Agave angustifolia Haw. Leaves as a Potential Source of Bioactive Compounds: Extraction Optimization and Extract Characterization.

The leaves of Agave angustifolia Haw. are the main agro-waste generated by the mezcal industry and are becoming an important source of bioactive compounds, such as phenolic compounds, that could be used in the food and pharmaceutical industries. Therefore, the extraction and identification of these phytochemicals would revalorize these leaf by-products. Herein, maceration and supercritical carbon dioxide (scCO2) extractions were optimized to maximize the phenolic and flavonoid contents and the antioxidant capacity of vegetal extracts of A. angustifolia Haw. In the maceration process, the optimal extraction condition was a water-ethanol mixture (63:37% v/v), which yielded a total phenolic and flavonoid content of 27.92 ± 0.90 mg EAG/g DL and 12.85 ± 0.53 µg QE/g DL, respectively, and an antioxidant capacity of 32.67 ± 0.91 (ABTS assay), 17.30 ± 0.36 (DPPH assay), and 13.92 ± 0.78 (FRAP assay) µM TE/g DL. Using supercritical extraction, the optimal conditions for polyphenol recovery were 60 °C, 320 bar, and 10% v/v. It was also observed that lower proportions of cosolvent decreased the polyphenol extraction more than pressure and temperature. In both optimized extracts, a total of 29 glycosylated flavonoid derivatives were identified using LC-ESI-QTof/MS. In addition, another eight novel compounds were identified in the supercritical extracts, showing the efficiency of the cosolvent for recovering new flavonoid derivatives.

Microstructural Characterization and Corrosion Behavior of Similar and Dissimilar Welded Advanced High-Strength Steels (AHSS) by Rotary Friction Welding.

Advanced high-strength steels (AHSSs) are designed for meeting strict requirements, especially in the automotive industry, as a means to directly influence the reduction in the carbon footprint. As rotary friction welding (RFW) has many important advantages over other welding technologies, it plays an important role in the automotive sector. On the above basis, in this work, combinations of the first (complex phase (CP)), second (TWIP (TW)), and third (quenched and partitioned (Q&P)) generations of similar and dissimilar high-alloyed advanced steels have been joined by the RFW process. Having a specific microstructure, rods of CP/CP, Q&P/Q&P, CP/TW, and Q&P/TW steels were welded by employing a homemade adaptation machine under fixed parameters. Microstructural characterization has allowed us to corroborate the metallic bonding of all the tested advanced steels and to identify the different zones formed after welding. Results indicate that the welding zone widens in the center of the workpiece, and under the current friction action, the intermixing region shows the redistribution of solute elements, mostly in the dissimilarly welded steels. Furthermore, because of their complex chemistry and the different mechanical properties of the used steels, dissimilarly welded steels present the most noticeable differences in hardness. The TWIP steel has the lower hardness values, whilst the CP and Q&P steels have the higher ones. As a direct effect of the viscoplastic behavior of the steels established by the thermomechanical processing, interlayers and oxidation products were identified, as well as some typical RFW defects. The electrochemical response of the welded steels has shown that the compositional and microstructural condition mostly affect the corrosion trend. This means that the dissimilarly welded steels are more susceptible to corrosion, especially at the TWIP-steel interface, which is attributed to the energy that is stored in the distorted microstructure of each steel plate as a consequence of the thermomechanical processing during RFW.

Comparative Methods for Quantification of Sulfate-Reducing Bacteria in Environmental and Engineered Sludge Samples.

This study aimed to compare microscopic counting, culture, and quantitative or real-time PCR (qPCR) to quantify sulfate-reducing bacteria in environmental and engineered sludge samples. Four sets of primers that amplified the dsrA and apsA gene encoding the two key enzymes of the sulfate-reduction pathway were initially tested. qPCR standard curves were constructed using genomic DNA from an SRB suspension and dilutions of an enriched sulfate-reducing sludge. According to specificity and reproducibility, the DSR1F/RH3-dsr-R primer set ensured a good quantification based on dsrA gene amplification; however, it exhibited inconsistencies at low and high levels of SRB concentrations in environmental and sulfate-reducing sludge samples. Ultimately, we conducted a qPCR method normalized to dsrA gene copies, using a synthetic double-stranded DNA fragment as a calibrator. This method fulfilled all validation criteria and proved to be specific, accurate, and precise. The enumeration of metabolically active SRB populations through culture methods differed from dsrA gene copies but showed a plausible positive correlation. Conversely, microscopic counting had limitations due to distinguishing densely clustered organisms, impacting precision. Hence, this study proves that a qPCR-based method optimized with dsrA gene copies as a calibrator is a sensitive molecular tool for the absolute enumeration of SRB populations in engineered and environmental sludge samples.

First Report of Alternaria alternata Causing Leaf Spot on Broccoli in Ecuador.

In Ecuador, broccoli (Brassica oleracea var. italica) production is located in the Andean region, specifically Cotopaxi-Ecuador (INEC, 2019). A leaf pathogen has been constantly observed in this area, showing brown circular necrosis surrounded by yellowish halo-like spots causing leaf death (Fig. 1a). This pathogen was believed to be Alternaria sp.; however, the species was not determined either using classical or molecular tools. In 2021, ten leaves showing similar symptoms were collected in Cotopaxi and sent for pathogen identification. Here, leaf explants (0.25 cm2) showing disease symptoms were surface sterilized with 2% sodium hypochlorite (NaClO) and 70% ethanol (C2H6O), rinsed with sterile water, and transferred to Potato Dextrose Agar (PDA) media. Petri dishes were incubated in darkness at 25°C for five days. The single hyphal tip method was used to purify the cultures on PDA. Fifteen pure isolates were obtained after incubating for 14 days. Isolates were incubated under blacklight for two days to induce fungal sporulation. All isolates presented early white cotton-like mycelium that later became dark green (Fig 1b). Under the microscope, we observed straight primary conidia in simple or branched chains. Also, the conidia were obclavate, long ellipsoids, moderate in size (19.5-43.9 µm in length, 7.1-17.2 µm in width), and septate with few longitudinal septa. Lastly, the conidium body can narrow itself into a secondary conidia (Fig 1c) (Woudenberg et al., 2013). According to colony and conidia morphology, isolates were identified as Alternaria sp. (Woudenberg et al., 2013). Five isolates were randomly selected for DNA extraction and sequencing of ITS (internal transcribed spacer; Chou, H.H. and Wu, W.S. 2002), TEF (translation elongation factor; O'Donnell et al., 1998), and RPB2 (RNA polymerase II second largest subunit; Liu et al., 1999) gene regions. DNA sequences obtained from each marker were identical for all isolates. Consensus sequences and alignment were built using ClustalX in MEGA X (Kumar et al., 2018). Consensus sequences were deposited in GenBank with the following accession numbers: ITS, ON982232; TEF, ON983964; RPB2, ON983963. A multilocus Bayesian inference phylogenetic tree was constructed in Beast software (version 1.8.4) using the concatenated sequences (Drummond et al., 2012; Maharachchikumbura et al., 2014). The isolates in our study clustered with isolates of Alternaria alternata, confirming their identity (Figure 2). For Koch's postulates, healthy broccoli plants were grown in sterile soil for six weeks. The fungal conidia were suspended in sterile distilled water (1×106 conidia/ml), and the leaves were inoculated by spraying the spore solution. The control treatment was sprayed with sterile distilled water alone. Plants were maintained at 28°C and had more than 85% relative humidity (Sigillo et al., 2020). Seven days after inoculation, plants showed chlorosis and necrosis. Ten days later, 100% of the treated leaves presented brown circular necrosis (Fig. 1d). Control plants showed no disease symptoms. Re-isolation of the pathogen from the diseased leaf tissue was performed as previously described. The isolates presented the exact morphology of pure cultures obtained from field-diseased leaves. The pathogenicity test was performed twice. To our knowledge, this is the first report on A. alternata being the causal agent of leaf spot on broccoli in Ecuador. Disease diagnosis contributes to providing strategies against this pathogen. Further investigations are needed to find biological/chemical techniques or cultivar resistance to control this pathogen in broccoli.

Influence of Grafting on Rootstock Rhizosphere Microbiome Assembly in Rosa sp. 'Natal Brier'.

The root microbiome is vital in plant development and health and is highly influenced by crop cultural practices. Rose (Rosa sp.) is the most popular cut flower worldwide. Grafting in rose production is a standard practice to increase yield, improve flower quality, or reduce root-associated pests and diseases. 'Natal Brier' is a standard rootstock used in most commercial operations in Ecuador and Colombia, leading countries in producing and exporting ornamentals. It is known that the rose scion genotype affects root biomass and the root exudate profile of grafted plants. However, little is known about the influence of the rose scion genotype on the rhizosphere microbiome. We examined the influence of grafting and scion genotype on the rhizosphere microbiome of the rootstock 'Natal Brier'. The microbiomes of the non-grafted rootstock and the rootstock grafted with two red rose cultivars were assessed using 16S rRNA and ITS sequencing. Grafting changed microbial community structure and function. Further, analysis of grafted plant samples revealed that the scion genotype highly influences the rootstock microbiome. Under the presented experimental conditions, the rootstock 'Natal Brier' core microbiome consisted of 16 bacterial and 40 fungal taxa. Our results highlight that the scion genotype influences root microbe's recruitment, which might also influence the functionality of assembled microbiomes.

Non-indigenous aquatic fauna in transitional waters from the Spanish Mediterranean coast: A comprehensive assessment.

Understanding drivers of spatial variation in non-indigenous species (NIS) is a key goal in invasion biology, but comprehensive assessments providing high-resolution data are extremely scarce. Anthropogenic modifications to transitional waters facilitate the invasion of NIS where they cause both ecological and economic important damage. By screening validated data sources, we conducted a comprehensive assessment of non-indigenous aquatic fauna in Spanish Mediterranean transitional waters (30 sites), as well as assessed introduction pathways, native regions, NIS assemblage patterns and temporal introduction rate. One hundred and twenty-nine NIS were inventoried, with 72 % established and more than half listed before 1980. Two intentional (release, escape) and two unintentional (contaminant, stowaway) introduction pathways were dominant. Recorded NIS originated mostly from North America and Asia. A clear nested pattern in NIS assemblages was observed across sites, suggesting secondary spread from the most invaded waters placed in the northern regions. Our updated inventory should be pivotal for designing prevention protocols and informing specific management plans on non-indigenous fauna in transitional waters.

Microclimate is a strong predictor of the native and invasive plant-associated soil microbiome on San Cristóbal Island, Galápagos archipelago.

Understanding the drivers that affect soil bacterial and fungal communities is essential to understanding and mitigating the impacts of human activity on vulnerable ecosystems like those on the Galápagos Islands. The volcanic slopes of these Islands lead to steep elevation gradients that generate distinct microclimates across small spatial scales. Although much is known about the impacts of invasive plant species on the above-ground biodiversity of the Galápagos Islands, little is known about their resident soil microbial communities and the factors shaping them. Here, we investigate the bacterial and fungal soil communities associated with invasive and native plant species across three distinct microclimates on San Cristóbal Island (arid, transition zone and humid). At each site, we collected soil at three depths (rhizosphere, 5 cm and 15 cm) from multiple plants. Sampling location was the strongest driver of both bacterial and fungal communities, explaining 73% and 43% of variation in the bacterial and fungal community structure, respectively, with additional minor but significant impacts from soil depth and plant type (invasive vs. native). This study highlights the continued need to explore microbial communities across diverse environments and demonstrates how both abiotic and biotic factors impact soil microbial communities in the Galápagos archipelago.

Survival of patients with severe mental disorders: Influence of social functioning.

BACKGROUND: Patients with severe mental disorders have a high risk of premature death due to the interaction of various factors. Social functioning is a strategic functional factor in understanding the course of psychotic disorders. AIM: Analyze the relationship between social functioning and its various dimensions and survival during a 10-year follow-up. METHOD: The Social Functioning Scale (SFS) was administered to 163 close relatives of patients under treatment at a Community Mental Health Unit. Survival was described by Kaplan-Meier analysis and any differences in survival by level of social functioning were found by long-rank analysis. Finally, Cox regression was used to predict premature mortality. RESULTS: Significant differences in mortality were identified in the interpersonal behavior dimension of social functioning, while there were no significant gender or diagnostic differences in the rest of the dimensions. The interpersonal behavior dimension and age were found to be factors predicting premature death. CONCLUSION: These findings show the protective effect of social functioning retained by patients with psychotic disorders on their survival, and the need to apply evidence-based psychotherapy focused on recovery of social functioning in the early stages of the disorder.

The association between hope and employment among individuals with multiple sclerosis: A hierarchical logistic regression model.

BACKGROUND: Most people with multiple sclerosis (MS) are employed at the time of their diagnosis; however, due to the unpredictable nature of MS, most exit the workforce shortly thereafter. A plethora of research has examined factors that negatively affect employment outcomes for people with MS. However, little is known about how hope, a modifiable positive psychology factor, affects employment. OBJECTIVE: This study examined the role of hope and its association with employment outcomes for people with MS. METHODS: Two-hundred and fifty-five adults with MS (mean ± SD age, 45.45 years ± 10.28) completed surveys about their MS, employment, disability-related stress, and hope. A three-step hierarchical logistic regression was conducted to examine the extent to which hope explains the variance in employment, over and above demographic and disability related covariates. RESULTS: The final model explained 28% of the variance in employment, suggesting that the model was able to distinguish people with MS who were employed versus those who were unemployed. Higher levels of hope were associated with an increased probability of being employed (OR = 4.65; 95% CI [1.98, 10.92]). CONCLUSION: This study supports that hope is associated with favorable employment outcomes for people with MS. Persons with MS may benefit from working with rehabilitation professionals to enhance their hope, and this study provides a foundation for the development of hope-based interventions to improve employment outcomes among this population.

Confiabilidad y validez de una escala de identidad organizacional en servicios de salud

Objetivo Validar la Escala de Identidad Organizacional (IDN) de algunas instituciones mexicanas de servicios de salud a través de análisis confirmatorio. Métodos Se utilizó una escala de identidad de quince ítems aplicados a una muestra de 214 trabajadores pertenecientes a seis clínicas de servicios de salud en el Estado de Hidalgo, México. Resultados El análisis de fiabilidad indicó que la IDN posee consistencia interna adecuada. Los análisis factorial exploratorio y confirmatorio permitieron identificar una estructura de tres factores (orgullo, pertenencia y significado). El factor orgullo muestra cargas estimadas más elevadas. Conclusión La versión final del instrumento presenta confiabilidad y validez adecuadas para la medición de la identidad organizacional.

Objective To validate the Organizational Identity Scale (IDN) for Mexican health service institutions through confirmatory analysis. Methodology We applied a fifteen-item identity scale to a sample of 214 workers from six health service clinics in Hidalgo, Mexico. Results The reliability analysis indicated that the IDN has adequate internal consistency. The exploratory and confirmatory factor analyses allowed us to identify a struc-ture of three factors (pride, belonging, and meaning). The pride factor shows higher estimated loads. Conclusion The final version of the instrument presents adequate reliability and validity for the measurement of organizational identity.

Dynamics of Microbial Communities during the Removal of Copper and Zinc in a Sulfate-Reducing Bioreactor with a Limestone Pre-Column System.

Biological treatment using sulfate-reducing bacteria (SRB) is a promising approach to remediate acid rock drainage (ARD). Our purpose was to assess the performance of a sequential system consisting of a limestone bed filter followed by a sulfate-reducing bioreactor treating synthetic ARD for 375 days and to evaluate changes in microbial composition. The treatment system was effective in increasing the pH of the ARD from 2.7 to 7.5 and removed total Cu(II) and Zn(II) concentrations by up to 99.8% and 99.9%, respectively. The presence of sulfate in ARD promoted sulfidogenesis and changed the diversity and structure of the microbial communities. Methansarcina spp. was the most abundant amplicon sequence variant (ASV); however, methane production was not detected. Biodiversity indexes decreased over time with the bioreactor operation, whereas SRB abundance remained stable. Desulfobacteraceae, Desulfocurvus, Desulfobulbaceae and Desulfovibrio became more abundant, while Desulfuromonadales, Desulfotomaculum and Desulfobacca decreased. Geobacter and Syntrophobacter were enriched with bioreactor operation time. At the beginning, ASVs with relative abundance <2% represented 65% of the microbial community and 21% at the end of the study period. Thus, the results show that the microbial community gradually lost diversity while the treatment system was highly efficient in remediating ARD.

Glycerol Valorization towards a Benzoxazine Derivative through a Milling and Microwave Sequential Strategy.

Glycerol and aminophenol intermolecular condensation has been investigated through a milling and microwave-assisted sequential strategy, towards the synthesis of a benzoxaxine derivative. Mechanochemical activation prior to the microwave-assisted process could improve the probability of contact between the reagents, and greatly favors the higher conversion of aminophenol. At the same time, following a mechanochemical-microwave sequential approach could tune the selectivity towards the formation of a benzoxazine derivative, which could find application in a wide range of biomedical areas.

Ten-year follow-up of social functioning and behaviour problems in people with schizophrenia and related disorders.

BACKGROUND: In recent years, several variables in the course of schizophrenia and related psychotic disorders have been studied. However, an instrumental analysis of the evolution of social functioning and behaviour problems has scarcely been explored. AIM: To analyse the evolution of social functioning and behaviour problems and find any diagnosis or gender differences. METHOD: The Social Functioning Scale (SFS) and the Behaviour Problems Inventory (BPI) were administered in Stages I (2003-2007) and II (2014-2017) to 100 close relatives of patients under treatment at a Community Mental Health Unit. A related samples t-test, analysis of variance and multivariate analysis of variance were performed to study the evolution and differences in social functioning and behaviour problems. Then a stepwise multiple linear regression analysis was done to predict the evolution of social functioning. RESULTS: No deterioration in the evolution of social functioning or behaviour problems was observed, and schizophrenia patient scores were lower. Women scored higher in withdrawal/social engagement, interpersonal behaviour, independence-performance, independence-competence and total social functioning, with no significant differences in behaviour problems. Previous social functioning, underactivity/social withdrawal and education are predictive factors in the evolution of social functioning. Conclusion: The results show the need for implementing psychosocial intervention programs that promote functional recovery and keep problems from becoming chronic.

Associations between mental health and job loss among middle- and low-income veterans and civilians during the COVID-19 pandemic: An exploratory study.

This study examined the relationship between job loss and mental health during the pandemic among a nationally representative sample of middle- and low-income military veterans and civilians. Participants were recruited from Amazon Mechanical Turk in May-June 2020. Our sample was comparable to the U.S. population with respect to key demographics (i.e., sex, race, ethnicity, and geographic region). More veterans were male (36.9% civilians vs. 74.1% veterans), and on average they were older than civilians (Mcivilians  = 47.86 vs. Mveterans  = 52.64). After controlling for sociodemographic factors, probable anxiety (adjusted odds ratio for veterans = 1.96, 95% [1.22-3.15]) was significantly associated with job loss among veterans, whereas among civilians, probable anxiety (adjusted odds ratio for civilians [AORc ] = 1.48, 95% [1.21-1.81]), probable COVID-19 era-related stress (AORc  = 1.73, 95% [1.45-2.07]), and loneliness (AORc  = 1.09, 95% [1.04-1.13]) were associated with job loss. Results demonstrated that veteran sample's effect sizes were larger than civilian sample's effect sizes; however, our moderation analyses results revealed that veteran status did not moderate the relationships between mental health and job loss. The findings in this study support a relationship between job loss and poorer mental health, suggesting that increased mental health services may be important to address ongoing effects of the COVID-19 pandemic.

Hunting Bioactive Molecules from the Agave Genus: An Update on Extraction and Biological Potential.

Agaves are plants used in the production of alcoholic beverages and fibers. Ever since ancient times, pre-Hispanic cultures in Mexico have used them in traditional medicine to cure different ailments. Over the years, studies of the active principles responsible for the therapeutic benefits of agaves have increased. Leaves and fibers are the main agro-wastes generated in tequila and mezcal production, while fibers are the main waste product in the textile sector. Different investigations have referred to the agro-waste from agave processing as a source of bioactive molecules called secondary metabolites (SM). Among them, phenols, flavonoids, phytosterols, and saponins have been extracted, identified, and isolated from these plants. The role of these molecules in pest control and the prospect of metabolites with the biological potential to develop novel drugs for chronic and acute diseases represent new opportunities to add value to these agro-wastes. This review aims to update the biological activities and recent applications of the secondary metabolites of the genus Agave.

Black Bean (Phaseolus vulgaris L.) Polyphenolic Extract Exerts Antioxidant and Antiaging Potential.

Phenolic compounds present in common beans (Phaseolus vulgaris L.) have been reported to possess antimicrobial, anti-inflammatory and ultraviolet radiation (UVR) protective properties. UVR from sunlight, which consists of UV-B and UV-A radiations, induces reactive oxygen species (ROS) and free radical formation, consequently activating proteinases and enzymes such as elastase and tyrosinase, leading to premature skin aging. The objective of this work was to extract, characterize and evaluate the antioxidant and antiaging potential of polyphenols from a black bean endemic variety. The polyphenolic extract was obtained from black beans by supercritical fluid extraction (SFE) using CO2 with a mixture of water-ethanol as a cosolvent and conventional leaching with a mixture of water-ethanol as solvent. The polyphenolic extracts were purified and characterized, and antioxidant potential, tyrosinase and elastase inhibitory potentials were measured. The extract obtained using the SFE method using CO2 and H2O-Ethanol (50:50 v/v) as a cosolvent showed the highest total phenolic compounds yield, with 66.60 ± 7.41 mg GAE/g coat (p > 0.05) and 7.30 ± 0.64 mg C3GE/g coat (p < 0.05) of anthocyanins compared to conventional leaching. Nineteen tentative phenolic compounds were identified in leaching crude extract using ESI-QTOF. Quercetin-3-D-galactoside was identified in crude and purified extracts. The purified SFC extract showed IC50 0.05 ± 0.002 and IC50 0.21 ± 0.008 mg/mL for DPPH and ABTS, respectively. The lowest IC50 value of tyrosinase inhibition was 0.143 ± 0.02 mg/mL and 0.005 ± 0.003 mg/mL of elastase inhibition for leaching purified extract. Phenolic compounds presented theoretical free energy values ranging from -5.3 to -7.8 kcal/mol for tyrosinase and -2.5 to -6.8 kcal/mol for elastase in molecular docking (in silico) studies. The results suggest that the purified extracts obtained by SFE or conventional leaching extraction could act as antioxidant and antiaging ingredients for cosmeceutical applications.

Development and validation of the social motivation scale in people with disabilities.

OBJECTIVE: Social effectiveness is key to success in the labor market. For decades, social motivation has been empirically studied as both a presumed cause and consequence of social effectiveness. Yet, few direct measures of social motivation exist, and even fewer have been validated with a disability population. This study provides the measurement structure and psychometric properties of a newly created measure of social motivation tested with a general disability population. RESEARCH DESIGN: Participants included 1,013 US adults with disabilities. Exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) were implemented to validate the measure. RESULTS: Results of the EFA suggest that a reduced 26-item inventory exhibits a 5-factor structure in a general population of people with disabilities. These results were confirmed with the CFA. Concurrent validity analysis revealed that most factors were significantly associated with relevant psychosocial variables in the expected directions. CONCLUSIONS: The Social Motivation Inventory provides a useful tool for enhancing understanding of social motivation in rehabilitation psychology and rehabilitation counseling research and practice. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Production of rhamnolipids by the Thermoanaerobacter sp. CM-CNRG TB177 strain isolated from an oil well in Mexico.

This study aimed to produce and characterize biosurfactants using the Thermoanaerobacter sp. CM-CNRG TB177 strain isolated from an oil field in Mexico, as well as assessing the influence of different carbon and nitrogen sources on the capacity of the produced surfactant to reduce the surface tension of water. The thin-layer chromatography (TLC) revealed that the obtained extract corresponds to a mono-rhamnolipid; the results of the ultra-performance-liquid chromatography/mass spectrometry (UPLC/MS) analysis revealed that the Thermoanaerobacter sp. CM-CNRG TB177 strain produces a mixture of three rhamnolipids, whose masses correspond to mono-rhamnolipid. The rhamnolipids mixture obtained using 2.5% molasses as carbon source diminished the surface tension of water to 29.67 mNm-1, indicating that the concentration of molasses influenced the capacity of the produced surfactant to reduce the surface tension of water. Also, the microorganism was not capable of growing in the absence of yeast extract as nitrogen source. To the best of our knowledge, the presented results describe for the first time the nature of the biosurfactant produced by a bacterium of the Thermoanaerobacter genus.Key points• Thermoanaerobacter sp. CM-CNRG TB177 produces biosurfactants, and its glycolipid nature is described for the first time.• The HPLC analysis revealed a mixture of three rhamnolipid congeners, and UPLC/MS analysis determined that two of the congeners are the rhamnolipids Rha-C8-C10 and Rha-C12-C10.• The lowest surface tension of 29.67 mNm-1 was obtained with molasses as source of carbon at a 2.5% concentration.

Methyl jasmonate-induced resistance to Delia platura (Diptera: Anthomyiidae) in Lupinus mutabilis.

BACKGROUND: Andean lupin (Lupinus mutabilis Sweet) is an important leguminous crop from South America with a high protein content. In Ecuador, lupin yields are severely affected by the infestation of Delia platura larvae on germinating seeds. The application of elicitor molecules with activity against herbivorous insects to control D. platura infestation constitutes an unexplored and promising alternative for chemical insecticides. In this study, methyl jasmonate (MeJA), hexanoic acid, menadione sodium bisulfite, and DL-ß-aminobutyric acid were evaluated for their ability to induce resistance against D. platura in three commercial lupin cultivars. RESULTS: Only seeds pretreated with MeJA significantly impaired insect performance during choice and no-choice assays. Additionally, fitness indicators such as seed germination and growth were not affected by MeJA treatment. To investigate the molecular mechanisms behind the MeJA-mediated resistance, RT-qPCR assays were performed. First, RT-qPCR reference genes were validated, showing that LmUBC was the most stable reference gene. Next, expression analysis over time revealed that MeJA application up-regulated the activity of the jasmonic acid biosynthetic genes LmLOX2 and LmAOS, together with other jasmonate-related defense genes, such as LmTPS1, LmTPS4, LmPI2, LmMBL, LmL/ODC, LmCSD1, and LmPOD. CONCLUSION: This study indicates that MeJA can be used as an environmentally friendly elicitor molecule to protect Andean lupin from D. platura attack without fitness cost. MeJA application induces plant defense responses to insects in Andean lupin that may be modulated by the onset of terpenoid biosynthesis, proteinase inhibitors, lectins, polyamines, and antioxidative enzymes. © 2021 Society of Chemical Industry.