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Agave lechuguilla agro-waste is a promising renewable material for biorefining purposes. The procurement of added-value co-products, such as bioactive phytochemicals, is required to improve bioprocesses and promote the bio-based economy of the productive areas of Mexico. In this study, we aimed to evaluate the effect of post-harvest management and enzymatic pretreatment as the first stages of the A. lechuguilla valorization process. Four drying methods were compared, and enzymatic hydrolysis was optimized to obtain a flavonoid-enriched extract applying ultrasound-assisted extraction. In both experiments, the total phenolic (TPC) and flavonoid (TFC) contents, HPLC-UV flavonoid profiles, and radical scavenging capacity (DPPH) were considered as response variables. The results demonstrated that light exposure during the drying process particularly affected the flavonoid content, whereas oven-dehydration at 40 °C in the dark preserved the flavonoid diversity and antioxidant functionality of the extracts. Flavonoid glycoside recovery, particularly anthocyanidins, was 1.5–1.4-fold enhanced by enzymatic hydrolysis using the commercial mix Ultraflo© under optimized conditions (pH 4, 40 °C, 180 rpm, and 2.5 h) compared to the unpretreated biomass. The extraction of flavonoids from A. lechuguilla bagasse can be carried out using a scalable drying method and enzymatic pretreatment. This study confirmed the potential of this agro-waste as a source of marketable natural products.

In the present study, we used a by-product from Agave lechuguilla (guishe) to test its antidiabetic effect, hypolipidemic activity, and capacity to mitigate the oxidative stress in kidney mitochondria from streptozotocin-induced diabetic rats. Orally, a crude aqueous extract from lyophilized guishe was administered over 5 weeks at different doses. Blood glucose and body weight were monitored. Also, blood chemistry, bilirubin, and alanine aminotransferase were assayed. Furthermore, the activity of catalase, thiobarbituric acid reactive species, mitochondrial superoxide dismutase, glutathione and glutathione peroxidase were determined in isolated kidney mitochondria. Our results show that guishe extracts have no antidiabetic properties at any dose. Nevertheless, it was able to diminish serum triglyceride levels and regulate the oxidative stress observed in isolated kidney mitochondria. These observations indicate that the aqueous extract from guishe can be used to treat abnormalities in serum lipids, as a hypolipidemic, and mitigate the oxidative stress, as an antioxidant, occurring during diabetes.

Studies conducted in northeastern Mexico have not provided information on the flora and vegetation associated with Dichromanthus cinnabarinus. Therefore, it is necessary to study the areas where this orchid is distributed to understand the plant vegetation interaction. Research questions: What plant species are associated with Dichromanthus cinnabarinus? What is the degree of similarity among the plant communities with which Dichromanthus cinnabarinus is associated? Study site: Northeastern Mexico, comprehending the states of Coahuila, Nuevo Leon and Tamaulipas. Methods: The study sites were selected consider-ing the presence of Dichromanthus cinnabarinus. Regarding the study of the plant struc-ture, the tree, shrub, and herbaceous strata were obtained by the methodology of quad-rants. Data were collected in April and August 2017. The results were analyzed using the Importance Value Index (IVI) for each stratum present and a Parsimony Analysis of En-demicity (PAE) for the plant communities. Results: In the study area, a total of 33 families, 60 genera and 69 species were registered. The representative families are Asteraceae with eight species, Asparagaceae with six, Fabaceae with five, followed by Cactaceae, Poaceae and Roasaceae with four species each. Regarding endemic species, a total of 11 species distributed in nine genera were registered in the study sites. Conclusions: In northeastern Mexico, Dichromanthus cinnabarinus is found associated with Aristida adscensionis L., Agave lechuguilla Torr. Bouteloua sp., Euphorbia antisyphilitica Zucc., Agave striata var. striata (Salm-Dyck) and Rhus virens Lindh. ex A. Gray. Moreover, Dichromanthus cin-nabarinus is observed in some sites with contrasting flora, according to the resulting list of endemic species. It is important to establish priority areas for wildlife conservation in northeastern Mexico.

The environmental pollution caused by oil and its derivatives is recognized as one of the most serious problems. Once spilled on the ground, most aliphatic compounds volatilize, while other hydrocarbons such as polycyclics persist on the surface causing an impact on the environment and living beings. There are a variety of techniques for treatment, but they have the disadvantage of being expensive, so viable alternatives have been sought such as bioremediation, which consist of making use of microorganisms and constitutes a very competitive technology, capable of achieving the biodegradation of hydrocarbons contained in the soils. Depending on the characteristics of the soil and the content of organic matter, the hydrocarbons of higher molecular weight and lower solubility can adsorb in the micropores of the soil particles, resulting in this being inaccessible as carbon and energy sources for the microorganisms. Therefore, surfactant agents that act by increasing bioavailability through the parallel action of the desorption and solubilization of the contaminant are required. This article compares 3 surfactant agents of natural origin, which analyze and discuss the effectiveness of each of them for the treatment of soils contaminated with hydrocarbons. Once the lechuguilla extract is obtained in cold and hot, the soil is washed, fats and oils are determined by soxhlet method and the Chemical Oxygen Demand (COD) is determined, finding a marked effectiveness of the cold lechuguilla extract (Agave lechuguilla).

The white maguey worm, Aegiale hesperiaris (Walker, 1856), is a gastronomic delicacy in Mexico, with high economic value. Aegiale hesperiaris is generally associated with the plant Agave salmiana Otto ex Salm-Dyck (Asparagales: Asparagaceae). However, lack of information about Ae. hesperiaris means that it is often confused with morphologically similar species such as Agathymus remingtoni D. Stallings & Thurner (Lepidoptera: Hesperiidae), a species generally found on Agave lechuguilla Torrey (Asparagales: Asparagaceae). Harvestings are made from all Agave L. (Asparagales: Asparagaceae) species on the assumption that all larvae will be Ae. hesperiaris. This has led to the belief that Ae. hesperiaris may have extended its diet breadth range and is actually infesting other Agave species. We collected larvae from A. lechuguilla and A. salmiana plants, in Hidalgo state, Mexico, and incubated them at 26°C, 50% RH and 12:12 light regime until adult emergence; adults were examined using morphological (male genitalia and wing patterns) and molecular techniques (partial COI sequences) to provide the data necessary for accurate species identification and allocation to host plant. Both species were successfully separated and identified as Ae. herperiaris feeding on A. salmiana and Ag. remingtoni feeding on A. lechuguilla, and a detailed description of the larval developmental stages and feeding behavior described. These results will facilitate the accurate identification of these two species in future studies.

This study focused on determining the optimal conditions for lead removal in aqueous solution models, by the spherical agglomeration technique (SAT), modifying the dose of Agave lechuguilla Torr. (lechuguilla) extract, used as biosurfactant. The SAT operating conditions at room temperature were: Initial pH 9, and constant agitation ω = 600 rpm. Experiments were performed under a 5x3 factorial design with five lechuguilla extract doses (0.3 - 2.0 g extract/g of pollutant), three different lead concentrations (1, 5 and 10 mg/L) and, for the SAT last stage, two different dosage ratio of CaCl2 (10:1 and 20:1 parts of Ca2+ by part of pollutant). Residual lead, sodium and calcium were determined by atomic absorption spectroscopy. According to statistical analysis, significant effects were observed for calcium dosages, initial lead concentration, extract dose and their interaction. The lead removal efficiency obtained by SAT reached 99.8%.

This paper presents an analysis of the floral and faunal remains of a single human coprolite recovered from Conejo Shelter, Texas (41VV162). The unique contents of this specimen warrant full description. Floral macrobotanical analysis revealed a high density of Agave lechuguilla and Dasylirion spp. fibers. Calcium oxalate crystals confirm the ingestion of Opuntia. Palynological analysis found evidence for a variety of plants with known economic and medicinal uses, with pollen from the Liliaceae (new: Asparagales) family predominating. Zooarchaeological analysis found the remains of a small rodent, evidently eaten whole, with no indication of preparation or cooking. Notably, the bones, scales and a fang of a snake in the Viperidae family were also recovered from the coprolite, which is the first direct archaeological evidence of venomous snake consumption known to the researchers. With the exception of the Viperidae remains, the coprolite evidence is consistent with previous research at Conejo Shelter and the Lower Pecos region. Recently assayed radiocarbon samples from this coprolite and a second, unprocessed coprolite from the same archaeological provenience produced a date range of 1460–1528 cal BP. Future analyses of coprolites from this lens and the surrounding contexts will further our current understanding of this unique gastrological event and better situate it in the context of diet patterns and paleoenvironmental adaptions in the Lower Pecos.

Agave lechuguilla has one of the widest distributions among other agave species in the Chihuahuan Desert. Their capacity to grow in poorly developed soils and harsh conditions has been related to their association with plant growth-promoting rhizobacteria. In this work, we explored how soil properties and plant growth stage influence the composition of the rhizobacterial communities, their interactions, and the enzymatic activity and abundance of nitrogen-fixing bacteria and organic phosphorus-mineralizing bacteria in two subregions of the Chihuahuan Desert. We found that mature plants of lechuguilla stimulated the activity and abundance of nutrient-improvement rhizobacteria, and these soil samples had a higher content of total organic carbon, ammonium (NH4) and nitrite + nitrate (NO2+NO3). Nutrient availability seems to be an essential driver of the bacterial community's structure since the genera with more connections (hubs) were those with known mechanisms related to the availability of nutrients, such as env. OPS17 (Bacteroidetes), Gemmatimonadaceae uncultured, S0134terrestrial group, BD211terrestrial group (Gemmatimonadetes), Chthoniobacteracea and Candidatus Udaeobacter (Verrucomicrobia). This work shows that the late growth stages of lechuguilla recruit beneficial bacteria that favor its establishment and tolerance to harsh conditions of the arid lands.

Agave lechuguilla waste biomass (guishe) is an undervalued abundant plant material with natural active compounds such as flavonoids. Hence, the search and conservation of flavonoids through the different productive areas have to be studied to promote the use of this agro-residue for industrial purposes. In this work, we compared the proportion of total flavonoid content (TFC) among the total polyphenolics (TPC) and described the variation of specific flavonoid profiles (HPLC-UV-MS/MS) of guishe from three locations. Descriptive environmental analysis, using remote sensing, was used to understand the phytochemical variability among the productive regions. Furthermore, the effect of extractive solvent (ethanol and methanol) and storage conditions on specific flavonoid recovery were evaluated. The highest TPC (16.46 ± 1.09 GAE/g) was observed in the guishe from region 1, which also had a lower normalized difference water index (NDWI) and lower normalized difference vegetation index (NDVI). In contrast, the TFC was similar in the agro-residue from the three studied areas, suggesting that TFC is not affected by the studied environmental features. The highest TFC was found in the ethanolic extracts (6.32 ± 1.66 QE/g) compared to the methanolic extracts (3.81 ± 1.14 QE/g). Additionally, the highest diversity in flavonoids was found in the ethanolic extract of guishe from region 3, which presented an intermedia NDWI and a lower NDVI. Despite the geo-climatic induced variations of the phytochemical profiles, the results confirm that guishe is a valuable raw material in terms of its flavonoid-enriched bioactive extracts. Additionally, the bioactive flavonoids remain stable when the conditioned agro-residue was hermetically stored at room temperature in the dark for nine months. Finally, the results enabled the establishment of both agro-ecological and biotechnological implications.

Resumen El venado cola blanca es la especie cinegética más importante en México. El conocimiento sobre los componentes de la vegetación es importante en los planes de manejo e influyen en la presencia y mantenimiento de ese taxón. Se caracterizó la diversidad taxonómica y productividad de un matorral desértico en Coahuila y se enfatizó el valor de dicho ecosistema en la conservación de las poblaciones del venado; para ello, se utilizaron la línea Canfield y el método Adelaide en las cuatro estaciones del año, de octubre 2018 a agosto 2019, en la Unidad de Manejo para la Conservación de la Vida Silvestre Rancho San Juan, Monclova, Coahuila. Se estimó el Índice de Valor de Importancia (IVI) de cada especie vegetal por estación y el índice de Diversidad de Shannon. La producción de biomasa se expresó en kg ha-1 por estación y estrato. Se identificaron 46 taxa de plantas, algunas forrajeras: Acacia berlandieri y Acacia rigidula, además de otras que ofrecen protección térmica: Cenchrus ciliaris y Yucca filifera. De acuerdo al IVI, Agave lechuguilla (59.78 %) en primavera, Hilaria mutica en verano (62.02 %) y otoño (86.59 %), así como Cenchrus ciliaris en invierno (107.00 %) registraron las cifras más altas. El estrato medio aportó mayor cantidad de biomasa (> 1 000 kg ha-1), a diferencia del estrato superior que produjo menos (≤ 250 kg ha-1). Los taxones del matorral desértico que conforman pastos y arbustos brindan los recursos fundamentales para el desarrollo de las poblaciones de Odocoileus virginianus en el lugar.

Introduction: In several regions of the world, Fusarium oxysporum causes losses on tomato crops; for control it, chemical fungicides are used. Nevertheless, these fungicides causing environmental and resistance problems; therefore, ecological alternatives as plant extracts have been developed. Due to the aim of this work, identify phytochemicals present in ethanolic and aqueous extracts from Agave lechuguilla qualitatively, Carya illinoinensis, Jatropha dioica, Larrea tridentata, and Lippia graveolens and determine their antifungal activity against F. oxysporum.Method: The plants collected from the northeast of Mexico; crudes and concentrated plant extracts obtained; the inhibition percentage and inhibitory concentration to 50 % (IC50) of F. oxysporum for each plant extract were determinate trough microdilution in the plate methodResults: The essential phytochemicals were flavonoids, saponins, tannins, and quinones. The antifungal activity showed at 1000 mg/L inhibition around 40 to 60% by aqueous crude extracts from leaves of L. graveolens and concentrated aqueous extracts from the stem of L. graveolens, respectively. The ethanolic extracts presented 100 % of inhibition for crude extracts of husk from C. illinoinensis; in leaves and stem from L. graveolens the inhibition started from 250 mg/L; for resuspended extracts, the inhibition started from 125 mg/L with L. graveolens stem and leaves; and finally in roots of A. lechuguilla and leaves from L. graveolens the inhibition started from to 250 and 500 mg/L respectively. The best IC50 was of 8.02 mg/L from the ethanolic resuspended extract of L. graveolens stem.Conclusion: The ethanolic plant extracts from L. graveolens, A. lechuguilla, and C. illinoinensis, showed 100 % of inhibiting activity against the development of F. oxysporum, representing an alternative for control of F. oxysporum.

Quantifying biomass is important for determining the carbon stores in land ecosystems. The objective of this study was to predict aboveground biomass (AGB) of Agave lechuguilla Torr., in the states of Coahuila (Coah), San Luis Potos&iacute, (SLP) and Zacatecas (Zac), Mexico. To quantify AGB, we applied the direct method, selecting and harvesting representative plants from 32 sampling sites. To predict AGB, the potential and the Schumacher&ndash, Hall equations were tested using the ordinary least squares method using the average crown diameter (Cd) and total plant height (Ht) as predictors. Selection of the best model was based on coefficient of determination (R2 adj.), standard error (Sxy), and the Akaike information criterion (AIC). Studentized residues, atypical observations, influential data, normality, variance homogeneity, and independence of errors were also analyzed. To validate the models, the statistic prediction error sum of squares (PRESS) was used. Moreover, dummy variables were included to define the existence of a global model. A total of 533 A. lechuguilla plants were sampled. The highest AGB was 8.17 kg, the plant heights varied from 3.50 cm to 118.00 cm. The Schumacher&ndash, Hall equation had the best statistics (R2 adj. = 0.77, Sxy = 0.418, PRESS = 102.25, AIC = 632.2), but the dummy variables revealed different populations of this species, that is, an equation for each state. Satisfying the regression model assumptions assures that the predictions of A. lechuguilla AGB are robust and efficient, and thus able to quantify carbon reserves of the arid and semiarid regions of Mexico.

Objective: to evaluate the nutritional quality of white worm larvae (Agathymus remingtoni) of the maguey lechuguilla plant (Agave lechuguilla).Design/Methodology/Approach: samples of A. remingtoni larvae were collected from the stems and leaves of wild maguey lechuguilla that grows in the hills of the community of San Francisco, Municipality of Epazoyucan, in the state of Hidalgo, Mexico. Proximate analysis was performed and the calcium and phosphorus contents were determined inlarvae samples.Results: larvae of A. remingtoni had a protein content of 33.69% on a dry basis, and 12.05% on a wet basis. Other results obtained were as follows: ethereal extract 15.97%, dry matter 35.76%, moisture 64.24%, ash 0.82%, crude fiber 0.85%, free nitrogen extract 6.07, calcium 0.40%, and phosphorus 0.56%.Limitations/Implications: During: in the literature review carried out, no reports were found on the nutritional quality of the white worm (Agathymus remingtoni) of maguey lechuguilla (Agave lechuguilla).Findings/Conclusions: Agathymus remingtoni larvae have excellent nutritional content, which makes them an alternative source of protein, fat, calcium, and phosphorus for human consumption and livestock feed.

Due to the environmental conditions presented in arid zones, it is expected to have a high influence of deterministic processes over the community assemblages. Symbiotic interactions with microorganisms could increase colonization and survival of plants in difficult conditions, independent of the plants physiological and morphological characteristics. In this context, the microbial communities associated to plants that inhabit these types of areas can be a good model to understand the community assembly processes. We investigated the influence of stochastic and deterministic processes in the assemblage of rhizosphere microbial communities of Agave lechuguilla and bulk soil on the Cuatro Cienegas Basin, a site known for its oligotrophic conditions. We hypothesize that rhizospheric microbial communities of A. lechuguilla differ from those of bulk soil as they differ in physicochemical properties of soil and biotic interactions, including not only the plant, but also their microbial co-occurrence networks, it is expected that microbial species usually critical for plant growth and health are more common in the rhizosphere, whereas in the bulk soil microbial species related to the resistance to abiotic stress are more abundant. In order to confirm this hypothesis, 16S rRNA gene was sequenced by Illumina from rhizospheric and bulk soil samples in two seasons, also the physicochemical properties of the soil were determined. Our results showed differences in bacterial diversity, community composition, potential functions, and interaction networks between the rhizosphere samples and the ones from bulk soil. Although community structure arises from a complex interplay between deterministic and stochastic forces, our results suggest that A. lechuguilla recruits specific rhizospheric microbes with functional traits that benefits the plant through growth promotion and nutrition. This selection follows principally a deterministic process that shapes the rhizospheric microbial communities, directed by the plant modifications around the roots but also subjected to the influence of other environmental variables, such as seasonality and soil properties. Interestingly, keystone taxa in the interactions networks, not necessarily belong to the most abundant taxonomic groups, but they have an important role by their functional traits and keeping the connections on the community network.

La lechuguilla es uno de los recursos forestales no maderables con mayor valor socioeconómico de las zonas áridas y semiáridas del noreste del país. El aprovechamiento de esta especie representa una de las principales actividades para los pobladores de esas regiones debido a que su recolección proporciona el sustento de 31,000 pobladores y sus familias. El objetivo del presente estudio fue determinar el turno técnico de la lechuguilla en poblaciones naturales, de cuatro procedencias del noreste de México: Jaumave, en el ejido La Independencia del municipio Jaumave Tamps., Paredón y La Sauceda ambos del municipio Ramos Arizpe, Coah. y Marte, municipio General Cepeda, Coah. El trabajo se inició en abril de 2005 con el corte de los cogollos de la planta en cada una de las localidades; a partir de esa fecha se les hicieron mediciones mensuales de crecimiento, hasta que alcanzaron una altura de 25 cm, dimensión mínima para su aprovechamiento, según la Norma Oficial Mexicana NOM-008-RECNAT-1996. El experimento se analizó mediante un diseño de parcelas divididas en cada localidad y se encontró significancia en los cuatro niveles a p ≤0.001. La localidad de Jaumave fue la primera en obtener el turno técnico a los 14 meses con una altura promedio del cogollo de 25.54 cm. La procedencia La Sauceda adquirió el turno técnico a los 22 meses; en contraste para el ejido Paredón, se extendió a los 25 meses y Marte a los 24 meses.

In this work, three Clostridium strains were tested for butanol production from Agave lechuguilla hydrolysates to select one for co-culturing. The agave hydrolysates medium was supplemented with nutrients and reducing agents to promote anaerobiosis. Clostridium acetobutylicum ATCC 824 had the highest butanol production (6.04 g/L) and was selected for further analyses. In the co-culture process, Bacillus subtilis CDBB 555 was used to deplete oxygen and achieve anaerobic conditions required for butanol production. The co-culture was prepared with C. acetobutylicum and B. subtilis without anaerobic pretreatment. Butanol production in co-culture from agave hydrolysates was compared with experiments using synthetic medium with glucose and a pure culture of C. acetobutylicum. The maximum butanol concentration obtained was 8.28 g/L in the co-cultured hydrolysate medium. Results obtained in the present work demonstrated that agave hydrolysates have the potential for butanol production using a co-culture of B. subtilis and C. acetobutylicum without anaerobic pretreatment.

The Tehuacan-Cuicatlan Valley, located at the southeast of the state of Puebla and the northeast of the state of Oaxaca in Central Mexico, south of the Trans-Mexican Volcanic Belt (TMVB), is of particular interest for understanding the evolutionary dynamics of arid and semi-arid environments, being one of the main reservoirs of biological diversity for the arid zones of North America, including the highest diversity of Agavaceae worldwide and high levels of endemism. Studying in detail the phylogeography, environmental history and population genetics of representative species will hopefully shed light on the evolutionary and ecological dynamics that generated the tremendous biodiversity and endemism of this important region in Mexico. We sequenced three non-coding regions of chloroplast genome of Agave kerchovei, a representative species of the Tehuacan Valley, generating 2,188 bp from 128 individuals sampled from eight populations throughout the species range. We used this data set to (i) characterize the levels of genetic diversity and genetic structure in A. kerchovei; (ii) predict the distribution of A. kerchovei for the present day, and to reconstruct the past geographical history of the species by constructing ecological niche models (ENM); and (iii) compare the levels of diversity in this species with those estimated for the widely distributed Agave lechuguilla. Agave kerchovei has high levels of total chloroplast genetic variation (Hd = 0.718), especially considering that it is a species with a very restricted distribution. However, intrapopulation diversity is low (zero in some populations), and genetic structure is high (F ST = 0.928, G ST = 0.824), which can be expected for endemic species with isolated populations. Our data suggest that Pleistocene glacial cycles have played an important role in the distribution of A. kerchovei, where the climatic variability of the region - likely associated with its topographic complexity - had a significant effect on the levels of genetic diversity and population dynamics, while the potential distribution of the species seems to be stable since the middle Holocene (6 kya). We conclude that in A. kerchovei there is a core group of populations in the Tehuacan Valley, and peripheric populations that appear to be evolving independently and thus the species is fundamentally an endemic species from the Tehuacan Valley while the populations outside the Valley appear to be in the process of incipient speciation.

Recientemente la biomasa del cogollo de Agave lechuguilla ha sido establecida como materia prima con potencial para la producción de etanol, sin embargo, el alto gasto energético en el pretratamiento requiere la búsqueda de métodos que lo minimicen y propicie una mejora en la factibilidad económica del proceso. En comparación con las tecnologías tradicionales, el pretratamiento biológico ofrece una alternativa en la que las enzimas de remoción de la lignina son capaces de desdoblar las estructuras complejas de la misma, sin el uso de químicos y con menor gasto energético. En este trabajo se probó el uso de Phanerochaete chrysosporium H-298 en la biomasa de Agave lechuguilla. Los dos factores ensayados para la optimización del proceso fueron el tiempo de incubación y la concentración de la fuente de nitrógeno. Los resultados mostraron una máxima deslignificación (36.15 %), se preservó la celulosa sin cambios significativos. Las condiciones óptimas de pretratamiento fueron: 60 días de incubación y una concentración de nitrógeno de 1M. La hidrólisis enzimática del material pretratado con el complejo enzimático Cellic® CTec3 mostró una máxima liberación de glucosa de 44.9 g L-1 a las 92 horas, con rendimiento de hidrólisis de 93.09 %, mayor al obtenido en la hidrólisis de la muestra sin pretratar (37.92 %). La concentración de etanol a las 10 horas de fermentación fue de 16.53 g L-1 (equivalente a una concentración >2 % v/v de etanol) con 5.7 g L-1 de glucosa remanente a ese tiempo de incubación.

Interactions between temperature and moisture on seed germination are not clearly understood. We hypothesized that high temperatures and low moisture would inhibit seed germination. We analyzed germination under four temperatures (18–36 °C) and under five water limiting conditions, using Polyethylene glycol (PEG) 6000 (0.0–1.0 MPa) for eight dominant species from Cactaceae ( Isolatocereus dumortieri , Echinocactus platyacanthus , and Ferocactus histrix ), Asparagaceae ( Yucca decipiens , Agave salmiana , and Agave lechuguilla ) and Fabaceae ( Acacia schaffneri and Prosopis laevigata ) from the Chihuahuan Desert. We used the September (when seed germination is more likely to occur) mean (18 °C), the historic highest mean temperature for this month (25 °C), the maximum temperature registered for the month (32 °C), and 36 °C, considering a 4 °C increase. Species had fewer seeds germinating with decreasing moisture and high temperature. Prosopis laevigata however, showed high germination across temperatures and on almost all water potentials. Isolatocereus dumortieri and E. platyacanthus had few seeds germinating at 18 °C but with a negative effect of low water potential for 18 °C and 36 °C. This is the first study including the combined effect of water potential and temperatures on germination of a set of Chihuahuan Desert species.

Different strategies were assessed for the production of ethanol from Agave lechuguilla that was pretreated by autohydrolysis. Separate hydrolysis and fermentation (SHF) was compared against simultaneous processes including simultaneous saccharification and fermentation (SSF) and prehydrolysis and simultaneous saccharification and fermentation (PSSF) using different solids (15%, 20%, and 25% w/w) and enzyme loadings (15 FPU/g, 20 FPU/g, and 25 FPU/g glucan). The results showed that the maximum ethanol concentration (53.7 g/L) and productivity (1.49 g/L h-1) was obtained at 36 h in the SHF configuration at the highest solids and enzyme loadings (25% w/v and 25 FPU/g glucan, respectively). The ethanol concentration and productivity obtained in the PSSF configuration at the same time were 45 g/L and 1.25 g/L h-1, respectively. The SSF configuration exhibited the lowest ethanol concentration and productivity (10.4 g/L and 0.29 g/L h-1, respectively) at 36 h. The enzyme used, Cellic CTec3, allowed for high glucose yields at the lower enzyme dosage assessed. The SHF configuration exhibited the best results. However, the PSSF configuration can be considered an attractive alternative because it eliminated the need for solid-liquid separation devices, which simplifies the industrial implementation of the process.

Microphyllous and rosetophyllous desert scrub plant communities dominate large parts of the state of Coahuila, Mexico, yet differences in how livestock grazing impacts these two plant communities are not well documented. In order to address this knowledge gap, we assessed livestock impact on plant species composition and vegetation structure in microphyllous and rosetophyllous desert scrublands in this northwestern Mexican state. We collected plant density, frequency, and cover data from sites with and without livestock grazing pressure that were otherwise similar in plant composition. We quantified intersite differences using the importance value index (IVI) and the Bray-Curtis similarity index. The species with the highest IVI for microphyllous scrubland were lechuguilla (Agave lechuguilla), honey mesquite (Prosopis glandulosa), and creosote bush (Larrea tridentata); however, in sites with presence of domestic herbivores, desert willow (Chilopsis linearis) and spiny hackberry (Celtis pallida) a...

About 10,500 years ago at the beginning of the Holocene, the first humans in the north of Mexico found themselves in the middle of an aridification process that culminated about 4000 years ago in the modern Chihuahuan Desert, which is the largest desert in North America and the second most diverse on Earth with about 3400 plant species, including cacti that reach their greatest diversity in this region. Nearly 25% of the species are endemic, most notably in the Cuatro Cienegas Basin with 86 plant taxa. The climate is hot-dry with summer rain. Most of the region has calcareous soils, although there are important outcrops of gypsum in patchy arrangements throughout the region. These environmental pressures have generated a variety of adaptive strategies among the organisms evolving here, resulting in great species’ richness. Creosote bush (Larrea tridentata) dominates in the driest sites, frequently accompanied by lechuguilla (Agave lechuguilla) and tarbush (Flourensia cernua); in the bajadas (lowlands) we find the less drought-tolerant plants such as yuccas (Yucca spp.) and sotol (Dasylirion wheeleri). Grasslands integrate grass and shrub mosaics, with species such as bush muhly (Muhlenbergia porteri), bluegrass (Bouteloua gracilis), and purple three-awn (Aristida purpurea). In gypsum outcrops a diverse flora with several endemics is found. The vegetation is highly variable, responding to water availability, physical–chemical and biological dynamics of soils and fires, among other factors. Currently, there are serious pressures modifying the natural dynamics of the desert, such as the indiscriminate extraction of water, agricultural and livestock practices, water and soil contamination, and invasive species that threaten this unique place.

The Chihuahuan desert is the largest and most diverse arid desert in North America. Geological and climatic events of the Miocene–Pliocene, as well as the climatic cyclical changes of the Pleistocene, had an important effect on the diversity patterns of the species in this desert. Several areas of the Chihuahuan desert have been identified as “refuges” in which the arid biota survived or thrived during the complex Pleistocene climate changes, including Cuatro Cienegas, and Mapimian valleys, among other areas. We analyzed bibliographic genetic structure information from plant and animal species of the Chihuahuan desert, using the data to explore for general phylogeographic patterns. Our hypothesis was that the recent history of the genetic diversity currently observed could be interpreted in terms of the effects of large-scale geological and climatic events that occurred during Miocene/Pliocene. We analyzed 24 studies, 9 involving plants (Agave lechuguilla, A. striata, A. stricta, A. victoria-reginae, Astrophytum spp., Berberis trifoliate, Ephedra compacta, Leucophyllum spp., Larrea tridentata), and the rest involving animals. We detected three main patterns: (1) An ancient differentiation of the North of the Chihuahuan desert in the Cochise filter barrier area, within the Late Miocene (~11.6–5.3 MY), supported by three species; (2) A North/South differentiation from the Chihuahuan desert into the Altiplano Norte and Altiplano Sur, broadly congruent with the Pliocene (~5.3–2.5 MY) supported by seven species; (3) A divergence congruent with the Pleistocene (~2.5 MY), involving recent events within lineages. Another commonly detected pattern is an East/West differentiation. The current genetic differentiation patterns of the Chihuahuan desert species can be explained, at least in part, in terms of Pleistocene climate dynamics along an altitudinal and latitudinal gradient of locally adapted populations that underwent cyclic processes of contraction, isolation, and divergence, followed by expansion and secondary contact.

Agave lechuguilla is one of the most abundant species in arid and semiarid regions of Mexico, and is used to extract fiber. However, 85 % of the harvested plant material is discarded. Previous bioprospecting studies of the waste biomass suggest the presence of bioactive compounds, although the extraction process limited metabolite characterization. This work achieved flavonoid profiling of A. lechuguilla in both processed and non-processed leaf tissues using transcriptomic analysis. Functional annotation of the first de novo transcriptome of A. lechuguilla (255.7 Mbp) allowed identifying genes coding for 33 enzymes and 8 transcription factors involved in flavonoid biosynthesis. The flavonoid metabolic pathway was mostly elucidated by HPLC-MS/MS screening of alcoholic extracts. Key genes of flavonoid synthesis were higher expressed in processed leaf tissues than in non-processed leaves, suggesting a high content of flavonoids and glycoside derivatives in the waste biomass. Targeted HPLC-UV-MS analyses confirmed the concentration of isorhamnetin (1251.96 μg), flavanone (291.51 μg), hesperidin (34.23 μg), delphinidin (24.23 μg), quercetin (15.57 μg), kaempferol (13.71 μg), cyanidin (12.32 μg), apigenin (9.70 μg) and catechin (7.91 μg) per gram of dry residue. Transcriptomic and biochemical profiling concur in the potential of lechuguilla by-products with a wide range of applications in agriculture, feed, food, cosmetics, and pharmaceutical industries.

El objetivo general de este trabajo fue encontrar un nuevo valor agregado a las hojas de las agaváceas, desecho de la agroindustria. Se estudiaron cuatro especies de agaves de tres estados de la república mexicana: Agave angustifolia (Oacaxa), Agave tequilana (Jalisco), Agave salmiana y Agave lechuguilla (Hidalgo). Luego de una clasificación taxonómica, fenológica, ecológica y etnobotánica (basados en morfología comparada), se sometieron a diversos análisis físicos (humedad, molienda, tamizaje, granulometría y características foliares, MEB) y químicos (cenizas grasas y aceites, proteínas, análisis TGA y DTGA, así como FTIR). Las especies de A. angustifolia y A. tequilana son las que presentan un óptimo tamaño de fibra para la elaboración de papel. Corresponde también a los mayores porcentajes de celulosa (44.3% y 36.8%) por DTGA. Del análisis proximal, se evidencia que las dos especies definidas como mejores para la obtención de pulpa de celulosa, presentan pequeñas diferencias significativas en contenidos de grasas, proteínas, material solubilizable en agua caliente (AT) como en solución moderadamente alcalina y/o alcohólica. The overall objective of this work was to find a new value to the leaves of agaváceas, waste of agribusiness. Four species of agaves were studied in three states of the Mexican Republic: Agave angustifolia (Oacaxa), Agave tequilana (Jalisco), Agave salmiana and Agave lechuguilla (Hidalgo). After a classification taxonomy, phenology, ecological and ethnobotanical (morphology), various physical analysis (moisture, grinding, screening, grading and leaf characteristics, SEM) and chemical (fat and oils, ash, proteins, TGA and DTGA and FTIR were subjected). The species of A. angustifolia and A. tequilana are those with an optimum size of fiber for papermaking. It also corresponds to the highest percentages of cellulose (44.3% and 36.8%) by DTGA. The proximate analysis, it appears that the two species defined as obtaining better for pulp, significant differences have small content of fat, protein, water solubilizable hot material (AT) and moderately alkaline and/or alcoholic solution.

Water availability during seed germination and seedling development is critical to plant development and establishment. The aim of this study was to determine the effects of four water potentials (ΨW) (−0.03, −0.48, −1.19 and −2.04 MPa) on seed germination, seedling root growth and root membrane stability of Agave lechuguilla Torr. and A. salmiana Otto ex Salm-Dyck. to explain the paradoxical situation of vegetatively propagated species producing large quantities of seeds in a dry climate. The results showed that seed water uptake and germination percentage were significantly lower at −1.19 and −2.04 MPa than at −0.03 MPa. The time to reach maximum seed germination increased at low ΨW. The final root length and root growth rate were higher in A. salmiana than in A. lechuguilla and decreased at ΨW of −1.19 and −2.04 MPa. Both Agave species increased root electrolyte leakage at ΨW of −1.19 MPa, which suggests changes in membrane integrity and stability in response to the water deficit. These germination and initial root growth responses could ensure the establishment of both Agave species during the rare periods with sufficient moisture availability and allow them to tolerate initial periods of low water availability, although with low establishment probability.

In this study, an ethanol extract of Agave lechuguilla was evaluated against six carcinogenic cell lines (HCT-15, MCF-7, PC-3, U-251, SK-LU-1 and K-562) with an inhibition of 75.7 &plusmn, 2.3% against the SK-LU-1 line. Based on the previous result, the extract was hydrolyzed and fractionated, to which the IC50 was determined, the cell line was more sensitive to the fractionated extract with an IC50 6.96 &plusmn, 0.15 &micro, g/mL. Characterization by mass spectrometry showed the presence of kaempferol, quercetin and a flavonoid dimer formed by afzelechin-4&beta, 8-quercetin, according to the generated fragmentation pattern. The fractionated extract presented cell death by apoptosis with 39.8% at 24 h. Molecular docking was performed with the molecules found to try to describe cell death by apoptosis through death receptors such as FasCD95, TNF-R1, DR4/5 and blocking signaling on the EGFR and K-Ras MAPK/ERK pathway, as well as through the intrinsic pathway activating tBID, which promotes the amplification of the apoptotic signal due to the activation of caspase-3, and consequently caspase-7. In addition to the activation of the IIb complex associated with cell death due to necroptosis.

In this study, an ethanol extract of Agave lechuguilla was evaluated against six carcinogenic cell lines (HCT-15, MCF-7, PC-3, U-251, SK-LU-1 and K-562) with an inhibition of 75.7 ± 2.3% against the SK-LU-1 line. Based on the previous result, the extract was hydrolyzed and fractionated, to which the IC50 was determined; the cell line was more sensitive to the fractionated extract with an IC50 6.96 ± 0.15 µg/mL. Characterization by mass spectrometry showed the presence of kaempferol, quercetin and a flavonoid dimer formed by afzelechin-4β-8-quercetin, according to the generated fragmentation pattern. The fractionated extract presented cell death by apoptosis with 39.8% at 24 h. Molecular docking was performed with the molecules found to try to describe cell death by apoptosis through death receptors such as FasCD95, TNF-R1, DR4/5 and blocking signaling on the EGFR and K-Ras MAPK/ERK pathway, as well as through the intrinsic pathway activating tBID, which promotes the amplification of the apoptotic signal due to the activation of caspase-3, and consequently caspase-7. In addition to the activation of the IIb complex associated with cell death due to necroptosis.

Hydrogen production from enzymatic hydrolysates of Agave lechuguilla pretreated by autohydrolysis was assessed in this work. The pretreatment was carried out in a high-pressure reactor using a solid/liquid ratio of 1:6 (w/v) at 190 °C for 30 min at 200 rpm. The pretreated solids were enzymatically hydrolyzed and then were digested with a treated mixed consortium under specified conditions with a Taguchi (L9(34)) experimental array. The results showed that the xylan was 65.2% solubilized during pretreatment, and the glucan preserved was 77.5% hydrolyzed, obtaining a hydrolysate with 55 g/L of glucose. The production of hydrogen after anaerobic digestion of hydrolysates was significantly influenced mainly by the temperature (80.6%) and glucose concentration (15.1%). The best conditions were 40 oC, glucose 20 g/L, inoculum 5% (v/v), and initial pH 7. Under optimal conditions, the hydrogen yield achieved was 3.48 mol H2/mol glucose consumed at 120 h.

Biomass productivity presents a challenging problem in arid and semi-arid areas. Despite a large need for energy in the form of solid biomass, liquid fuel or needs for animal feed, these regions remain largely unproductive. A convenient way to overcome this challenge is to utilize plants with high water-use efficiency. Agave lechuguilla is an example of a highly productive (3.8 tons ha-1 yr-1 ) desert plant that holds the potential for producing biomass with minimal water resources. For this purpose, a global suitability map has been developed showing areas where this plant can be planted, and its productivity was assessed. A Maxent model was used and was further refined by excluding protected areas and used lands (urban, agriculture, etc..). Productivity assessment provides a good way forward for prioritizing the regional utilization of this plant. This study provides an initial analysis for the use of arid and semi-arid regions for biomass production. Results indicate the potential generation of 93.8 million tons per year of dry biomass if the suitable areas were fully utilized. The analytical method can be readily applied to other potential plant species to optimize the use of certain areas.

Antifungal activity of water, ethanol, lanolin and cocoa butter plant extracts derived from seven Mexican Chihuahuan desert inhabiting plant species (Larrea tridentata, Flourensia cernua, Agave lechuguilla, Opuntia ficus-indica, Lippia graveolens, Carya illinoensis and Yucca filifera) were evaluated against Phytophthora cinnamomi. All plant extracts were active against Phytophthora cinnamomi. Two (L. tridentata and F. cernua) out of seven plant species tested had the optimal antifungal activity against this fungus specie, with minimum inhibitory concentration (MIC) values as low as 6.96 and 8.6 mg/L. Some of the plant extracts had moderate to low activity against P. cinnamomi, and the variations of active polyphenolic (condensed and hydrolysable tannins) compounds in the plant extracts estimated via colorimetric methods indicated that the inhibitory activity may not based on a general metabolic toxicity but perhaps the antifungal potency is conferred by group or groups of toxic metabolites. Based on the antifungal activity, crude plant extracts may be a cost effective way of protecting crops against P. cinnamomi. Because plant extracts contain several antifungal compounds, the development of resistant pathogens to these plant extracts may be delayed. Key words: Antifungal activity, plant extracts, polyphenols, MIC50 P. cinamomi.