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Fulltext Effects of nano-selenium and/or vitamin E supplementation on growth performance, antioxidant status, histopathology and resistance to Aspergillus flavus in Nile tilapia (Oreochromis niloticus)

Bazina WK, Tawfik WA, Abd Elghany NA, Saadony S, Abdul Kari Z, Alamoudi MO, et al.

BMC Vet Res, 2025 Feb 05;21(1):50.
PMID: 39910528 DOI: 10.1186/s12917-025-04471-y

BACKGROUND: This study aimed to evaluate the effects of selenium nanoparticles (SeNPs) and/or vitamin E (VE) on the growth, body composition, metabolic parameters, histopathology, and resistance of Nile tilapia to Aspergillus flavus.
RESULTS: Monosex Nile tilapia fingerlings were sourced from the Bazina farm and hatchery in Ismailia Governorate, Egypt, where the experiment was also conducted. The fish were acclimatized for 15 days before the trial. A total of 240 fingerlings (average weight 46 ± 3.0 g/fish) were divided equally across 12 concrete tanks (1 × 1 × 1.2 m, 1 m³ capacity), with 20 fish per tank. The fish were fed a control diet (T0), which was a basal diet with no supplementation, or one of three experimental diets for 60 days: T1 (1 mg SeNPs/kg), T2 (100 mg VE/kg), and T3 (1 mg SeNPs + 100 mg VE/kg). The experiment followed a completely randomized design (CRD) with three replicates per treatment. The combination of SeNPs and VE (T3) resulted in the best feed conversion ratio. A slight but significant increase (P

Matched MeSH terms: Disease Resistance/drug effects
Fulltext Evaluation of disease resistance and tolerance to elevated temperature stress of the selected tissue-cultured Kappaphycus alvarezii Doty 1985 under optimized laboratory conditions

Azizi A, Mohd Hanafi N, Basiran MN, Teo CH

3 Biotech, 2018 Aug;8(8):321.
PMID: 30034985 DOI: 10.1007/s13205-018-1354-4

Information on the abiotic stress tolerance and ice-ice disease resistance properties of tissue-cultured Kappaphycus alvarezii is scarce and can pose a big hurdle to a wider use of tissue-cultured seaweed in the industry. Here, we reported on a study of seaweed-associated bacteria diversity in farmed and tissue-cultured K. alvarezii, and ice-ice disease resistance and elevated growth temperature tolerance of tissue-cultured K. alvarezii in laboratory conditions. A total of 40 endophytic seaweed-associated bacteria strains were isolated from 4 types of K. alvarezii samples based on their colony morphologies, Gram staining properties and 16S rRNA gene sequences. Bacteria strains isolated were found to belong to Alteromonas sp., Aestuariibacter sp., Idiomarina sp., Jejuia sp., Halomonas sp., Primorskyibacter sp., Pseudoalteromonas sp., Ruegeria sp., Terasakiella sp., Thalassospira sp. and Vibrio sp. Vibrio alginolyticus strain ABI-TU15 isolated in this study showed agar-degrading property when analyzed using agar depression assay. Disease resistance assay was performed by infecting healthy K. alvarezii with 105 cells/mL Vibrio sp. ABI-TU15. Severe ice-ice disease symptoms were detected in farmed seaweeds compared to the tissue-cultured K. alvarezii. Besides disease resistance, tissue-cultured K. alvarezii showed better tolerance to the elevated growth temperatures of 30 and 35 °C. In conclusion, our overall data suggests that tissue-cultured K. alvarezii exhibited better growth performance than farmed seaweeds when exposed to elevated growth temperature and ice-ice disease-causing agent.

Matched MeSH terms: Disease Resistance
Fulltext 27 years of benthic and coral community dynamics on turbid, highly urbanised reefs off Singapore

Guest JR, Tun K, Low J, Vergés A, Marzinelli EM, Campbell AH, et al.

Sci Rep, 2016 11 08;6:36260.
PMID: 27824083 DOI: 10.1038/srep36260

Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3-4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6-7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates.

Matched MeSH terms: Disease Resistance
Fulltext Plant disease control: understanding the roles of toxins and phytoalexins in host-pathogen interaction

Magaji G. Usman, Tijjani Ahmadu, Adamu Jibrin Nayaya, Aisha M. Dodo

The Pertanika Journal of Scholarly Research Reviews, 2018;4(1):54-66.
MyJurnal

Naturally, plant habitats are exposed to several potential effects of biotic and different abiotic environmental challenges. Several types of micro-organisms namely; bacteria, viruses, fungi, nematodes, mites, insects, mammals and other herbivorous animals are found in large amounts in all ecosystems, which lead to considerable reduction in crop productivity. These organisms are agents carrying different diseases that can damage the plants through the secretion of toxic-microbial poisons that can penetrate in the plant tissues. Toxins are injurious substances that act on plant protoplast to influence disease development. In response to the stress effect, plants defend themselves by bearing some substances such as phytoalexins. Production of phytoalexins is one of the complex mechanisms through which plants exhibit disease resistance. Several findings specifically on phytoalexins have widen the understanding in the fields of plant biochemistry and molecular biology. However, this review reports the interaction of toxins and phytoalexins in plant-pathogen cycle, research progress on the association of phytoalexins with plant disease resistance as well as the role of the phytoalexins in plant disease control.

Matched MeSH terms: Disease Resistance
Proteomic analysis of stored core oil palm trunk (COPT) sap identifying proteins Related to stress, disease resistance and differential gene/protein expression

Marhaini Mostapha, Noorhasmiera Abu Jahar, Sarani Zakaria, Sharifah Nabihah Syed Jaafar, Kamalrul Azlan Azizan, Wan Mohd Aizat

Sains Malaysiana, 2018;47:1259-1268.

Oil palm is the major crop grown and cultivated in various Asian countries such as Malaysia, Indonesia and Thailand.
The core of oil palm trunk (COPT) consists of high sugar content, hence suitable for synthesis of fine chemicals and
biofuels. Increase of sugar content was reported previously during prolonged COPT storage. However, until now, there
has been no report on protein profiles during storage. Therefore, in this study, protein expression of the COPT during the
storage period of one to six weeks was investigated using sodium dodecyl sulphate polyacrylamide gel electrophoresis
(SDS-PAGE) coupled with optical density quantification and multivariate analyses for measuring differentially expressed
proteins. Accordingly, protein bands were subjected to tryptic digestion followed by tandem mass spectrometry (nanoLCMS/MS)
protein identification. The results from SDS-PAGE showed consistent protein bands appearing across the biological
replicates ranging from 10.455 to 202.92 kDa molecular weight (MW) regions. The findings from the principal component
analysis (PCA) plot illustrated the separation pattern of the proteins at weeks 4 and 5 of storage, which was influenced
mainly by the molecular weights of 14.283, 25.543, 29.757, 30.549, 31.511, 34.585 and 84.395 kDa, respectively. The
majority of these proteins are identified as those involved in stress- and defense-related, disease resistance, as well
as gene/protein expression processes. Indeed, these proteins were mostly upregulated during the later storage period
suggesting that long-term storage may influence the molecular regulation of COPT sap.

Matched MeSH terms: Disease Resistance
Single-nucleotide polymorphism markers within MVA and MEP pathways among Hevea brasiliensis clones through transcriptomic analysis

Abdul Rahman SN, Bakar MFA, Singham GV, Othman AS

3 Biotech, 2019 Nov;9(11):388.
PMID: 31656726 DOI: 10.1007/s13205-019-1921-3

In this study, RNA sequencing of several Hevea brasiliensis clones grown in Malaysia with different annual rubber production yields and disease resistance was performed on the Illumina platform. A total of 29,862,548 reads were generated, resulting in 101,269 assembled transcripts that were used as the reference transcripts. A similarity search against the non-redundant (nr) protein databases presented 83,771 (83%) positive BLASTx hits. The transcriptome was annotated using gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Pfam database. A search for putative molecular markers was performed to identify single-nucleotide polymorphisms (SNPs). Overall, 3,210,629 SNPs were detected and a total of 1314 SNPs associated with the genes involved in MVA and MEP pathways were identified. A total of 176 SNP primer pairs were designed from sequences that were related to the MVA and MEP pathways. The transcriptome of RRIM 3001 and RRIM 712 were subjected to pairwise comparison and the results revealed that there were 1262 significantly differentially expressed genes unique to RRIM 3001, 1499 significantly differentially expressed genes unique to RRIM 712 and several genes related to the MVA and MEP pathways such as AACT, HMGS, PMK, MVD, DXS and HDS were included. The results will facilitate the characterization of H. brasiliensis transcriptomes and the development of a new set of molecular markers in the form of SNPs from transcriptome assembly for the genotype identification of various rubber varieties with superior traits in Malaysia.

Matched MeSH terms: Disease Resistance
Fulltext A new insight to biomarkers related to resistance in survived-white spot syndrome virus challenged giant tiger shrimp, Penaeus monodon

Mohd Ghani F, Bhassu S

PeerJ, 2019;7:e8107.
PMID: 31875142 DOI: 10.7717/peerj.8107

The emergence of diseases such as white spot disease has become a threat to Penaeus monodon cultivation. Although there have been a few studies utilizing RNA-Seq, the cellular processes of host-virus interaction in this species remain mostly anonymous. In the present study, P. monodon was challenged with WSSV by intramuscular injection and survived for 12 days. The effect of the host gene expression by WSSV infection in the haemocytes, hepatopancreas and muscle of P. monodon was studied using Illumina HiSeq 2000. The RNA-Seq of cDNA libraries was developed from surviving WSSV-challenged shrimp as well as from normal healthy shrimp as control. A comparison of the transcriptome data of the two groups showed 2,644 host genes to be significantly up-regulated and 2,194 genes significantly down-regulated as a result of the infection with WSSV. Among the differentially expressed genes, our study discovered HMGB, TNFSF and c-Jun in P. monodon as new potential candidate genes for further investigation for the development of potential disease resistance markers. Our study also provided significant data on the differential expression of genes in the survived WSSV infected P. monodon that will help to improve understanding of host-virus interactions in this species.

Matched MeSH terms: Disease Resistance
Fulltext A Meta-Analysis of Quantitative Trait Loci Associated with Multiple Disease Resistance in Rice (Oryza sativa L.)

Kumar IS, Nadarajah K

Plants (Basel), 2020 Nov 05;9(11).
PMID: 33167299 DOI: 10.3390/plants9111491

Rice blast, sheath blight and bacterial leaf blight are major rice diseases found worldwide. The development of resistant cultivars is generally perceived as the most effective way to combat these diseases. Plant disease resistance is a polygenic trait where a combinatorial effect of major and minor genes affects this trait. To locate the source of this trait, various quantitative trait loci (QTL) mapping studies have been performed in the past two decades. However, investigating the congruency between the reported QTL is a daunting task due to the heterogeneity amongst the QTLs studied. Hence, the aim of our study is to integrate the reported QTLs for resistance against rice blast, sheath blight and bacterial leaf blight and objectively analyze and consolidate the location of QTL clusters in the chromosomes, reducing the QTL intervals and thus identifying candidate genes within the selected meta-QTL. A total of twenty-seven studies for resistance QTLs to rice blast (8), sheath blight (15) and bacterial leaf blight (4) was compiled for QTL projection and analyses. Cumulatively, 333 QTLs associated with rice blast (114), sheath blight (151) and bacterial leaf blight (68) resistance were compiled, where 303 QTLs could be projected onto a consensus map saturated with 7633 loci. Meta-QTL analysis on 294 QTLs yielded 48 meta-QTLs, where QTLs with membership probability lower than 60% were excluded, reducing the number of QTLs within the meta-QTL to 274. Further, three meta-QTL regions (MQTL2.5, MQTL8.1 and MQTL9.1) were selected for functional analysis on the basis that MQTL2.5 harbors the highest number of QTLs; meanwhile, MQTL8.1 and MQTL9.1 have QTLs associated with all three diseases mentioned above. The functional analysis allows for determination of enriched gene ontology and resistance gene analogs (RGAs) and other defense-related genes. To summarize, MQTL2.5, MQTL8.1 and MQTL9.1 have a considerable number of R-genes that account for 10.21%, 4.08% and 6.42% of the total genes found in these meta-QTLs, respectively. Defense genes constitute around 3.70%, 8.16% and 6.42% of the total number of genes in MQTL2.5, MQTL8.1 and MQTL9.1, respectively. This frequency is higher than the total frequency of defense genes in the rice genome, which is 0.0096% (167 defense genes/17,272 total genes). The integration of the QTLs facilitates the identification of QTL hotspots for rice blast, sheath blight and bacterial blight resistance with reduced intervals, which helps to reduce linkage drag in breeding. The candidate genes within the promising regions could be utilized for improvement through genetical engineering.

Matched MeSH terms: Disease Resistance
Fulltext Enhancement of Live Food Nutritional Status with Essential Nutrients for Improving Aquatic Animal Health: A Review

Samat NA, Yusoff FM, Rasdi NW, Karim M

Animals (Basel), 2020 Dec 21;10(12).
PMID: 33371528 DOI: 10.3390/ani10122457

At the present time, no artificial larval diet is capable of entirely fulfilling the dietary requirements of several larval fish and crustacean species. Zooplankton live food is the basic foundation of fish larviculture, and successful rearing of fish larvae still heavily depends on an adequate supply of nutritious live food. Despite being important, the production protocols of copepods and cladocerans (Moina) are still underdeveloped in hatcheries. Rotifers and Artemia are the most commonly used live foods. However, these live foods are evidently lacking in crucial nutrient constituents. Hence, through nutrient enrichment, live food with the nutritional profile that meets the requirements of fish larvae can be produced. With the aim to maximize the effectiveness of production to optimize profitability, it is important to evaluate and improve culture techniques for the delivery of micro- and macro-nutrients as feed supplements to larvae in aquaculture systems. Bioencapsulation and enrichment are the evolving techniques in aquaculture that are commonly employed to enhance the nutritional quality of live food by integrating nutrients into them, which subsequently improves the growth, survival, and disease resistance of the consuming hosts. This review aims to highlight some of the approaches and methods used to improve the nutritional quality of live food by modifying their nutrient composition, which could have immense promise in the enhancement of aquatic animal health.

Matched MeSH terms: Disease Resistance
Potentials of Aloe barbadensis inclusion in fish feeds on resilience to Aeromonas hydrophila infection in freshwater fish Labeo rohita

Palaniyappan S, Sridhar A, Kari ZA, Téllez-Isaías G, Ramasamy T

Fish Physiol Biochem, 2023 Dec;49(6):1435-1459.
PMID: 37996691 DOI: 10.1007/s10695-023-01266-6

Aquatic bacterial pathogens can cause severe economic loss in aquaculture industry. An opportunistic pathogen, Aeromonas hydrophila is responsible for Motile Aeromonas Septicemia, leading to high mortality rates in fish. The present study was focused on the efficacy of Aloe barbadensis replacing fishmeal diets on hematological, serum biochemical, antioxidant, histopathological parameters, and disease resistance against A. hydrophila infection in Labeo rohita. Isonitrogenous fishmeal replaced diets (FMR) were prepared with varying levels of A. barbadensis at D1 (0%) (control), D2 (25%), D3 (50%), D4 (75%) and D5 (100%) then fed to L. rohita. After 60 days of post-feeding, the experimental fish were challenged with A. hydrophila. Blood and organs were collected and examined at 1- and 15-days post infection (dpi). The results demonstrated that on 1 dpi, white blood cells (WBC), total protein, cholesterol and low-density lipoprotein (LDL) levels were significantly increased in D3 diet fed groups. The D2 and D3 diet fed group showed decreasing trends of serum glutamic pyruvic transaminase (SGPT) and antioxidant enzymes activity on 15 dpi. The histopathological architecture results clearly illustrated that the D3 diet fed group had given a higher protective effect by reducing the pathological changes associated with A. hydrophila infection in liver, intestine and muscle. Higher percentage of survival rate was also observed in D3 diet fed group. Therefore, the present study suggested that the dietary administration of A. barbadensis up to 50% fishmeal replacement (D3 diet) can elicit earlier antioxidant activity, innate immune response and improve survival rate in L. rohita against A. hydrophila infection.

Matched MeSH terms: Disease Resistance
Proteomic insights into fruit-pathogen interactions: managing biotic stress in fruit

Putra AI, Khan MN, Kamaruddin N, Khairuddin RFR, Al-Obaidi JR, Flores BJ, et al.

Plant Cell Rep, 2025 Feb 13;44(3):54.
PMID: 39945834 DOI: 10.1007/s00299-025-03443-8

Proteomics has revealed complex immune responses in fruits, leading to the identification of potential disease biomarkers and resistance mechanisms. Fruit diseases caused by fungal and bacterial pathogens present critical challenges to global food security by reducing fruit shelf life and quality. This review explores the molecular dynamics of fruit-pathogen interactions using advanced proteomic techniques. These approaches include mass spectrometry-based identification, gel-based, and gel-free strategies, tailored to the unique compositions of fruit tissues for accurate protein extraction and identification. Proteomic studies reveal pathogen-induced changes in fruit proteomes, including the upregulation of defence-related proteins and suppression of metabolic pathways crucial for pathogen survival. Case studies on tomatoes, apples, and bananas highlight specific pathogen-responsive proteins, such as PR proteins and enzymes involved in ROS scavenging, which play roles in disease resistance mechanisms. The review further demonstrates the utility of proteomic data in identifying early disease biomarkers, guiding genetic improvements for disease resistance, and optimizing pathogen control measures. Integrating proteomic insights with transcriptomics and metabolomics provides a multidimensional understanding of fruit-pathogen interactions, paving the way for innovative solutions in agriculture. Future research should prioritize multi-omics approaches and field-level validations to translate laboratory findings into practical applications. The advancements discussed underscore the transformative role of proteomics in improving food security and sustainability amid challenges posed by climate change and increasing global food demand.

Matched MeSH terms: Disease Resistance
Dietary Euphorbia hirta Extract Improved the Resistance of Sharptooth Catfish Clarias gariepinus to Aeromonas hydrophila

Sheikhlar A, Meng GY, Alimon R, Romano N, Ebrahimi M

J Aquat Anim Health, 2017 Dec;29(4):225-235.
PMID: 28937913 DOI: 10.1080/08997659.2017.1374310

Aqueous and methanol extracts of lemon Citrus limon peel, Euphorbia hirta (aerial parts), and fenugreek Trigonella foenum-graecum seeds were tested for their in vitro antimicrobial activities against the bacterium Aeromonas hydrophila. A swab paper disk method showed that the methanol extract of E. hirta (EHE) had the largest inhibition zone and the lowest minimal inhibitory concentration compared to all other herbal extracts. Based on these results, EHE was included in the diets of Sharptooth Catfish Clarias gariepinus at 0 (control), 2, 5, or 7 g/kg of diet (experiment 1). Each treatment was conducted in triplicate, with 30 fish (mean weight ± SE = 9.4 ± 0.4 g) in each replicate. After 30 d, the growth, feed intake, hepatosomatic index (HSI), and plasma biochemical parameters were measured. With a separate batch of Sharptooth Catfish, the efficacy of the EHE diets in conferring fish resistance to A. hydrophila over 30 d was compared to that of a diet containing oxytetracycline (OTC; experiment 2). Six treatments were conducted in triplicate groups of 30 fish (mean weight ± SE = 9.0 ± 0.3 g); the Control fish were fed the control diet and were not injected with A. hydrophila, while the Control-AH and OTC-AH groups were infected with A. hydrophila and were fed either the control diet or the diet containing OTC at 1 g/199 g. The other three treatments included fish that were injected with A. hydrophila but fed diets with increasing EHE at 2, 5, or 7 g/kg. Experiment 1 showed no change to growth, feeding efficiency, HSI, or plasma biochemical parameters. In experiment 2, however, fish that were fed dietary EHE at 5 g/kg had significantly lower mortality than the Control-AH group, with further resistance observed for fish fed EHE at 7 g/kg. Dietary OTC was more effective than EHE as a prophylactic to A. hydrophila infection in Sharptooth Catfish. Nevertheless, EHE can potentially be a valuable dietary supplement to improve the resistance of Sharptooth Catfish to A. hydrophila infection. Received May 3, 2017; accepted August 24, 2017.

Matched MeSH terms: Disease Resistance*
Fulltext The Use of Genetic and Gene Technologies in Shaping Modern Rapeseed Cultivars (Brassica napus L.)

Ton LB, Neik TX, Batley J

Genes (Basel), 2020 09 30;11(10).
PMID: 33008008 DOI: 10.3390/genes11101161

Since their domestication, Brassica oilseed species have undergone progressive transformation allied with the development of breeding and molecular technologies. The canola (Brassica napus) crop has rapidly expanded globally in the last 30 years with intensive innovations in canola varieties, providing for a wider range of markets apart from the food industry. The breeding efforts of B. napus, the main source of canola oil and canola meal, have been mainly focused on improving seed yield, oil quality, and meal quality along with disease resistance, abiotic stress tolerance, and herbicide resistance. The revolution in genetics and gene technologies, including genetic mapping, molecular markers, genomic tools, and gene technology, especially gene editing tools, has allowed an understanding of the complex genetic makeup and gene functions in the major bioprocesses of the Brassicales, especially Brassica oil crops. Here, we provide an overview on the contributions of these technologies in improving the major traits of B. napus and discuss their potential use to accomplish new improvement targets.

Matched MeSH terms: Disease Resistance/genetics
Fulltext The effects of polymorphisms in 7 candidate genes on resistance to Salmonella Enteritidis in native chickens

Tohidi R, Idris IB, Malar Panandam J, Hair Bejo M

Poult Sci, 2013 Apr;92(4):900-9.
PMID: 23472012 DOI: 10.3382/ps.2012-02797

Salmonella enterica serovar Enteritidis infection is a common concern in poultry production for its negative effects on growth as well as food safety for humans. Identification of molecular markers that are linked to resistance to Salmonella Enteritidis may lead to appropriate solutions to control Salmonella infection in chickens. This study investigated the association of candidate genes with resistance to Salmonella Enteritidis in young chickens. Two native breeds of Malaysian chickens, namely, Village Chickens and Red Junglefowl, were evaluated for bacterial colonization after Salmonella Enteritidis inoculation. Seven candidate genes were selected on the basis of their physiological role in immune response, as determined by prior studies in other genetic lines: natural resistance-associated protein 1 (NRAMP1), transforming growth factor β3 (TGFβ3), transforming growth factor β4 (TGFβ4), inhibitor of apoptosis protein 1 (IAP1), caspase 1 (CASP1), lipopolysaccharide-induced tumor necrosis factor (TNF) α factor (LITAF), and TNF-related apoptosis-inducing ligand (TRAIL). Polymerase chain reaction-RFLP was used to identify polymorphisms in the candidate genes; all genes exhibited polymorphisms in at least one breed. The NRAMP1-SacI polymorphism correlated with the differences in Salmonella Enteritidis load in the cecum (P = 0.002) and spleen (P = 0.01) of Village Chickens. Polymorphisms in the restriction sites of TGFβ3-BsrI, TGFβ4-MboII, and TRAIL-StyI were associated with Salmonella Enteritidis burden in the cecum, spleen, and liver of Village Chickens and Red Junglefowl (P < 0.05). These results indicate that the NRAMP1, TGFβ3, TGFβ4, and TRAIL genes are potential candidates for use in selection programs for increasing genetic resistance against Salmonella Enteritidis in native Malaysian chickens.

Matched MeSH terms: Disease Resistance*
Fulltext Identification of quantitative trait loci for blast resistance in BC₂F₃ and BC₂F5 advanced backcross families of rice

Rahim HA, Bhuiyan MA, Lim LS, Sabu KK, Saad A, Azhar M, et al.

Genet. Mol. Res., 2012;11(3):3277-89.
PMID: 23079822 DOI: 10.4238/2012.September.12.11

Advanced backcross families derived from Oryza sativa cv MR219/O. rufipogon IRGC105491 were utilized for identification of quantitative trait loci (QTL) for blast resistance using simple sequence repeat markers. Two hundred and sixty-one BC(2)F(3) families were used to construct a linkage map, using 87 markers, which covered 2375.2 cM of 12 rice chromosomes, with a mean density of 27.3 cM. The families were evaluated in a greenhouse for resistance to blast disease caused by pathotypes P7.2 and P5.0 of Magnaporthe oryzae. Five QTLs (qBL5.1, qBL5.2, qBL6.1, qBL8.1, and qBL10.1) for pathotype P5.0 and four QTLs (qBL5.3, qBL5.4, qBL7.1, and qBL8.2) for pathotype P7.2 were identified using the BC(2)F(3) families. Another linkage map was also constructed based on 31 BC(2)F(5) families, using 63 SSR markers, which covered 474.9 cM of 9 rice chromosomes, with a mean density of 8.01 cM. Five suggestive QTLs (qBL11.2, qBL11.3, qBL12.1, qBL12.2, qBL12.3) and one putative QTL (qBL2.1) were identified for pathotype P7.2. Also, seven suggestive QTLs (qBL1.1, qBL2.2, qBL4.1, qBL4.2, qBL5.3, qBL8.3, and qBL11.1) were detected for pathotype P5.0. We conclude that there is a non-race-specific resistance spectrum of O. rufipogon against M. oryzae pathotypes.

Matched MeSH terms: Disease Resistance/genetics*
Fulltext Analyses of hypomethylated oil palm gene space

Low ET, Rosli R, Jayanthi N, Mohd-Amin AH, Azizi N, Chan KL, et al.

PLoS One, 2014;9(1):e86728.
PMID: 24497974 DOI: 10.1371/journal.pone.0086728

Demand for palm oil has been increasing by an average of ∼8% the past decade and currently accounts for about 59% of the world's vegetable oil market. This drives the need to increase palm oil production. Nevertheless, due to the increasing need for sustainable production, it is imperative to increase productivity rather than the area cultivated. Studies on the oil palm genome are essential to help identify genes or markers that are associated with important processes or traits, such as flowering, yield and disease resistance. To achieve this, 294,115 and 150,744 sequences from the hypomethylated or gene-rich regions of Elaeis guineensis and E. oleifera genome were sequenced and assembled into contigs. An additional 16,427 shot-gun sequences and 176 bacterial artificial chromosomes (BAC) were also generated to check the quality of libraries constructed. Comparison of these sequences revealed that although the methylation-filtered libraries were sequenced at low coverage, they still tagged at least 66% of the RefSeq supported genes in the BAC and had a filtration power of at least 2.0. A total 33,752 microsatellites and 40,820 high-quality single nucleotide polymorphism (SNP) markers were identified. These represent the most comprehensive collection of microsatellites and SNPs to date and would be an important resource for genetic mapping and association studies. The gene models predicted from the assembled contigs were mined for genes of interest, and 242, 65 and 14 oil palm transcription factors, resistance genes and miRNAs were identified respectively. Examples of the transcriptional factors tagged include those associated with floral development and tissue culture, such as homeodomain proteins, MADS, Squamosa and Apetala2. The E. guineensis and E. oleifera hypomethylated sequences provide an important resource to understand the molecular mechanisms associated with important agronomic traits in oil palm.

Matched MeSH terms: Disease Resistance/genetics
Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture

Steuernagel B, Periyannan SK, Hernández-Pinzón I, Witek K, Rouse MN, Yu G, et al.

Nat Biotechnol, 2016 Jun;34(6):652-5.
PMID: 27111722 DOI: 10.1038/nbt.3543

Wild relatives of domesticated crop species harbor multiple, diverse, disease resistance (R) genes that could be used to engineer sustainable disease control. However, breeding R genes into crop lines often requires long breeding timelines of 5-15 years to break linkage between R genes and deleterious alleles (linkage drag). Further, when R genes are bred one at a time into crop lines, the protection that they confer is often overcome within a few seasons by pathogen evolution. If several cloned R genes were available, it would be possible to pyramid R genes in a crop, which might provide more durable resistance. We describe a three-step method (MutRenSeq)-that combines chemical mutagenesis with exome capture and sequencing for rapid R gene cloning. We applied MutRenSeq to clone stem rust resistance genes Sr22 and Sr45 from hexaploid bread wheat. MutRenSeq can be applied to other commercially relevant crops and their relatives, including, for example, pea, bean, barley, oat, rye, rice and maize.

Matched MeSH terms: Disease Resistance/genetics*
Fulltext Haplotype divergence and multiple candidate genes at Rphq2, a partial resistance QTL of barley to Puccinia hordei

Yeo FK, Wang Y, Vozabova T, Huneau C, Leroy P, Chalhoub B, et al.

Theor Appl Genet, 2016 Feb;129(2):289-304.
PMID: 26542283 DOI: 10.1007/s00122-015-2627-5

Rphq2, a minor gene for partial resistance to Puccinia hordei , was physically mapped in a 188 kbp introgression with suppressed recombination between haplotypes of rphq2 and Rphq2 barley cultivars.

Matched MeSH terms: Disease Resistance/genetics*
Quercetin and taxifolin enhance immunity in Chinese sucker (Myxocyprinus asiaticus) and increase its resistance to Aeromonas hydrophila

Han M, Zhu X, Li D, Si Q, Zhu T, Zhou Z, et al.

Comp Biochem Physiol Part D Genomics Proteomics, 2025 Jun;54:101369.
PMID: 39644864 DOI: 10.1016/j.cbd.2024.101369

This study investigated the effects of short-term exposure to flavonoids, specifically quercetin and taxifolin, on the transcriptomic responses of Chinese sucker (Myxocyprinus asiaticus) to validate their influence on gene expression related to immunity, antioxidant activity, and metabolism. Using transcriptomic data, we also analyzed their influence on relevant immune genes and examined the Chinese suckers' resistance to A. hydrophila. Oxidative stress, immune defense, and glucose metabolism of Chinese suckers were tested to assess potential enhancements. Significant alterations were observed in multiple immune-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in the liver of Chinese suckers, notably the complement and coagulation cascades, degradation of aromatic compounds, and xenobiotic metabolism by cytochrome P450. The key immune markers such as UGT, MPO, C3, and C4 were highlighted in these pathways, underlining their importance in fish immunity. Additionally, oxidative stress related KEGG pathways were notably influenced after exposure to quercetin and taxifolin, displaying markers such as CYP3A, superoxide dismutase, GST, malondialdehyde, and catalase. Quercetin particularly affected the enzymatic activity of glucose oxidase, hexokinase, phosphofructokinase, and ATPase, which are enzymes related to stress responses in fish. Antimicrobial tests revealed that both flavonoids enhanced Chinese suckers' defense against A. hydrophila by bolstering oxidative stress resistance and immunity. These results provided valuable insights for using flavonoids to enhance fish immunity.

Matched MeSH terms: Disease Resistance/drug effects
Identification of the amino acids in the Major Histocompatibility Complex class II region of Scottish Blackface sheep that are associated with resistance to nematode infection

Stear A, Ali AOA, Brujeni GN, Buitkamp J, Donskow-Łysoniewska K, Fairlie-Clarke K, et al.

Int J Parasitol, 2019 09;49(10):797-804.
PMID: 31306661 DOI: 10.1016/j.ijpara.2019.05.003

Lambs with the Major Histocompatibility Complex DRB1*1101 allele have been shown to produce fewer nematode eggs following natural and deliberate infection. These sheep also possess fewer adult Teladorsagia circumcincta than sheep with alternative alleles at the DRB1 locus. However, it is unclear if this allele is responsible for the reduced egg counts or merely acts as a marker for a linked gene. This study defined the MHC haplotypes in a population of naturally infected Scottish Blackface sheep by PCR amplification and sequencing, and examined the associations between MHC haplotypes and faecal egg counts by generalised linear mixed modelling. The DRB1*1101 allele occurred predominately on one haplotype and a comparison of haplotypes indicated that the causal mutation or mutations occurred in or around this locus. Additional comparisons with another resistant haplotype indicated that mutations in or around the DQB2*GU191460 allele were also responsible for resistance to nematode infections. Further analyses identified six amino acid substitutions in the antigen binding site of DRB1*1101 that were significantly associated with reductions in the numbers of adult T. circumcincta.

Matched MeSH terms: Disease Resistance/genetics; Disease Resistance/immunology

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