Endophytic Bacteria Pseudomonas aeruginosa PM389 Subsists Host’s (Triticum aestivum) Immune Response for Gaining Entry Inside the Host

The present study was designed to compare the defense response of the host plant towards endophytic bacteria Pseudomonas aeruginosa PM389 and pathogenic bacteria Erwinia carotovora and to correlate the level of defense enzymes vis-a-vis bacterial colonization in the host. Wheat seedlings were treated with 107-108 cells ml-1 endophytic and pathogenic bacteria in the separate experimental set-up, and the level of plant defense enzyme was measured at various time intervals. Comparatively reduced level of most defense enzymes was produced in endophytic bacteria treated plants. While the endophytic bacterial population was almost constant after 24 HAI (hour after inoculation), the population of pathogenic bacteria kept fluctuating during the study period from 24 HAI. Unlike pathogenic bacteria, we observed attenuated defense response in challenged host plants towards endophytic bacteria, which helps endophytes establish inside plant. This study would be useful for understanding the mechanism of colonization and strategies of endophytes to fight against the host defense response.

Selenium/Chitosan-Folic Acid Metal Complex Ameliorates Hepatic Damage and Oxidative Injury in Male Rats Exposed to Sodium Fluoride

Continuous exposure to sodium fluoride (NaF) imbalances the oxidative status in the body. The current study investigated the effect of the selenium/chitosan-folic (Se/chitosan-folic acid) novel metal complex on oxidative injury and tissue damage in the hepatic tissues of male rats exposed to (NaF). Male rats received NaF (10.3 mg/kg) and Se/chitosan-folic acid (0.5 mg/Kg) orally for successive 30 days. Male rats exposed to NaF showed multi-histopathological alterations in the hepatic tissues including degenerative changes. NaF exposure elevated hepatic oxidative stress markers, lipid peroxidation, and lowered the antioxidant defense enzymes. Se/chitosan-folic acid novel complex supplementation significantly prevented hepatic injury, suppressed reactive oxygen species (ROS) generation and lipid peroxidation, and enhanced the antioxidant defense enzymes. In addition, Se/chitosan-folic acid supplementation improved the hepatic tissues of NaF-exposed male rats. In conclusion, the Se/chitosan-folic acid novel metal complex protects against NaF-induced oxidative injury and tissue injury in the hepatic tissues of male rats. The Se/chitosan-folic acid novel metal complex upregulated the hepatic tissues and enhanced the antioxidant defense enzymes in male rats.

Physiology Response and Resistance Evaluation of Twenty Coconut Germplasm Resources under Low Temperature Stress

Coconut (Cocos nucifera L.) is a tropical evergreen crop with high economic value. Low temperature is one of the main environmental factors that limit coconut productivity. Therefore, it is necessary and significant to research the growth trend and physiological changes of coconuts under a low temperature environment. In this study, the physiological response of 20 coconut germplasm resources is presented in an integrated perspective to provide a holistic view of the behavior of coconut trees facing cold stress under four temperature conditions (25 °C, 15 °C, 10 °C, 5 °C). It was shown that low temperature would lead to the increase of relative electrical conductivity, MDA content, soluble protein content, and proline content. In addition, the activities of defense enzymes (SOD, POD, CAT, APX) were increased to resist the cold environment. In a comprehensive analysis, it was revealed that coconut germplasms with high cold resistance, such as C2, C7, and C10 as well as POD activity, proline content, and soluble protein content, were defined as representatives for coconut cold resistance evaluation. Through the exploration of osmotic adjustment substances and defense enzymes, the breeding and quality improvement of cold-resistant coconut varieties could be promoted. As a result, understanding the physiological response and tolerance mechanisms of coconuts to low temperature stress was essential, as this perception may serve as the foundation for coconut resistance evaluation, cultivation, and breeding.

Differential Responses of Cucurbita pepo to Podosphaera xanthii Reveal the Mechanism of Powdery Mildew Disease Resistance in Pumpkin

Powdery mildew is one of the most destructive diseases and the major cause to the production losses of cucurbit worldwide. A number of strategies have been developed and applied to discover suitable and safer methods to manage the occurrence of powdery mildew disease in pumpkins (Cucurbita pepo L.), but information is limited in screening tolerant germplasms and exploring their mechanisms in preventing the disease occurrence at physiological, biochemical, and molecular levels. Therefore, we investigated the responses of two commercial pumpkin cultivars to Podosphaera xanthii infection. Compared with mock-inoculated seedlings, few small and sparse powdery areas were observed on the leaves of the Sixing F1 cultivar on the 13th day after inoculation with P. xanthii, whereas a large number of diseased powdery areas and a layer of white powdery mildew were observed on the surface of Jin12 F1 leaves. The inoculation duration (7, 9, 11, and 13 days) significantly and continuously increased the disease incidence and index of pumpkin seedlings. The contents of H2O2, MDA, lignin, and total phenolics in the leaves of Sixing F1 and Jin12 F1 cultivars were markedly increased after inoculation with P. xanthii. However, the Sixing F1 cultivar exhibited much less reactive oxygen species (ROS) accumulation, a lower rate of lipid peroxidation, and a higher level of lignin and total phenolics contents after inoculation than the Jin12 F1 cultivar. Compared with untreated control pumpkin seedlings, significantly higher activities and gene expressions of the phenylpropanoids pathway enzymes (PAL and PPO), ROS scavenging defense enzymes (SOD, CAT, POD, and APX), and other salicylic acid (SA) signaling pathway marker genes were observed in the leaves of both cultivars after P. xanthii inoculation at different inoculation time points. These enhancements were significantly higher in Sixing F1 than Jin12 F1. Our results indicate that the Sixing F1 cultivar exhibited a much stronger ability in resistance to P. xanthii infection than the Jin12 F1 cultivar. Our results suggest that one possible mechanism of C. pepo cultivars to prevent the pathogen P. xanthii infection is by activating and enhancing the activity and gene expression of the phenylpropanoids pathway to synthesize phenolic substances and lignin, ROS scavenging defense enzymes to eliminate the harmful effects of ROS, and signaling pathway marker gene expression to improve plant disease resistance.

Overexpression of DBF-Interactor Protein 6 Containing an R3H Domain Enhances Drought Tolerance in Populus L. (Populus tomentosa)

Drought is the primary disaster that endangers agricultural production, including animal husbandry, and affects the distribution, growth, yield, and quality of crops. Previous study had revealed that DIP, as a potential regulator of DBF activity, played an important role in response to drought stress in maize. In this study, a total of 67 DIPs were identified from seventeen land plants, including six tobacco DIPs (NtDIPs). NtDIP6 gene was further selected as a candidate gene for subsequent experiments based on the phylogenetic analysis and structural analysis. The transgenic tobacco and poplar plants over-expressing NtDIP6 gene were generated using the Agrobacterium- mediated method. Although there was not phenotypic difference between transgenic plants and wild-type plants under normal conditions, overexpression of the NtDIP6 gene in transgenic tobacco and poplar plants enhanced the drought tolerance under drought treatments in comparison with the wild type. The content of antioxidant defense enzymes peroxidase (POD), catalase (CAT), and the photosynthetic rate increased in NtDIP6-Ox transgenic tobacco and poplar plants, while the content of malondialdehyde decreased, suggesting that the overexpression of NtDIP6 enhances the antioxidant capacity of transgenic poplar. Furthermore, the results of qRT-PCR showed that the level of expression of drought-related response genes significantly increased in the NtDIP6-Ox transgenic plants. These results indicated that NtDIP6, as a positive response regulator, improves drought stress tolerance by scavenging superoxide via the accumulation of antioxidant defense enzymes.

Effect of Xenon on the Phosphorylation of Glycogen Synthase Kinase 3β and Antioxidant Enzymes in Rat Brain

Relevance. The increase in the number of severe brain injuries due to stroke and traumatic brain injury determines the need to study and develop effective strategies for neuroprotection. The article highlights new mechanisms of the neuroprotective action of the inhalation anesthetic xenon based on the data of our own experimental studies.Aim of study. To assess the effect of anesthesia with xenon at a concentration of 0.5 MAC (minimum alveolar concentration) on the phosphorylation of glycogen synthase kinase 3β (GSK-3β) and the content of antioxidant defense enzymes in the rat brain.Material and methods. The effect of inhalation anesthesia with xenon on the phosphorylation of the GSK-3β enzyme in comparison with lithium chloride, as well as on the content of heme oxygenase, catalase, and Mn-superoxide dismutase in rat brain homogenates was studied by immunoblotting.Results. The use of xenon at a concentration of 0.5 MAA causes an almost twofold increase in the content of the phosphorylated form of the GSK-3β enzyme in comparison with the control (p<0.05) and significantly increases the pool of antioxidant defense enzymes: heme oxygenase by 50% (p <0.05) and Mn-superoxide dismutase by 60% (p<0.05).Conclusion. The conducted experimental study revealed new molecular mechanisms of action of the inhalation anesthetic xenon. The effect of xenon on the pool of enzymes involved in the protection of the brain from oxidative distress was found. The data obtained indicate the prospects for using xenon and require further research in this direction. The use of xenon at a concentration of 50 vol.% (0.5 MAA) for 30 minutes does not affect the content of the glycogen synthase-3β enzyme, at the same time causing an almost twofold increase in its phosphorylated form, the glycogen synthase-3β enzyme, and is accompanied by a significant increase the content of heme oxygenase, Mn-superoxide dismutase and a slight increase in the content of catalase in rat brain homogenates. Thus, the results of the study suggest that one of the possible mechanisms of the neuroprotective effect of xenon is the phosphorylation of glycogen synthase-3β, which prevents the opening of the mitochondrial pore, inhibiting the death of mitochondria-mediated apoptosis of neurons and increasing the level of antioxidant protection in them.

Prospects for the use of highly effective and safe stimulants of embryogenesis in poultry farming

To increase the embryonic and postembryonic viability of poultry, along with selection work, optimization of the microclimate parameters of poultry houses and rations, it is also advisable to develop resource-saving and environmentally friendly methods of using biologically active substances. It was shown that the treatment of eggs with a composition of solutions of natural metabolites (colamine, succinic acid and Ribav) in optimal concentrations stopped and prevented the negative effects of stress. Positive biochemical and morphological changes were observed in the development of chick embryos. An increase in chick withdrawal, a decrease in all incubation waste, an increase in the activity of antioxidant defense enzymes, and a decrease in the content of malondialdehyde in the blood serum of chickens were found.

Induction of Phytoalexins Gliceoline and Proteins Related to Defense in Soybean Cotyledon Treated With Yeast

Yeasts can induce mechanisms of plant resistance due to compounds with eliciting characteristics, so the aim of this work was to evaluate the effect of yeast on the induction of phytoalexins gliceoline, peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase from soy cotyledons. To determine the defense enzymes, soybean seeds were sown and the cotyledons treated with sterile distilled water, Cryptococcus laurentii (AH 03-1), Pichia guilliermondii (AH 16-2), Rhodotorula glutinis (AH 14-3), Sporidiobolus johnsonii (AH 16-1) and Zygoascus hellenicus (AH 14-1). Biochemical analyzes of the formation of phytoalexins and the activity of the enzymes peroxidase, polyphenoloxidase, phenylalanine ammonia-lyase and total proteins were performed. For phytoalexins glycerolins the yeasts Cryptococcus laurentii (AH 03-1) and Zygoascus hellenicus (AH 14-1) promoted an increase of 83.65% and 78.75% in the formation of this compound. Cryptococcus laurentii (AH 03-1) increased peroxidase activity by 36.84%, while for polyphenoloxidase, the Pichiaguilliermondii e yeasts (AH 16-2), Rhodotorula glutinis (AH 14-3), Sporidiobolus johnsonii (AH 16-1) and Zygoascus hellenicus (AH 14-1), increased the activity of this enzyme by 33.33%, 28.00%, 33.33% and 33.33%, respectively. For phenylalanine ammonia-lyase, Cryptococcus laurentii (AH 03-1) and Zygoascushellenicus (AH 14-1) promoted an increase of 75.57% and 78.86%, respectively, in their activity. The results demonstrate the potential of yeasts studied in the induction of phytoalexins glyceolins and in the activity of peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase in soybean cotyledons.