Increased Disease Resistance Research Articles

Transcriptomic Analysis Reveals the Molecular Defense Mechanisms of Poa pratensis Against Powdery Mildew Fungus Blumeria graminis f. sp. Poae

Kentucky bluegrass (Poa pratensis L.) is a valuable cool-season turfgrass widely utilized for forage, turf, and ecological purposes; however, its productivity and ornamental value are significantly compromised by powdery mildew, caused by Blumeria graminis f. sp. Poae, which negatively affects turf quality. In the present study, we examined the interactions between P. pratensis varieties and B. graminis, focusing on primary haustorium formation at 24 h post-inoculation and the formation of germ tubes at 48 h post-inoculation. We explored the molecular mechanisms underlying the response of different P. pratensis varieties at 48 h post-inoculation via transcriptomic techniques. Our results revealed that the primary haustorium formation rate in ‘Taihang’ at 24 h after B. graminis inoculation was significantly lower than that in ‘Explorer’ and ‘Black Jack’. The conidia of B. graminis could form two to five germ tubes, and the proportion of conidia that formed five germ tubes in ‘Taihang‘ at 48 h post-inoculation was significantly lower than that in the other two varieties. Transcriptome analysis revealed 680,765 transcripts as unigenes. A total of 9983 unigenes were identified as differentially expressed genes in one or more varieties of P. pratensis after inoculation with powdery mildew compared with the control. In total, 6284 differentially expressed genes were upregulated in ‘Taihang’, which was substantially greater than those in ‘Black Jack’ (4530) and ‘Explorer’ (4666). Moreover, 2843 differentially expressed genes were specific to ‘Taihang’, whereas 1644 and 1590 unique differentially expressed genes were specific to ‘Explorer’ and ‘Black Jack’, respectively. The specifically expressed genes play crucial roles in determining the disease resistance of powdery mildew. Notably, the expression of genes encoding chitinase, gamma-glutamyltranspeptidase 1, UDP-arabinopyranose mutase 1, oxalate oxidase 2, mitogen-activated protein kinase kinase 1-like, tryptophan decarboxylase, and aromatic L-amino acid decarboxylase was closely related to powdery mildew resistance in ‘Taihang’, making them promising candidate genes for studying resistance to powdery mildew in P. pratensis. This study identified critical genes involved in powdery mildew resistance in P. pratensis, providing a basis for future gene mining and molecular breeding to increase disease resistance in P. pratensis.

Evaluation on the Efficacy of Farrerol in Inhibiting Shoot Blight of Larch (Neofusicoccum laricinum).

Neofusicoccum laricinum is the causal agent of larch shoot blight, a fungal disease affecting several species of larch. It causes severe damage, including stunting and mortality. This study aims to address the severe impact of larch shoot blight by evaluating the effect of farrerol on the inhibition of Neofusicoccum laricinum in Larix olgensis. We used LC-MS/MS and weighted gene co-expression network analysis to investigate farrerol's effects on Neofusicoccum laricinum and identify associated genes in resistant and susceptible larch. Our study identified significant differences in metabolite profiles between resistant and susceptible cultivars, with higher concentrations of farrerol showing complete inhibition of N. laricinum. Additionally, specific genes associated with farrerol content were up-regulated in resistant larch. Farrerol at higher concentrations completely inhibited N. laricinum, showing a strong correlation with increased disease resistance. This research suggests that farrerol enhances disease resistance in larch and provides a foundation for developing disease-resistant larch varieties based on antifungal metabolite traits.

Synergistic interactions of biocontrol agents and chemical fungicides enhance the disease resistance in Vigna radiata (L.) against Macrophomina phaseolina-associated with dry root rot

Macrophomina phaseolina, a necrotrophic fungus responsible for dry root rot disease in Vigna radiata L. (greengram) causes extensive yield losses. Biocontrol agents are reported to suppress phytopathogens, mitigate biotic stress, and improve growth and yield of plants. Here, Bacillus subtilis PSB-5 and Trichoderma sp. TD-6 along with chemical fungicides; mancozeb (MZB) and carbendazim (CBZM) were evaluated alone/or in combination for their effectiveness against M. phaseolina-induced root rot disease in greengram. B. subtilis and Trichoderma sp. suppressed phyto-fungal growth by 72 and 78 %, respectively. Both bioagents synthesized indole-3-acetic acid, ammonia, and solubilized insoluble phosphate, released antimicrobial substances including siderophore, hydrogen cyanide, and various extracellular lytic enzymes. Further, efficacy of bioagents and fungicides (at 50 and 100 ppm) were tested (single and combined) against M. phaseolina-infected greengram cultivated in pot soils. While evaluating, bioagents and fungicides increased plant height, biomass, and vigor indices of infected greengram in order: PSB-5 + TD-6 > PSB-5 > TD-6 > MZB + CBZM (100 ppm) > CBZM (100 ppm) > MZB (100 ppm). Further, among treatment, dual inoculation of bioagents (B. subtilis + Trichoderma), maximally increased total chlorophyll (59.4 %), carotenoid (68 %), root phosphorous (69.6 %), root nitrogen (65.7 %), total soluble protein (80 %), soluble sugar (76 %), pod yield (82.3 %) and seed protein (68 %) over infected plants. Moreover, biotic stress-induced oxidative stress biomarkers (proline, malondialdehyde, electrolyte leakage) and reactive oxygen species were significantly (p ≤ 0.05) lowered in fungal-infected greengram following fungicides and bioagents application. Furthermore, combined inoculation of bioagents significantly (p ≤ 0.05) reduced percent disease index (PDI) and increased % protection in biotic-stressed greengram. Besides, bioagents potentially increased disease resistance in M. phaseolina-infected greengram plants by modulating defense responses such as activities of β-1, 3 glucanase, catalase, phenylalanine ammonia lyase, polyphenol oxidase, peroxidase, and superoxide dismutase which significantly protected plants from fungal pathogen. Soil populations of pathogen and bioagents declined and considerably increased, respectively, at harvest. Application of antagonistic bacterial and fungal strains enhances greengram resistance to M. phaseolina while concurrently offering agriculture an environmentally friendly choice. Also, these strains can be applied as biocontrol agents in disease suppression over chemical fungicides.

The response of microbiome assembly within different niches across four stages to the cultivation of glyphosate-tolerant and conventional soybean varieties.

Plants are inherently connected with the microbiome, which plays a crucial role in regulating various host plant biological processes, including immunity, nutrient acquisition, and resistance against abiotic and biotic stresses. Many factors affect the interaction between plants and microbiome. In this study, microbiome samples were collected from five niches (bulk soil, rhizoplane, root endosphere, phylloplane, and leaf endosphere) across four developmental stages (seedling, flowering, podding, and maturity) of various soybean varieties. Composition and structure of bacterial and fungal communities were analyzed using 16S rRNA gene and ITS (Internally Transcribed Spacer) region amplicon sequencing. It was observed that both niches and developmental stages significantly impact on the assembly and composition of soybean microbiome. However, variety, presence of a transgene, and glyphosate application had minimal effects on microbial communities. The dominant microbiome varied across the five niches, with most containing beneficial microbial communities capable of promoting plant growth or increasing disease resistance. Types and abundance of the dominant microbes affected network stability, potentially resulting in functional changes in different ecological niches. This study provides theoretical evidence for microbial protection of plants against diseases and demonstrates that systematic analysis of the composition and diversity of soybean microbiomes can contribute to the development of biological control technologies.

What's the beef with gene editing? An investigation of factors influencing U.S. consumers’ acceptance of beef from gene-edited cattle

Gene-editing technology provides promising opportunities for livestock industries by enabling precise genetic modifications that enhance desirable traits such as increased disease resistance, heat tolerance, and nutritional quality. With gene-edited beef products entering the market soon, understanding consumers’ acceptance is critical. Using structural equation modeling, the study aimed to determine how key psychological and social factors influence U.S. consumers’ attitudes toward gene editing and their behavioral intentions toward ground beef from gene-edited cattle. Results indicate that knowledge, subjective social norms, and perceived benefits positively influenced attitudes, while perceived risks and food technology neophobia negatively influenced attitudes. Subjective social norms, perceived benefits, and attitudes positively influenced behavioral intentions, while perceived risks and food technology neophobia negatively influenced intentions. Attitudes acted as a partial mediator, significantly mediating the effects of subjective social norms, perceived benefits, perceived risks, and food technology neophobia on behavioral intentions. Improving consumers’ behavioral intentions toward ground beef from gene-edited cattle hinges on cultivating more favorable attitudes toward the technology. Thus, collaborative efforts by scientists, producers, policymakers, extension agents, and agricultural communicators should seek to increase consumers’ perceived benefits and improve subjective social norms, as these factors were most influential.

Current Advances in the Black Tiger Shrimp Penaeus monodon Culture: A Review

ABSTRACTThe increasing high‐end market demand for the black tiger shrimp Penaeus monodon has brought tremendous industry opportunities. Although the industry has tried its best to increase production, according to the report data from the Food and Agriculture Organization (FAO), annual global production has shown no significant upward trend over the past decade. Besides that, newly implemented policies such as seafood safety and food security negatively impacted the industry and reduced production. However, P. monodon cultivation is still promising due to its larger body size and higher market acceptance as a premium product. Over the years, numerous studies have been conducted to increase the production of P. monodon by optimizing its culture conditions, implementing new culture system, increasing disease resistance to disease such as WSSV, AHPND, WFD, implementation of pre‐ and probiotics in feed, and selective breeding programs to increase genetic diversity and population of P. monodon broodstock. This review provides an overview of the current advances in P. monodon broodstock cultivation, thereby providing an essential baseline for P. monodon aquaculture. Areas needing urgent research focus are also highlighted. Future research should take great strides and take into account the impact of future climate change scenario during P. monodon culture and optimization, and increase biosecurity measures to prevent its introduction as an alien species in wild settings.

Experimental evolution for improved postinfection survival selects for increased disease resistance in Drosophila melanogaster.

Disease resistance (defined as the host capacity to limit systemic infection intensity) and disease tolerance (defined as the host capacity to limit infection-induced damage) are 2 complementary defense strategies that help the hosts maximize their survival and fitness when infected with pathogens and parasites. In addition to the underlying physiological mechanisms, the existing theory postulates that these 2 strategies differ in terms of the conditions under which each strategy evolves in the host populations, their evolutionary dynamics, and the ecological and epidemiological consequences of their evolution. Here, we explored if one or both of these strategies evolve when host populations are subjected to selection for increased postinfection survival. We experimentally evolved Drosophila melanogaster populations, selecting for the flies that survived an infection with the entomopathogen Enterococcus faecalis. We found that the host populations evolved increased disease resistance in response to selection for increased survival. This was despite the physiological costs associated with increased resistance, the expression of which varied with the phase of infection. We did not find evidence of any change in disease tolerance in the evolved host populations.

Assessment of breeding and genetic parameters of milk productivity indicators of zebu cows-a prominent type of black-and-white breed

The article presents the results of an evaluation of the breeding and genetic parameters of milk productivity and breeding qualities of zeboid-type black-and-white cows. The level of coefficient of variability, interrelation and coefficient of heritability of indicators of dairy productivity of cows for the first, third and highest lactation in the herd of the Experimental station “Snegiri” — a branch of the Federal State Budgetary Institution of Science “N.V. Tsitsin Main Botanical Garden of the Russian Academy of Sciences” (Istra district, Moscow region) has been established. Currently, the herd at the experimental station consists of hybrid cattle created by crossbreeding black-and-white cattle with various zeboid subspecies (New Zealand, Indian, Azerbaijani, and Cuban), as well as with purebred Holstein-Friesians. As a result of extensive breeding work involving distant hybridization, unique animals have been developed that exhibit increased disease resistance, significant adaptive potential, and are undemanding in terms of feed and housing conditions under intensive milk production technology. Generally, the milk from zeboidtype black-and-white cattle is characterized by a comparatively higher concentration of nutrients — fats, proteins, milk sugar, and essential amino acids. The high nutritional value of the milk, combined with the enhanced adaptive abilities, characterizes the zeboid-type black-and-white cattle as potentially valuable animals, making breeding work with them justifiably highly relevant. The evaluation of breeding and genetic parameters will help uncover the potential for milk productivity, determine the directions for breeding work, and adjust selection methods to further enhance production and improve the breeding qualities of this type of dairy cattle.

Plant Cell Wall Polysaccharide O-Acetyltransferases.

Plant cell walls are largely composed of polysaccharide polymers, including cellulose, hemicelluloses (xyloglucan, xylan, mannan, and mixed-linkage β-1,3/1,4-glucan), and pectins. Among these cell wall polysaccharides, xyloglucan, xylan, mannan, and pectins are often O-acetylated, and polysaccharide O-acetylation plays important roles in cell wall assembly and disease resistance. Genetic and biochemical analyses have implicated the involvement of three groups of proteins in plant cell wall polysaccharide O-acetylation: trichome birefringence-like (TBL)/domain of unknown function 231 (DUF231), reduced wall acetylation (RWA), and altered xyloglucan 9 (AXY9). Although the exact roles of RWAs and AXY9 are yet to be identified, members of the TBL/DUF231 family have been found to be O-acetyltransferases responsible for the O-acetylation of xyloglucan, xylan, mannan, and pectins. Here, we provide a comprehensive overview of the occurrence of O-acetylated cell wall polysaccharides, the biochemical properties, structural features, and evolution of cell wall polysaccharide O-acetyltransferases, and the potential biotechnological applications of manipulations of cell wall polysaccharide acetylation. Further in-depth studies of the biochemical mechanisms of cell wall polysaccharide O-acetylation will not only enrich our understanding of cell wall biology, but also have important implications in engineering plants with increased disease resistance and reduced recalcitrance for biofuel production.

Altering cold-regulated gene expression decouples the salicylic acid-growth trade-off in Arabidopsis.

In Arabidopsis (Arabidopsis thaliana), overproduction of salicylic acid (SA) increases disease resistance and abiotic stress tolerance but penalizes growth. This growth-defense trade-off has hindered the adoption of SA-based disease management strategies in agriculture. However, investigation of how SA inhibits plant growth has been challenging because many SA-hyperaccumulating Arabidopsis mutants have developmental defects due to the pleiotropic effects of the underlying genes. Here, we heterologously expressed a bacterial SA synthase gene in Arabidopsis and observed that elevated SA levels decreased plant growth and reduced the expression of cold-regulated (COR) genes in a dose-dependent manner. Growth suppression was exacerbated at below-ambient temperatures. Severing the SA-responsiveness of individual COR genes was sufficient to overcome the growth inhibition caused by elevated SA at ambient and below-ambient temperatures while preserving disease- and abiotic-stress-related benefits. Our results show the potential of decoupling SA-mediated growth and defense trade-offs for improving crop productivity.

Melatonin as a modulator of MAPK cascade and ROS-RNS feedforward loop during plant pathogen interaction

Sustainable agricultural practices encounter formidable obstacles posed by a diverse array of biotic stressors, including fungi, bacteria, viruses, viroids, phytoplasma, and nematodes, which are widespread across the globe. The severity of these stressors is shaped by variables such as weather patterns, cropping techniques, cultivation methodologies, crop varieties, and their resistance capabilities. Melatonin, a multifunctional compound present in various organisms, plays vital roles, especially in enhancing plant resilience to environmental challenges. Its use can alleviate the negative effects of abiotic factors on plants. Recent research indicates its positive influence on plant defense against biotic stresses. In this review, we discuss the contributions of melatonin in enhancing plant resilience against pathogenic attacks by initiating early defense responses, regulating reactive oxygen species (ROS) and reactive nitrogen species (RNS) levels, and interacting with signaling pathways involved in plant defense mechanisms. Following pathogenic attacks, ROS and RNS are rapidly generated, forming an interconnected loop with melatonin, termed the melatonin-ROS-RNS feedforward loop. We discuss how the loop, which may be present in the mitochondria and chloroplasts, increases disease resistance at the earliest possible stage of pathogen entry while providing on-site defense. We also consider the development of the melatonin receptor-mitogen-activated protein kinase (MAPK) cascade and the emergence of phytohormone pathways in plants, and how melatonin interacts with these signaling pathways to drive defense responses. This multifunctional compound holds promise for sustainable agricultural practices by potentially mitigating the negative impacts of various biotic stressors on crop yield and quality.

Multigenerational Adaptation Can Enhance the Pathogen Resistance of Plants via Changes in Rhizosphere Microbial Community Assembly.

Plants withstand pathogen attacks by recruiting beneficial bacteria to the rhizosphere and passing their legacy on to the next generation. However, the underlying mechanisms involved in this process remain unclear. In our study, we combined microbiomic and transcriptomic analyses to reveal how the rhizosphere microbiome assembled through multiple generations and defense-related genes expressed in Arabidopsis thaliana under pathogen attack stress. Our results showed that continuous exposure to the pathogen Pseudomonas syringae pv tomato DC3000 led to improved growth and increased disease resistance in a third generation of rps2 mutant Arabidopsis thaliana. It could be attributed to the enrichment of specific rhizosphere bacteria, such as Bacillus and Bacteroides. Pathways associated with plant immunity and growth in A. thaliana, such as MAPK signaling pathways, phytohormone signal transduction, ABC transporter proteins, and flavonoid biosynthesis, were activated under the influence of rhizosphere bacterial communities. Our findings provide a scientific basis for explaining the relationship between beneficial microbes and defense-related gene expression. Understanding microbial communities and the mechanisms involved in plant responses to disease can contribute to better plant management and reduction of pesticide use.

Rice SRO1a Contributes to Xanthomonas TAL Effector-mediated Expression of Host Susceptible Genes.

Xanthomonas species infect many important crops and cause huge yield loss. These pathogens deliver transcription activator-like (TAL) effectors into the cytoplasm of plant cells. TAL effectors move to host nuclei, directly bind to the promoters of host susceptible genes, and activate their transcription. However, the molecular mechanisms by which TAL effectors induce host transcription remain unclear. We herein demonstrated that TAL effectors interacted with the SIMILAR TO RCD ONE (SRO) family proteins OsSRO1a and OsSRO1b in nuclei. A transactivation assay using rice protoplasts indicated that OsSRO1a and OsSRO1b enhanced the activation of the OsSWEET14 promoter by the TAL effector AvrXa7. The AvrXa7-mediated expression of OsSWEET14 was significantly reduced in ossro1a mutants. However, the overexpression of OsSRO1a increased disease resistance by up-regulating the expression of defense-related genes, such as WRKY62 and PBZ1. This was attributed to OsSRO1a and OsSRO1b also enhancing the transcriptional activity of WRKY45, a direct regulator of WRKY62 expression. Therefore, OsSRO1a and OsSRO1b appear to positively contribute to transcription mediated by bacterial TAL effectors and rice transcription factors.

Overexpression of NB-LRR Gene AtRPM1(D505V) Improved Drought and Salt Resistance and Decreased Cold Tolerance in Transgenic Rice

Abiotic stimuli severely restrict the growth and development of plants, resulting in massive losses in the quality and yield of crops. Exploring genes that can improve crop tolerance to abiotic stress is important. In a previous study, we found that overexpression of the Arabidopsis nucleotide-binding domain leucine-rich repeat (NB-LRR) gene AtRPM1(D505V) increased disease resistance in rice. In this research, we found that AtRPM1(D505V) transgenic plants were more sensitive to abscisic acid (ABA) than wild type (WT) plants. Abiotic-stress resistance in AtRPM1(D505V) transgenic plants was investigated. We found that AtRPM1(D505V) transgenic plants exhibited improved resistance to drought and salt stress; the phonotype and survival rates of transgenic rice were better than WT plants. The expression of stress responsive genes including OsDREB2A, OsDREB2B, OsRD22, and OsRD29A were significantly upregulated in AtRPM1(D505V) overexpressed plants than in WT plants. Moreover, the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were significantly increased in AtRPM1(D505V) overexpressed plants than in WT plants under drought and salt stress. Under cold stress, the expression of stress responsive genes and the activities of antioxidant enzymes in AtRPM1(D505V) transgenic plants were significantly lower than in WT plants. Our research demonstrated that AtRPM1(D505V) confers drought and salt resistance to transgenic rice. Therefore, AtRPM1(D505V) could act as a potential candidate gene to cultivate drought- and salt-tolerant plants.

Effects of Ramulus mori oligosaccharides on growth performance, serum physiological and biochemical parameters, and immunomodulation in largemouth bass (Micropterus salmoides)

This study examined the effects of dietary Ramulus mori oligosaccharides (RMO) supplementation on the growth, antioxidant capacity, and immunomodulatory capacity in largemouth bass (Micropterus salmoides). Fingerlings weighing 26.82 ± 0.31 g were randomly divided into three groups that were fed either the basal diet, supplementation with 0.5% RMO, or supplementation with 1.0% RMO. The feeding trial lasted 80 days, after which the fish were experimentally challenged with largemouth bass iridovirus (LMBV). The integration of RMO into the diet resulted in a slower rate of weight gain for largemouth bass, and it also led to an elevation in the feed coefficient. RMO supplementation significantly declined the serum levels of triglycerides, total cholesterol, and low-density lipoprotein, and lowered the activities of aspartate aminotransferase and alanine aminotransferase (P < 0.05); increased the levels of serum total protein, albumin, and lysozyme (P < 0.05); and increased the survival rate of fish infected with LMBV. Additionally, RMO supplementation boosted the activity of superoxide dismutase in both serum and liver, decreased the malondialdehyde content, and enhanced the total antioxidant capacity of serum and liver. The addition of RMO to the diet can also lower the phenomenon of liver vacuolization and upregulate the gene expression of liver sod and cat, reduce the expression of pro-inflammatory factors tnf-α and il-8, and regulate the intestinal microbiota structure. In summary, RMO supplementation to a pelleted compound feed could improve the antioxidant capacity, increase disease resistance, affect the gut microbial composition, and protect the liver health of largemouth bass, showing the potential for development of this aquafeed additive.

Detoxifying bacterial genes for deoxynivalenol epimerization confer durable resistance to Fusarium head blight in wheat.

Fusarium head blight (FHB) and the presence of mycotoxin deoxynivalenol (DON) pose serious threats to wheat production and food safety worldwide. DON, as a virulence factor, is crucial for the spread of FHB pathogens on plants. However, germplasm resources that are naturally resistant to DON and DON-producing FHB pathogens are inadequate in plants. Here, detoxifying bacteria genes responsible for DON epimerization were used to enhance the resistance of wheat to mycotoxin DON and FHB pathogens. We characterized the complete pathway and molecular basis leading to the thorough detoxification of DON via epimerization through two sequential reactions in the detoxifying bacterium Devosia sp. D6-9. Epimerization efficiently eliminates the phytotoxicity of DON and neutralizes the effects of DON as a virulence factor. Notably, co-expressing of the genes encoding quinoprotein dehydrogenase (QDDH) for DON oxidation in the first reaction step, and aldo-keto reductase AKR13B2 for 3-keto-DON reduction in the second reaction step significantly reduced the accumulation of DON as virulence factor in wheat after the infection of pathogenic Fusarium, and accordingly conferred increased disease resistance to FHB by restricting the spread of pathogenic Fusarium in the transgenic plants. Stable and improved resistance was observed in greenhouse and field conditions over multiple generations. This successful approach presents a promising avenue for enhancing FHB resistance in crops and reducing mycotoxin contents in grains through detoxification of the virulence factor DON by exogenous resistance genes from microbes.

Vitamin C Alleviates Intestinal Inflammation Caused by Aeromonas hydrophila in Juvenile Blunt Snout Bream (Megalobrama amblycephala)

Vitamin C (VC) can be used to increase disease resistance in practice in intensive aquaculture. But it is still unconfirmed whether VC could alleviate inflammation and what dosage is suitable. This study investigated the effects of dietary VC on the immunity and enteritis of juvenile blunt snout bream (Megalobrama amblycephala) challenged with Aeromonas hydrophila. The fish were fed with VC levels ranging from 25.35 to 2231.98 mg/kg for 60 days. After that, fish fed with 150.65 mg/kg, 573.79 mg/kg, and 2231.98 mg/kg VC were challenged with A. hydrophila orally to simulate enteritis. The results showed that 285.39 and 573.79 mg/kg dietary VC significant improved growth performance and feed utilization. Dietary VC (573.79 and 1133.79 mg/kg) significantly enhanced the serum immune parameters, antioxidant enzymes’ activities, and relative gene expressions of ikbα and cat in the liver in the 60-day feeding trail. The survival rate was significantly higher in 573.79 mg/kg dietary VC group than the other two treatments. Cytokines were activated after the bacteria challenge. Dietary 573.79 mg/kg VC caused significantly higher TNF-α level at 12 hpi and maintained a high level of IL-8 at 48 to 72 h compared to other treatments. In conclusion, more than 500 mg/kg VC was needed to maintain the health of blunt snout bream juveniles. Suitable VC would activate cytokines to increase disease resistance along with antioxidant enzymes.

Pengaruh Pemberian Bakteri dan Trichoderma viride dari Isolat Usus Larva Black Soldier Fly (BSF) terhadap Ketahan Penyakit Cabai Keriting (Capsicum annuum)

Capsicum annuum (curly red chili) is an important commodity for the community. The addition of chemical pesticides is used by farmers to increase plant disease resistance. The use of chemical pesticides is harmful to the environment and can have long-term effects if consumed. Therefore, biopesticide innovation is needed. Black Soldier Fly (BSF) is an insect that has bacteria and fungi in its gut. Bacteria and fungi found in BSF intestinal isolates can function as antimicrobials for plants. Because of this, in this study investigated the effect of the bacteria and fungi Trichoderma viride in increasing disease resistance in C. annuum plants. There were 4 treatments in this study, namely the administration of chemical fungicides, BSF bacterial formula, T. viride. BSF, and a mixture of bacteria and T. viride BSF. The results obtained were analyzed by calculating the Intensity of Attack (IS) score, microscopic observations in the laboratory, and statistical tests. The IS score of the control plants was 75.0%, the fungicide treatment was 37.5%, the bacterial treatment alone was 33.3%, the T. viride treatment was 19.4%, and the mixed treatment of bacteria and T. viride was 4.2%. All plants were attacked by leaf spot disease by Cercospora sp. Control plants were attacked by Sclerotium rolfsii fungus wilt and powdery mildew by Leveillula taurica and jaundice. Jaundice also attacked plants treated with T. viride only and bacteria only. The normality and homogeneity tests show that the data is not normal and not homogeneous but H1 is acceptable based on the Kruskal Wallis test. The conclusion of this study is that bacteria and T. viride from BSF are able to increase disease resistance in curly chili plants, but are not yet effective in preventing disease caused by Cercospora sp.

Dietary garden cress (Lepidium sativum) seeds mitigate the effect of aflatoxin B1 contamination on growth, antioxidant status, AFB1 residues, immune response, and tissue architecture of Oreochromis niloticus

The contamination of fish diets with aflatoxin B1 (AFB1) poses a significant hazard to the aquaculture sector. This study investigates the efficacy of supplementing Nile tilapia (Oreochromis niloticus) diets with garden cress (Lepidium sativum) seeds (GCS) to mitigate the adverse effects of AFB1. For this purpose, a factorial design was utilized, consisting of a 2×3 arrangement of treatments. This included two contamination levels of AFB1: (0 and 2 mg kg−1 diet). Within each contamination level, three dietary levels of GCS were used (0 %, 1 %, and 2 %). The study involved 270 healthy O. niloticus with an average weight of 25.14 ± 0.39 g (45 fish/group and 15 fish/replicate). The duration of the trial was 60 days. The study evaluated growth performance, hematological indices, hepatorenal function, immune and antioxidant indicators, histomorphology of organs, AFB1 residues in muscles, and fish resistance to Aeromonas hydrophila. The results indicated that GCS dietary supplementation significantly counteracted AFB1-induced growth retardation and reduced fish survival. Additionally, GCS effectively reversed the anemia, leukopenia, hypoproteinemia, hypoalbuminemia, and hypoglobulinemia that were produced by AFB1. Moreover, GCS dietary supplementation significantly suppressed the AFB1-induced increase in serum bilirubin, hepatic enzymes, kidney damage products, cortisol, and glucose. Additionally, the inclusion of GCS in the fish's diet effectively eliminated the accumulation of AFB1 in their muscles. Moreover, GCS supplementation demonstrated significant restoration of depleted antioxidant and innate immune components induced by AFB1. Furthermore, GCS significantly reduced the degenerative changes in renal, hepatic, splenic, and small intestine tissues caused by AFB1. Fish fed a GCS-fortified diet and exposed to AFB1 displayed restored disease resistance when challenged with A. hydrophila. In conclusion, supplementing Nile tilapia diets with GCS at 2 %, even in the presence the AFB1 contamination, significantly enhanced the fish growth, improved health, and increased disease resistance while reducing AFB1 residues, thereby benefiting consumer health.

Exploring the nutritional value of corn fermented protein as a replacement for soybean meal in diets for juvenile channel catfish (Ictalurus punctatus): Impacts on production performance, intestinal health, and disease resistance

The use of corn fermented protein (CFP) can be a promising alternative ingredient to replace soybean meal (SBM) in aquafeeds, because of its attractive price and constant supply. In this study, the apparent digestibility of CFP was evaluated with channel catfish (Ictalurus punctatus), followed by a comparative feeding trial in which dehulled, solvent extracted SBM in the control diet was incrementally replaced with graded levels of CFP. A slight but significantly higher apparent protein digestibility coefficient was observed for SBM (91%) compared to CFP (89%). However, phosphorus and lipid were twice as available from CFP than SBM. A 60-day feeding trial was conducted, testing the gradual replacement of SBM by CFP on an equalnitrogen basis at 0, 25, 50, 75, and 100%. Channel catfish juveniles (∼11.6 g) were stocked in 30 aquaria (30 fish/ 110-L tank; n = 6) operating as a recirculating system and offered the experimental diets to apparent satiation twice daily. No differences were observed for hepatosomatic index, survival, or serum superoxide dismutase and lysozyme activities. Also, no treatment effects were observed for whole-body protein, ash, and protein conversion efficiency. However, weight gain, feed efficiency, intraperitoneal fat, and whole-body lipid were significantly affected by the dietary treatments with CFP able to replace up to 40 to 58% of the SBM in the diet while providing similar fish performance and body composition as fish fed the control diet. Digesta samples from the posterior segment of the intestine were subjected to DNA extraction, followed by 16S rRNA gene (V3-V4 region) sequencing to profile the intestinal microbiota. A higher relative abundance of Aeromonas spp. was observed for fish fed the control diet. The remaining fish from the feeding trial were challenged with Edwardsiella ictaluri, and cumulative survival was monitored for 21 days. Survival after the bacterial challenge gradually increased as the inclusion levels of CFP increased in the diets, with the 100% replacement treatment being significantly different from the control diet. In conclusion, CFP is a promising alternative plant protein ingredient with high protein and phosphorus digestibility, and it can replace up to 40 to 58% of the SBM in feed formulations for juvenile channel catfish based on weight gain and feed efficiency while potentially increasing disease resistance against E. ictaluri.