Avocado Research Articles

Potensi Buah Alpukat (Persea americana Mill.) sebagai Media Alternatif Pertumbuhan Jamur Fusarium sp.

Potensi Buah Alpukat (Persea americana Mill.) sebagai Media Alternatif Pertumbuhan Jamur Fusarium sp.

Identification of Phytophthora cinnamomi CRN effectors and their roles in manipulating cell death during Persea americana infection

The oomycete Phytophthora cinnamomi is a devastating plant pathogen with a notably broad host range. It is the causal agent of Phytophthora root rot (PRR), arguably the most economically important yield-limiting disease in Persea americana (avocado). Despite this, our understanding of the mechanisms P. cinnamomi employs to infect and successfully colonize avocado remains limited, particularly regarding the pathogen’s ability to maintain its biotrophic and necrotrophic lifestyles during infection. The pathogen utilises a large repertoire of effector proteins which function in facilitating and establishing disease in susceptible host plants. Crinkling and necrosis effectors (CRN/Crinklers) are suspected to manipulate cell death to aid in maintenance of the pathogens biotrophic and necrotrophic lifestyles during different stages of infection. The current study identified 25 P. cinnamomi CRN effectors from the GKB4 genome using an HMM profile and assigned putative function to them as either cell death inducers or suppressors. Function was assigned to 10 PcinCRNs by analysing their RNA-seq expression profiles, relatedness to other functionally characterised Phytophthora CRNs and tertiary protein predictions. The full-length coding sequences for these PcinCRNs were confirmed by Sanger sequencing, six of which were found to have two divergent alleles. The presence of alleles indicates that the proteins encoded may perform contradicting functions in cell death manipulation, or function in different host plant species. Overall, this study provides a foundation for future research on P. cinnamomi infection and cell death manipulation mechanisms.

Statistical physics analysis of the adsorption of reactive red 141dye on residual avocado peel (Persea americana) chemically modified with H2SO4 and HNO3

The preparation and adsorption properties of avocado peels treated with H2SO4 and HNO3 for the removal of reactive red 141 dye are reported in this manuscript. Equilibrium adsorption of this organic dye on the two adsorbents was experimentally quantified at pH 6.5 and 298.15–328.15 K. An advanced physical model that assumed the formation of a finite number of layers of the adsorbed pollutant molecules on the adsorption sites was used to estimate the steric and energetic parameters of the dye adsorption mechanism. The modeling results showed dye molecular aggregation, in which each adsorption site of avocado peels treated with H2SO4 and HNO3 adsorbed several dye molecules simultaneously at different temperatures. The results also demonstrated that dye adsorption on avocado peels treated with these acids was exothermic. The estimated adsorption energies for the dye-treated biomass and dye-dye interactions indicated aphysisorption associated with van der Waals forces and hydrogen bonding. The outcomes of this study contribute with insights into the adsorption mechanisms of dye molecules using treated avocado peels with the aim of developing sustainable water treatment methods according with a circular economy approach.

Transesterification of Persea americana seed oil to methyl ester using bio-based heterogeneous catalyst: Optimization and techno-economic analysis

The techno-economic analysis of producing biodiesel from agrarian wastes at optimal condition was carried out. The acid activated empty palm fruit bunch ash (AAEPFBA) catalyzed the methyl ester production. The AAEPFBA catalyst was synthesized from waste palm fruit bunch, and modified with phosphoric acid. The activation was best achieved by adding H3PO4 acid in a ratio of 1:2 (g/ml). The modification of the catalyst increased the alkaline properties and surface area and decreased the particle size and adsorption energy. The process variables of temperature 61.9 °C, reaction time of 3.09 h, methanol/oil molar ratio of 10.2:1, catalyst concentration of 3.14wt%, and agitation speed of 321.54 rpm at a desirability of one gave an experimental optimal yield of biodiesel as 90.3%. Based on the experimental study, 3062 liters (2728kg) of biodiesel was evaluated annually. The annual operating cost, payback period, and internal rate of return are ₦2201288, 1.5years, and 7.6%, respectively. The sensitivity analysis of oil purchase cost, biodiesel selling price, and labour cost on Return on investment, PBP, IRR, and Net present value were investigated. In this study, the relative biodiesel selling price is a determinant of the profitability of producing avocado pear seed oil methyl ester. The overall results show that investors can embark on biodiesel production using avocado pear seed oil, and AAEPFBA as feedstocks.

Ethanolic extract of Persea americana Mill. (Lauraceae) seeds induced antiestrogenic effects in young female Wistar rats.

The ethanol extract of Persea americana seeds was found to inhibit the development of estrogen-dependent conditions in female Wistar rats, suggesting the ability of its secondary metabolites to interact with estrogen receptors (ERs), either as partial agonists or as antagonists. To test this hypothesis, the abovementioned extract was assessed for its ability to mimic and/or antagonize estradiol effects. Two experiments were conducted in ovariectomized (OVX) rats: (1) animals were treated with estradiol valerate (E2V; 1 mg/kg) or P.americana at doses of 25 and 50 mg/kg; (2) animals were treated with E2V alone (0.75 mg/kg) or in combination with P.americana at the abovementioned doses. Treatments were given orally for 3days and animals were sacrificed for biochemical and histological analyses of the uterus and vagina. When administered alone, P.americana did not change the histomorphology of both organs (uterus and vagina). In combination with E2V, P.americana decreased uterine weight [30 % decrease (p<0.001) at 25 mg/kg and 24 % (p<0.01) at 50 mg/kg] and epithelium height (37 % decrease). This was associated with decreased estradiol levels (at least 86 % decrease, p<0.001) in the uterus. Similarly, vagina epithelium height decreased by at least 34 % (p<0.05) when E2V was co-administered with P.americana. The seed extract of P.americana contains ER antagonist secondary metabolites accounting for its ability to inhibit the development of estrogen-dependent conditions in female rats.

[Analysis of the electrophoretic profiles of the protein extracts of the species Manihot esculenta (Crantz, 1975), Persea Americana (Mill., 1768) and Actinidia delicious (A. Chevalier., 1984), and their association with the latex-fruit syndrome for searching for potential allergens].

Determine the electrophoretic profiles of the extracts of Manihot esculenta, Actinidia Deliciosa and Persea Americana and their possible relationship with Latex-Fruit Syndrome. Protein extracts of M. esculenta, P. Americana and A. Deliciosa were prepared through the processes of maceration and solvent extraction from plant samples. In the case of the avocado, a prior extraction by soxhlet was carried out to eliminate the fat. The extracts were vacuum filtered, dialyzed and finally lyophilized. Separation of proteins based on molecular weight was performed by SDS PAGE electrophoresis. The electrophoretic profiles obtained were compared with the allergenic proteins previously identified in the latex extract, in order to determine a possible relationship with Latex-Fruit Syndrome, depending on the molecular weight. The extracts of M. esculenta and P. Americana showed a wide range of protein fractions with molecular weights varying from 10 to 250 KD, finding that the region with the highest concentration of bands was between 20 and 89 KD, (60 and 65%), respectively. A 20-band profile was obtained for the M. esculenta extract (Figure 1), with seven bands sharing similar weights with the latex allergens (Hev b 1, Hev b 2, Hev b3, Hev b 4, Hev b 5, Hev b 6.03, Hev b 8 and Hev b 10) (3-5). For the P. Americana extract, 20 bands were also observed (Figure 2), seven of which presented approximate weights to the Latex allergens (Hev b 1, Hev b 2 Hev b 4 Hev b 6.01 Hev b 6.03 Hev b 8 , Hev b 10 Hev b 11 Hev b 14). The Kiwi extract showed two bands of 19.1 and 22.9 KD, with weights close to latex proteins (figure 3), (Hev b 3 and Hev b 6.01), and allergens (Act d 2 and Act d 6), reported in the literature for this fruit. When analyzing the relationship between the separated protein fractions and the latex allergens described in the literature, a possible association of 35% was found for the extracts of M. esculenta and P. Americana, and 10% for A. Delicious, with great relevance being the association found with the allergens Hev b 4, Hev b 2, Hev 8 and Hev b 11, which are involved in Latex-Fruit Syndrome. The electrophoretic profiles of the prepared extracts were determined and compared with the Latex allergens. This information generates a contribution for the development of new research and advances in the standardization of these extracts on a large scale and for their future use in diagnostic tests.

Ajuste osmótico y rendimiento de dos variedades de palta (Persea americana), Hass y Fuerte, con sistema de riego por goteo, en zona andina del Perú

The cultivation of avocado (Persea Americana) is not only essential from an economic point of view, but also plays a crucial role in the nutrition, health and well-being of populations around the world. The study was carried out in Ayacucho -Peru (latitude: 12° 53' 57'' S, longitude: 74° 16' 55'' W and altitude: 2596 masl), with the objective of evaluating the effect of the use of the technical drip irrigation system on the production and yield of two varieties of avocado, Hass and Fuerte. The study was based on the use of an irrigation system with programming by treatment with avocado plants installed in plots of 500 m² in 6 sectors, with a density of 5 x 5 m, whose age was between 5 to 16 years, of the which were considered 12 plants (6 plants with drip irrigation and 6 plants as a control with gravity irrigation). Irrigation was carried out right at the flowering and production stage, guaranteeing adequate water supply in periods of water deficit, between February and June 2022. The experimental design was a complete randomized block, with six blocks of 20 plants each. The harvest carried out reported yields of 67.96 ± 8.8 t/ha under technical irrigation and 26.42 ± 4.93 t/ha under gravity irrigation, an increase of 157% with respect to the latter. As for the varieties, the Fuerte avocado had the highest yield 49.38 ± 23.06 t/ha compared to the Hass variety (45.0 ± 21.14 t/ha), the maximum yield occurred with drip irrigation for the Fuerte variety (71.09 ± 8.38 t/ha), this is explained by the energy expenditure in the osmotic adjustment potential which drastically decreases the yield potential with traditional gravity irrigation, obtaining a minimum yield in Hass of 25.18 ± 4.44 t/ha.

A telomere-to-telomere gap-free reference genome assembly of avocado provides useful resources for identifying genes related to fatty acid biosynthesis and disease resistance

Abstract Avocado (Persea americana Mill.) is an economically valuable plant because of the high fatty acid content and unique flavor of its fruits. Its fatty acid content, especially the relatively high unsaturated fatty acid content, provides significant health benefits. We herein present a telomere-to-telomere gapless genome assembly (841.6 Mb) of West Indian avocado. The genome contains 40,629 predicted protein-coding genes. Repeat sequences account for 57.9% of the genome. Notably, all telomeres, centromeres, and a nucleolar organizing region are included in this genome. Fragments from these three regions were observed via fluorescence in situ hybridization. We identified 376 potential disease resistance-related nucleotide-binding leucine-rich repeat genes. These genes, which are typically clustered on chromosomes, may be derived from gene duplication events. Five NLR genes (Pa11g0262, Pa02g4855, Pa07g3139, Pa07g0383, and Pa02g3196) were highly expressed in leaves, stems, and fruits, indicating they may be involved in avocado disease responses in multiple tissues. We also identified 128 genes associated with fatty acid biosynthesis and analyzed their expression patterns in leaves, stems, and fruits. Pa02g0113, which encodes one of 11 stearoyl-acyl carrier protein desaturases mediating C18 unsaturated fatty acid synthesis, was more highly expressed in the leaves than in the stems and fruits. These findings provide valuable insights that enhance our understanding of fatty acid biosynthesis in avocado.

TEST OF RESISTANCE OF ALPUKAT (Persea americana mill) FRUIT EXTRACT ON THE GROWTH OF THE Streptococcus mutans

Introduction: Streptococcus mutans  is one of the normal flora living in the oral cavity, but in excessive amounts is the main causative agent of dental caries. The active compounds of alkaloids, saponins and quinones in avocado pulp extract is an antibacterial alternative that can inhibit the growth of Streptococcus mutans  in the oral cavity. The aim of this research was to determine the inhibitory power that contain in avocado pulp against Streptococcus mutans . Materials and Methods: This study used 4 concentrations namely 25%, 50%, 75% and 100% with each repetition 4 times. Avocado pulp extraction was carried out by maceration method using 96% ethanol solvent. Inhibition zone testing was carried out using the Kirby baurer method. Results and Discussions: The zone of inhibition was determined using the Kruskal wallis test, which showed that there were significant differences in various concentrations against the growth of Streptococcus mutans  bacteria. Avocado fruit pulp extract is able to inhibit the growth of Streptococcus mutans  bacteria because avocado fruit pulp extract has active compounds that cause antibacterial activity. Active compounds of avocado fruit flesh that are efficacious as antibacterials are alkaloids, saponins and quinones. Conclusion: Avocado pulp extract has been proven to have an antibacterial effect against Streptococcus mutans  with an effective concentration level of 100%. Increasing the concentration of avocado pulp extract was also shown to affect the diameter of Streptococcus mutans  inhibition zone

Green synthesis of bio-mediated silver nanoparticles from Persea americana peels extract and evaluation of their biological activities: In vitro and in silico insights

In this article, Persea americana aqueous peels extract was used to synthesize silver nanoparticles in a simple and environmentally friendly manner. The properties of synthesized silver nanoparticles (AV-AgNPs) were studied via several techniques, including UV–vis spectroscopy, DLS, TEM, EDX, and FTIR. The UV–Vis spectra analysis revealed that the highest absorption peak occurred at 428 nm, providing strong evidence for forming AV-AgNPs. The TEM results indicate that the synthesized AV-AgNPs were uniformly dispersed, exhibiting a spherical shape with an average size of 24 nm. EDX imaging also confirmed the presence of AgNPs. FTIR analysis shows P. americana's phenolic compounds and proteins significantly contribute to AV-AgNP synthesis and stabilization. In addition, the antimicrobial activity of AV-AgNPs was assessed against pathogenic bacteria commonly found in humans, exhibiting a moderate zone of inhibition against the selected pathogens. Additionally, AV-AgNPs were used in antioxidant studies with the robust antioxidant properties 2, 2 diphenyl-1-picrylhydrazyl (DPPH). In vitro studies have shown that AV-AgNPs can remarkably inhibit α-amylase in a dose-dependent manner, indicating their potential as antidiabetic agents. In silico research, it was revealed that naringenin derived from P. americana exhibited a strong binding to S. typhi and B. cereus (−8.7 and −7.5 kcal/mol, respectively). At the same time, quercetin demonstrated a high binding affinity and energy to α-Amylase (−8.9 kcal/mol). This study presents the first investigation into the biosynthesis of AgNPs utilizing the aqueous peel extract derived from P. americana with multiple uses, including antioxidant, antimicrobial, and antidiabetic activity.

Identity, pathogenicity and genetic diversity of Lasiodiplodia associated with stem-end rot of avocado in China.

Stem-end rot (SER) causes brown necrotic lesions in the pulp near the base of the fruit pedicel and is one of the most devastating postharvest diseases of avocados in all avocado growing regions of the world. China's avocado industry is growing very rapidly, and the planting area is expanding, but little is known about the pathogens and genetic diversity of avocado SER. To determine the causal agents of SER, avocado fruits were sampled from the main avocado-producing areas in China during 2020 and 2021. Fungal isolates were obtained from SER symptomatic avocado fruits and identified by morphology combined with phylogenetic analysis of internal transcribed spacer (ITS), translation elongation factor 1-α (EF1-α) and β-tubulin (TUB2) gene sequences. All 101 isolates belonged to Lasiodiplodia spp., and four Lasiodiplodia species were identified, namely L. pseudotheobromae (59.41%), L. theobromae (24.75%), L. mahajangana (7.92%), L. euphorbiaceicola (1.98%), and six others are classified as Lasiodiplodia sp. (5.94%). There were only slight morphological differences in colonies and conidia of these four species of Lasiodiplodia. The pathogenicity tests showed symptoms of SER, and the 92.08% of the isolates exhibited a high level of virulence on avocado (disease index > 70), related to the disease severity on avocado fruit. All tested isolates grew well under conditions from 23 to 33℃. There was a significant difference in mycelial growth between the four species of Lasiodiplodia after treatment with high temperature or low temperature. L. pseudotheobromae growth was the fastest at 13 to 18℃, but was the lowest at 38℃ (P < 0.05). Red pigment could be produced by all tested isolates after culturing for 7 days at 38℃. The mycelial growth rate was the fastest on PDA medium, and the slowest on OMA medium but promoted spore formation (P < 0.05). In addition, was determined the genetic diversity of Lasiodiplodia pathogenic species associated with SER collected from avocado, mango, guava and soursop fruits was determined. A total of 74 isolates were clustered into 4 main ISSR groups by unweighted pair-group method with arithmetic mean (UPGMA) analysis, and the classification of this group was related to the host. Extensive diversity was detected in the Lasiodiplodia populations. The diverse geographical origins and host species significantly influenced the population differentiation, and most of the genetic variation occurred within populations (P < 0.001). This is the first study to identify the major pathogens of avocado SER in China and to survey their occurrence, pathogenicity and include a comparative analysis of genetic diversity with Lasiodiplodia spp. causing SER on other fruit hosts. Collectively, the Lasiodiplodia species complex affecting avocado showed high pathogenicity and diversity, while L. pseudotheobromae was the most frequently isolated species in China. The results of this study provide insights into the aspects of epidemic of SER disease caused by Lasiodiplodia species, which will help in developing strategies for the management and control of stem end-rot in avocado.

Evaluation of Pork Quality and Carcass Attributes in Growing Pigs Fed Processed Avocado (Persea americana) Seed Meal

With the escalating prices of conventional feed ingredients, there is an urgent requirement to investigate sustainable alternatives that have the potential to improve performance, carcass yield, and meat quality. Twenty-four growing pigs (mixed sexes) were utilized to assess the carcass and sensory attributes of pork derived from pigs fed a diet incorporating processed Avocado (Persea americana) seed meal. The pigs were divided into four groups of six, and further replicated thrice with two pigs each, following a completely randomized design. The feeding trial spanned 70 days, during which the pigs were randomly allocated to one of the four dietary treatments containing 0 %, 2.5 %, 5 %, and 7.5 %, and designated as T1, T2, T3, and T4 respectively. At the end of the study, eight pigs (two per treatment) were randomly selected for carcass assessment. The results revealed a noteworthy increase in carcass yield with significant differences (p&lt;0.05) between pigs in treatment 3, followed by treatments 2 and 4, which did not exhibit significant differences (p&gt;0.05), whereas pigs in treatment 1 displayed the lowest carcass yield. Significant differences (p&lt;0.05) were observed in primal cuts (except for the chump chop), with treatment 3 yielding the highest values, followed by treatments 2, 1, and 4, respectively. Organ weights showed no significant differences (p&gt;0.05), suggesting that the inclusion of Avocado seed meal did not adversely affect the organs. There was a decrease in abdominal fat with increasing levels of Avocado seed meal, while the meat-to-bone ratio increased in treatment 3, followed by treatment 2, with treatment 1 exhibiting the least increase. The sensory evaluation revealed notable differences (p&lt;0.05) in all assessed parameters, except for colour. Treatment 3 displayed significantly higher values across all parameters. Overall acceptability scores positioned treatment 3 as the highest, followed by treatment 2, while treatments 4 and 1 received the lowest scores. In conclusion, incorporating processed avocado seed meal at a 5% dietary inclusion level improved both the carcass attributes and sensory quality of pork.

Valorization of avocado (Persea americana) residual paste: Microwave-assisted extraction, optimization and addition to an artisanal pork ham

ABSTRACT Recovering biocompounds from industrial by-products is crucial to avoid food waste. Microwave-assisted extraction (MAE) has been employed to recover some biocompounds from vegetal matrices using ethanol and his solutions as solvent. Optimization of MAE conditions over total soluble polyphenols (TSP) and antioxidant capacity (DPPH and FRAP) from avocado residual paste (ARP) from oil industry was carried out. Optimal extract was used to elaborate an artisanal ham. Using response surface methodology (RSM), optimal conditions for MAE were 480 W of power, absolute ethanol as solvent, and extraction time of 180 s. The extract contained TSP of 31.24 mg GAE/g DW, DPPH inhibition of 24.51 mg TE/g DW and FRAP inhibition of 21.58 mg TE/g DW. The extract was added in the ham formulation at 0, 0.5, 1, and 1.5% w/w. Ham with 1% extract had the highest scores for acceptance. Extracts from ARP may be used in ham with adequate sensory attributes.

Unravelling the Influence of Chlorogenic Acid on the Antioxidant Phytochemistry of Avocado (Persea americana Mill.) Fruit Peel.

Oxidative stress is pivotal in the pathology of many diseases. This study investigated the antioxidant phytochemistry of avocado (Persea americana Mill.) peel. Different solvent extracts (dichloromethane, ethyl acetate, methanol, and water) of avocado peel were subjected to total phenol and flavonoid quantification, as well as in vitro radical scavenging and ferric reducing evaluation. The methanol extract was subjected to gradient column chromatographic fractionation. Fraction 8 (eluted with hexane:chloroform:methanol volume ratio of 3:6.5:0.5, respectively) was subjected to LC-MS analysis. It was assessed for cellular inhibition of lipid peroxidation and lipopolysaccharide (LPS)-induced ROS and NO production. The DPPH radical scavenging mechanism of chlorogenic acid was investigated using Density Functional Theory (DFT). The methanol extract and fraction 8 had the highest phenol content and radical scavenging activity. Chlorogenic acid (103.5 mg/mL) and 1-O-caffeoylquinic acid (102.3 mg/mL) were the most abundant phenolics in the fraction. Fraction 8 and chlorogenic acid dose-dependently inhibited in vitro (IC50 = 5.73 and 6.17 µg/mL) and cellular (IC50 = 15.9 and 9.34 µg/mL) FeSO4-induced lipid peroxidation, as well as LPS-induced ROS (IC50 = 39.6 and 28.2 µg/mL) and NO (IC50 = 63.5 and 107 µg/mL) production, while modulating antioxidant enzyme activity. The fraction and chlorogenic acid were not cytotoxic. DFT analysis suggest that an electron transfer, followed by proton transfer at carbons 3'OH and 4'OH positions may be the radical scavenging mechanism of chlorogenic acid. Considering this study is bioassay-guided, it is logical to conclude that chlorogenic acid strongly influences the antioxidant capacity of avocado fruit peel.

Shelf-Life Management and Ripening Assessment of 'Hass' Avocado (Persea americana) Using Deep Learning Approaches.

Avocado production is mostly confined to tropical and subtropical regions, leading to lengthy distribution channels that, coupled with their unpredictable post-harvest behavior, render avocados susceptible to significant loss and waste. To enhance the monitoring of 'Hass' avocado ripening, a data-driven tool was developed using a deep learning approach. This study involved monitoring 478 avocados stored in three distinct storage environments, using a 5-stage Ripening Index to classify each fruit's ripening phase based on their shared characteristics. These categories were paired with daily photographic records of the avocados, resulting in a database of labeled images. Two convolutional neural network models, AlexNet and ResNet-18, were trained using transfer learning techniques to identify distinct ripening indicators, enabling the prediction of ripening stages and shelf-life estimations for new unseen data. The approach achieved a final prediction accuracy of 88.8% for the ripening assessment, with 96.7% of predictions deviating by no more than half a stage from their actual classifications when considering the best side of the samples. The average shelf-life estimates based on the attributed classifications were within 0.92 days of the actual shelf-life, whereas the predictions made by the models had an average deviation of 0.96 days from the actual shelf-life.

Near-freezing temperature suppresses avocado (Persea americana Mill.) fruit softening and chilling injury by maintaining cell wall and reactive oxygen species metabolism during storage

To enhance the postharvest quality of avocado (Persea americana Mill.) fruit, this study investigates alterations in cell wall metabolism and reactive oxygen species (ROS) metabolism during near-freezing temperature (NFT) storage, and explores their impact on fruit softening. The fruit was stored at 25 °C, 5 °C, 2 °C, and NFT, respectively. NFT storage retarded firmness loss and chilling injury in comparison with 25 °C, 5 °C, and 2 °C. NFT storage delayed the decrease of ionic-soluble pectin (ISP) and cellulose (CLL) contents by suppressing cell wall degradation enzyme activities. Correlation analysis showed that cell wall degradation enzyme activities were positively correlated to rates of ethylene release and respiration. Moreover, NFT storage maintained higher levels of DPPH and ABTS scavenging abilities, activities of superoxide dismutase, peroxidase, and catalase, as well as ascorbate-glutathione cycle (ascorbic acid, glutathione, glutathione disulfide, ascorbate peroxidase, cycle-related enzymes), thereby inhibited the increase of ROS content, malondialdehyde content, and cell membrane permeability. Fruit firmness and chilling injury were correlated with the contents of hydrogen (H2O2), superoxide anion (O2.-), ISP, and CLL. These results suggested that NFT could suppress fruit softening and chilling injury by inhibiting cell wall degradation through delaying respiration and ethylene production and suppressing ROS production via activation of antioxidant systems, thereby maintaining quality and prolonged storage life during avocado fruit storage.

Therapeutic Potential of &amp;lt;i&amp;gt;Persea americana &amp;lt;/i&amp;gt;Stem Bark in Lipopolysaccharide (LPS) Induced Hepatic Inflammation and Oxidative Stress in Mice

This study investigated the potential of &amp;lt;i&amp;gt;Persea americana&amp;lt;/i&amp;gt; stem bark for the treatment of inflammation and oxidation in mice. Oxidative stress occurs in the body when there is serious imbalance between the generation of free radicals and the antioxidant defense system, inflammation is a natural defense mechanism against pathogens and it is associated with many pathogenic diseases such as microbial and viral infections, exposure to allergens, radiation and toxic chemicals, autoimmune and chronic diseases, obesity, consumption of alcohol, tobacco use, and a high-calorie diet. Plants offer significant potentials for development of new anti-inflammatory therapies and treatment of diseases associated with inflammation and Oxidation. Stem bark of &amp;lt;i&amp;gt;Persea ameriacna&amp;lt;/i&amp;gt; was extracted using EtOH/H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O (80:20 v/v), the extract obtained was subjected to maceration using 3 different solvents, hexane fraction (PAHF), Ethyl-acetate fraction (PAEF) and methanol fraction (PAMF). The methanol fraction came out with the highest yield and was used for the animal study, 30 male mice was divided into 3 different groups, LPS was introduced in one of the groups, PAMF was later administered to the same group, The experiment shows that the extract was able to demonstrate significant reduction in inflammation and also ameliorate oxidation in mice. In conclusion the methanolic fraction of &amp;lt;i&amp;gt;Persea americana&amp;lt;/i&amp;gt; stem bark might contain beneficial phytochemicals that can be explored as potential anti-inflammatory and oxidative therapy.

The six-spotted spider mite, Eotetranychus sexmaculatus (Riley) (Trombidiformes: Tetranychidae) in Australia, New Zealand, Japan and USA: a revised morphological and molecular-based concept, synonyms, and related species

Based on morphological and molecular evidence, Eotetranychus asiaticus Ehara is confirmed as a junior synonym of E. sexmaculatus (Riley). Eotetranychus queenslandicus Manson differs to E. sexmaculatus in some morphological characters states, and currently there is insufficient evidence to confirm if it is also a junior synonym. We therefore propose that it remains a valid species until fresh material can be collected from the type host (Codiaeum variegatum (L.) A.Juss.; Euphorbiaceae) in the type location (Freshwater, Queensland, Australia) for molecular analysis and further comparisons. Eotetranychus sexmaculatus is confirmed as present in Australia and New Zealand. Our analyses indicate that specimens identified as E. sexmaculatus from avocado (Persea americana Mill.; Lauraceae) in Western Australia and New Zealand, and specimens of E. asiaticus from the type host (Ficus erecta Thunb.; Moraceae) and type location (Tomigusuku, Okinawa, Japan) are conspecific with specimens of E. sexmaculatus recently collected from the type host (Citrus sp.; Rutaceae) and type location (Florida, USA), with 0–3.6% divergence in a fragment (451 bp) of cytochrome oxidase subunit I (COI), and 0–0.3% in the ribosomal internal transcribed spacer II (ITS2) gene. Herein we redefine E. sexmaculatus, providing a revised diagnosis, notes on leg chaetotaxy, and variation in the shape of the aedeagus—which is a keystone feature critical for determining species boundaries of spider mite species that have males. Our findings also reinforce the potential of the eupathidion on the palptarsus suζ (i.e. the spinneret) for species diagnoses.

Effect of Co-Inoculation with Growth-Promoting Bacteria and Arbuscular Mycorrhizae on Growth of Persea americana Seedlings Infected with Phytophthora cinnamomi.

Avocado is one of the most in-demand fruits worldwide and the trend towards its sustainable production, regulated by international standards, is increasing. One of the most economically important diseases is root rot, caused by Phythopthora cinnamomi. Regarding this problem, antagonistic microorganism use is an interesting alternative due to their phytopathogen control efficiency. Therefore, the interaction of arbuscular mycorrhizal fungi of the phylum Glomeromycota, native to the Peruvian coast (GWI) and jungle (GFI), and avocado rhizospheric bacteria, Bacillus subtilis and Pseudomonas putida, was evaluated in terms of their biocontrol capacity against P. cinnamomi in the "Zutano" variety of avocado plants. The results showed that the GWI and Bacillus subtilis combination increased the root exploration surface by 466.36%. P. putida increased aerial biomass by 360.44% and B. subtilis increased root biomass by 433.85%. Likewise, P. putida rhizobacteria showed the highest nitrogen (24.60 mg ∙ g-1 DM) and sulfur (2.60 mg ∙ g-1 DM) concentrations at a foliar level. The combination of GWI and Bacillus subtilis was the treatment that presented the highest calcium (16.00 mg ∙ g-1 DM) and magnesium (8.80 mg ∙ g-1 DM) concentrations. The microorganisms' multifunctionality reduced disease severity by 85 to 90% due to the interaction between mycorrhizae and rhizobacteria. In conclusion, the use of growth promoting microorganisms that are antagonistic to P. cinnamomi represents a potential strategy for sustainable management of avocado cultivation.

Comparative transcriptional analysis of Persea americana MYB, WRKY and AP2/ERF transcription factors following Phytophthora cinnamomi infection.

Plant cells undergo extensive transcriptional reprogramming following pathogen infection, with these reprogramming patterns becoming more complex when pathogens, such as hemibiotrophs, exhibit different lifestyles. These transcriptional changes are often orchestrated by MYB, WRKY and AP2/ERF transcription factors (TFs), which modulate both growth and defence-related gene expression. Transcriptional analysis of defence-related genes in avocado (Persea americana) infected with Phytophthora cinnamomi indicated differential immune response activation when comparing a partially resistant and susceptible rootstock. This study identified 226 MYB, 82 WRKY, and 174 AP2/ERF TF-encoding genes in avocado, using a genome-wide approach. Phylogenetic analysis revealed substantial sequence conservation within TF groups underscoring their functional significance. RNA-sequencing analysis in a partially resistant and susceptible avocado rootstock infected with P. cinnamomi was indicative of an immune response switch occurring in either rootstock after 24 and 6 h post-inoculation, respectively. Different clusters of co-expressed TF genes were observed at these times, suggesting the activation of necrotroph-related immune responses at varying intervals between the two rootstocks. This study aids our understanding of avocado immune response activation following P. cinnamomi infection, and the role of the TFs therein, elucidating the transcriptional reprogramming disparities between partially resistant and susceptible rootstocks.