Activity Of Stress-related Enzymes Research Articles

Gradual effects of gradient concentrations of perfluorooctane sulfonate on the antioxidant ability and gut microbiota of red claw crayfish (Cherax quadricarinatus)

Perfluorooctane sulfonate (PFOS) is a typical persistent organic pollutant that is characterized by environmental persistence, bioaccumulation, and toxicity. In this study, we investigated the gut microbial response of the red claw crayfish Cherax quadricarinatus after 28 days of exposure to 0 ng/L, 1 ng/L, 10 μg/L, or 10 mg/L of PFOS as a stressor. We measured oxidative stress-related enzyme activities and expression of molecules related to detoxification mechanisms to evaluate the toxic effects of PFOS. We found that PFOS disturbed microbial homeostasis in the gut of C. quadricarinatus, resulting in increased abundance of the pathogen Shewanella and decreased abundance of the beneficial bacterium Lactobacillus. The latter especially disturbed amino acid transport and carbohydrate transport. We also found that the activities of glutathione S-transferase and glutathione peroxidase were positively correlated with the expression levels of cytochrome P450 genes (GST1-1, GSTP, GSTK1, HPGDS, UGT5), which are products of PFOS-induced oxidative stress and play an antioxidant role in the body. The results of this study provided valuable ecotoxicological data to better understand the biological fate and effects of PFOS in C. quadricarinatus.

Application of Bacillus Coagulans as Paraprobiotic Against Acute Hepatopancreatic Necrosis Disease in Shrimp.

Paraprobiotics, known as non-viable or ghost probiotics, have attracted attention for their benefits over live microbial cells. This study was designed to investigate the paraprobiotic effects of heat-killed Bacillus coagulans on the white leg shrimp Litopenaeus vannamei. The paraprobiotic formulation was prepared in three different concentrations including B. coagulans 1 (107 cells g-1 diet), B. coagulans 2 (108 cells g-1 diet), and B. coagulans 3 (109 cells g-1 diet) through heat inactivation method. Preliminary toxicity assessments revealed that post-larvae shrimps (mean weight ± SE: 0.025 ± 0.007g) treated with B. coagulans 1, 2 and 3 paraprobiotic formulations exhibited no mortality, confirming the non-toxic nature of the formulated diet. In a 90-day feeding trial involving juvenile shrimps (mean weight ± SE: 0.64 ± 0.05g), growth parameters and feed conversion ratios improved in all experimental groups. Subsequently, these shrimps were challenged with Vibrio parahaemolyticus, revealing that paraprobiotic-fed shrimps exhibited significant survival rate improvements. Oxidative stress-related enzyme activities, such as superoxide dismutase and catalase, increased in paraprobiotic-fed shrimps post-Vibrio challenge, while the challenged control group showed decreased activity (p < 0.001). Nitric oxide levels are also increased in paraprobiotic-treated shrimp, with B. coagulans 3 showing a significant rise in nitric oxide activity (p < 0.001). This study further demonstrated the positive impact of paraprobiotic treatment on digestive enzymes, immune-related parameters (e.g., total hemocyte count, prophenoloxidase, and respiratory burst activity), and overall disease resistance. These findings suggest that B. coagulans paraprobiotics have the potential to enhance antioxidant, antibacterial, and immune-related responses in L. vannamei, making them a valuable addition to shrimp aquaculture.

Biological synthesis of nickel nanoparticles using extracellular metabolites of Bacillus sphaericus: Characterization and vector-borne disease control applications

In this study, we use extracellular metabolites of Bacillus sphaericus culture for the biosynthesis of nickel nanoparticles (BS@NiNPs) and potential larvicidal activity against Anopheles subpictus and Culex quinquefasciatus as well as against Rhipicephalus (Boophilus) annulatus (adult cattle tick). The extracellular metabolites derived from B. sphaericus culture acts as strong reducing and capping agents, allowing biosynthesis of the BS@NiNPs. Characterization of the synthesized NiNPs was carried out using various techniques, including UV–vis spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The FTIR spectroscopy analysis revealed significant peaks at specific wavenumbers (3435, 2923, 1646, 1406, and 1115 cm−1), indicating the presence of functional groups from biomolecules involved in the synthesis of BS@NiNPs. XRD analysis confirms well-defined peaks observed at 2θ = 31.72°, 45.40°, 56.43°, and 75.32°, which correspond to the lattice planes of 100, 101, 102, and 103 reflections, respectively. SEM and TEM images showed that the NiNPs exhibited spherical to oval shapes with clustered morphology with an average diameter of the grain size is about 23 ± 2.00. The BS@NiNPs exhibited significant parasitic action against A. subpictus and C. quinquefasciatus as well as adult cattle tick R. (B) annulatus. It is noteworthy that bacterial pathogens such as Bacillus species are commonly used for vector bio-control management due to their spore-forming characteristics. Therefore, the toxicity of BS@NiNPs-treated mosquito larvae and cattle ticks was analyzed for stress-related enzyme activities, including carboxylesterases, β-glucosidases, and glutathione S-transferases. In summary, our work shows that BS@NiNPs have the potential to be an efficient larvicide against ticks and mosquito larvae. The results of this study help to design environmentally benign and long-lasting methods for biological control, addressing the problems posed by vector-borne diseases.

Improving the resilience of rice seedlings to low temperature stress through seed priming

To feed the ever-growing worldwide population, rice production in all the three (fall, winter and summer) seasons has become essential. With the increase in global climatic change, the occurrence of low temperature stress in winter particularly at seed germination stage is becoming more intense is posing a greater challenge to rice production worldwide including India. A more effective method to improve rice seed germination under low temperature stress is seed priming. The goal of the current study was to determine how different chemicals can withstand low temperatures stress through seed priming. The experiment consisted of sixteen treatment combinations (two genotypes and eight seed priming treatments) which were laid out in a 2 factorial CRD. Among the different seed priming treatments imposed, the seeds primed with salicylic acid (0.5 mM) recorded significantly higher seed germination (92.3% and 93%), seedling length (24 cm), seedling dry weight (150 mg) and seedling vigour index-Ⅰ (2239) and vigour index-Ⅱ (13,996) and better stress related enzyme activities (peroxidase, catalase and superoxide dismutase activities) compared to other treatments during seed germination under low temperature stress.

Study on the Adaptive Regulation of Light on the Stress Response of Mandarin Fish (Siniperca chuatsi) with Re-Feeding after Starvation.

Light influences the stress response to environmental stimuli and feeding behaviors of Siniperca chuatsi and, thus, is an important regulator of normal growth and development. In this study, we first explored the important role of light on the digestive and stress capacity of S. chuatsi by studying the changes in physiological and biochemical indicators of S. chuatsi, taking the re-feeding after starvation as the constant environmental stimulus and the light intensity as the adjustable environmental stimulus. The activity of protease and lipase was generally higher in the stomach tissues than in the intestinal tissues, especially lipase, which was higher in stomach tissues under all light conditions, and the protease and lipase activity peaked in the stomach tissues of S. chuatsi at a light intensity of 18.44 ± 3.00 lx and in intestinal tissues at 11.15 ± 2.01 lx, respectively, indicating that greater light intensity increased the digestive capacity of stomach tissues, whereas lower light intensity facilitated the digestive capacity of intestinal tissues. The tissues of the gill, stomach, and intestine had relatively high activity of stress-related enzymes, whereas the tissues of the brain, kidney, liver, and plasma samples had relatively low activity of enzymes. Collectively, the results show that light intensity at 11.15 ± 2.01 lx promoted digestive capacity in the intestine and enhanced the anti-stress ability of S. chuatsi in response to stress induced by re-feeding after starvation. These findings should prove useful for artificial breeding of S. chuatsi.

Evaluation of immobilized microspheres of Clonostachys rosea on Botrytis cinerea and tomato seedlings

Tomato (Solanum lycopersicum L.) is a popular vegetable crop which is widely cultivated around the world. However, the production of tomatoes is threatened by several phytopathogenic agents, including gray mold (Botrytis cinerea Pers.). Biological control using fungal agents such as Clonostachys rosea plays a pivotal role in managing gray mold. However, these biological agents can negatively be influenced by environmental factors. However, immobilization is a promising approach to tackle this issue. In this research, we used a nontoxic chemical material, sodium alginate as a carrier to immobilize C. rosea. For this, sodium alginate microspheres were prepared using sodium alginate prior to embedding C. rosea. The results showed that C. rosea was successfully embedded in sodium alginate microspheres, and immobilization enhanced the stability of the fungi. The embedded C. rosea was able to suppress the growth of gray mold efficiently. In addition, the activity of stress related enzymes, peroxidase superoxidase dismutase and polyphenol oxidation was promoted in tomatoes treated with the embedded C. rosea. By measuring photosynthetic efficiency, it was noted that the embedded C. rosea has positive impacts on tomato plants. Taken together, these results indicate that immobilization of C. rosea improved its stability without detrimentally affecting its efficiency on gray mold suppression and tomato growth. The results of this research can be used as a basis for research and development of new immobilized biocontrol agents.

Polyethylene microplastic exposure and concurrent effect with Aeromonas hydrophila infection on zebrafish.

Microplastics are widely distributed in the environment, raising significant concerns owing to their potential negative effects on humans. Zebrafish were used in this study to assess the toxicity of microplastic exposure. Adult zebrafish were exposed to polyethylene (PE) microplastics with smooth clustered sphere shapes and diameters of 75-100µm for 35days. Survival rates of the zebrafish were not significantly affected, whereas growth rates were. Analyses on oxidative stress-related enzyme activities showed that glutathione (GSH), glutathione peroxidase (GSH-PX), and glutathione s-transferase (GST) production in the intestines was stimulated when exposed to low concentrations of microplastics (0.1 and 1mg/L), while superoxide dismutase (SOD), catalase (CAT), GSH, and GSH-PX production was suppressed when exposed to 10mg/L microplastics. Enzyme activities in the muscles were much less affected. Intestinal injuries and changes in colony structure in the intestines were observed in zebrafish following exposure to microplastics. After 35days of exposure, concurrent exposure to microplastics and Aeromonas hydrophila did not increase zebrafish mortality compared with those challenged by bacteria alone. This study confirms that intestinal enzyme activities of zebrafish are altered by exposure to PE microplastics but mortality and bacterial infection were not significantly affected under the tested conditions.

Effects of Feeding Frequency and Dietary Protein/Carbohydrate Ratios on Gilthead Seabream (Sparus aurata) Intestinal Functionality and Health

The present study evaluated the effects of feeding frequency (FF) and dietary protein/carbohydrate (P/CH) ratios on intestinal histomorphology, microbiota profile, and digestive and oxidative stress-related enzyme activities of gilthead seabream (Sparus aurata). To this purpose, two practical diets were formulated: one with 50% P and 10% CH (P50/CH10) and other with 40% P and 20% CH (P40/CH20). Triplicate groups of fish with9.1±0.01 gwere fed these diets for 60 days until visual satiation at a FF of 1, 2, or 3 meals per day. Distal intestine histomorphology was not affected by diet composition or FF. However, the pyloric caeca (PC) of fish fed 1 meal per day presented more gut fold height alterations than the other groups, except in fish fed diet P50/CH10 3 meals per day, where no changes was observed. Fish fed diet P40/CH20 3 meals per day also presented higher PC submucosa cellularity than the other groups. Fish fed diet P40/CH20 presented a higher number of operational taxonomic units, microbial richness, and diversity indices than fish fed diet P50/CH10. Amylase was the only measured digestive enzyme affected by the experimental conditions, presenting higher activity in fish fed diet P50/CH10 once per day. Glucose-6-phosphate dehydrogenase activity was lower in fish fed 2 meals per day than only 1. While catalase activity was lower in fish fed 2 than 3 meals per day. Glutathione reductase activity was the only measured parameter affected both by dietary P/CH ratio and FF, being inferior in fish fed once per day the P50/CH10 diet than the P40/CH20 diet and, also in the P50/CH10 diet, to fish fed 1 than those fed 3 meals per day. Overall, no major interactions was observed between dietary P/CH ratio and FF; however, a P40/CH20 diet fed 2 meals per day might be recommended for gilthead seabream juveniles.

The Differences between the Effects of a Nanoformulation and a Conventional Form of Atrazine to Lettuce: Physiological Responses, Defense Mechanisms, and Nutrient Displacement.

The rapid development of nanotechnology influences the developments within the agro-sector. An example is provided by the production of nanoenabled pesticides with the intention to optimize the efficiency of the pesticides. At the same time, it is important to collect information on the unintended and unwanted adverse effects of emerging nanopesticides on nontarget plants. Currently, this information is limited. In the present study, we compared the effects of a nanoformulation of atrazine (NPATZ) and the nonencapsulated atrazine formulation (ATZ) on physiological responses, defense mechanisms, and nutrient displacement in lettuce over time with the applied concentrations ranging from 0.3 to 3 mg atrazine per kg soil. Our results revealed that both NPATZ and ATZ induced significant decreases in plant biomass, chlorophyll content, and protein content. Additionally, exposure to NPATZ and ATZ caused oxidative stress to the lettuce plant and significantly elevated the activities of the tested ROS scavenger enzymes in plant tissues. These results indicate that NPATZ and ATZ cause distinct adverse impacts on lettuce plants. When comparing the adverse effects in plants after exposure to NPATZ and ATZ, no obvious differences in plant biomass and chlorophyll content were observed between NPATZ and ATZ treatments at the same exposure concentration regardless of exposure duration. An enhanced efficiency of the active ingredient of the nanopesticide as compared to the conventional formulation was observed after long-term exposure to the high concentration of NPATZ, as it induced higher impacts on plants in terms of the end points of the contents of protein, superoxide anion (O2˙–), and MDA, and the activities of stress-related enzymes as compared to the same concentration of ATZ. Furthermore, exposure to both NPATZ and ATZ disrupted the uptake of mineral nutrients in plants, and the differences in the displacement of nutrients between the NPATZ and ATZ treatments depended on the element type, plant organ, exposure concentration, and time. Overall, the application dose of a nanopesticide should balance their increased herbicidal efficiency with the long-term adverse effects in order to maximize the desired impact while minimizing adverse impacts; only then will we be able to understand the potential impact of nanopesticides on the environment.

CaFtsH06, A Novel Filamentous Thermosensitive Protease Gene, Is Involved in Heat, Salt, and Drought Stress Tolerance of Pepper (Capsicum annuum L.).

Harsh environmental factors have continuous negative effects on plant growth and development, leading to metabolic disruption and reduced plant productivity and quality. However, filamentation temperature-sensitive H protease (FtsH) plays a prominent role in helping plants to cope with these negative impacts. In the current study, we examined the transcriptional regulation of the CaFtsH06 gene in the R9 thermo-tolerant pepper (Capsicum annuum L.) line. The results of qRT-PCR revealed that CaFtsH06 expression was rapidly induced by abiotic stress treatments, including heat, salt, and drought. The CaFtsH06 protein was localized to the mitochondria and cell membrane. Additionally, silencing CaFtsH06 increased the accumulation of malonaldehyde content, conductivity, hydrogen peroxide (H2O2) content, and the activity levels of superoxide dismutase and superoxide (·O2−), while total chlorophyll content decreased under these abiotic stresses. Furthermore, CaFtsH06 ectopic expression enhanced tolerance to heat, salt, and drought stresses, thus decreasing malondialdehyde, proline, H2O2, and ·O2− contents while superoxide dismutase activity and total chlorophyll content were increased in transgenic Arabidopsis. Similarly, the expression levels of other defense-related genes were much higher in the transgenic ectopic expression lines than WT plants. These results suggest that CaFtsH06 confers abiotic stress tolerance in peppers by interfering with the physiological indices through reducing the accumulation of reactive oxygen species, inducing the activities of stress-related enzymes and regulating the transcription of defense-related genes, among other mechanisms. The results of this study suggest that CaFtsH06 plays a very crucial role in the defense mechanisms of pepper plants to unfavorable environmental conditions and its regulatory network with other CaFtsH genes should be examined across variable environments.

Physiological, Developmental, and Biomarker Responses of Zebrafish Embryos to Sub-Lethal Exposure of Bendiocarb

Bendiocarb is a broad-spectrum insecticide recommended for malaria control by the World Health Organization (WHO). Still, bendiocarb poses a toxic risk to populations of nontargeted aquatic organisms. Thus, our study was aimed to evaluate the sub-lethal effects of bendiocarb exposure on zebrafish (Danio rerio) embryos by assessing of physiological, developmental, and biochemical parameters. Bendiocarb-induced adverse effects on embryonic development, larval growth, heart rate, changes in phase II detoxifying enzyme glutathione-S-transferase (GST) activity, oxidative stress-related enzyme activities (superoxide dismutase (SOD), catalase (CAT)), and the damage-linked biomarker lipid peroxidation (LPO) in early life stage zebrafish were investigated. Our results highlight that the selected nonlethal concentrations (96 h median lethal concentration in this study was 32.52 mg/L−1) of bendiocarb inflicted adverse effects resulting in embryo deformities (96 h EC50 = 2.30 mg L−1), reduced body- and notochord length (above 0.75 and 0.39 mg L−1 bendiocarb concentrations at 96 hpf, respectively), oxidative stress, and altered heart rate (above 0.4 mg L−1 at 48 hpf) in the studied model system.

A new method for evaluating the effects of insecticidal proteins expressed by transgenic plants on ectoparasitoid of target pest

Transgenic Bt insect-resistant plants are highly resistant to Lepidoptera stockpile pest Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae), a storage pest. Habrobracon hebetor (Say) (Hymenoptera: Braconidae), which is an ectoparasitic wasp of Indian meal moth, may be exposed to the Bt protein through the food chain. In the current study, high dose of Cry1C protein was injected into the hemolymph of P. interpunctella by microinjection, and the hemolymph was used as the carrier to deliver Bt protein to the H. hebetor. Using this method, we developed a new Tier-1 risk assessment system for ectoparasitoid, successfully avoided "host/prey quality-mediated effect," and improve the accuracy of safety evaluation. Results showed that injected Cry1C was stable and bioactive in the hemolymph of P. interpunctella parasitized by H. hebetor, and high dose of Cry1C has no negative impacts on egg hatching rate, developmental duration from egg to adult, survival egg to adult, pupa weight, adults weight (male and female), adult longevity and reproduction, and activity of stress-related enzymes of H. hebetor. However, the hemolymph of P. interpunctella injected into Galanthus nivalis L. agglutinin (the positive control) had significant negative impact on these biological parameters of H. hebetor. The results indicate that H. hebetor are not sensitive to Cry1C protein at the tested concentration and there were no detrimental effects of Cry1C protein on any biological parameters tested in the present study. More importantly, we constructed a new efficient and simple system for the biosafety assessment on the larvae of ectoparasitoid of target pest.

Triacontanol Promotes the Fruit Development and Retards Fruit Senescence in Strawberry: A Transcriptome Analysis.

Triacontanol (TA) is a non-toxic, pollution-free, low-cost, high-efficiency, broad-spectrum plant growth regulator that plays an important role in plant growth and development, but its regulation mechanism of strawberry (Sweet charlie, Fragaria × ananassa Duch.) fruit development is still unclear. In this study, we showed that TA treatment (50 μM) could promote fruit development by up-regulating factors related to fruit ripening-related growth and development. TA increased fruit sugar content and anthocyanin accumulation, and many stress-related enzyme activities. In the meantime, Illumina RNA-Seq technology was used to evaluate the effect of TA treatment on strawberry fruit senescence. The results showed that 9338 differentially expressed genes (DEGs) were obtained, including 4520 up-regulated DEGs and 4818 down-regulated DEGs. We performed gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these DEGs. The results showed that TA treatment caused changes in transcript levels related to cellular processes, hormones and secondary metabolism, such as DNA metabolic processes, flavonoid synthesis, and plant hormone signal transduction. Bioinformatics analysis showed that many transcription factors were related to fruit maturity. Taken together, this study will provide new insights into the mechanism of strawberry development and postharvest response to TA treatment.

Assessing the effects of Cry2Aa protein on Habrobracon hebetor (Hymenoptera: Braconidae), a parasitoid of Indian meal moth, Plodia interpunctella (lepidoptera: Pyralidae).

Transgenic crops express Cry proteins exhibit high resistant to target insect pests. When we evaluate the effects of Cry proteins on the parasitoid of target insect pest via tritrophic experiments (transgenic plant-target insect pest-parasitoid) host quality of parasitoids might decrease because of insecticidal protein ingestion, this would cause host-quality mediated effects and influence the accuracy of biosafety assessment. In the current study, high dose of Cry2Aa protein was injected into the hemolymph of Plodia interpunctella by microinjection, and the hemolymph was used as the carrier to deliver Cry protein to Habrobracon hebetor, which has been previously reported as an ectoparasitoid of P. interpunctella larval, in order to avoid the "host-quality mediated effects". Results showed that injected Cry2Aa remained at high concentration and bioactive in the hemolymph of P. interpunctella parasitized by H. hebetor, the hemolymph of P. interpunctella could be used as carriers of Cry protein to H. hebetor, and high dose of Cry2Aa have no negative impacts on the development time, weight of pupa, sex ratio, adults weight (male and female), adult longevity and fecundity, and the activity of stress-related enzymes of H. hebetor. However, the hemolymph of P. interpunctella injected into Galanthus nivalis agglutinin (the positive control) showed significant negative impact on these parameters measured in the present study of H. hebetor. This indicated that Cry2Aa protein had no detrimental effects on the biological parameters of H. hebetor measured in the current study. Meanwhile, this study provides a new method for the safety evaluation of the ectoparasitoids of target pest and might be expanded to the other species of ectoparasitoids of target insects of Cry proteins in biosafety risk assessment.

The Effect of Cadmium on the Activity of Stress-Related Enzymes and the Ultrastructure of Pea Roots.

The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the ultrastructure of roots of Pisum sativum L. after seven days of Cd treatment (10, 50, 100, and 200 μM CdSO4). Our results showed that phenylalanine ammonia-lyase (PAL) activity and the amount of Cd accumulated in the roots were significantly positively correlated with the Cd concentration used in our experiment. However, Cd caused a decrease of all studied antioxidative enzyme activities (i.e., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX)). The analysis of the ultrastructure (TEM) showed various responses to Cd, depending on Cd concentrations. In general, lower Cd concentrations (50 and 100 μM CdSO4) mostly resulted in increased amounts of oil bodies, plastolysomes and the accumulation of starch granules in plastids. Meanwhile, roots treated with a higher concentration of Cd (200 μM CdSO4) additionally triggered protective responses such as an increased deposition of suberin lamellae in the endodermal cell walls. This indicates that Cd induces a complex defense response in root tissues.

N-3 Canola oil effectively replaces fish oil as a new safe dietary source of DHA in feed for juvenile Atlantic salmon.

Limited availability of fish oils (FO), rich in n-3 long-chain (≥C20) PUFA, is a major constraint for further growth of the aquaculture industry. Long-chain n-3 rich oils from crops GM with algal genes are promising new sources for the industry. This project studied the use of a newly developed n-3 canola oil (DHA-CA) in diets of Atlantic salmon fingerlings in freshwater. The DHA-CA oil has high proportions of the n-3 fatty acids (FA) 18 : 3n-3 and DHA and lower proportions of n-6 FA than conventional plant oils. Levels of phytosterols, vitamin E and minerals in the DHA-CA were within the natural variation of commercial canola oils. Pesticides, mycotoxins, polyaromatic hydrocarbons and heavy metals were below lowest qualifiable concentration. Two feeding trials were conducted to evaluate effects of two dietary levels of DHA-CA compared with two dietary levels of FO at two water temperatures. Fish increased their weight approximately 20-fold at 16°C and 12-fold at 12°C during the experimental periods, with equal growth in salmon fed the FO diets compared with DHA-CA diets. Salmon fed DHA-CA diets had approximately the same EPA+DHA content in whole body as salmon fed FO diets. Gene expression, lipid composition and oxidative stress-related enzyme activities showed only minor differences between the dietary groups, and the effects were mostly a result of dietary oil level, rather than the oil source. The results demonstrated that DHA-CA is a safe and effective replacement for FO in diets of Atlantic salmon during the sensitive fingerling life-stage.

Growth promotion and disease resistance induced in Anthurium colonized by the beneficial root endophyte Piriformospora indica

BackgroundAnthurium andraeanum, an important ornamental flower, has to go through a growth-delaying period after transfer from tissue culture to soil, which requires time and extra costs. Furthermore, during this period, the plantlets are highly susceptible to bacterial infections, which results in impaired development and severe losses. Here, we aimed to address whether application of the endophytic fungus, Piriformospora indica protects the A. andraeanum root system during the critical propagation period, and whether P. indica reduce the mortality rate by stimulating the host’s resistance against diseases.ResultsWe demonstrate that P. indica shortens the recovery period of Anthurium, promotes growth and confers disease resistance. The beneficial effect of P. indica results in faster elongation of Anthurium roots early in the interaction. P. indica-colonized plants absorb more phosphorus and exhibit higher photosynthesis rates than uncolonized control plants. Moreover, higher activities of stress-related enzymes, of jasmonic acid levels and mRNA levels of jasmonic acid-responsive genes suggest that the fungus prepares the plant to respond more efficiently to potentially upcoming threats, including bacterial wilt.ConclusionThese results suggest that P. indica is a helpful symbiont for promoting Anthurium rooting and development. All our evidences are sufficient to support the disease resistance conferred by P. indica through the plant-fungal symbiosis. Furthermore, it implicates that P. indica has strong potential as bio-fertilizer for utilization in ornamental plant cultivation.

μEvaluation of microcystin-LR absorption using an in vivo intestine model and its effect on zebrafish intestine

Microcystin-LR (MC-LR) is regarded as one of the most toxic microcystins (MCs) isoforms. Microcystins could cause multiple organs dysfunction, and more attention has been drawn to the toxic effects on the gastrointestinal disorder. By using ex vivo everted gut sac model in 6 fish (Carassius auratus, Megalobrama amblycephala, Hypophthalmichthys molitrix, Aristichthys nobilis, Ctenopharyngodon idellus and Cyprinus carpio) and determining the accumulation of MC-LR in zebrafish intestine, we found a dose-dependent manner in the absorption and accumulation of MC-LR. Until now, little studies have been reported concerning the gut microbiota composition caused by different MC-LR exposure. The present study is the first time characterized the phylogenetic composition and taxonomic of the bacterial communities growth in the intestines of zebrafish treated with MC-LR using 16S rRNA pyrosequencing. After 30 days of treatment with 0, 1, 5 or 20 μg/L MC-LR, the alpha and beta diversity did not generate significant differences, indicating the existence of a core microbiota. However, db-RDA analysis showed that treatment with 20 μg/L MC-LR changed the characteristics of high abundances microbiota. The expression of Oatp2b1, stress related enzyme activities in gut and their associations with gut microbiota were also determined. The identified phylotypes including Actinobacteria, Lactobacillus and some opportunistic pathogens highlight the increasing risks of pathogen invasion and recovery tendency via potential probiotics resistance in zebrafish exposed to MC-LR.

Genome-wide identification and expression analysis of the apple ASR gene family in response to Alternaria alternata f. sp. mali.

The ABA/water stress/ripening-induced (ASR) gene family exists universally in higher plants, and many ASR genes are up-regulated during periods of environmental stress and fruit ripening. Although a considerable amount of research has been performed investigating ASR gene response to abiotic stresses, relatively little is known about their roles in response to biotic stresses. In this report, we identified five ASR genes in apple (Malus × domestica) and explored their phylogenetic relationship, duplication events, and selective pressure. Five apple ASR genes (Md-ASR) were divided into two clades based on phylogenetic analysis. Species-specific duplication was detected in M. domestica ASR genes. Leaves of 'Golden delicious' and 'Starking' were infected with Alternaria alternata f. sp. mali, which causes apple blotch disease, and examined for the expression of the ASR genes in lesion areas during the first 72 h after inoculation. Md-ASR genes showed different expression patterns at different sampling times in 'Golden delicious' and 'Starking'. The activities of stress-related enzymes, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia lyase (PAL), and polyphenoloxidase (PPO), and the content of malondialdehyde (MDA) were also measured in different stages of disease development in two cultivars. The ASR gene expression patterns and theses physiological indexes for disease resistance suggested that Md-ASR genes are involved in biotic stress responses in apple.

Biochemical changes involved in self-incompatibility in two cultivars of olive (Olea europaea L.) during flower development

ABSTRACTBiochemical analyses were carried out to characterise the basis of self-incompatibility in the olive (Olea europaea L.) cultivars ‘Amygdalolia’ and ‘Konservalia’. Multiple interactions between cells of different types, origin, and function occur in the pistil. Endogenous factors play important roles in ovary and fruit development before (Stage 1) and during pollination (Stage 2), and after fertilisation (Stage 3). Changes in carbohydrate, protein, H2O2, and calcium ion concentrations, and in peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase activities in pistil tissue before and during pollination, and after fertilisation were investigated. In both cultivars, H2O2 concentrations were significantly higher in pistil tissue before pollination, after which they started to decrease in Stage 2 and continued non-significantly in Stage 3. Peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase activities were lower at Stage 1 and Stage 2, whereas these enzyme activities increased at Stage 3 in both cultivars. The lowest concentration of calcium ions was observed at Stage 1, whereas at Stage 2, calcium ion concentrations increased and reached their highest level, then decreased at Stage 3. Calcium ion concentrations in ‘Konservalia’ were higher than in ‘Amygdalolia’. In ‘Konservalia’, the highest protein concentration was observed at Stage 2. No significant differences were found in carbohydrate concentrations between the two cultivars. The biological significance of the presence of these products may differ between Stage 1, when they have a defence function, Stage 2 when there are interactions between pollen and pistil, and Stage 3 after fertilisation. This study provides support for the hypothesis that there is a correlation between self-incompatibility, stress-related enzyme activities, and calcium ion concentrations in the pistils of olive.