Juglans Regia Research Articles

Arbuscular mycorrhizal fungi and intercropping Vicia villosa mediate plant biomass, soil properties, and rhizosphere metabolite profiles of walnuts

Intercropping is a prevalent soil management strategy within orchards, whereas it is unclear how inoculation with arbuscular mycorrhizal (AM) fungi and intercropping affect tree growth, soil properties, and rhizosphere metabolite profiles. This study investigated the effects of inoculation with Diversispora spurca and intercropping with hairy vetch (Vicia villosa) on biomass production, soil available nutrients, water-stable aggregate (WSA) distribution, phosphatase activity, and secondary metabolite profiles in walnuts (Juglans regia). The intercropping only elevated soil nitrate N levels and WSA distribution at the 0.5–2 mm size, and also triggered 2159 differential metabolites (1378 up-regulated and 781 down-regulated), with armillaramide as the most prominently up-regulated metabolite, followed by the substance diminished upon D. spurca inoculation. Conversely, D. spurca inoculation increased walnut biomass, WSA distribution across the 0.25 − 2 mm size, and acid and neutral phosphatase activities, as well as triggered 2489 differential metabolites (897 up-regulated and 1592 down-regulated), with pteroside D being highest up-regulated differential metabolite, allowing a competitive advantage to AM plants in combating soil pathogens. Despite significantly suppressing root AM fungal colonization and biomass production in AM walnuts, intercropping significantly increased soil ammonium and nitrate N levels in AM walnuts as well as WSAs at the 1–4 mm size, exhibiting a synergistic effect. Flavone and flavonol biosynthesis and pyruvate metabolism were simultaneously involved following AM inoculation or intercropping. Co-application of AM inoculation and intercropping triggered 1006 differential metabolites, with urocanic acid being the most up-regulated metabolite, although it decreased following AM inoculation, suggesting the involvement of mycorrhizal hyphae in soil histidine uptake. Under intercropping, AM inoculation elicited 418 differential metabolites, with the most up-regulated metabolite being implicated in flavonoid pathways. AM inoculation primarily triggered the biosynthesis of unsaturated fatty acids, regardless of intercropping or not, implying a potential increase in unsaturated fatty acid contents of walnut kernels. It concluded that AM inoculation and intercropping interactively affected walnut growth, soil attributes, and soil microenvironment.Graphical

Anti-neoplastic Effects of Juglans Regia L. Green Fruit Pericarp on Breast Cancer Cell Lines

Background: Recently, more attention has been paid to the use of complementary medicine in breast cancer (BC) treatment. Juglans green fruit pericarp was found to have anti-cancer characteristics. Objectives: We aimed here to assess the possible anti-proliferative effects of methanolic extract of Juglans green fruit pericarp in BC cell lines. Methods: MCF-7 and MDA-MB-231 cells were examined with different concentrations of Juglans green fruit pericarp extract. The cell viability was investigated using a 3 - 2, 5-diphenyl tetrazolium bromide (MTT) assay. Also, different phases of the cell cycle were analyzed utilizing a flow cytometry method. Finally, the ability of cancer cells to create colonies was studied post-treatment with Juglans green fruit pericarp. Results: Our findings showed that the methanol extract has substantial cytotoxicity on MCF-7 and MDA-MB-231 cell lines. We also observed a significant arrest in the G0/G1 phase in cancer cells post-treatment with the methanol extract. Conclusions: In summary, our results introduced a cytotoxic property for Juglans green fruit pericarp methanol extract for MCF-7 and MDA-MB-231 cell lines. Future studies are needed to further evaluate its utility as a potential complementary therapy for BC.

Genome-Wide Identification of UGT Genes and Analysis of Their Expression Profiles During Fruit Development in Walnut (Juglans regia L.)

Walnut (Juglans regia L.) possesses the ability to prevent coronary heart disease and promote cardiovascular health. This ability can be attributed to their rich content of polyphenols, particularly flavonoids. The biosynthesis of flavonoids is reliant on the catalytic activity of uridine diphosphate glycosyltransferase (UGT). However, the identification of UGTs in walnut has not been reported. In the current study, a total of 124 UGT genes containing the PSPG box were identified from the walnut genome. Based on phylogenetic analysis, the 124 UGTs could be classified into 16 distinct groups, which exhibited an uneven distribution across the 16 chromosomes. Subcellular localization prediction analysis revealed that approximately 78.23% of walnut UGT proteins were predominantly localized in the cytoplasmic compartment. Furthermore, motif annotation confirmed that motifs 1, 2, and 3 represented conserved structural features within UGT proteins, while interestingly, around 56.5% of walnut UGT members lacked introns. Through the analysis of promoter cis-regulatory elements, it was revealed that JrUGTs are involved in photoresponse, hormonal regulation, and other physiological responses. In conjunction with transcriptome analysis and quantitative expression, approximately 39% of UGT genes in walnut exhibited high expression levels during early fruit development. Correlation analysis between UGT genes’ expression and phenolic content in walnut indicated that JrUGT6, JrUGT38, JrUGT39, JrUGT58, JrUGT69, JrUGT75, and JrUGT82 might be involved in phenolic biosynthesis in walnut. This comprehensive study provides an overview of the UGT genes in walnut, serving as a valuable reference and theoretical foundation for further investigations into the biological functions of JrUGTs in flavonoid biosynthesis.

Food and Environment During the Late Roman Age at the Site of Alba Fucens (Abruzzi, Italy)

Archaeobotanical analyses in Italy are uneven in terms of geographical and chronological distribution. Amongst the different regions, Abruzzi is poorly represented, with only one study covering the Roman Age. In this framework, the analyses carried out on carpological remains collected from the Late Roman (late 5th–early 6th century AD) filling of a well in the Sanctuary of Hercules in Alba Fucens represents an important addition to the state of the art. The plant assemblage consists of over 1500 remains attributed to 68 different taxa. These are partly represented by gathered fruit plants, such as Corylus avellana, Juglans regia and Sambucus nigra, while cereals and pulses are missing. An interesting aspect is represented by evergreen plants (Pinus pinea and Cupressus sempervirens) that are likely to have been used for ritual purposes rather than for human consumption. Finally, the impressive amount of ruderal and spontaneous plants represents a unicum for this type of study, allowing us to describe the past environment surrounding Alba Fucens, characterized by substantial water availability, Apennine grasslands and influenced by human presence.

Aspects of introduction and prospects for the use of Juglans L. representatives in Central Russia

Background. Human health security is an important goal of contemporary society. The combination of beneficial properties in Juglans nuts makes them one of the most valuable plant genetic resources, capable of ensuring a wholesome supply of nutrients required by the human organism. The Persian walnut (Juglans regia L.) has the largest set of useful agronomic traits among the representatives of the genus, except for winter hardiness. Its cultivation in areas farther to the north from the conventional area of distribution for commercial walnut orchards would be possible if Juglans spp. with higher resistance to unfavorable climate conditions could be involved. Interspecies hybridization can be used to increase winter hardiness in walnut. The objective of this study was to analyze the gene pool of Juglans L. and screen its bioresource collection at the arboretum of the Russian Research Institute of Fruit Crop Breeding (VNIISPK) in the context of useful agronomic indicators promising for plant breeding and landscaping. Materials and methods. The study was carried out in the VNIISPK arboretum (Orel Province, 53°00’N, 36°00’E) where 7 Juglans spp. are maintained. Results and conclusion. The results of the screening highlighted J. mandshurica Maxim., J. cordiformis Maxim., and Vekhov’s hybrid (J. cinerea L. × J. mandshurica Maxim.) as the most resistant to adverse environmental effects. They are recommended for use in plant breeding and landscaping programs under the conditions of Central Russia. A seedling of cv. ‘Astakhovsky’ demonstrated the best agronomic indicators among the Persian walnut (J. regia) genotypes. It can be used by breeders to develop new cultivars with useful agronomic traits for the environmental conditions of the region of study.

Evidence of the involvement of Xylella fastidiosa in the occurrence of walnut leaf scorch in Xinjiang, China.

Walnut (Juglans regia Linn.) leaf scorch (WLS) was first reported in 2012 in Hotan, Xinjiang, China (Zhang et al., 2012). Initially, brown spots appear at the apex of the leaflets with slight shrinking. These spots spread inward along the leaf margins in a flame-like pattern. The scorched areas curl inward with a yellow halo. No powdery or bacterial signs were observed on the leaf surface. In severe cases, the leaves dried up and shrank, affecting the entire tree. However, new leaves did not show any signs of scorching. We collected 300 symptomatic leaf samples from 10-12 year-old trees of the susceptible WLS species Wen185, located in Daryaboyi (40°72'N, 80°49'E), Xakal (40°69'N, 80°52'E), and Karatal (40°73'N, 80°39'E) for X. fastidiosa PCR detection analysis. X. fastidiosa was detected in asymptomatic leaves of trees with severe WLS, as well as in asymptomatic leaves of trees exhibiting mild WLS symptoms, and it was even found in asymptomatic leaves of trees without any WLS symptoms.To isolate X. fastidiosa, walnut leaves with petioles were disinfected with 3% bleach for 10 minutes, followed by four washes in autoclaved deionized water. The midrib and petiole of the leaf were cut off with a sterile blade, and a 2 mm to 3 mm section was excised. Then, the cut ends were squeezed with a pair of pliers, and the sap was blotted onto Periwinkle Wilt (PW) plates (Davis et al. 1983). The plates were sealed with parafilm and incubated at 28°C in the dark, with daily observations for the development of individual colonies. The sap collected from 5 out of 20 leaf samples with scorch symptoms and from 20 leaves without symptoms never showed bacterial growth in PW.. Six colonies were tested and confirmed positive for X. fastidiosa using the RST31 and RST33 primer pair (Minsavage et al., 1994). The uploaded sequence accession numbers are PP871340-PP871342. Blast analysis of Multilocus Sequence Typing (MLST) sequences from the isolated strain using the X. fastidiosa MLST Database (http://pubmlst.org/xfastidiosa) revealed a perfect match with sequences of alleles leuA_3, petC_3, malF_, cysG_3, holC_4, nuoL_3, and gltT_3 (PP871343-PP871349). Using MEGA software to concatenate the MLST single gene fragments and construct a ML multi-gene fragment phylogenetic tree through Maximum Likelihood (ML) analysis, the bacterium was identified as X. fastidiosa subsp. multiplex To fulfill Koch's postulates, a purified colony from the PW plate was suspended in 500 μL of deionized water at 1×10^8 CFU·mL-1. A sterilized 5 ml medical needle was used to prick a small hole on the main branch, 5 cm from the base, of three-year-old walnut seedlings, and the bacterial solution was injected into the small hole. Three biological replicates were performed for each treatment (5 μL and 10 μL of bacterial solution, deionized water), and the experiment was repeated three times. Scorching symptoms were observed three months after inoculation in 11 out of the 15 seedlings inoculated with a 10 μL bacterial solution, and isolation of X. fastidiosa occurred in leaf samples from 5 of these seedlings, completing Koch's postulates. Walnut seedlings with water stayed asymptomatic, PCR negative. To our knowledge, X. fastidiosa has been found infecting grapes (Chu, 2001) in Shaanxi, China and pears (Su et al., 2016) in Taiwan, China. This is the first report of X. fastidiosa involvement in WLS in China. Further research on the occurrence of the disease will help prevent the spread of the disease.

Desulfurization of simulated and commercial liquid fuel on nano-ZnO fabricated walnut shells.

The current investigation involved the development of activated carbon, juglans regia activated carbon (JRACs), from walnut shells, scientifically known as Juglans regia. The ZnO nanorods were loaded on the activated carbon and referred to as ZnO@JRACs. Desulfurization efficiency was assessed through batch adsorption and compared to commercial activated carbon known as DARCO. The materials were characterized using PXRD (powder X-ray diffraction), FTIR (Fourier-transform infrared spectroscopy), ICP-AES (inductively coupled plasma atomic emission spectroscopy), BET (Brunauer-Emmett-Teller) surface area analysis, TEM (transmission electron microscopy) imaging, and TGA (thermal gravimetric analysis). The findings indicated that the materials have oxygen functionalities, a porous morphology, and a substantial specific surface area (BET) of 1269.92 m2/g for ZnO@JRACs. Zn atom concentration in the ZnO@JRACs surface was determined to be 1.16 atomic percent using ICP-AES. Desulfurization experiments were conducted on three liquid fuels, namely a single component model fuel, MSF (multicomponent simulated fuel), and commercial fuel (kerosene), under optimized conditions (8g/L adsorbent dosage in 10mL of fuel, 15min of contact time at room temperature). The conditions effectively removed ~ 98.9% of dibenzothiophene (DBT) from the single component model fuel. The observed order for adsorption capacity is as follows: ZnO@JRACs (63.6mgg-1) > JRACs (46.3mgg-1) > DARCO (26.1mgg-1). The analysis of multicomponent simulated fuel (MSF) using gas chromatography-flame photometric detector (GC-FPD) revealed significant removal percentages for different types of thiophenic sulfur. Specifically, the removal percentages were ~ 46.2%, 97.6%, and 99.4% for benzothiophene, dibenzothiophene, and 4, 6-dimethyldibenzothiophene, respectively. Kinetic studies have shown that the adsorption process is governed by a pseudo second-order reaction. Additional thermodynamic studies were conducted to further investigate the mechanism of adsorption. The spent synthesized composite ZnO@JRACs were thermally regenerated and can be reused for up to four cycles.

Chemical compositions and oxidative stabilities of cold-pressed walnut oils (Juglans regia L.): Effects of chemical refining, water degumming, and molecular distillation.

Walnut oils are of important academic and economic value, and are becoming one of the most important woody oils. Accurate and moderate refining techniques are required to produce high-quality walnut oils. In this work, walnut oils obtained from cold processing were refined in three typical techniques, mainly chemical refining, water degumming, and molecular distillation. Physicochemical properties (acid value and peroxide value [POV]), minor components (tocopherol, polyphenols, and phytosterol), oxidative stability indices, and volatile compounds were analyzed to find out the appropriate refining method for the cold-pressed walnut oils. Quality indices of all the refined oils from the three different refining methods met the requirements of the national standard, of which the POV of chemically refined oil (0.241g/100g) was higher than crude oil (0.058g/100g). Water degumming was most suitable for retaining of bioactive compounds, for example, the tocopherol was 259.40mg/kg, the polyphenols was 44.54mgGAE/kg, and the phytosterol was 987.32mg/kg, but oxidation stability of the obtained oil (3.09h) was lower than that of molecular distilled oil (4.18h). Initial physicochemical properties especially the POV had a significant impact on oxidation stability. There is a trade-off between the retention of nutrients and extending shelf life, indicating appropriate refining techniques should be developed; that is, water degumming is suggested to be involved in producing high-quality cold-pressed walnut oils.

Biological characterization and in vitro fungicide screening of a new causal agent of walnut leaf spot in Guizhou Province, China.

Walnut (Juglans regia L.) is a widely grown nut plant worldwide, including in Guizhou Province, located in southwest China. The high quality and special taste make Guizhou walnuts, particularly those produced in Hezhang County, a "Chinese National Geographical Indication Product" that substantially contributes to the local economy and grower's income. In July 2022, a serious occurrence of leaf spot disease was observed in a walnut plantation area, Shuitang Town, Hezhang County, Guizhou Province, China (27°07'67″N, 104°64'61″E). The causal agent was identified as Didymella segeticola through morphological characterization and amplification and sequencing of the internal transcribed spacer (ITS) region, beta-tubulin (TUB) gene, and glyceraldehyde-3-phosphate dehydrogenase (G3PD) gene. Koch's postulates, including re-isolation and identification, were performed to confirm its pathogenicity on healthy leaves. To our knowledge, this is the first report of D. segeticola causing leaf spot on walnuts worldwide. Further, to determine its biological characteristics, which could be utilized for future disease management, the effects of temperature, light, and carbon and nitrogen resources on mycelial growth, conidia production, and conidia germination and the effects of humidity on conidia germination were studied. The optimum temperature for mycelial growth of representative strain D. segeticola C27 was 20°C. Increasing the light period significantly decreased conidia production and conidia germination. Maltose and beef extract were the best carbon and nitrogen sources, respectively, for the pathogen. Conidia germination was enhanced at 90% humidity. In vitro screening of effective fungicides was conducted. Among the 20 screened fungicides, difenoconazole showed the best inhibition rate, with an EC50 (concentration for 50% of the maximal effect) of 0.0007 μg/mL. Tetramycin also showed sufficient inhibitory effects against D. segeticola, with an EC50 value of 0.0009 μg/mL. Our study provides new insights into the causal agent of walnut leaf spot in Guizhou, China, as well as the first pathogen characteristics and promising candidate fungicides for its management.

New Ophiostoma species associated with Dryocoetes himalayensis and decline of Juglans regia in Czechia

AbstractA new ophiostomatoid fungus involved in the decline of walnuts was discovered in Czechia. The fungus was isolated from necrotic wood surrounding the larval galleries of Dryocoetes himalayensis, the alien bark beetle attacking walnut trees. This insect species is rather unique within hardwood-associated bark beetle species for its aggressiveness and ability to attack apparently healthy trees. The isolated fungus, associated with an exotic insect vector is described as a new species, Ophiostoma juglandis sp. nov., based on its unique morphology and phylogenetic position. The pathogenicity tests confirmed the aggressiveness of the species to both Juglans regia and J. nigra plants, manifested by formation of extensive bleeding and necrotic lesions. The symbiotic relationship between O. juglandis and D. himalayensis is expected due to massive presence of the fungal spores on surface of adult beetles in pits forming the elytral striae. In the case of hardwood-associated ophiostomatoid fungal species, phytopathogenicity is very rarely observed. The described species is exceptional in this ability, which corresponds to the aggressive behaviour of its vector. The role of the fungus in walnut tree mortality caused by D. himalayensis is discussed.

The role of selected nutraceuticals in management of prediabetes and diabetes: An updated review of the literature. Part II.

We have already published a review about the results of clinical trials evaluating the effects of selected nutraceuticals on glycemia in humans. In this second part, we describe the role of other nutraceuticals involved in dysglycemia. The available evidence showed promising hypoglycemic effects of the nutraceuticals reviewed both for their efficacy and safety profile. However, contradictory results as regard the efficacy of some supplements such as Allium sativum, Juglans regia, and Lycium barbarum on glucose homeostasis have emerged from some clinical studies. Other nutraceuticals including Aloe vera, Amorphophallus Konjac, Bauhinia forficata, Coccinia, Ganoderma lucidum, Ipomoea batatas, and Lupinus mutabilis require larger and long-term studies rigorously designed to confirm their hypoglycemic effects due to the scarce data available and the poor quality of clinical trials. Further studies are also required for Cinnamomum, Cynara scolymus, Momordica charantia, Olea europaea, and Opuntia streptacantha. Moreover, well-designed large and long-term clinical trials including the use of standardized nutraceutical preparations are necessary for Phaseolus vulgaris and Vaccinium myrtillus.

Megafire smoke exposure jeopardizes tree carbohydrate reserves and yield.

The global incidence of megafires is on the rise, leading to extensive areas being shrouded in dense smoke for prolonged periods, spanning days or weeks1. Here, by integrating long-term regional observations of non-structural carbohydrate content in trees across California's Central Valley with spatiotemporal satellite data, we present compelling evidence that dense smoke plumes negatively impact carbohydrate stores in three tree species: Prunus dulcis, Pistacia vera and Juglans regia. Our findings show that the presence of smoke causes a significant decrease in total non-structural carbohydrates, with reductions in the accumulation of both soluble sugar and starch reserves. This decline in carbohydrate levels persists through the trees' dormancy period into the next season's bloom, culminating in a reduced yield. Our results highlight a previously unrecognized wildfire threat that could affect plant health and ecosystem stability in both agricultural and natural environments.

Behavioral, Physiological, and Molecular Mechanisms Underlying the Adaptation of Helicoverpa armigera to the Fruits of a Marginal Host: Walnut (Juglans regia).

In northwest China, changes in cultivation patterns and the scarcity of preferred hosts have forced Helicoverpa armigera to feed on the marginal host walnut (Juglans regia). However, the mechanisms allowing this adaptation remain poorly understood. Here, we investigated the behavioral, physiological, and molecular mechanisms underlying the local adaptation of this pest to walnut fruits. The green husk and shell generally contained higher levels of phytochemicals than the kernel. Bioassays revealed that the phytochemical-rich green husk and shell were less preferred, reduced larval fitness and growth, and elevated the activity of detoxification enzymes compared to the nutrient-rich kernel, which were further supported by a larger number of upregulated detoxification genes in insects fed green husks or shells based on transcriptome sequencing. Together, these data suggest that P450 genes (LOC110371778) may be crucial to H. armigera adaptation to the phytochemicals of walnuts. Our findings provide significant insight into the adaptation of H. armigera to walnut, an alternative host of lower quality. Meanwhile, our study provides a theoretical basis for managing resistance to H. armigera larvae in walnut trees and is instrumental in developing comprehensive integrated pest management strategies for this pest in walnut orchards and other agricultural systems.

The adsorption mechanism and optimal dosage of walnut shell biochar for chloramphenicol

Biochar derived from biomass pyrolysis has proven to be an excellent material for pesticide adsorption and can be used as soil amendment for pesticide non-point pollution. However, the adsorption and desorption mechanisms for certain biochar and pesticide are still unclear. In this study, we investigated the properties of biochar derived from walnut (Juglans regia L.) shell (WSB), and used batch equilibrium method to investigate the adsorption and desorption behavior for chlorantraniliprole (CAP). The physical-chemical analysis showed that there were mainly lignin charcoal of alkyl carbon, methoxyl carbon, aromatic carbon, and carboayl carbon as the primary carbon compounds of WSB. The π - π electron donor acceptor interaction, electrostatic interaction, and hydrogen bond were the primary adsorption mechanisms of the WSB adsorption. Batch equilibrium study under 298 K showed that WSB application in the soil significantly improved the adsorption ability for CAP, and the adsorption behavior was a mono-layer adsorption process as Langmuir model fitted the adsorption isotherm data better than the Freundlich model. While Freundlich model analysis showed that WSB addition to the soil changed the isothermal adsorption line from the S style to the L style. The spontaneous degree reaction of sorbents from strong to weak was in the following order: 5%-WSB >7%-WSB >10%-WSB >1%-WSB >3%-WSB > soil > WSB, and the maximum application effect was achieved at 5 % (m/m) WSB dosage mixed with the soil. Therefore, we considered that WSB addition in soil increased its CAP adsorption capacity, and 5 % (m/m) WSB application was the best choice for CAP pollution control. These data will contribute to the adsorption mechanism and the optimal use dosage of WSB for CAP pollution control.

Green chemistry approach for the synthesis of CrxCu1-xO nanoparticles: An investigation of the structural and dielectric properties

Chromium (Cr)-doped copper oxide (CrxCu1-xO, x = 0, 0.02, 0.04, 0.06, 0.10) nanoparticles were prepared by a green chemistry approach using Juglans regia fruit extract. The characteristics of pristine and Cr-doped CuO were examined in relation to the concentration of the dopant (2, 4, 6, and 10mol%) using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) Scanning electron microscopy (SEM), Energy dispersive analysis (EDX), and UV-Vis. spectroscopy (UV-Vis). According to the XRD results, the synthesized samples exhibited a polycrystalline nature and monoclinic crystal structure. It was discovered that the average grain size varies from 22.4nm to 17.82nm because of the addition of dopants. The optical analysis revealed an increase in the band gap from 1.62 to 3.10eV. We performed the dielectric analysis of pure and Cr-doped CuO nanoparticles and analyzed the behavior of dielectric parameters like dielectric constant, dielectric loss, and ac conductivity with frequency. The dielectric constant and loss exhibit a decreasing trend with frequency whereas ac conductivity demonstrates an increasing trend with frequency and composition.

Assessment of Phytochemical Characteristics of Walnut (Juglans regia) Leaves: Determination of Nutritional Value and Quantitative Content of Phenolic Compounds

This study aimed to assess the nutritional value of walnut leaves (Juglans regia), investigate the content of major polyphenolic compounds in walnut leaves, and assess the potential of walnut leaves as a phytogenic supplement to poultry diets. The nutritional composition of dried ground walnut leaves (crude protein, crude fat, crude fiber, calcium, phosphorus, vitamin E, b-carotene) was assessed according to generally accepted methods. The quantitative content of individual groups of polyphenols, such as total phenols, hydroxycinnamic acids, flavonoids, and juglon, was determined spectrophotometrically. The content of the sum of tannins was determined by the titrimetric method. Walnut leaves contain a high content of b-carotene (295.0 μg/g) and natural antioxidant vitamin E (128.8 μg/g). The protein content was noted at the level of 12.5%, the fiber content - 12.86%. In a significant amount, calcium and phosphorus accumulated in walnut leaves - 2.04% and 0.23%, respectively. The content of the total hydroxycoric acids in terms of chlorogenic acid in walnut leaves was 24.3 mg/g, the total content of phenolic compounds in gallic acid equivalent was 14.4 mg/g, flavonoids in rutin equivalent was 20.2 mg/g, and juglone was 2.72 mg/g. The content of total tannins in walnut leaves was 124.5 mg/g. The high nutritional value of walnut leaves compared to alfalfa meal and the presence of a number of biologically active polyphenolic compounds in a significant amount give grounds to consider this phyto-raw material not only as a valuable feed component, but also as a source of natural antioxidants.

Complete mitochondrial genome assembly of Juglans regia unveiled its molecular characteristics, genome evolution, and phylogenetic implications

BackgroundThe Persian walnut (Juglans regia), an economically vital species within the Juglandaceae family, has seen its mitochondrial genome sequenced and assembled in the current study using advanced Illumina and Nanopore sequencing technology.ResultsThe 1,007,576 bp mitogenome of J. regia consisted of three circular chromosomes with a 44.52% GC content encoding 39 PCGs, 47 tRNA, and five rRNA genes. Extensive repetitive sequences, including 320 SSRs, 512 interspersed, and 83 tandem repeats, were identified, contributing to genomic complexity. The protein-coding sequences (PCGs) favored A/T-ending codons, and the codon usage bias was primarily shaped by selective pressure. Intracellular gene transfer occurred among the mitogenome, chloroplast, and nuclear genomes. Comparative genomic analysis unveiled abundant structure and sequence variation among J. regia and related species. The results of selective pressure analysis indicated that most PCGs underwent purifying selection, whereas the atp4 and ccmB genes had experienced positive selection between many species pairs. In addition, the phylogenetic examination, grounded in mitochondrial genome data, precisely delineated the evolutionary and taxonomic relationships of J. regia and its relatives. We identified a total of 539 RNA editing sites, among which 288 were corroborated by transcriptome sequencing data. Furthermore, expression profiling under temperature stress highlighted the complex regulation pattern of 28 differently expressed PCGs, wherein NADH dehydrogenase and ATP synthase genes might be critical in the mitochondria response to cold stress.ConclusionsOur results provided valuable molecular resources for understanding the genetic characteristics of J. regia and offered novel perspectives for population genetics and evolutionary studies in Juglans and related woody species.

A Comprehensive Review of Molecular Mechanisms, Pharmacokinetics, Toxicology and Plant Sources of Juglanin: Current Landscape and Future Perspectives.

Juglanin (kaempferol 3-O-α-L-arabinofuranoside) is a flavonol glycoside occurring in many plants, including its commercial sources Juglans regia, Polygonum aviculare and Selliguea hastata. Recent extensive studies have explored the potential of using juglanin in various pathological conditions, including cardiovascular disorders, central nervous and skeletal system disorders, metabolic syndrome, hepatic injury, and cancers. The results indicated a wide range of effects, like anti-inflammatory, anti-oxidant, anti-fibrotic, anti-thrombotic, anti-angiogenic, hepatoprotective, hypolipidemic, hypoglycemic, anti-apoptotic (normal cells), and pro-apoptotic (cancer cells). The health-promoting properties of juglanin can be attributed to its influence on many signaling pathways, associated with SIRT1, AMPK, Nrf2, STING, TLR4, MAPKs, NF-κB, AKT, JAK, and their downstream genes. This review primarily summarizes the current knowledge of molecular mechanisms, pharmacokinetics, biocompatibility, and human use safety of juglanin. In addition, the most promising new plant sources and other existing challenges and prospects have also been reviewed and discussed, aiming to provide direction and rationale for the further development and broader pharmaceutical application of juglanin.

Acute cardiorenal dysfunctions induced by isoprenaline in Wistar rats: Mitigating potential of Juglans regia hull extract

The present study aimed to determine the attenuating properties of Juglans regia hull extract (JRHE) in mitigating isoprenaline (ISO) induced cardiorenal dysfunctions in Wistar rats. Thirty adult Wistar rats were randomly allocated to five groups with six animals in each group. Group I served as control; group II animals were administered ISO and group III received JRHE alone whereas group IV and V received JRHE and quercetin along with ISO, respectively. Administration of ISO in rats induced cardiac and renal tissue damage as reflected by significantly (p < 0.05) increased plasma activities of creatine kinase-myocardial band, lactate dehydrogenase, acetylcholinesterase, arylesterase, blood urea nitrogen, creatinine along with altered antioxidant biomarkers viz. total antioxidant status, total thiols, superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and increased (p < 0.05) lipid and protein peroxidation in cardiac and renal tissues. Histopathological findings corroborated that ISO has inflicted significant damage on cardiac and renal tissues. Repeated administration of JRHE significantly (p < 0.05) reduced the severity of ISO-induced alterations in blood, cardiac and renal biomarkers. In addition to restoring the levels of altered cardio-renal antioxidant enzymes, JRHE also ameliorated histopathological lesions in cardiac and renal tissues in ISO-treated rats.

First report of Neofusicoccum nonquaesitum causing branch dieback of English walnut (Juglans regia) in Maule region, Chile

English walnut (Juglans regia) cultivation has been expanding in recent years in Chile, with a surface of 9,000 ha planted in the Maule Region (35° 26' S, 71° 40' W), central Chile. In a field survey conducted between August (2022) and January (2023) in three localities of the Maule Region, several declined trees were observed. English walnuts exhibited small chlorotic leaves, cankers, dead twigs, and dieback of branches, with an incidence of 10 to 35% of trees affected per orchard. Internally, diseased branches exhibit brown to dark brown wood cankers. Symptomatic branches (n = 30) were collected and surface disinfected with 96% ethanol, and flamed. Pieces of wood (approximately 5 mm) were placed on potato dextrose agar (PDA), supplemented with 0.005% tetracycline, 0.01% streptomycin, and 0.1% Igepal CO-630 (Díaz et al. 2018), and incubated at 22°C for 5 days in darkness. Four isolates (VLC-1-6-20, VLC-1-10-20, VLC-1-12-20, and VLC-1-15-20) exhibited moderate growth rates (16.4 mm/day), developing a white hue to olivaceous black colonies after 7 days at 22°C on PDA. Chlamydospores were absent. Black pycnidia were formed individually or in clusters. The isolates produced aseptate, hyaline, and fusiform, with base truncate conidia measuring 24.8 ± 1.6 x 6.8 ± 0.63 µm (l/w = 3.1; n = 50). The four isolates characterized were amplified using of the internal transcribed spacer (ITS1/ITS4), a portion of beta-tubulin (Bt2a/Bt2b), and part of the translation elongation factor 1- α (EF1-728/EF1-968) genes (Phillips et al. 2013). Blast analyses showed 100, 99 and 100 % identity with ex-type isolate PD-484 of Neofusicoccum nonquaesitum for ITS (deposited as GenBank accession no. PP697845 to PP697848), Bt (PP789576 to PP789579) and EF1 (PP830824 to PP830827) regions, respectively. Combined phylogenetic analysis using MEGA 7 software and the maximum likelihood test clustered the four isolates with ex-type of N. nonquaesitum. Pathogenicity was performed using two isolates (VLC-1-6-20 and VLC-1-10-20), which were inoculated in healthy tree walnuts cv. Chandler (8 years old), using 40 μl of mycelial suspension (105 fragments of mycelium/ml) on rounded wounds in the middle of each attached young branch (n=30 branches) (Twizeyimana et al. 2013). Sterile distilled water was used as a control treatment. Pathogenicity tests were repeated twice. After 6 months, necrotic streaks with mean lengths of 13 mm and 28 mm were observed in the middle of wounded young branches. No necrotic lesions were observed in the control treatments. Reisolation of N. nonquaesitum was positive (100%) only from inoculated branches and molecularly identified (EF1-a), fulfilling Koch’s postulates. Previously, N. nonquaesitum has been reported causing dieback on English walnut in California (Chen et al. 2014). To our knowledge, this is the first report of N. nonquaesitum causing canker and branch dieback of English walnut in central Chile. Previously, Diplodia mutila, Dothiorella sarmentorum, and N. austral have been associated with walnut dieback in Chile (Díaz et al. 2018; Iqbal et al. 2023; Barcos et al. 2023). In conclusion, it is imperative to implement epidemiological studies to avoid the spread and severity of branch dieback of walnuts in the Maule region, central Chile.