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BACKGROUND: Phytophthora root rot, a major constraint in chile pepper production worldwide, is caused by the soil-borne oomycete, Phytophthora capsici. This study aimed to detect significant regions in the Capsicum genome linked to Phytophthora root rot resistance using a panel consisting of 157 Capsicum spp. genotypes. Multi-locus genome wide association study (GWAS) was conducted using single nucleotide polymorphism (SNP) markers derived from genotyping-by-sequencing (GBS). Individual plants were separately inoculated with P. capsici isolates, 'PWB-185', 'PWB-186', and '6347', at the 4-8 leaf stage and were scored for disease symptoms up to 14-days post-inoculation. Disease scores were used to calculate disease parameters including disease severity index percentage, percent of resistant plants, area under disease progress curve, and estimated marginal means for each genotype. RESULTS: Most of the genotypes displayed root rot symptoms, whereas five accessions were completely resistant to all the isolates and displayed no symptoms of infection. A total of 55,117 SNP markers derived from GBS were used to perform multi-locus GWAS which identified 330 significant SNP markers associated with disease resistance. Of these, 56 SNP markers distributed across all the 12 chromosomes were common across the isolates, indicating association with more durable resistance. Candidate genes including nucleotide-binding site leucine-rich repeat (NBS-LRR), systemic acquired resistance (SAR8.2), and receptor-like kinase (RLKs), were identified within 0.5 Mb of the associated markers. CONCLUSIONS: Results will be used to improve resistance to Phytophthora root rot in chile pepper by the development of Kompetitive allele-specific markers (KASP®) for marker validation, genomewide selection, and marker-assisted breeding.

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Ralstonia solanacearum species complex (RSSC) is a phytopathogenic bacterial group that causes bacterial wilt in several crops, being potato (Solanum tuberosum) one of the most important hosts. The relationship between the potato plant ionome (mineral and trace elements composition) and the resistance levels to this pathogen has not been addressed until now. Mineral content of xylem sap, roots, stems and leaves of potato genotypes with different levels of resistance to bacterial wilt was assessed in this work, revealing a positive correlation between divalent calcium (Ca) cation concentrations and genotype resistance. The aim of this study was to investigate the effect of Ca on bacterial wilt resistance, and on the growth and virulence of RSSC. Ca supplementation significantly decreased the growth rate of Ralstonia pseudosolanacearum GMI1000 in minimal medium and affected several virulence traits such as biofilm formation and twitching motility. We also incorporate for the first time the use of microfluidic chambers to follow the pathogen growth and biofilm formation in conditions mimicking the plant vascular system. By using this approach, a reduction in biofilm formation was observed when both, rich and minimal media, were supplemented with Ca. Assessment of the effect of Ca amendments on bacterial wilt progress in potato genotypes revealed a significant delay in disease progress, or a complete absence of wilting symptoms in the case of partially resistant genotypes. This work contributes to the understanding of Ca effect on virulence of this important pathogen and provides new strategies for an integrated control of bacterial wilt on potato. IMPORTANCE: Ralstonia solanacearum species complex (RSSC) includes a diverse group of bacterial strains that cause bacterial wilt. This disease is difficult to control due to pathogen aggressiveness, persistence, wide range of hosts, and wide geographic distribution in tropical, subtropical, and temperate regions. RSSC causes considerable losses depending on the pathogen strain, host, soil type, environmental conditions, and cultural practices. In potato, losses of $19 billion per year have been estimated for this pathogen worldwide. In this study, we report for the first time the mineral composition found in xylem sap and plant tissues of potato germplasm with different levels of resistance to bacterial wilt. This study underscores the crucial role of calcium (Ca) concentration in the xylem sap and stem in relation to the resistance of different genotypes. Our in vitro experiments provide evidence of Ca's inhibitory effect on the growth, biofilm formation, and twitching movement of the model RSSC strain R. pseudosolanacearum GMI1000. This study introduces a novel element, the Ca concentration, which should be included into the integrated disease control management strategies for bacterial wilt in potatoes.

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Three F2-derived biparental doubled haploid (DH) maize populations were generated for genetic mapping of resistance to common rust. Each of the three populations has the same susceptible parent, but a different resistance donor parent. Population 1 and 3 consist of 320 lines each, population 2 consists of 260 lines. The DH lines were evaluated for their susceptibility to common rust in two years and with two replications in each year. For phenotyping, a visual score (VS) for susceptibility was assigned. Additionally, unmanned aerial vehicle (UAV) derived multispectral and thermal infrared data was recorded and combined in different vegetation indices ("remote sensing", RS). The DH lines were genotyped with the DarTseq method, to obtain data on single nucleotide polymorphisms (SNPs). After quality control, 9051 markers remained. Missing values were "imputed" by the empirical mean of the marker scores of the respective locus. We used the data for comparison of genome-wide association studies and genomic prediction when based on different phenotyping methods, that is either VS or RS data. The data may be interesting for reuse for instance for benchmarking genomic prediction models, for phytopathological studies addressing common rust, or for specifications of vegetation indices.

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Damiana (Turnera diffusa Willd) was evaluated in vitro for antioxidant and antibacterial activities against Staphylococcus aureus and Streptococcus pyogenes (as a preliminary screening assessment) by high-performance thin-layer chromatography (HPTLC)-Direct bioautography. A study was performed in vivo to evaluate the effects of Damiana enriched diets at 0.5 % on immune parameters in mucus and serum and gene expression in Almaco Jack (Seriola rivoliana) intestine after two and four weeks; an infection with Aeromonas hydrophila at 1x107 colony forming units (CFU) followed and an ex vivo study was carried out using head-kidney leukocytes. Ferric reducing ability of plasma (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays showed high antioxidant activities in Damiana leaves; even in the ABTS assay, Damiana at 300 µg/mL showed similar activity to ascorbic acid - the standard control. Damiana exhibited strong in vitro antimicrobial activity against S. aureus and S. pyogenes. In vivo studies showed a strong enhancement of myeloperoxidase, nitric oxide, superoxide dismutase, and catalase activities in mucus and serum of S. rivoliana supplemented with Damiana; their immunological response enhanced after infection with A. hydrophila. IL-1ß, TNF-α, and IL-10 gene expressions upregulated in the fish intestine challenged with the bacterium. Piscidin and macrophage (MARCO) receptor gene expression up-regulated at week 4 and down-regulated after infection. Intestinal histology results confirm that Damiana not cause inflammation or damage. Finally, the ex vivo study confirmed the immunostimulant and protective effects of Damiana through increased phagocytic, respiratory burst, myeloperoxidase activities and nitric oxide generation before and upon the bacterial encounter. These results support the idea that Damiana has the potential as an immunostimulant additive for diets in aquaculture by enhancing immune parameters and protecting Almaco Jack against A. hydrophila infections upon four weeks of supplementation.

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Hoof diseases are a major welfare and economic issue in the global dairy cattle production industry, which can be minimized through improved management and breeding practices. Optimal genetic improvement of hoof health could benefit from a deep understanding of the genetic background and biological underpinning of indicators of hoof health. Therefore, the primary objectives of this study were to perform genome-wide association studies, using imputed high-density genetic markers data from North American Holstein cattle, for 8 hoof-related traits: digital dermatitis, sole ulcer, sole hemorrhage, white line lesion, heel horn erosion, interdigital dermatitis, interdigital hyperplasia, and toe ulcer, and a hoof health index. De-regressed estimated breeding values from 25,580 Holstein animals were used as pseudo-phenotypes for the association analyses. The genomic quality control, genotype phasing, and genotype imputation were performed using the PLINK (version 1.9), Eagle (version 2.4.1), and Minimac4 software, respectively. The functional genomic analyses were performed using the GALLO R package and the DAVID platform. We identified 22, 34, 14, 22, 28, 33, 24, 43, and 15 significant markers for digital dermatitis, heel horn erosion, interdigital dermatitis, interdigital hyperplasia, sole hemorrhage, sole ulcer, toe ulcer, white line lesion disease, and the hoof health index, respectively. The significant markers were located across all autosomes, except BTA10, BTA12, BTA20, BTA26, BTA27, and BTA28. Moreover, the genomic regions identified overlap with various previously reported quantitative trait loci for exterior, health, meat and carcass, milk, production, and reproduction traits. The enrichment analyses identified 44 significant gene ontology terms. These enriched genomic regions harbor various candidate genes previously associated with bone development, metabolism, and infectious and immunological diseases. These findings indicate that hoof health traits are highly polygenic and influenced by a wide range of biological processes.

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Sugarcane diseases can be controlled by an integrated management approach where biotechnological tools can successfully contribute. The Obispo Colombres Agroindustrial Experimental Station (EEAOC) in Tucumán (Argentina's main sugarcane producer) has successfully implemented multiple strategies that greatly enhance the productivity of sugarcane fields. The local breeding program develops resistant varieties by applying molecular markers to reveal the presence of Bru1 gene for brown rust resistance throughout the EEAOC germplasm collection. In addition, SNP alleles linked to novel sources of resistance were identified following a selective genotyping strategy. Another strategy is the implementation of a seed cane sanitation project using hydrothermal therapy, an in vitro culture technique, molecular diagnosis of diseases, and bionanoparticles. As a result, the incidence of systemic diseases has significantly decreased in the production fields. More recently, the use of biological products has shown to be effective for disease control in EEAOC varieties. In summary, several biotechnological strategies including molecular markers associated with resistant sources, in vitro culture of apical meristems, molecular diagnostic techniques, and the use of bioproducts are being successfully used for the sustainable management of sugarcane diseases in Tucumán, Argentina.

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Developing coffee cultivars resistant to multiple diseases by combining resistance genes is a top priority in breeding programs. To create cultivars resistant to diseases and nematodes, we transferred genes for resistance to bacterial infections caused by Pseudomonas coronafaciens pv. garcae, which causes bacterial halo blight (BHB), and P. amygdali pv. tabaci, which causes bacterial leaf spots (BLS), into Arabica coffee. Genetic analyses were conducted on breeding populations to estimate the number and function of genes that confer resistance to BHB and BLS. In total, 2,109 plants in the F2 generation and reciprocal backcrosses were inoculated with P. coronafaciens pv. garcae, while 1,996 plants were inoculated with P. amygdali pv. tabaci. Results showed that resistance to both pathogens had a heritability of 0.99, and the segregations of resistance indicated that each disease was controlled by a single dominant gene. The analyses also revealed that the resistance genes for BHB and BLS were linked, with an average distance of 10.75 cM between them on the same chromosome.

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Organic acids (OAs) are a class of feed additives that have prophylactic and inhibitory properties against pathogenic bacteria. In this study, we investigated growth performance, innate immune response, gut microbiota, and disease resistance against Francisella orientalis F1 in Nile tilapia (Oreochromis niloticus) fed different doses of Bacti-nil®Aqua, a blend of short- and medium-chain OAs. For 21 days, 680 juvenile tilapias were fed a control diet or diets supplemented with a 0.3% (D3) or 0.5% (D5) OA blend. The feed conversion rate of fish fed the 0.5% enriched diet was considerably lower (p < 0.05) than that of the fish fed the basal diet. Lysozyme and serum bactericidal activities were significantly elevated following OA administration. After infection, no differences in the diversity and composition of gut microbiota were observed between the groups. After the bacterial challenge, the mortality was significantly lower in group D5 (p < 0.01). The diet supplemented with Bacti-nil®Aqua (Adisseo) improved the immune response and resistance of tilapia juveniles against F. orientalis infection. Thus, this OA blend could serve as a feed additive with good activity against F. orientalis.

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BACKGROUND: Hevea brasiliensis is severely affected by the fungal disease caused by Phytophthora spp. Significant loss of rubber yield is widespread and extensive use of chemical fungicides has resulted in health and environmental problems. OBJECTIVE: This work aims to extract and identify the latex serum peptides from a disease tolerant clone of H. brasiliensis, and study the inhibitory efficacy against pathogenic bacteria and fungi. METHODS: Serum peptides were extracted from H. brasiliensis BPM24 using mixed lysis solution. Low molecular weight peptides were screened and fractionated by solid-phase extraction and then identified by tandem mass spectrometry. Total and fractionated serum peptides were assayed for bacterial and fungal inhibition using broth microdilution and poisoned food methods. An inhibitory control study in the greenhouse was also performed using susceptible clones for pre and postinfection with Phytophthora spp. RESULTS: Forty-three serum peptide sequences were successfully identified. Thirty-four peptides matched with the proteins associated with plant defense response signaling, host resistance, and adverse environmental factors. The inhibitory study of total serum peptides demonstrated antibacterial and anti-fungal properties. The greenhouse study exhibited disease inhibitory efficacy of 60% for the treatment of Phytophthora spp. in post-infected plants and 80% for pre-treated samples. CONCLUSION: Latex serum peptides from disease tolerant H. brasiliensis revealed several proteins and peptides associated with plant defense and disease resistance. The peptides play a vital role for defense against bacteria and fungi pathogens, including Phytophthora spp. Enhanced disease protection can be obtained when the extracted peptides were applied to the susceptible plants before exposure to the fungi. These findings provided an insight and may pave the way for the development of biocontrol peptides from natural resources.

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BACKGROUND: Tambaqui, Colossoma macropomum, is the most important native fish species farmed in South America, particularly in Brazil, where its production is limited in the southern and southeastern regions due to disease outbreaks caused by the parasite Ichthyophthirius multifiliis. Therefore, genome level analysis to understand the genetic architecture of the host resistance against I. multifiliis is fundamental to improve this trait in tambaqui. The objective of the present study was to map QTL (quantitative trait loci) associated with resistance to I. multifiliis in tambaqui by GWAS (genome-wide association study). METHODS AND RESULTS: Individuals belonging to seven families, which were previously submitted to an experimental challenge to assess the natural resistance to the parasite I. multifiliis, were used for genomic analysis. A total of 7717 SNPs were identified in this population by ddRAD (double digest restriction site associated DNA). GWAS revealed four SNPs significantly associated in the LGs (linkage groups) 2, 9, 11 and 20 for the traits time of death and parasite load. The SNPs explained a low proportion of the variance to I. multifiliis resistance for time of death and parasite load (about 0.622% and 0.375%, respectively). The SNPs were close to 11 genes related to the immune system: abcf3, znf830, ccr9, gli3, ackr4, tbata, ndr2, tgfbr3, nhej1, znf644b, and cldn10a. CONCLUSIONS: In conclusion, the resistance to I. multifiliis is probably under polygenic control in tambaqui, in which different QTLs of low variance can be involved in the immune responses against this ectoparasite.

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Bean leaf crumple virus (BLCrV) is a novel begomovirus (family Geminiviridae, genus Begomovirus) infecting common bean (Phaseolus vulgaris L.), threatening bean production in Latin America. Genetic resistance is required to ensure yield stability and reduce the use of insecticides, yet the available resistance sources are limited. In this study, three common bean populations containing a total of 558 genotypes were evaluated in different yield and BLCrV resistance trials under natural infection in the field. A genome-wide association study identified the locus BLC7.1 on chromosome Pv07 at 3.31 Mbp, explaining 8 to 16% of the phenotypic variation for BLCrV resistance. In comparison, whole-genome regression models explained 51 to 78% of the variation and identified the same region on Pv07 to confer resistance. The most significantly associated markers were located within the gene model Phvul.007G040400, which encodes a leucine-rich repeat receptor-like kinase subfamily III member and is likely to be involved in the innate immune response against the virus. The allelic diversity within this gene revealed five different haplotype groups, one of which was significantly associated with BLCrV resistance. As the same genome region was previously reported to be associated with resistance against other geminiviruses affecting common bean, our study highlights the role of previous breeding efforts for virus resistance in the accumulation of positive alleles against newly emerging viruses. In addition, we provide novel diagnostic single-nucleotide polymorphism markers for marker-assisted selection to exploit BLC7.1 for breeding against geminivirus diseases in one of the most important food crops worldwide.

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A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. After acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-¹) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1, T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-¹) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

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Abstract A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. Aftrer acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-1) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1,T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Resumo Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-1) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

RESUMO

A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. After acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-¹) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1, T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.(AU)

Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-¹) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.(AU)

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Abstract A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. Aftrer acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-1) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1,T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Resumo Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-1) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

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Banana (Musa spp.), which is one of the world's most popular and most traded fruits, is highly susceptible to pests and diseases. Pseudocercospora musae, responsible for Sigatoka leaf spot disease, is a principal fungal pathogen of Musa spp., resulting in serious economic damage to cultivars in the Cavendish subgroup. The aim of this study was to characterize genetic components of the early immune response to P. musae in Musa acuminata subsp. burmannicoides, var. Calcutta 4, a resistant wild diploid. Leaf RNA samples were extracted from Calcutta 4 three days after inoculation with fungal conidiospores, with paired-end sequencing conducted in inoculated and non-inoculated controls using lllumina HiSeq 4000 technology. Following mapping to the reference M. acuminata ssp. malaccensis var. Pahang genome, differentially expressed genes (DEGs) were identified and expression representation analyzed on the basis of gene ontology enrichment, Kyoto Encyclopedia of Genes and Genomes orthology and MapMan pathway analysis. Sequence data mapped to 29,757 gene transcript models in the reference Musa genome. A total of 1073 DEGs were identified in pathogen-inoculated cDNA libraries, in comparison to non-inoculated controls, with 32% overexpressed. GO enrichment analysis revealed common assignment to terms that included chitin binding, chitinase activity, pattern binding, oxidoreductase activity and transcription factor (TF) activity. Allocation to KEGG pathways revealed DEGs associated with environmental information processing, signaling, biosynthesis of secondary metabolites, and metabolism of terpenoids and polyketides. With 144 up-regulated DEGs potentially involved in biotic stress response pathways, including genes involved in cell wall reinforcement, PTI responses, TF regulation, phytohormone signaling and secondary metabolism, data demonstrated diverse early-stage defense responses to P. musae. With increased understanding of the defense responses occurring during the incompatible interaction in resistant Calcutta 4, these data are appropriate for the development of effective disease management approaches based on genetic improvement through introgression of candidate genes in superior cultivars.

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Recent advances in biotechnology have helped increase tissue transformation efficiency and the frequency and specificity of gene editing to an extent that introducing allelic variants directly in elite varieties has become possible. In comparison to the conventional approach of crossing an elite recipient line with an exotic donor parent to introduce the trait of interest followed by repeated backcrossing, direct introduction of major-effect allelic variants into elite varieties saves time and resources, and eliminates yield drag resulting from the residual donor genes at the end of backcrossing.

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Background: Plant innate immunity relies on a broad repertoire of receptor proteins that can detect pathogens and trigger an effective defense response. Bioinformatic tools based on conserved domain and sequence similarity are within the most popular strategies for protein identification and characterization. However, the multi-domain nature, high sequence diversity and complex evolutionary history of disease resistance (DR) proteins make their prediction a real challenge. Here we present RFPDR, which pioneers the application of Random Forest (RF) for Plant DR protein prediction. Methods: A recently published collection of experimentally validated DR proteins was used as a positive dataset, while 10x10 nested datasets, ranging from 400-4,000 non-DR proteins, were used as negative datasets. A total of 9,631 features were extracted from each protein sequence, and included in a full dimension (FD) RFPDR model. Sequence selection was performed, to generate a reduced-dimension (RD) RFPDR model. Model performances were evaluated using an 80/20 (training/testing) partition, with 10-cross fold validation, and compared to baseline, sequence-based and state-of-the-art strategies. To gain some insights into the underlying biology, the most discriminatory sequence-based features in the RF classifier were identified. Results and Discussion: RD-RFPDR showed to be sensitive (86.4 ± 4.0%) and specific (96.9 ± 1.5%) for identifying DR proteins, while robust to data imbalance. Its high performance and robustness, added to the fact that RD-RFPDR provides valuable information related to DR proteins underlying properties, make RD-RFPDR an interesting approach for DR protein prediction, complementing the state-of-the-art strategies.

Assuntos

RESUMO

Antibiotic usage to control infectious diseases in shrimp aquaculture has led to serious problems on antimicrobial resistance. An alternative to mitigate this issue is the use of probiotics, which can be easily administered by feed and water. This study examines immunomodulatory and protective effects of the marine yeasts Debaryomyces hansenii CBS8339 (Dh) and Yarrowia lipolytica Yl-N6 (Yl) -alone and mixed-in white shrimp Penaeus vannamei post-larvae. Administration routes (fed and water alone or in combination), supplementation frequency and time elapsed after the last dietary supplement were tested on growth and gene expression of penaeidin, lectin, lysozyme, superoxide dismutase, catalase, and peroxidase, as well as survival upon Vibrio parahaemolyticus IPNGS16 challenge. Penaeidin and lectin genes were upregulated in post-larvae fed orally with Yl or combined Dh + Yl. Higher growth and survival for yeast supplementation treatments were observed compared to the control group, mainly when yeasts (Dh + Yl) and administration routes (feed and water) were combined. In conclusion, mixed yeast and combined administration routes improved growth and immunity against V. parahaemolyticus.

Assuntos

RESUMO

Banana is the most popular fruit in the world, with a relevant role in food security for more than 400 million people. However, fungal diseases cause substantial losses every year. A better understanding of the banana immune system should facilitate the development of new disease-resistant cultivars. In this study, we performed a genome-wide analysis of the leucine-rich repeat receptor-like protein (LRR-RLP) disease resistance gene family in a wild banana. We identified 78 LRR-RLP genes in the banana genome. Remarkably, seven MaLRR-RLPs formed a gene cluster in the distal part of chromosome 10, where resistance to Fusarium wilt caused by Foc race 1 has been previously mapped. Hence, we proposed these seven MaLRR-RLPs as resistance gene candidates (RGCs) for Fusarium wilt. We also identified seven other banana RGCs based on their close phylogenetic relationships with known LRR-RLP proteins. Moreover, phylogenetic analysis of the banana, rice, and Arabidopsis LRR-RLP families revealed five major phylogenetic clades shared by these plant species. Finally, transcriptomic analysis of the MaLRR-RLP gene family in plants treated with Foc race 1 or Foc TR4 showed the expression of several members of this family, and some of them were upregulated in response to these Foc races. Our study provides novel insights into the structure, distribution, evolution, and expression of the LRR-RLP gene family in bananas as well as valuable RGCs that will facilitate the identification of disease resistance genes for the genetic improvement of this crop.

Assuntos