Iron/Copper/Phosphate nanocomposite as antimicrobial, antisnail, and wheat growth-promoting agent.

BACKGROUND: One of the current challenges is to secure wheat crop production to meet the increasing global food demand and to face the increase in its purchasing power. Therefore, the current study aimed to exploit a new synthesized nanocomposite to enhance wheat growth under both normal and drought regime. The effectiveness of this nanocomposite in improving the microbiological quality of irrigation water and inhibiting the snail's growth was also assessed. RESULTS: Upon the employed one-step synthesis process, a spherical Fe/Cu/P nanocomposite was obtained with a mean particle size of 4.35 ± 1.524 nm. Cu2+, Fe2+, and P4+ were detected in the dried nanocomposite at 14.533 ± 0.176, 5.200 ± 0.208, and 34.167 ± 0.203 mg/ml concentration, respectively. This nanocomposite was found to exert antibacterial activity against Escherichia coli and Salmonella typhi. It caused good inhibition percent against Fusarium oxysporum (43.5 ± 1.47%) and reduced both its germination rate and germination efficiency. The lethal concentration 50 (LC50) of this nanocomposite against Lanistes carinatus snails was 76 ppm. The treated snails showed disturbance in their feeding habit and reached the prevention state. Significant histological changes were observed in snail digestive tract and male and female gonads. Drought stress on wheat's growth was mitigated in response to 100 and 300 ppm treatments. An increase in all assessed growth parameters was reported, mainly in the case of 100 ppm treatment under both standard and drought regimes. Compared to control plants, this stimulative effect was accompanied by a 2.12-fold rise in mitotic index and a 3.2-fold increase in total chromosomal abnormalities. CONCLUSION: The finding of the current study could be employed to mitigate the effect of drought stress on wheat growth and to enhance the microbiological quality of irrigation water. This is due to the increased efficacy of the newly synthesized Fe/Cu/P nanocomposite against bacteria, fungi, and snails. This methodology exhibits potential for promoting sustainable wheat growth and water resource conservation.

Enhancing drought tolerance in Malva parviflora plants through metabolic and genetic modulation using Beauveria bassiana inoculation.

BACKGROUND: Enhancing crops' drought resilience is necessary to maintain productivity levels. Plants interact synergistically with microorganisms like Beauveria bassiana to improve drought tolerance. Therefore, the current study investigates the effects of biopriming with B. bassiana on drought tolerance in Malva parviflora plants grown under regular irrigation (90% water holding capacity (WHC)), mild (60% WHC), and severe drought stress (30% WHC). RESULTS: The results showed that drought stress reduced the growth and physiological attributes of M. parviflora. However, those bioprimed with B. bassiana showed higher drought tolerance and enhanced growth, physiological, and biochemical parameters: drought stress enriched malondialdehyde and H2O2 contents. Conversely, exposure to B. bassiana reduced stress markers and significantly increased proline and ascorbic acid content under severe drought stress; it enhanced gibberellic acid and reduced ethylene. Bioprimed M. parviflora, under drought conditions, improved antioxidant enzymatic activity and the plant's nutritional status. Besides, ten Inter-Simple Sequence Repeat primers detected a 25% genetic variation between treatments. Genomic DNA template stability (GTS) decreased slightly and was more noticeable in response to drought stress; however, for drought-stressed plants, biopriming with B. bassiana retained the GTS. CONCLUSION: Under drought conditions, biopriming with B. bassiana enhanced Malva's growth and nutritional value. This could attenuate photosynthetic alterations, up-regulate secondary metabolites, activate the antioxidant system, and maintain genome integrity.

Characterization and genomics identification of key genes involved in denitrification-DNRA-nitrification pathway of plant growth-promoting rhizobacteria (Serratia marcescens OK482790).

BACKGROUND: A wide variety of microorganisms, including bacteria, live in the rhizosphere zone of plants and have an impact on plant development both favorably and adversely. The beneficial outcome is due to the presence of rhizobacteria that promote plant growth (PGPR). RESULTS: In this study, a bacterial strain was isolated from lupin rhizosphere and identified genetically as Serratia marcescens (OK482790). Several biochemically and genetically characteristics were confirmed in vitro and in vivo to determine the OK482790 strain ability to be PGPR. The in vitro results revealed production of different lytic enzymes (protease, lipase, cellulase, and catalase), antimicrobial compounds (hydrogen cyanide, and siderophores), ammonia, nitrite, and nitrate and its ability to reduce nitrate to nitrite. In silico and in vitro screening proposed possible denitrification-DNRA-nitrification pathway for OK482790 strain. The genome screening indicated the presence of nitrite and nitrate genes encoding Nar membrane bound sensor proteins (NarK, NarQ and NarX). Nitrate and nitrite reductase encoding genes (NarI, NarJ, NarH, NarG and NapC/NirT) and (NirB, NirC, and NirD) are also found in addition to nitroreductases (NTR) and several oxidoreductases. In vivo results on wheat seedlings confirmed that seedlings growth was significantly improved by soil inoculation of OK482790 strain. CONCLUSIONS: This study provides evidence for participation of S. marcescens OK482790 in nitrogen cycling via the denitrification-DNRA-nitrification pathway and for its ability to produce several enzymes and compounds that support the beneficial role of plant-microbe interactions to sustain plant growth and development for a safer environment.

Genetic diversity of a global collection of maize genetic resources in relation to their subspecies assignments, geographic origin, and drought tolerance.

The genetic diversity among an international collection of 40 maize accessions has been evaluated using DNA ISSR fingerprinting. Among the 180 ISSR markers scored by 15 primers, 161 markers (89.59%) were polymorphic and 19 were unique in 16 accessions. A cluster tree based on the average distance coefficients and the Dice similarity indices divided the accessions into three major groups, each including clusters of accessions assigned to their subspecies. However, a low level of genetic differentiation among the accessions was demonstrated by the STRUCTURE analysis of ISSR data in agreement with the low gene flow (Nm) value among the accessions. A scatter diagram of the principal component analysis (PCA) based on ISSR data analysis revealed that the accessions were differentiated into three groups comparable to those produced by the cluster analysis, in which some accessions of the same subspecies showed a close similarity to each other. A scatter diagram of the principal coordinate analysis (PCoA) based on the drought tolerance indices (DTIs) showed that nine genetically similar accessions share drought tolerance characteristics; these include four of subsp. indurata, three of subsp. everata, and two of subsp. indentata. An abundance of unique ISSR alleles found in the 16 accessions, including the nine drought-tolerant accessions, represents rich untapped genetic resources and these accessions may be exploited in the future breeding of maize commercial lines.

Preserving the adaptive salt stress response activity of a tissue-specific promoter with modulating activity.

BACKGROUND: The Arabidopsis "Redox Responsive Transcription Factor1" (RRTF1) promoter is transiently activated by salt stress in roots over 6 h period, followed by an adaptation phase during which its activity returns to baseline levels, even if the salt stress is prolonged. This enables the short-term production of genes that, while initially advantageous to the plant, will have long-term detrimental effects if expressed at high levels indefinitely. RESULTS: In this paper, we demonstrate that the RRTF1 promoter salt adaption response is a dominant feature of the promoter, that cannot be overwritten by a strong enhancer. While maintaining the transient activation profile of the RRTF1 promoter, linking it to the 35S enhancer results in a significant boost of salt stress induction in roots. CONCLUSION: The RRTF1 promoter's enhanced and still adaptable activity could become a useful tool in plant biotechnology.

Quantitative RT-PCR detection of human noroviruses and hepatitis A virus in fresh produce and surface water used for irrigation in the Mansoura and Giza regions, Egypt.

Surface water used as an irrigation source can be a significant source of viral contamination of fresh produce. Enteric viruses such as hepatitis A virus (HAV) and human norovirus genogroup I (HNoV GI) and genogroup II (HNoV GII) can be transmitted to human via fresh produce when irrigated with contaminated water or when prepared by infected food handlers. In the current study, we investigated the presence of HAV, HNoV GI and GII in fresh produce and surface water used in cultivation of this produce using real-time PCR. Samples were collected from six different points in the Mansoura and Giza regions, Egypt. Our analysis showed that at least one virus was found in 41.6% (30/72) of surface water samples and 27% (13/48) of fresh produce samples. HAV (23/72) with a mean viral concentration = 4 × 106 genome copies/litre (GC/L) was the most frequently identified virus in surface water samples, followed by human norovirus genogroup II (HNoV GII) (15/72, with a mean concentration = 1.2 × 106 GC/L, and human noroviruses genogroup I (HNoV GI) (12/72, with a mean concentration = 1.4 × 104 GC/L). Additionally, HAV (10/48) with a mean concentration = 5.2 × 105 genome copies/gram (GC/g) was also the most frequently detected virus in the fresh produce samples, followed by HNoV GII (8/48, with a mean concentration = 1.7 × 104 GC/g); meanwhile, HNoV GI (6/48) was less detected virus with a mean concentration = 3 × 103 GC/g. This work suggests a wide prevalence of human enteric viruses in surface waters and fresh produce, which is of concern when the fresh produce is eaten raw. Thus, additional monitoring for viral pathogens in irrigation water and food is needed to increase the awareness of this issue to rise the control measures to reduce illness from contaminated food.

Detection of Norovirus and Hepatitis A Virus in Strawberry and Green Leafy Vegetables by Using RT-qPCR in Egypt.

There is an upward trend of consumption of organic fresh vegetables due to consumer demand for healthy foods without chemical additives. On the other hand, the number of food borne outbreaks associated with contaminated fresh produce has raised, being human norovirus genogroup I (GI), GII and hepatitis A virus (HAV) the most commonly reported causative agents. This study aimed to detect the presence of these viruses in green leafy vegetables (watercress, leek, coriander, and parsley) and strawberry using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Samples were collected from the Egyptian regions of Kalubia, Giza, and Mansoura. Overall HAV average occurrence in fresh strawberry was 48% with a mean concentration of 6.1 × 103 GC/g; Also NoV GI overall average occurrence was 25% with a mean concentration of 9.7 × 102 genome copies (GC)/g, while NoV GII was 40% with a mean concentration of 2.4 × 103 GC/g. For strawberry collected directly from Kalubia farms, neither HAV nor HNoV GI & GII were detected. In green leafy vegetable samples, the occurrence of HAV was 31.2% with a mean concentration of 9.2 × 104 GC/g, while occurrence of NoV GI and NoV GII were 20% and 30% with a mean concentrations of 1.1 × 104 and 2.03 × 103 GC/g, respectively. In conclusion, the importance of a virus surveillance program for soft fruits and fresh vegetables is highlighted by the outcomes of this study. Our findings should help with the management and control of microbial concerns in fresh foods, reducing the danger of consuming contaminated foods.

Molecular identification and antimicrobial activities of some wild Egyptian mushrooms: Bjerkandera adusta as a promising source of bioactive antimicrobial phenolic compounds.

BACKGROUND: The discovery of potential, new cost-effective drug resources in the form of bioactive compounds from mushrooms is one way to control the resistant pathogens. In the present research, the fruiting bodies of five wild mushrooms were collected from Egypt and identified using internal transcribed spacer region (ITS) of the rRNA encoding gene and their phylogenetic relationships, antimicrobial activities, and biochemical and phenolic compounds were evaluated. RESULTS: The sequences revealed identity to Bjerkandera adusta, Cyclocybe cylindracea, Agrocybe aegerita, Chlorophyllum molybdites, and Lentinus squarrosulus in which Cyclocybe cylindracea and Agrocybe aegerita were closely related, while Chlorophyllum molybdites was far distant. Cyclocybe cylindracea and Agrocybe aegerita showed 100% similarity based on the sequenced ITS-rDNA fragment and dissimilar antimicrobial activities and chemical composition were detected. Bjerkandera adusta and Cyclocybe cylindracea showed strong antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Streptococcus pneumoniae, and Candida albicans. This activity could be attributed to the detected phenolic and related compounds' contents. CONCLUSION: Our finding provides a quick and robust implement for mushroom identification that would facilitate mushroom domestication and characterization for human benefit.

Rhamnolipids Nano-Micelles as a Potential Hand Sanitizer.

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.

Nanoparticles induce genetic, biochemical, and ultrastructure variations in Salvadora persica callus.

BACKGROUND: Salvadora persica is an endangered medicinal plant due to difficulties in its traditional propagation. It is rich in bioactive compounds that possess many pharmaceutical, antimicrobial activities and widely used in folk medicine. The current study aims at in vitro propagation of Salvadora persica and the application of different nanoparticles (NPs) to induce the synthesis of bioactive and secondary metabolites within the plant. The cellular and genetic responses to the application of different NPs were evaluated. RESULTS: The impact of nanoparticles NPs (ZnO, SiO2, and Fe3O4) on callus growth of Salvadora persica and the production of its active constituent benzyl isothiocyanate was examined, regarding some oxidative stress markers, antioxidant enzymes, and genetic variabilities. An encouraging impact of 0.5 mg/l ZnO NPs on benzyl isothiocyanate production was shown reaching up to 0.905 mg/g callus fresh weight in comparison to 0.539 mg/g in control callus. This was associated with decreasing hydrogen peroxide content and increasing superoxide dismutase and peroxidase activities. The deposition of the NPs on cellular organelles was detected using a transmission microscope. Fifteen Inter-Simple Sequence Repeats (ISSR) primers detected an overall, 79.1% polymorphism among different treatments. A reduction in genomic DNA template stability (GTS) was made and was more pronounced in higher doses of different NPs. CONCLUSION: This study is a stepping stone in developing a productive protocol for in vitro production of benzyl isothiocyanate from Salvadora persica using NPs as a valuable anticancer compound.

Responsiveness and Adaptation to Salt Stress of the REDOX-RESPONSIVE TRANSCRIPTION FACTOR 1 (RRTF1) Gene are Controlled by its Promoter.

The REDOX-RESPONSIVE TRANSCRIPTION FACTOR 1 (RRTF1) gene encodes a member of the ERF/AP2 transcription factor family involved in redox homeostasis. The RRTF1 gene shows tissue-specific responsiveness to various abiotic stress treatments including a response to salt stress in roots. An interesting feature of this response is an adaptation phase that follows its activation, when promoter levels revert to a base line level, even if salt stress is maintained. It is unclear if adaption is controlled by a switch in promoter activity or by changes in transcript levels. Here we show that the RRTF1 promoter is sufficient for the control of both activation and adaptation to salt stress. As constitutive expression of RRTF1 turned out to be detrimental to the plant, we propose that promoter-regulated adaptation evolved as a protection mechanism to balance the beneficial effects of short-term gene activation and the detrimental effects of long-term gene expression.