Search

Plant growth and resilience to abiotic stresses, such as soil salinity and drought, depend intricately on nitrogen metabolism. This review explores nitrogen's regulatory role in plant responses to these challenges, unveiling a dynamic interplay between nitrogen availability and abiotic stress. In the context of soil salinity, a nuanced relationship emerges, featuring both antagonistic and synergistic interactions between salinity and nitrogen levels. Salinity-induced chlorophyll depletion in plants can be alleviated by optimal nitrogen supplementation; however, excessive nitrogen can exacerbate salinity stress. We delve into the complexities of this interaction and its agricultural implications. Nitrogen, a vital element within essential plant structures like chloroplasts, elicits diverse responses based on its availability. This review comprehensively examines manifestations of nitrogen deficiency and toxicity across various crop types, including cereals, vegetables, legumes, and fruits. Furthermore, we explore the broader consequences of nitrogen products, such as N2O, NO2, and ammonia, on human health. Understanding the intricate relationship between nitrogen and salinity, especially chloride accumulation in nitrate-fed plants and sodium buildup in ammonium-fed plants, is pivotal for optimizing crop nitrogen management. However, prudent nitrogen use is essential, as overapplication can exacerbate nitrogen-related issues. Nitrogen Use Effi- ciency (NUE) is of paramount importance in addressing salinity challenges and enhancing sustainable crop productivity. Achieving this goal requires advancements in crop varieties with efficient nitrogen utilization, precise timing and placement of nitrogen fertilizer application, and thoughtful nitrogen source selection to mitigate losses, particularly urea-based fertilizer volatilization. This review article delves into the multifaceted world of plant nitrogen metabolism and its pivotal role in enabling plant resilience to nutritional stress and abiotic challenges. It offers insights into future directions for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Due to their low cost and ability to synthesize lipids for sustainable biodiesel production, oleaginous fungus has recently gained more prominence than other microorganisms. The new oleaginous fungus Aspergillus carneus OQ275240's dry biomass, lipid content, and lipid yield were all optimized in this work, using the response surface methodology-based Box–Behnken design. Analysis of variance (ANOVA) was also used to examine the experimental data, and multiple regression analysis was used to fit the data to a second-order polynomial equation. Three independent variables, such as the concentration of yeast, glucose, and phosphorus, were examined for their mutual impacts. Maximum dry biomass (0.024 g/50 mL), lipid content (36.20%), and lipid yield (8.70 mg/50 mL) were achieved at optimal concentrations of 2.68 g/L of yeast, 20.82 g/L of glucose, and 0.10 g/L of phosphorus, respectively, showing that the actual data and predictions of the models were in good agreement. A. carneus OQ275240 has a favorable fatty acid profile that can be used to successfully create biodiesel, as shown by the presence of palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1) in its fatty acid methyl esters (FAMEs) profile. Furthermore, the qualities of the biodiesel were investigated, and it was found that they fell within the parameters established by the international specifications EN 14214 (Europe) and ASTM D6751-08 (United States). These findings point to the newly evaluated filamentous fungal strain as a potential feedstock for the production of high-quality biodiesel. [ABSTRACT FROM AUTHOR]

Background. The carcinogenic, mutagenic, and teratogenic chemicals such as aflatoxin are a worldwide health problem. Aspergillus spp., responsible for most cases of aflatoxin contamination, are common in the environment and spread easily to many different types of food. The objectives of this study were to conduct a survey of fungi associated with three soil invertebrates in Taif, Saudi Arabia, identify these isolates and explore mycotoxins formation. Methods. In total, 114 fungal isolates were collected from various soil invertebrates (millipedes, Armadillidium vulgare and Porcellio laevis) in Taif, Saudi Arabia, among them, 22 isolates were identified as Aspergillus spp. based on morphological and molecular characteristics followed by both Fusarium and Penicillium. Results.The sequences of ITS 1 and ITS 4 were utilized. Using bootstrap analysis, phylogenetic tree was split into two distinct clusters. Five sub clusters were included inside the first major cluster, and their bootstrap value was 99%. While, there were two small clusters in the second major cluster. All the tested Aspergillus strains were able to have a single PCR fragment amplified using the primer AspTef. TEF-1 DNA sequence bootstrap analysis with 1,000 replicates revealed two distinct groups. Additionally, the Aspergillus isolates were grouped into two different clusters with about 65% genetic similarity using ISSR-PCR analysis. The standard polymerase chain reaction was used to effectively amplify the Aopks, afl-A and omt-A genes in aflatoxigenic Aspergillus strains. Four Aspergillus strains used in this investigation were shown to generate aflatoxin B1. While, three Aspergillus stains showed ochratoxin genes. Conclusions. In conclusion, the results indicate significant differences in the fungal community between ecoregions and soil invertebrates. Moreover, mycotoxin detection and identification among Aspergillus isolates were elucidated. This study could shed light on the risk of mycotoxin contamination along the supply chain. [ABSTRACT FROM AUTHOR]

Rhizoctonia solani is a species complex composed of many genetically diverse anastomosis groups (AG) and their subgroups. It causes economically important diseases of soybean worldwide. However, the global genetic diversity and distribution of R. solani AG associated with soybean are unknown to date. In this study, the global genetic diversity and distribution of AG associated with soybean were investigated based on rDNA-ITS sequences deposited in GenBank and published literature. The most prevalent AG, was AG-1 (40%), followed by AG-2 (19.13%), AG-4 (11.30%), AG-7 (10.43%), AG-11 (8.70%), AG-3 (5.22%) and AG-5 (3.48%). Most of the AG were reported from the USA and Brazil. Sequence analysis of internal transcribed spacers of ribosomal DNA separated AG associated with soybean into two distinct clades. Clade I corresponded to distinct subclades containing AG-2, AG-3, AG-5, AG-7 and AG-11. Clade II corresponded to subclades of AG-1 subgroups. Furthermore, AG and/or AG subgroups were in close proximity without corresponding to their geographical origin. Moreover, AG or AG subgroups within clade or subclades shared higher percentages of sequence similarities. The principal coordinate analysis also supported the phylogenetic and genetic diversity analyses. In conclusion, AG-1, AG-2, and AG-4 were the most prevalent AG in soybean. The clade or subclades corresponded to AG or AG subgroups and did not correspond to the AG's geographical origin. The information on global genetic diversity and distribution will be helpful if novel management measures are to be developed against soybean diseases caused by R. solani. [ABSTRACT FROM AUTHOR]

Banana bunchy top disease (BBTD), caused by a Banana Bunchy Top Virus (BBTV), is the most devastating viral disease of bananas. The genome of multipartite BBTV is about 1 Kb in size and comprises six circular single-stranded (ss) DNA components, namely DNA-R, C, S, M, U3, and N. Gene expression in multipartite DNA viruses is highly flexible due to variations in the copy number and transcript levels of individual genomic components. This enables them to adapt to changing conditions and maintain optimal fitness. In the current study, the copy number of each genetic component of BBTV and its transcript level were determined in the leaf, midrib, and root tissue of the infected banana plant. The results of the study showed that DNA copies (copies/ng) were higher in midrib (11,105 ± 10,704.42), followed by leaf (6902.91 ± 1651.14), and were lowest in root (23.49 ± 9.21) tissues. In contrast, the transcript level was highest in the root (312.45 ± 106.69) and lowest in the midrib (0.72 ± 0.16). This suggests that BBTV independently regulates the transcriptional level of each DNA component. The distribution of BBTV in different tissues assists the identification of significantly higher viral load tissues for early and sensitive disease diagnosis, which will be beneficial for better disease management. [ABSTRACT FROM AUTHOR]

Nanotechnology is a burning field of scientific interest for researchers in current era. Diverse plant materials are considered as potential tool in green chemistry based technologies for the synthesis of metal nanoparticles (NPs) to cope with the hazardous effects of synthetic chemicals, leading to severe abiotic climate change issues in today's agriculture. This study aimed to determine the synthesis and characterization of metal-based nanoparticles using extracts of the selected plant Calotropis gigantea and to evaluate the enzyme-inhibition activities and antibacterial and antifungal activity of extracts of metal-based zinc nanoparticles using C. gigantea extracts. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). C. gigantea was examined for antimicrobial activity against clinical isolates of bacteria and fungi. The water, ethanolic, and acetone extracts of C. gigantea were studied for their antagonistic action against bacterial strains (E. coli, S. aureus, P. multocida, and B. subtilis) and selected fungal strains (A. paracistic, F. solani, A. niger, S. ferrugenium, and R. nigricans). In vitro antimicrobial activity was determined by the disc diffusion method, where C. gigantea was tested for AChE and BChE inhibitory activity using Ellman's methodology. The kinetic analysis was performed by the proverbial Berthelot reaction for urease inhibition. The results showed that out of all the extracts tested, ethanolic and water extracts possessed zinc nanoparticles. These extracts showed the maximum zone of inhibition against F. solani and P. multocida and the lowest against S. ferrugenium and B. subtilis. A potential source of AChE inhibitors is certainly provided by the abundance of plants in nature. Numerous phyto-constituents, such as AChE and BChE inhibitors, have been reported in this communication. Water extract was active and has the potential for in vitro AChE and BChE inhibitory activity. The urease inhibition with flower extracts of C. gigantea revealed zinc nanoparticles in water extracts that competitively inhibited urease enzymes. In the case of cholinesterase enzymes, it was inferred that the water extract and zinc nanoparticles have more potential for inhibition of BChE than AChE and urease inhibition. Furthermore, zinc nanoparticles with water extract are active inthe inhibition of the bacterial strains E. coli, S. aureus, and P. multocida and the fungal strains A. paracistic, F. solani, and A. niger. [ABSTRACT FROM AUTHOR]

The current work is aimed at isolating and identifying new Entomopathogenic bacterium (EPB) strains associated with Steinernema feltiae and assessing the EPB’s biocontrol potential on Aphis punicae and Aphis illinoisensis adults in the laboratory. From S. feltiae, five bacterial isolates were isolated and molecularly characterized. Lysinibacillus xylanilyticus strain TU-2, Lysinibacillus xylanilyticus strain BN-13, Serratia liquefaciens strain TU-6, Stenotrophomonas tumulicola strain T5916-2-1b, and Pseudochrobactrum saccharolyticum strain CCUG are the strains. Pathogenicity tests demonstrated that bacterial cells were more toxic against the two aphid species than bacterial cell-free supernatants. S. tumulicola strain T5916-2-1b cells and filtrate were reported to have the strongest potential to kill A. punicae and A. illinoisensis individuals within 6 h after treatment, with 100% mortality of both insects 24 and 48 h after treatment. Based on the results of the study, it looked like endogenous Steinernemaassociated EPB could be used directly as a biocontrol agent for A. punicae and A. illinoisensis. [ABSTRACT FROM AUTHOR]

Plant tissue culture technique employed for the identification and isolation of bioactive phytocompounds has numerous industrial applications. It provides potential benefits for different industries which include food, pharmaceutical and cosmetics. Various agronomic crops i.e., cereals, fruits, vegetables, ornamental plants and forest trees are currently being used for in vitro propagation. Plant tissue culture coupled with biotechnological approaches leads towards sustainable agricultural development providing solutions to major food security issues. Plants are the rich source of phytochemicals with medicinal properties rendering them useful for the industrial production of pharmaceuticals and nutraceuticals. Furthermore, there are numerous plant compounds with application in the cosmetics industry. In addition to having moisturizing, anti-ageing, anti-wrinkle effects; plant-derived compounds also possess pharmacological properties such as antiviral, antimicrobial, antifungal, anticancer, antioxidant, anti-inflammatory, and anti-allergy characteristics. The in vitro propagation of industrially significant flora is gaining attention because of its several advantages over conventional plant propagation methods. One of the major advantages of this technique is the quick availability of food throughout the year, irrespective of the growing season, thus opening new opportunities to the producers and farmers. The sterile or endangered flora can also be conserved by plant micro propagation methods. Hence, plant tissue culture is an extremely efficient and cost-effective technique for biosynthetic studies and bio-production, biotransformation, or bioconversion of plantderived compounds. However, there are certain limitations of in-vitro plant regeneration system including difficulties with continuous operation, product removal, and aseptic conditions. For sustainable industrial applications of invitro regenerated plants on a large scale, these constraints need to be addressed in future studies. [ABSTRACT FROM AUTHOR]

Transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) spectroscopy were applied to evaluate the tin dioxide nanoparticles (SnO2 NPs) amalgamated by the sol-gel process. XRD was used to examine the tetragonal-shaped crystallite with an average size of 26.95 (±1) nm, whereas the average particle size estimated from the TEM micrograph is 20.59 (±2) nm. A dose-dependent antifun3al activity was performed against two fungal species, and the activity was observed to be increased with an increase in the concentration of SnO2 NPs. The photocatalytic activity of SnO2 NPs in aqueous media was tested using Rhodamine 6G (Rh-6G) under solar light illumination. The Rh-6G was degraded at a rate of 0.96 × 10−2 min for a total of 94.18 percent in 350 min. [ABSTRACT FROM AUTHOR]

Aphids are serious pests of a wide range of agricultural crops, including pomegranates and grapevines. In addition, due to the negative environmental impacts of chemical insecticides, these pests are developing important resistance against aphicides. Therefore, one alternative method to control aphids is the use of essential oils (EO). The present study aimed to evaluate the insecticidal activity of Citrus aurantium and C. reticulata peel EO at different concentrations and with different exposure periods to pomegranate and grapevine aphids, Aphis punicae and A. illinoisensis via the topical application method under laboratory conditions. The results reveal that C. aurantium L. EO had greater toxicity against pomegranate and grapevine aphids, with LC50 of 0.37 and 0.82 μL/mL, respectively, at 48 h after application. The highest repellence effect was estimated for C. aurantium EO, at 2.5 μL/cm2, on A. punicae, with a value of 100% after an exposure time of 3 h, in contrast to the 88% repellence estimated for A. illinoisensis. The GC-MS investigation of both essential oils identified limonene, 3-carene, pinene, and p-cymene as active substances that could be attributed to the effects observed. Overall, our results offer a potential tool to control the two aphid species and could help in the development of integrated insect management in pomegranate and grapevine fields. [ABSTRACT FROM AUTHOR]

Green mold (caused by Trichoderma harzianum) is a destructive disease in mushrooms which limits commercial production. The present investigation was carried out to verify the in vitro and in vivo effect of locally available botanicals and bacterial biocontrol agents against this disease. The in vitro evaluation of ethanol extract of botanicals against mycelial growth of T. harzianum at 1, 2, and 3% concentrations showed that Juglans regia and Allium sativum exhibited maximum mycelial growth inhibition of 84.9 and 79.8%, respectively. When the same botanicals were tested against the mycelial growth of A. bisporus, it was observed that J. regia, Curcuma longa, and Azadirachta mellea were least inhibitory (4.66–7.4%). From the in vivo evaluation of plant botanicals at 2% concentration, J. regia and C. longa had the highest average weight (11.8–11.9 g) of a single fruit body and a combined button yield of 11.3–11.9 kg/quintal compost. Among the bacterial bioagents evaluated in vitro, Pseudomonas flourescens, Azotobacter sp., and Bacillus subtilis displayed stimulatory effects of varying degrees on the mycelial growth of A. bisporus but exhibited antagonistic effects on T. harzianum. B. subtilis-38, and P. flourescens-104. Azotobacter-108 caused the highest mycelial growth inhibition of 97.6, 97.4, and 90.3% of T. harzianum, respectively. The current study reveals that the integration of botanical and bacterial antagonists in pathogen-infested white button mushroom casing reduces green mold infection with corresponding yield gains. [ABSTRACT FROM AUTHOR]

The present systematic research on cultural, morphological, and pathogenic variability was carried out on eighty isolates of Sclerotinia sclerotiorum collected from major common bean production belts of North Kashmir. The isolates were found to vary in both cultural and morphological characteristics such as colony color and type, colony diameter, number of days for sclerotia initiation, sclerotia number per plate, sclerotial weight, and size. The colony color ranged between white and off-white with the majority. The colony was of three types, in majority smooth, some fluffy, and a few fluffy-at-center-only. Colony diameter ranged between 15.33 mm and 29 mm after 24 h of incubation. The isolates took 4 to 7 days for initiation of sclerotia and varied in size, weight, and number per plate ranging between 14 and 51.3. The sclerotial arrangement pattern on plates was peripheral, sub peripheral, peripheral, and subperipheral, arranged at the rim and scattered. A total of 22 Mycelial compatibility groups (MCGs) were formed with seven groups constituted by a single isolate. The isolates within MCGs were mostly at par with each other. The six isolates representing six MCGs showed variability in pathogenicity with isolate G04 as the most and B01 as the least virulent. The colony diameter and disease scores were positively correlated. Sclerotia were observed to germinate both myceliogenically and carpogenically under natural temperate conditions of Kashmir. Germplasm screening revealed a single resistant line and eleven partially resistant lines against most virulent isolates. [ABSTRACT FROM AUTHOR]

Pistachio nuts can become colonized by mycotoxigenic fungi, especially Aspergillus flavus, resulting in contamination with aflatoxins (AFs). We examined the effect of gaseous O3 (50–200 ppm; 30 min; 6 L/min) on (a) in vitro germination, (b) mycelial growth, and (c) aflatoxin B1 (AFB1) production on a milled pistachio nut-based medium at different water activity (aw) levels and at 30 °C. This was complimented with in situ studies exposing raw pistachio nuts to 50–200 ppm of O3. Exposure of conidia to gaseous O3 initially resulted in lower germination percentages at different aw levels. However, 12 h after treatment, conidial viability recovered with 100% germination after 24–48 h. Growth rates of mycelial colonies were slightly decreased with the increase of the O3 dose, with significant inhibition only at 0.98 aw. The production of AFB1 after O3 treatment and storage for 10 days was stimulated in A. flavus colonies at 0.98 aw. Raw pistachio nuts inoculated with A. flavus conidia prior to O3 exposure showed a significant decrease in population after 20 days of storage. However, AFB1 contamination was stimulated in most O3 treatments. The relationship between exposure concentration, time and prevailing aw levels on toxin control needs to be better understood for these nuts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Induced resistance against several plant pathogens was reported using different beneficial plant growth‐promoting microorganisms. The potential of five fungal isolates, Trichoderma harzianum GT 3‐2, Fusarium equiseti GF 18‐3, F. equiseti GF 19‐1, Phoma sp. GS 10‐1 and Phoma sp. GS 14‐1, to stimulate tomato growth and resistance against bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000 was evaluated. RESULTS: Based on the results of disease severity and growth promotion experiments, GF 18‐3 exhibited the best results among all fungal isolates. Treatment with barley grain inocula (BGI) and culture filtrate (CF) of the isolates promoted tomato growth and suppressed the pathogen in pot trials. Furthermore, expressions of the pathogenesis‐related genes (PR‐1, β‐1,3‐glucanase A, β‐1,3‐glucanase B and LOX) were relatively higher than the control in the leaves of tomato plants treated with both BGI and CF. The transcription levels remained consistently higher than the control plants for 6 days post‐inoculation with pathogen. CONCLUSION: Taken together, the results indicate that the tested fungal isolates have the potential to promote tomato growth and induce systemic resistance against the bacterial speck disease. Analysis of certain PR gene expression revealed significant activation in both BGI and CF treatments, leading to stimulated resistance against the pathogen. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The present study was carried out to analyze the potential of fungi isolated from the rhizosphere of soybean, brinjal, tomato, and potato plants. The density of fungi varied in the pot soil and rhizosphere after Paecilomyces formosus MD12 treatment. The P. formosus MD12 population was 6.3 ± 0.13 x 104 CFU g-1 in the pot planted with brinjal, and the population increased in the rhizosphere (6.72 ± 0.41 x 104 CFU g-1). P. formosus MD12 was cultured in the production medium, and the supernatant was used for egg inhibition studies on a root-knot nematode parasite, Meloidogyne incognita. It was revealed that maximum egg inhibition (94.7 ± 6.2%) was obtained at 100% concentration of extract. The culture supernatant from P. formosus MD12 affected the development of M. incognita juvenile, and the mortality rate was maximum after 96 h (95 ± 6%). Mortality was reduced when treated with 25%, 50%, and 75% supernatant. At 1 x 107 mL-1 of spore suspension, we found reductions of 71.6 ± 3.3% nematode populations in the soil, 60.7 ± 2.2% from the root, and 63.6 ± 2.4% egg mass compared with the control in the pot experiment. The culture supernatant applied at the 10% level showed a maximum mean reduction of the nematode population in roots (72.4 ± 2.2%), soil (77.9 ± 2.5%), and egg masses (73.2 ± 1.5%), respectively. The presence of P. formosus MD12 in a soil environment could antagonize nematode parasites and improve soil amendment. The P. formosus MD12 strain showed good biocontrol ability against the root-knot nematode, M. incognita, under in vitro and green house experimental condition. [ABSTRACT FROM AUTHOR]

Fourier transform infrared spectroscopy (FTIR) spectroscopy detects functional groups such as vibrational bands like N-H, O-H, C-H, C = O (ester, amine, ketone, aldehyde), C = C, C = N (vibrational modes of a tetrapyrrole ring) and simply C = N. The FTIR of these bands is fundamental to the investigation of the effect of biochar (BC) treatment on structural changes in the chlorophyll molecules of both plants that were tested. For this, dried leaf of Spinacia oleracia (spinach) and Trigonella corniculata (fenugreek) were selected for FTIR spectral study of chlorophyll associated functional groups. The study's primary goal was to investigate the silent features of infrared (IR) spectra of dried leave samples. The data obtained from the current study also shows that leaf chlorophyll can mask or suppress other molecules' FITR bands, including proteins. In addition, the C = O bands with Mg and the C9 ketonic group of chlorophyll are observed as peaks at1600 (0%BC), 1650 (3%BC) and 1640, or near to1700 (5%BC) in spinach samples. In fenugreek, additional effects are observed in the FTIR spectra of chlorophyll at the major groups of C = C, C = O and C9 of the ketonic groups, and the vibrational bands are more evident at C-H and N-H of the tetrapyrrole ring. It is concluded that C-N bands are more visible in 5% BC treated spinach and fenugreek than in all other treatments. These types of spectra are useful in detecting changes or visibility of functional groups, which are very helpful in supporting biochemical data such as an increase in protein can be detected by more visibility of C-N bands in FTIR spectra. [ABSTRACT FROM AUTHOR]

Microbial natural biocides have attracted much more attention in recent years in order to avoid the unrestricted use of chemical biocides in the environment. The aim of this study is to analyze the antibacterial and antifungal activities of secondary metabolites and growth promoting, nematicidal, and soil enzyme activity mediated by Trichoderma hamatum FB10. The bactericidal and fungicidal activities were performed using cell-free extract. Results revealed that the selected strain exert antibacterial activity against Acidovorax avenae, Erutimacarafavora, and Xanthomonas campestris. The selected fungal strain FB10 showed antagonistic activity against fungal pathogens such as, S. sclerotiorum, Rhizoctonia solani, Alternaria radicina, Alternaria citri, and Alternaria dauci. Among the bacterial pathogens, A. avenae showed least MIC (30 ± 2.5 µg/mL) and MBC (70 ± 1.25 µg/mL) values. T. hamatum FB10 strain synthesized bioactive volatile secondary metabolite, which effectively inhibited the growth of bacteria and fungi and indicated the presence of 6-pentyl-alpha-pyrone as the major compound (67.05%). The secondary metabolite synthesized by T. hamatum FB10 showed nematicidal activity against M. incognita eggs. Egg hatch inhibition was 78 ± 2.6% and juvenile stage mortality rate was 89 ± 2.5% when the strain FB10 was treated with nematode. The cell free extract of T. hamatum FB10 showed protease, amylase, cellulase, chitinase, glucanase activities. T. hamatum FB10 inoculated with green gram increased 11% plant height, compared to the control. The fresh weight of the experimental group inoculated with T. hamatum FB10 increased 33.6% more compared to the control group. The green gram seedlings inoculated with T. hamatum FB10 increased 18% more dry weight than control group. Soil enzymes such as, urease, phosphatase, catalase and saccharase were improved in the soil inoculated with T. hamatum FB10. These biochemical components play potent role in soil fertility, energy conversion, and in soil organic matter conversion. [ABSTRACT FROM AUTHOR]

Pistachio nuts are an economically important commodity produced by many countries. They can be colonized by mycotoxigenic fungi, especially Aspergillus flavus , resulting in contamination with aflatoxins (AFs) , especially aflatoxin B1 (AFB1), a Class 1a carcinogen. The objectives were to examine the effect of interactions between the two key abiotic factors, temperature and water activity (a w ) on (a) in vitro growth and AFB1 production by four strains of A. flavus isolated from pistachio nuts, on a milled pistachio nut medium modified ionically (NaCl) and non-ionically (glycerol) in the range 20–35°C and 0.995–0.85 a w , (b) colonization of layers of raw pistachio nuts stored at different interacting temperature x a w conditions and on relative AFB1 production and (c) develop models to produce contour maps of the optimal and marginal boundary conditions for growth and AFB1 production by up to 4 strains of this species. On pistachio nut-based media, optimum growth of four strains of A. flavus was at 0.98–0.95 a w and 30–35°C. Optimum AFB1 production was at 30–35°C and 0.98 a w . No significant differences in growth was found on ionic and non-ionically modified media. Colonization of layers of raw pistachio nuts was slower and contamination with AFB1 significantly less than in in vitro studies. Contour maps based on the pooled data for up to four strains (in vitro , in situ) showed the optimum and marginal conditions for growth and AFB1 production. These data can be used to identify those conditions which represent a high, intermediate or low risk of colonization and AFB1 contamination in the pistachio nut processing chain. These results are discussed in the context of the development of appropriate intervention strategies to minimize AFB1 contamination of this economically important commodity. [ABSTRACT FROM AUTHOR]

Simple Summary: For sustainable agriculture, there is a need to identify and evaluate more biocontrol agents, including entomopathogenic nematodes (EPNs). In this study, EPNs and their associated entomopathogenic bacteria symbionts (EPBs) were isolated and identified from 320 soil samples collected in Taif, Saudi Arabia. The biocontrol efficacy of EPNs and EPBs was also evaluated against third instar larvae of the pomegranate butterfly, Virachola livia, and the carob moth, Ectomyelois ceratoniae, two important insect pests of pomegranate, under laboratory conditions. Our results show that the EPNs Steinernema spp. were more virulent than Heterorhabditis spp. against the two pomegranate insects. In addition, the EPB Stenotrophomonas maltophilia CQ1, isolated from Steinernema spp., surpassed Pseudomonas mosselii SJ10, associated with Heterorhabditis spp., in their ability to kill V. livia or E. ceratoniae larvae. We conclude that either application of EPNs' infective juveniles (IJs) or their associated EPBs could serve as potential biocontrol agents for V. livia and E. ceratoniae. Virachola livia (Lepidoptera: Lycaenidae) and Ectomyelois ceratoniae (Lepidoptera: Pyralidae) are the key pests of pomegranates in Saudi Arabia that are managed mainly using broad-spectrum pesticides. Interactions between the entomopathogenic nematodes (EPNs) Steinernematids, and Heterorhabditids, and their entomopathogenic bacterial symbionts (EPBs) have long been considered monoxenic 2-partner associations responsible for killing insects and, therefore, are widely used in insect pest biocontrol. However, there are limited reports identifying such organisms in Taif, Saudi Arabia. The current study aimed to identify the EPNs and their associated bacteria isolated from Taif, Saudi Arabia, and evaluate their biocontrol potential on third instar larvae of V. livia and E. ceratoniae under laboratory conditions. A total of 35 EPN isolates belonging to Steinernema (20) and Heterorhabditis (15) were recovered from 320 soil samples. Twenty-six isolates of symbiotic or associated bacteria were isolated from EPNs and molecularly identified as Xenorhabdus (6 isolates), Photorhabdus (4 isolates), Pseudomonas (7), or Stenotrophomonas (9). A pathogenicity assay revealed that Steinernema spp. were more virulent than Heterorhabditis spp. against the two pomegranate insects, with LC50 values of 18.5 and 13.6 infective juveniles (IJs)/larva of V. livia for Steinernema spp. and 52 and 32.4 IJs/larva of V. livia for Heterorhabditis spp. at 48 and 72 h post-treatment, respectively. Moreover, LC50 values of 9 and 6.6 IJs/larva (Steinernema spp.) and 34.4 and 26.6 IJs/larva (Heterorhabditis spp.) were recorded for E. ceratoniae larvae at 48 and 72 h post-treatment. In addition, the EPB Stenotrophomonas maltophilia CQ1, isolated from Steinernema spp., surpassed Pseudomonas mosselii SJ10, associated with Heterorhabditis spp., in their ability to kill V. livia or E. ceratoniae larvae within 6 h post-application, resulting in 100% mortality in both insects after 24 and 48 h of exposure. We conclude that either application of EPNs' IJs or their associated EPBs could serve as potential biocontrol agents for V. livia and E. ceratoniae. [ABSTRACT FROM AUTHOR]

There is little knowledge of the effect of acclimatization of Aspergillus flavus strains to climate-related abiotic factors and the subsequent effects on growth and aflatoxin B1 (AFB1) production. In this study, two strains of A. flavus (AB3, AB10) were acclimatized for five generations in elevated CO2 (1000 ppm × 37 °C) on a milled pistachio-based medium. A comparison was made of the effects of non-acclimatized strains and those that were acclimatized when colonizing layers of pistachio nuts exposed to 35 or 37 °C, 400 or 1000 ppm CO2, and 0.93 or 0.98 water activity (aw), respectively. Acclimatization influenced the fitness in terms of the growth of one strain, while there was no significant effect on the other strain when colonizing pistachio nuts. AFB1, production was significantly stimulated after ten days colonization when comparing the non-acclimatized and the acclimatized AB3 strain. However, there was no significant increase when comparing these for strain AB10. This suggests that there may be inter-strain differences in the effects of acclimatization and this could have a differential influence on the mycotoxin contamination of such commodities. [ABSTRACT FROM AUTHOR]

Ectomyelois ceratoniae (Lepidoptera: Pyralidae) is the primary pest of pomegranates in Saudi Arabia and is mostly controlled using broad-spectrum pesticides. Providing environmentally sound choices to limit reliance on chemical management is a major challenge in the control of E. ceratoniae and, as a consequence, in the protection of pomegranate crops from its invasion. Entomopathogenic bacteria (EPB) symbiotically associated with entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling or aerial pests. The bacterium symbiont (EPB) is the real insect-killing biocontrol agent, while the nematode (EPN) serves as a vector. We wondered whether the EPB vector, which is extremely vulnerable to adverse environmental conditions, like drought, high temperatures, and repellent soil microorganisms, could be omitted. We intended to evaluate the biocontrol potential of directly applied EPB cells and cell-free culture media (CFCM) on the larval instar E. ceratoniae. Xenorhabdus budapestensis DSM 16342 (EMA), X. szentirmaii DSM 16338 (EMC), and Photorhabdus luminescens ssp. laumondi (TT01) strains were used. After three days of exposure, the cells of EMA, EMC, and TT01 strains resulted in 100%, 88%, and 79.3% larval mortality rates, respectively. The applied EMA CFCM resulted in 53.7% larval mortality, indicating the presences of (at least) one extremely strong component produced by EMA. We concluded that the direct application of either the EPB cells or the CFCM must be a prospective alternative biocontrol of E. ceratoniae, especially to protect the important fruit (pomegranate, Punica granatum) cultivars. Especially, newly identified local EPB isolates could be applied as bio-pesticides for integrated management practices or organic pomegranate production. [ABSTRACT FROM AUTHOR]

Pistachio nuts are an important economic tree nut crop which is used directly or processed for many food-related activities. They can become colonized by mycotoxigenic spoilage fungi, especially Aspergillus flavus, mainly resulting in contamination with aflatoxins (AFs), especially aflatoxin B1 (AFB1). The prevailing climate in which these crops are grown changes as temperature and atmospheric CO2 levels increase, and episodes of extreme wet/dry cycles occur due to human industrial activity. The objectives of this study were to evaluate the effect of interacting Climate Change (CC)-related abiotic factors of temperature (35 vs. 37 °C), CO2 (400 vs. 1000 ppm), and water stress (0.98–0.93 water activity, aw) on (a) growth (b) aflD and aflR biosynthetic gene expression and (c) AFB1 production by two strains A. flavus (AB3, AB10) in vitro on milled pistachio-based media and when colonizing layers of shelled raw pistachio nuts. The A. flavus strains were resilient in terms of growth on pistachio-based media and the colonisation of pistachio nuts with no significant difference when exposed to the interacting three-way climate-related abiotic factors. However, in vitro studies showed that AFB1 production was significantly stimulated (p < 0.05), especially when exposed to 1000 ppm CO2 at 0.98–0.95 aw and 35 °C, and sometimes in the 37 °C treatment group at 0.98 aw. The relative expression of the structural aflD gene involved in AFB1 biosynthesis was decreased or only slightly increased, relative to the control conditions at elevated CO, regardless of the aw level examined. For the regulatory aflR gene expression, there was a significant (p < 0.05) increase in 1000 ppm CO2 and 37 °C for both strains, especially at 0.95 aw. The in situ colonization of pistachio nuts resulted in a significant (p < 0.05) stimulation of AFB1 production at 35 °C and 1000 ppm CO2 for both strains, especially at 0.98 aw. At 37 °C, AFB1 production was either decreased, in strain AB3, or remained similar, as in strain AB10, when exposed to 1000 ppm CO2. This suggests that CC factors may have a differential effect, depending on the interacting conditions of temperature, exposure to CO2 and the level of water stress on AFB1 production. [ABSTRACT FROM AUTHOR]

Accumulation of heavy metals (HMs) by ornamental plants (OPs) from contaminated agriculture soils is a unique technique that can efficiently reduce the metal load in the food chain. Amaranthus tricolor L. has attractive characteristics acquiring a higher growth rate and large biomass when grown at heavy metal contaminated soils. Site-specific detailed information is not available on the use of A. tricolor plant in metal phytoremediation from the polluted sites. The study aimed to enhance the uptake of HMs (Pb, Zn, and Cu) via amending poultry litter extract (PLE), vinasse sugarcane (VSC), and humic acid (HA) as natural mobilized organic materials compared to ethylene diamine tetraacetic acid (EDTA), as a common mobilized chemical agent by A. tricolor plant. The studied soils collected from Helwan, El-Gabal El-Asfar (Cairo Governorate), Arab El-Madabeg (Assiut Governorate), Egypt, and study have been conducted under pot condition. Our results revealed all organic materials in all studied soils, except EDTA in EL-Gabal El-Asfar soil, significantly increased the dry weight of the A. tricolor plant compared to the control treatment. The uptake of Pb and Zn significantly (p > 0.05) increased due to applying all organic materials to the studied soils. HA application caused the highest uptake as shown in Pb concentration by more than 5 times in Helwan soil and EDTA by 65% in El-Gabal El-Asfar soil while VSC increased it by 110% in El-Madabeg soil. Also, an increase in Zn concentration due to EDTA application was 58, 42, and 56% for Helwan, El-Gabal El-Asfar, and El-Madabeg soil, respectively. In all studied soils, the application of organic materials increased the remediation factor (RF) than the control. El-Madabeg soil treated with vinasse sugarcane gave the highest RF values; 6.40, 3.26, and 4.02% for Pb, Zn, and Cu, respectively, than the control. Thus, we identified A. tricolor as a successful ornamental candidate that, along with organic mobilization amendments, most efficiently develop soil health, reduce metal toxicity, and recommend remediation of heavy metal-contaminated soils. Additionally, long-term application of organic mobilization amendments and continued growth of A. tricolor under field conditions could be recommended for future directions to confirm the results. [ABSTRACT FROM AUTHOR]

Lipoic acid (LA) and melatonin (MT) are pleiotropic molecules participating in plant stress resistance by modulating cellular biochemical changes, ion homeostasis, and antioxidant enzyme activities. However, the combined role of these two molecules in counteracting the detrimental impacts of salinity stress is still unknown. In the present study, we determined the effects of exogenous LA (0.5 µM), MT (1 µM) and their combination (LA + MT) on growth performance and biomass accumulation, photosynthetic pigments, enzymatic and non-enzymatic antioxidant activities, and ions homeostatic in canola (Brassica napus L.) seedlings under salinity stress (0, 100 mM) for 40 days. The results indicate that exogenous application of LA + MT improved the phenotypic growth (by 25 to 45%), root thickness (by 68%), number of later lateral roots (by 52%), root viability (by 44%), and root length (by 50%) under salinity stress. Moreover, total soluble protein, chlorophyll pigments, the concentration of superoxide dismutase (SOD), catalase peroxidase (CAT), and ascorbic peroxidase (ASA) increased with the presence of salt concentration into the growth media and then decreased with the addition of LA + MT to saline solution. Leaf protein contents and the degradation of photosynthetic pigments were lower when LA + MT treatments were added into NaCl media. The proline and phenol contents decreased in the exogenous application of LA + MT treatments more than individual LA or MT treatments under the salinity stress. The incorporation of LA or MT or a combination of LA + MT to saline solution decreased salinity-induced malondialdehyde and electrolyte leakage. In conclusion, the alteration of metabolic pathways, redox modulation, and ions homeostasis in plant tissues by the combined LA and MT application are helpful towards the adaptation of Brassica napus L. seedlings in a saline environment. The results of this study provide, for the first time, conclusive evidence about the protective role of exogenous LA + MT in canola seedlings under salinity stress. [ABSTRACT FROM AUTHOR]

This study aimed to generate predictive models for growth, sporulation, and ochratoxin A (OTA) production under abiotic climatic variables, including temperatures (15–35 °C) and water activity levels (0.99–0.90 aw) by Aspergillus ochraceus group. The data were divided into three sets: one for training, one for testing, and the third one for model validation. Optimum growth occurred at 0.95 aw and 25 °C and 0.95 aw and 30 °C for A. westerdijkiae and A. steynii, respectively. Significantly improved A. westerdijkiae and A. steynii spore production occurred at 0.95 aw and 20 °C and 0.90 aw and 35 °C, respectively. A. steynii and A. westerdijkiae produced the majority of OTA at 35 °C and 0.95 aw and 25–30 °C at 0.95–0.99 aw, respectively. The accuracy of the third-order polynomial regression model reached 96% in growth cases, 94.7% in sporulation cases, and 90.9% in OTA production cases; the regression coefficients (R2) ranged from 0.8819 to 0.9978 for the Aspergillus ochraceus group. A reliable agreement was reached between the predicted and observed growth, sporulation, and OTA production. The effects of abiotic climatic variables on growth, sporulation, and OTA production of A. ochraceus group have been effectively defined, and the models generated were responsible for adequately predicted and validated models against data from other strains within A. ochraceus group that had been published in the literature under the current treatments. These models could be successfully implemented to predict fungal growth and OTA contamination on food matrices for these strains under these conditions. [ABSTRACT FROM AUTHOR]

The changing climate and global warming have rendered existing surface water insufficient, which is projected to adversely influence the irrigated farming systems globally. Consequently, groundwater demand has increased significantly owing to increasing population and demand for plant-based foods especially in South Asia and Pakistan. This study aimed to determine the potential areas for groundwater use for agriculture sector development in the study area Lower Dir District. ArcGIS 10.4 was utilized for geospatial analysis, which is referred to as Multi Influencing Factor (MIF) methodology. Seven parameters including land cover, geology, soil, rainfall, underground faults (liniment) density, drainage density, and slope, were utilized for delineation purpose. Considering relative significance and influence of each parameter in the groundwater recharge rating and weightage was given and potential groundwater areas were classified into very high, high, good, and poor. The result of classification disclosed that the areas of 113.10, 659.38, 674.68, and 124.17 km2 had very high, high, good, and poor potential for groundwater agricultural uses, respectively. Field surveys for water table indicated groundwater potentiality, which was high for Kotkay and Lalqila union councils having shallow water table. However, groundwater potentiality was poor in Zimdara, Khal, and Talash, characterized with a very deep water table. Moreover, the study effectively revealed that remote sensing and GIS could be developed as potent tools for mapping potential sites for groundwater utilization. Furthermore, MIF technique could be a suitable approach for delineation of groundwater potential zone, which can be applied for further research in different areas. [ABSTRACT FROM AUTHOR]

Nitrogen (N) losses are prevalent under South East Asia's due to high N fertilizer inputs, but low N fertilizer use efficiency. This leaves a large quantity of reactive N at risk of loss to the environment. Biochar has been found to reduce N losses across a variety of soil types, however, there is limited data available for semi-arid climates, particularly at a field-scale. Herein we present an exploration of the biological and chemical enhancement effects observed of a cotton stalk-based biochar on wheat growth and yield under arid field conditions. The biochar was treated with urea-N and biofertilizer (bio-power) in different treatment setups. The six experimental treatments included; (i) a full N dose "recommended for wheat crops in the region" (104 kg N ha−1) as a positive control; (ii) a half N dose (52 kg N ha−1); (iii) a half N dose + biofertilizer (4.94 kg ha−1) as a soil mixture; (iv) a half N dose + biofertilizer as a seed inoculation; (v) a full N dose as broadcast + biochar (5 t ha−1) inoculated with biofertilizer; and (vi) a full N dose loaded on biochar + biofertilizer applied as a soil mixture. The half dose N application or biofertilizer addition as soil mix/seed inoculated/biochar inoculation with biofertilizer caused reduced wheat growth and yield compared to the control (conventional N fertilization). However, co-application of chemically enhanced biochar (loaded with a full N dose) and biofertilizer as soil mixture significantly increased the crop growth rate (CGR) and leaf area index (LAI). A significantly higher crop growth and canopy development led to a higher light interception and radiation use efficiency (RUE) for total dry matter (TDM) and grain yield (11% greater than control) production compared to the control. A greater grain yield, observed for the full N dose loaded on biochar + biofertilizer applied as a soil mixture, is attributed to prolonged N availability as indicated by greater plant and soil N content at harvest and different crop growth stages, respectively. The present study has improved our understanding of how the application of nitrogen loaded biochar and biofertilizer as soil mixtures can synergize to positively affect wheat growth and soil-nitrogen retention under arid environmental conditions. [ABSTRACT FROM AUTHOR]

Weed-competitive rice cultivars, a viable tool for integrated weed management of rice-field weeds, may greatly reduce the weed pressure and excessive dependence on herbicide in controlling weeds. Based on this premise, field experiments were conducted in 2018 and 2019 during the monsoon and winter rice-growing seasons at the Agronomy Field Laboratory of Bangladesh Agricultural University, Bangladesh, to evaluate the weed competitiveness of the selected rice varieties. A total of 42 monsoon and 28 winter rice varieties from Bangladesh were evaluated under "weedy" and "weed-free" conditions in the puddled transplanted system of cultivation. The field experiments were designed with three replications in a randomized complete block design. The results revealed that weed competition greatly reduces the yield of rice, and relative yield loss was 15–68% and 20–50% in monsoon and winter season rice, respectively. The lowest relative yield losses were recorded in monsoon rice from the variety BU dhan 1 (18%) and from the winter rice BRRI hybrid dhan5 (23.7%), which exhibited high weed tolerance. The weed competitive index (WCI) greatly varied among the varieties in both seasons and the monsoon season, ranging from 0.4 to 2.8, and the highest value was recorded from the hybrid variety Dhani Gold followed by BU dhan 1. In winter season rice, the WCI varied 0.25 to 2.4 and the highest value was recorded from the variety BRRI hybrid dhan3, followed by hybrid variety Heera 6. In monsoon rice, hybrid Dhani Gold was the most productive, but BU dhan 1 was the most weed competitive variety. Among the winter-grown varieties, the hybrid Heera 6 was the most productive, and the most weed competitive. Our research confirmed a high degree of variability in weed competitiveness among the 70 Bangladeshi rice varieties tested. [ABSTRACT FROM AUTHOR]

Deteriorating soil fertility and gradually decreasing rice productivity along with higher greenhouse gas emissions from paddy fields have emerged as serious threats to the sustainability of rice production and food security. Rice production in the subtropical environment in Bangladesh is mostly dependent on synthetic inorganic fertilizer to maintain productivity; however, the inorganic fertilizer has negative effects on global warming. Climate-smart and resilient agricultural production systems are major concerns nowadays to meet sustainable development goals. The study was conducted to evaluate the optimum rate and source of organic amendments on rice productivity and soil fertility along with CH4 emission. A total of nine nutrient combinations were used in the study. The CH4 emission, soil redox potential (Eh), soil pH, soil nitrogen and organic carbon, available phosphorus, rice grain and straw were greatly affected by the application of different rates and sources of the nutrient. However, the soil exchangeable K content, plant height, and harvest index were not affected. Among the treatments, the application of 75% recommended fertilizer (RF) + biosolid 2 t ha−1 (T3) was the most effective and showed the superior performance in terms of available P (12.90 ppm), the number of grains panicle−1 (121), and 1000-grain weight (24.6g), rice grain, and straw yield along with the moderate CH4 emission (18.25 mg m−2h−1). On the other hand, the lowest soil Eh (−158 mV) and soil pH (6.65) were measured from the treatment T3. The finding of this study revealed that the application of 75% of RF + biosolid 2 t ha−1 can be recommended as the preferable soil amendment for boosting rice yield, reduce CH4 emissions, and sustainably maintain soil fertility. Furthermore, this finding may help to introduce preferable soil amendment doses, which will contribute to boosting rice productivity and economic turnouts of the farmers. [ABSTRACT FROM AUTHOR]

Background: Bacillus species produce antimicrobial lipopeptides (LPs) and methyl jasmonate (MeJA) induces resistance in harvested fruits against postharvest pathogens. However, there is limited evidence of the combined efficacy of Bacillus LPs and MeJA to suppress postharvest diseases., Results: This study presents the combined effect of Bacillus LPs and MeJA to suppress P. digitatum and P. italicum associated with green and blue mold of lemon. Eight Bacillus strains were screened in a direct antagonism plate assay, where Bacillus subtilis LLCG89 and B. atrophaeus HFZ23 exhibited the highest inhibition of both molds. Subsequently, in an in vitro assay, LPs extracted from LLCG89 demonstrated the highest antifungal activity against both pathogens compared to HFZ23. When combined with MeJA, LLCG89 LPs reduced the lesion diameter and disease incidence of blue and green mold on lemon fruit. Co-application of MeJA and LLCG89 LPs decreased the levels of MDA, H 2 O 2 , and electrolyte leakage compared to single treatments and controls. Furthermore, treatment with MeJA and LLCG89 LPs increased the activities of defense enzymes including SOD, CAT, POD, PPO, CHI, GLU, APX, and PAL with peak activity between 48 to 72 h. The co-application of MeJA and LLCG89 LPs showed the highest enzyme activity compared to the control. Postharvest quality analysis indicated that co-application of LLCG89 LPs and MeJA showed little impact on fruit quality., Conclusion: The findings of our study highlight the potential of Bacillus-derived LPs and MeJA as effective tools for managing the Penicillium decay of lemons by maintaining fruit quality. © 2025 Society of Chemical Industry., (© 2025 Society of Chemical Industry.)

There is little knowledge of the effect of acclimatization of Aspergillus flavus strains to climate-related abiotic factors and the subsequent effects on growth and aflatoxin B 1 (AFB 1 ) production. In this study, two strains of A. flavus (AB3, AB10) were acclimatized for five generations in elevated CO 2 (1000 ppm × 37 °C) on a milled pistachio-based medium. A comparison was made of the effects of non-acclimatized strains and those that were acclimatized when colonizing layers of pistachio nuts exposed to 35 or 37 °C, 400 or 1000 ppm CO 2 , and 0.93 or 0.98 water activity (a w ), respectively. Acclimatization influenced the fitness in terms of the growth of one strain, while there was no significant effect on the other strain when colonizing pistachio nuts. AFB 1 , production was significantly stimulated after ten days colonization when comparing the non-acclimatized and the acclimatized AB3 strain. However, there was no significant increase when comparing these for strain AB10. This suggests that there may be inter-strain differences in the effects of acclimatization and this could have a differential influence on the mycotoxin contamination of such commodities.