low genetic yield potential and susceptibility to disease contribute to low productivity in sesame. However, the genetic basis of sesame yield- and disease-related traits remains unclear. Here, we represent the construction of a high-density bin map of sesame using whole genome sequencing of an F2 population derived from 'Yizhi' and 'Mingdeng Zhima'. A total of 2766 Bins were categorized into 13 linkage groups. Thirteen significant QTLs were identified, including ten QTLs related to yield, two QTLs related to Sesame Fusarium wilt (SFW) disease, and one QTL related to seed color. Among these QTLs, we found that SFW-QTL1.1 and SFW-QTL1.2 were major QTLs related to Fusarium wilt disease, explaining more than 20% of the phenotypic variation with LOD > 6. SCC-QTL1.1 was related to seed coat color, explaining 52% of the phenotypic variation with LOD equal to 25.3. This suggests that seed color traits were controlled by a major QTL. Candidate genes related to Fusarium wilt disease and seed color in the QTLs were annotated. We discovered a significant enrichment of genes associated with resistance to late blight. These genes could be spectral disease resistance genes and may have a role in the regulation of Fusarium wilt disease resistance. Our study will benefit the implementation of marker-assisted selection (MAS) for the genetic improvement of disease resistance and yield-related traits in sesame.

Improvement of Quality and Disease Resistance for a Heavy-Panicle Hybrid Restorer Line, R600, in Rice (Oryza sativa L.) by Gene Pyramiding Breeding.

The utilization of heavy-panicle hybrid rice exemplifies the successful integration of architectural enhancement and heterosis, which has been widely adopted in the southwest rice-producing area of China. Iterative improvement in disease resistance and grain quality of heavy-panicle hybrid rice varieties is crucial to promote their sustainable utilization. Here, we performed a molecular design breeding strategy to introgress beneficial alleles of broad-spectrum disease resistance and grain quality into a heavy-panicle hybrid backbone restorer line Shuhui 600 (R600). We successfully developed introgression lines through marker-assisted selection to pyramid major genes (Wxb + ALKA-GC + Pigm + Xa23) derived from three parents (Huanghuazhan, I135, I488), which significantly enhance grain quality and confer resistance to rice blast and bacterial blight (BB). The improved parental R600 line (iR600) exhibited superior grain quality and elevated disease resistance while maintaining the heavy-panicle architecture and high-yield capacity of R600. Moreover, the iR600 was crossed with male sterility line 608A to obtain a new heavy-panicle hybrid rice variety with excellent eating and cooking quality (ECQ) and high yield potential. This study presents an effective breeding strategy for rice breeders to expedite the improvement of grain quality and disease resistance in heavy-panicle hybrid rice.

Engineering a conserved immune coreceptor into a primed state enhances fungal resistance in crops without growth penalty.

Plants must tactically balance immunity and growth when combating lethal pathogens like fungi. CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1), a conserved cell-surface co-receptor for the fungal elicitor chitin, enables plants to induce chitin-triggered immunity to counteract fungal invasion. Previously, we reported that bacterial infection can prime CERK1 through juxtamembrane (JM) phosphorylation to enhance fungal resistance, which only occurs in Arabidopsis (Arabidopsis thaliana) and its close relatives in Brassicaceae. Here, we aim to transfer the priming mechanism of Arabidopsis CERK1 (AtCERK1) to crop CERK1 via JM substitution. We revealed in protoplasts that the entire AtCERK1 JM variable region (AtJM) is essential for imparting the bacterial elicitor flg22-induced primed state to the Nicotiana benthamiana CERK1 (NbCERK1). The NbCERK1 chimera containing AtJM (NbCERK1AtJM) and similarly constructed rice (Oryza sativa) OsCERK1AtJM could undergo flg22-induced JM phosphorylation and confer enhanced antifungal immunity upon bacterial co-infection. Moreover, the NbCERK1AtJM+3D derivative with AtJM phosphomimetic mutations to mimic a constant primed state and similarly constructed OsCERK1AtJM+3D were sufficient to mediate strengthened chitin responses and fungal resistance in transgenic plants independent of bacterial infection. Importantly, no growth and reproduction defects were observed in these plants. Taken together, this study demonstrates that manipulating the primed state of a cell-surface immune receptor offers an effective approach to improve disease resistance in crops without compromising growth and yield and showcases how fundamental insights in plant biology can be translated into crop breeding applications.

Expression of Trichoderma spp. endochitinase gene improves red rot disease resistance in transgenic sugarcane.

Sugarcane (Saccharum spp.)is an economically useful crop grown globally for sugar, ethanol and biofuel production. The crop is vulnerable to fungus Colletotrichum falcatum known to cause red rot disease. The pathogen hydrolyses stalk parenchyma cells where sucrose is accumulated resulting in upto 75% losses in sugar recovery. In this study, transgenic sugarcane having resistance against red rot was developed by introducing Trichoderma spp. endochitinase following Agrobacterium mediated transformation. The transgene introduction and expression in genetically modified plants were verified through qRT-PCR revealing upto 6-fold enhancement in endochitinase expression than non-transgenic plants. Hyperspectral Imaging of transgenic plants displayed altered leaf reflectance spectra and vegetative indices that were positively correlated with ransgene expression. The bioassay with virulent pathotypes of C. falcatumCF08 and CF13 known for epiphytotic occurrence resulted in identification of resistant plant Chit 3-13.The plants with higher reflectance also displayed improved disease resistance, implying their early classification into resistant/susceptible. The losses in sucrose content were minimized (up to 4-fold) in inoculated resistant plant Chit 3-13 as compared to susceptible non-transgenic plant, and a fewer pathogen hyphae were detected in vascular cells of the former through optical microscopy. The electron micrographs confirmed sucrose-filled stalk parenchyma cells in Chit 3-13; in contrast, cells of non-transgenic inoculated plant were depleted of sucrose. The active sites involved in cleaving 1-4 β-glycoside bonds of N-acetyl-d-glucosaminein the pathogen hyphal walls were detected through endochitinase protein structural modelling. The transgenic sugarcane is an important source for in trogressingred rot resistance in plant breeding programs.

“Unveiling the genetic symphony: Diversity and expression of chicken IFITM genes in Aseel and Kadaknath breeds”

In this investigation, single nucleotide variants (SNVs) within the chicken interferon-inducible transmembrane protein (chIFITM) genes were explored in Aseel and Kadaknath breeds. Comparative analysis with the GRCg6a reference genome revealed 9 and 16 SNVs in the chIFITM locus for Aseel and Kadaknath breeds, respectively. When referencing the Genome Reference Consortium GRCg7b, Kadaknath exhibited 10 variants, contrasting with none in Aseel. Notably, 17, 8, 2, and 5 SNVs were identified in chIFITM1, chIFITM2, chIFITM3, and chIFITM5 genes, with chIFITM1 showing the highest polymorphism in Kadaknath, featuring 10 intronic variants, including three SNVs (rs16457112, rs16457111, and rs313341707) common to both breeds. Two synonymous exonic variants (g.1817767C > A and g.1819102C > T) were also noted in chIFITM1. Although chIFITM protein sequences were generally conserved, genetic variations clustered predominantly in UTR and intronic regions. Examination of immune response dynamics in live embryos uncovered notable variations in chIFITM gene expression across diverse organs and chicken breeds. Specifically, chIFITM1 mRNA was abundant in cecal tonsils for both breeds and bursa of Aseel (7.61 folds), but it was absent in the heart and lung tissues of both breeds. Conversely, chIFITM3 consistently exhibited heightened expression, particularly in bursa of Aseel (10.23 folds). Whereas mRNA of the chIFITM2 gene was found to be abundant in the heart of Kadaknath (11.03 folds) and lung of both breeds. Furthermore, the expression pattern of chIFITM5 diverged between the two breeds, the heart of Kadaknath chickens showed highest (10.45 folds). The study discovered that breed-specific genetic variants within these genes present a potential pathway for selection and breeding to improve disease resistance in chicken. The observed genetic variation among chicken populations highlights the critical importance of these variants in reinforcing virus resistance, exhibiting applicability across a wide range of breeds.

ANAX4 is a downstream molecule of LGP2 and promotes GCRV proliferation

This study explored the key molecules and signal pathways in the pathogenesis of grass carp reovirus (GCRV). Using immunoprecipitation mass spectrometry and Co-IP validation, the protein CiANXA4 was identified which interacts indirectly with CiLGP2. CiANXA4 encodes 321 amino acids, including 4 ANX domains. To explore the role of CiANXA4 in the anti-GCRV immune response, we used overexpression and siRNA knockdown in cells. The results showed that overexpression of the CiANXA4 gene significantly increased the mRNA content of vp2 and vp7 in GCRV-infected cells, and the virus titer greatly increased. Knockdown of CiANXA4 significantly inhibited the mRNA levels of vp2 and vp7, and the protein levels of viral protein VP7 also significantly decreased. This suggests that CiANXA4 promotes viral proliferation. Further, we demonstrate that the ANX3 and ANX4 domains are key domains that limit CiANXA4 function by constructing domain-deletion mutants. Finally, we investigated the relationship between CiLGP2 and CiANXA4. RT-PCR and Western blot results showed that CiLGP2 mRNA and protein expression levels were not affected by CiANXA4 overexpression. In contrast, overexpression of CiLGP2 resulted in significant reductions in CiANXA4 mRNA and protein levels. This suggests that the function of CiANXA4 is restricted by CiLGP2, and CiANXA4 is a downstream molecule of CiLGP2. These results reveal that CiANXA4 plays a critical role in the anti-GCRV innate immune response of grass carp, and provides new targets and strategies to develop antiviral drugs and improve disease resistance in grass carp.

The MAP4 kinase NbM4K3 regulates immune responses in Nicotiana benthamiana

The mitogen-activated protein kinase kinase kinase kinase (M4K) family is evolutionarily conserved across plants and animals. In Arabidopsis, the protein kinase SIK1, an M4K member, is known to positively modulate reactive oxygen species (ROS) production during pattern-triggered immunity (PTI) by stabilizing BIK1, a key receptor-like cytoplasmic kinase (RLCK). While homologs of SIK1 exhibit conserved protein domain architectures across a range of land plants, their functional conservation remains incompletely understood. This study investigates the functional conservation and divergence of SIK1 homologs, focusing particularly on NbM4K3 in Nicotiana benthamiana. Silencing NbM4K3 resulted in an impairment of the flg22-induced ROS burst and expression of PTI marker genes. Additionally, silencing NbM4K3 led to diminished protein accumulation of RLCKs, while overexpression of the RLCKs prominently enhanced the flg22-induced ROS burst in NbM4K3-silenced plants. Furthermore, NbM4K3-silenced plants exhibited a compromised hypersensitive response (HR), reduced ROS accumulation, and diminished expression of effector-triggered immunity (ETI) marker genes when challenged with the avirulent strains Ralstonia solanacearum GMI1000 and Pseudomonas syringae DC3000, suggesting that NbM4K3 is a positive regulator of ETI. The attenuated HR phenotype observed in NbM4K3-silenced plants upon expression of RipP1 or RipE1, two avirulent type III effectors of GMI1000, further supports the affirmative role of NbM4K3 in ETI. In summary, our data indicate that the M4K NbM4K3 positively regulates both PTI and ETI in N. benthamiana, potentially by stabilizing RLCKs. These findings not only strengthen the role of M4K family in plant immunity but also suggest its potential in improving disease resistance in plants.

Deciphering the role of rhizosphere microbiota in modulating disease resistance in cabbage varieties

BackgroundCabbage Fusarium wilt (CFW) is a devastating disease caused by the soil-borne fungus Fusarium oxysporum f. sp. conglutinans (Foc). One of the optimal measures for managing CFW is the employment of tolerant/resistant cabbage varieties. However, the interplay between plant genotypes and the pathogen Foc in shaping the rhizosphere microbial community, and the consequent influence of these microbial assemblages on biological resistance, remains inadequately understood.ResultsBased on amplicon metabarcoding data, we observed distinct differences in the fungal alpha diversity index (Shannon index) and beta diversity index (unweighted Bray–Curtis dissimilarity) within the rhizosphere of the YR (resistant to Foc) and ZG (susceptible to Foc) cabbage varieties, irrespective of Foc inoculation. Notably, the Shannon diversity shifts in the resistant YR variety were more pronounced following Foc inoculation. Disease-resistant plant variety demonstrate a higher propensity for harboring beneficial microorganisms, such as Pseudomonas, and exhibit superior capabilities in evading harmful microorganisms, in contrast to their disease-susceptible counterparts. Furthermore, the network analysis was performed on rhizosphere-associated microorganisms, including both bacteria and fungi. The networks of association recovered from YR exhibited greater complexity, robustness, and density, regardless of Foc inoculation. Following Foc infection in the YR rhizosphere, there was a notable increase in the dominant bacterium NA13, which is also a hub taxon in the microbial network. Reintroducing NA13 into the soil significantly improved disease resistance in the susceptible ZG variety, by directly inhibiting Foc and triggering defense mechanisms in the roots.ConclusionsThe rhizosphere microbial communities of these two cabbage varieties are markedly distinct, with the introduction of the pathogen eliciting significant alterations in their microbial networks which is correlated with susceptibility or resistance to soil-borne pathogens. Furthermore, we identified a rhizobacteria species that significantly boosts disease resistance in susceptible cabbages. Our results indicated that the induction of resistance genes leading to varied responses in microbial communities to pathogens may partly explain the differing susceptibilities of the cabbage varieties tested to CFW.-meKq2qaHpqpKck3NvZ8m1Video

Isolation, Identification, and Biocontrol Mechanisms of Endophytic Burkholderia arboris DHR18 from Rubber Tree against Red Root Rot Disease.

Red root rot disease is a devastating fungal disease of rubber trees caused by Ganoderma pseudoferreum (Wakef). Biocontrols using beneficial microorganisms are safe and sustainable. We isolated a DHR18 endophytic bacterium from a healthy rubber tree to obtain a new efficient antagonistic bacterium for red root rot disease affecting rubber trees and evaluated the mechanism of action involved using a double culture assay, genome annotation analysis, and the ethyl acetate extraction method. The results revealed that the DHR18 strain inhibits G. pseudoferreum growth and has broad-spectrum antifungal activity by secreting cell wall hydrolases (proteases and chitinases), indole-3-acetic acid, and siderophores. Furthermore, it fixes nitrogen and is involved in biofilm formation and phosphate solubilisation, improving disease resistance and tree growth. The results showed that the antifungal substances secreted by DHR18 are mainly lipopeptides. Simultaneously, DHR18 enhanced the rubber tree resistance to G. pseudoferreum by increasing the activities of defence enzymes superoxide dismutase, phenylalanine ammonia lyase, peroxidase, catalase, and polyphenol oxidase. The results indicate that B. arboris DHR18 has biocontrol potential and could be used as a candidate strain for the control of red root rot disease in rubber trees.

Identification of Nonsynonymous SNPs in Immune-Related Genes Associated with Pneumonia Severity in Pigs.

We previously showed that several polymorphisms in genes encoding pattern recognition receptors that cause amino acid substitutions alter pathogen recognition ability and disease susceptibility in pigs. In this study, we expanded our analysis to a wide range of immune-related genes and investigated polymorphism distribution and its influence on pneumonia in multiple commercial pig populations. Among the polymorphisms in 42 genes causing 634 amino acid substitutions extracted from the swine genome database, 80 in 24 genes were found to have a minor allele frequency of at least 10% in Japanese breeding stock pigs via targeted resequencing. Of these, 62 single nucleotide polymorphisms (SNPs) in 23 genes were successfully genotyped in 862 pigs belonging to four populations with data on pneumonia severity. Association analysis using a generalized linear mixed model revealed that 12 SNPs in nine genes were associated with pneumonia severity. In particular, SNPs in the cellular receptor for immunoglobulin G FCGR2B and the intracellular nucleic acid sensors IFI16 and LRRFIP1 were found to be associated with mycoplasmal pneumonia of swine or porcine pleuropneumonia in multiple populations and may therefore have wide applications in the improvement of disease resistance in pigs. Functional analyses at the cellular and animal levels are required to clarify the mechanisms underlying the effects of these SNPs on disease susceptibility.

The RING-finger ubiquitin E3 ligase TaPIR1 targets TaHRP1 for degradation to suppress chloroplast function

Chloroplasts are key players in photosynthesis and immunity against microbial pathogens. However, the precise and timely regulatory mechanisms governing the control of photosynthesis-associated nuclear genes (PhANGs) expression in plant immunity remain largely unknown. Here we report that TaPIR1, a Pst-induced RING-finger E3 ubiquitin ligase, negatively regulates Pst resistance by specifically interacting with TaHRP1, an atypical transcription factor histidine-rich protein. TaPIR1 ubiquitinates the lysine residues K131 and K136 in TaHRP1 to regulate its stability. TaHRP1 directly binds to the TaHRP1-binding site elements within the PhANGs promoter to activate their transcription via the histidine-rich domain of TaHRP1. PhANGs expression induces the production of chloroplast-derived ROS. Although knocking out TaHRP1 reduces Pst resistance, TaHRP1 overexpression contributes to photosynthesis, and chloroplast-derived ROS production, and improves disease resistance. TaPIR1 expression inhibits the downstream activation of TaHRP1 and TaHRP1-induced ROS accumulation in chloroplasts. Overall, we show that the TaPIR1-mediated ubiquitination and degradation of TaHRP1 alters PhANGs expression to disrupt chloroplast function, thereby increasing plant susceptibility to Pst.

Chitinase Gene FoChi20 in Fusarium oxysporum Reduces Its Pathogenicity and Improves Disease Resistance in Cotton.

Chitinase genes, as a class of cell wall hydrolases, are essential for the development and pathogenesis of Fusarium oxysporum f.sp. vasinfectum (F. ox) in cotton, but related research focused on chitinase genes are limited. This study explored two island cotton root secretions from the highly resistant cultivar Xinhai 41 and sensitive cultivar Xinhai 14 to investigate their interaction with F. ox by a weighted correlation network analysis (WGCNA). As a result, two modules that related to the fungal pathogenicity emerged. Additionally, a total of twenty-five chitinase genes were identified. Finally, host-induced gene silencing (HIGS) of FoChi20 was conducted, and the cotton plants showed noticeably milder disease with a significantly lower disease index than the control. This study illuminated that chitinase genes play crucial roles in the pathogenicity of cotton wilt fungi, and the FoChi20 gene could participate in the pathogenesis of F. ox and host-pathogen interactions, which establishes a theoretical framework for disease control in Sea Island cotton.

Dietary Psidium guajava, guava leaf extract protects Oreochromis niloticus, Nile tilapia from Pseudomonas aeruginosa infection and enhances growth

This study investigated the impact of dietary guava leaf extract (GLE) on immunity, resistance to Pseudomonas aeruginosa infection, and growth in Oreochromis niloticus (Nile tilapia). Four groups of fish (28.6 g.fish−1) were fed diets supplemented with ethanolic GLE at 0 (control), 3, 5, or 7 g.fish−1 diet (GLE0diet, GLE3diet, GLE5diet, GLE7diet) at 28 °C. Fish were fed thrice daily at 15 g.kg−0.8.d−1 for 42 days. Innate immune parameters, including mucus-bactericidal activity (MBA), serum-bactericidal activity (SBA), bacterial agglutination activity (BAA), and phagocytic activity (PA), were assessed on days 14, 28, and 42. Weight gain (WG), specific growth rate (SGR), and feed conversion ratio (FCR) were measured on day 42. Post-feeding, fish were injected with P. aeruginosa, and mortality was recorded for 30 days. Results showed that GLE7diet significantly increased MBA, SBA, BAA, and PA by 1.8-, 3.3-, 4.2-, and 3.5-fold, respectively, compared to control. GLE7diet also showed the highest significant reduction in post-challenge mortality (21 %) compared to the control group (83 %). Growth metrics for GLE7diet showed WG of 43.8 g, SGR of 2.21%.d−1, and FCR of 1.19, compared to WG of 37.1 g, SGR of 1.98%.d−1, and FCR of 1.41 in the control group. SGR showed an exponential increase (R² = 0.935) and FCR a decrease (R² = 0.958) with increasing GLE levels. GLE5diet and GLE7diet significantly increased MBA at all-time points compared to control. GLE7diet significantly increased SBA on days 14, 28, and 42 compared to control. GLE7diet significantly enhanced BAA at all-time points. GLE5diet and GLE7diet significantly increased PA at all time points compared to control. GLE7diet led to increased expression of IL-1, IL-6, IFN-α, IFN-β, and TNF-α genes, particularly from 10 to 30 days post-infection. Dietary GLE at 7 g.kg−1 significantly enhanced innate and acquired immune responses, growth performance, and resistance to P. aeruginosa in Nile tilapia. This study recommended incorporating 7 g.kg−1 GLE in Nile tilapia diets to improve disease resistance and growth performance.

Transcriptome analysis of resistant and susceptible Medicago truncatula genotypes in response to spring black stem and leaf spot disease

Ascochyta blights cause yield losses in all major legume crops. Spring black stem (SBS) and leaf spot disease is a major foliar disease of Medicago truncatula and Medicago sativa (alfalfa) caused by the necrotrophic fungus Ascochyta medicaginicola. This present study sought to identify candidate genes for SBS disease resistance for future functional validation. We employed RNA-seq to profile the transcriptomes of a resistant (HM078) and susceptible (A17) genotype of M. truncatula at 24, 48, and 72 h post inoculation. Preliminary microscopic examination showed reduced pathogen growth on the resistant genotype. In total, 192 and 2,908 differentially expressed genes (DEGs) were observed in the resistant and susceptible genotype, respectively. Functional enrichment analysis revealed the susceptible genotype engaged in processes in the cell periphery and plasma membrane, as well as flavonoid biosynthesis whereas the resistant genotype utilized calcium ion binding, cell wall modifications, and external encapsulating structures. Candidate genes for disease resistance were selected based on the following criteria; among the top ten upregulated or downregulated genes in the resistant genotype, upregulated over time in the resistant genotype, hormone pathway genes, plant disease resistance genes, receptor-like kinases, contrasting expression profiles in QTL for disease resistance, and upregulated genes in enriched pathways. Overall, 22 candidate genes for SBS disease resistance were identified with support from the literature. These genes will be sources for future targeted mutagenesis and candidate gene validation potentially helping to improve disease resistance to this devastating foliar pathogen.

Diversity and potential functional role of phyllosphere-associated actinomycetota isolated from cupuassu (Theobroma grandiflorum) leaves: implications for ecosystem dynamics and plant defense strategies.

Exploring the intricate relationships between plants and their resident microorganisms is crucial not only for developing new methods to improve disease resistance and crop yields but also for understanding their co-evolutionary dynamics. Our research delves into the role of the phyllosphere-associated microbiome, especially Actinomycetota species, in enhancing pathogen resistance in Theobroma grandiflorum, or cupuassu, an agriculturally valuable Amazonian fruit tree vulnerable to witches' broom disease caused by Moniliophthora perniciosa. While breeding resistant cupuassu genotypes is a possible solution, the capacity of the Actinomycetota phylum to produce beneficial metabolites offers an alternative approach yet to be explored in this context. Utilizing advanced long-read sequencing and metagenomic analysis, we examined Actinomycetota from the phyllosphere of a disease-resistant cupuassu genotype, identifying 11 Metagenome-Assembled Genomes across eight genera. Our comparative genomic analysis uncovered 54 Biosynthetic Gene Clusters related to antitumor, antimicrobial, and plant growth-promoting activities, alongside cutinases and type VII secretion system-associated genes. These results indicate the potential of phyllosphere-associated Actinomycetota in cupuassu for inducing resistance or antagonism against pathogens. By integrating our genomic discoveries with the existing knowledge of cupuassu's defense mechanisms, we developed a model hypothesizing the synergistic or antagonistic interactions between plant and identified Actinomycetota during plant-pathogen interactions. This model offers a framework for understanding the intricate dynamics of microbial influence on plant health. In conclusion, this study underscores the significance of the phyllosphere microbiome, particularly Actinomycetota, in the broader context of harnessing microbial interactions for plant health. These findings offer valuable insights for enhancing agricultural productivity and sustainability.