RESUMO
Agave tequilana stems store fructan polymers, the main carbon source for tequila production. This crop takes six or more years for industrial maturity. In conducive conditions, agave wilt disease increases the incidence of dead plants after the fourth year. Plant susceptibility induced for limited photosynthates for defense is recognized in many crops and is known as "sink-induced loss of resistance". To establish whether A. tequilana is more prone to agave wilt as it ages, because the reduction of water-soluble carbohydrates in roots, as a consequence of greater assembly of highly polymerized fructans, were quantified roots sucrose, fructose, and glucose, as well as fructans in stems of agave plants of different ages. The damage induced by inoculation with Fusarium solani or F. oxysporum in the roots or xylem bundles, respectively, was recorded. As the agave plant accumulated fructans in the stem as the main sink, the amount of these hexoses diminished in the roots of older plants, and root rot severity increased when plants were inoculated with F. solani, as evidence of more susceptibility. This knowledge could help to structure disease management that reduces the dispersion of agave wilt, dead plants, and economic losses at the end of agave's long crop cycle.
Assuntos
Agave , Frutanos , Fusarium , Doenças das Plantas , Raízes de Plantas , Agave/microbiologia , Agave/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Frutanos/metabolismo , Doenças das Plantas/microbiologia , Fusarium/patogenicidade , Hexoses/metabolismo , Caules de Planta/microbiologia , Caules de Planta/metabolismoRESUMO
Excess consumption of sweetened beverages is associated with a global rise in metabolic diseases. Tamarind and partially-hydrolyzed agave syrup have potential for developing healthier beverages. Our objective was to develop a functional beverage using these ingredients (PH-AS-B). We also evaluate shelf-life stability (physicochemical, microbiological, and antioxidant properties) and health effects in C57BL/6 mice compared with tamarind beverages sweetened with glucose or fructose. Optimal tamarind extraction conditions were a 1:10 ratio (g pulp/mL water) and boiling for 30 min, and the resulting beverage had a shelf life of two months at 4 °C. Non-volatile metabolites were identified using HPLC/MS. PH-AS-B was associated with decreased blood cholesterol (5%) and triglyceride (20-35%) concentrations in healthy mice as well as lower lipid (82%) concentrations and evidence of protein oxidation (42%) in the liver, compared with glucose- and fructose-sweetened tamarind beverages. In conclusion, PH-AS-B was stable and associated with beneficial metabolic properties in healthy mice.
Assuntos
Agave , Xarope de Milho Rico em Frutose , Tamarindus , Camundongos , Animais , Agave/metabolismo , Camundongos Endogâmicos C57BL , Glucose/metabolismo , Bebidas , Edulcorantes/metabolismo , Frutose/metabolismoRESUMO
Fructans found in agave are called agavins, highly branched neo-fructans. They are essential on the yield and quality of Tequila production. The need for agave specimens with higher accumulation of agavins became essential before the growing demand of such products. To get such specimens, understanding agavins metabolism is a quintessential requirement. For this, a more efficient biological model is required. The recently reclassified Agave amica possesses the potential to gather the requirements for becoming such a model. Therefore, this study dealt with the characterization of carbohydrates in the bulbs of A. amica focusing on fructans. Moreover, it tested and described its feasibility as model for the accelerated study of agavins. Infrared analysis unveiled potential content of fructans in the bulbs of A. amica. Furthermore, high performance thin layer chromatography detected fructooligosaccharides. High performance anion exchange chromatography confirmed a polydisperse mixture of branched fructans. Gas chromatography-mass spectrometry analysis demonstrated agavins like structures in the bulbs of A. amica. Moreover, total fructan content and multivariate data analysis through bulb's age demonstrated their correlation. Thus, the presence of agavins, their correlation with phenology, and their technical advantages highlighted the feasibility of this species as a potential new biological model for the study of agavins' metabolism.
Assuntos
Agave , Agave/metabolismo , Carboidratos , Cromatografia em Camada Fina , Frutanos/metabolismoRESUMO
BACKGROUND AND SCOPE: Crassulacean acid metabolism (CAM) is an intriguing physiological adaptation in plants that are widespread throughout many ecosystems. Despite the relatively recent mechanistic understanding of CAM in plant physiology, evidence from historical records suggests that ancient cultures in the Americas also recognized the value of CAM plants. Agave species, in particular, have a rich cultural legacy that provides a foundation for commercially valued products. Here, we review that legacy and potential relationships between ancient values and the needs of modern-day climate adaptation strategies. CONCLUSIONS: There are many products that can be produced from Agave species, including food, sugar, fibre and medicines. Traditional knowledge about agricultural management and preparation of plant products can be combined with new ecophysiological knowledge and agronomic techniques to develop these resources in the borderland region of the southwestern USA and Mexico. Historical records of pre-Columbian practices in the Sonoran desert and remnants of centuries-old agriculture in Baja California and Sonora demonstrate the climate resilience of Agave agriculture. Commercial growth of both tequila and bacanora indicates the potential for large-scale production today, but also underscores the importance of adopting regenerative agricultural practices to accomplish environmentally sustainable production. Recent international recognition of the Appellation of Origin for several Agave species produced for spirits in Mexico might provide opportunities for agricultural diversification. In contrast, fibre is currently produced from several Agave species on many continents. Projections of growth with future climate change suggest that Agave spp. will be viable alternatives for commodity crops that suffer declines during drought and increased temperatures. Historical cultivation of Agave affirms that these CAM plants can supply sugar, soft and hard fibres, medicines and food supplements.
Assuntos
Agave , Metabolismo Ácido das Crassuláceas , Agave/metabolismo , Ecossistema , México , Açúcares/metabolismoRESUMO
BACKGROUND: Pentatricopeptide repeat (PPR) proteins play an essential role in the post-transcriptional regulation of genes in plastid genomes. Although important advances have been made in understanding the functions of these genes, there is little information available on chloroplastic PPR genes in non-model plants and less in plants without chloroplasts. In the present study, a comprehensive and multifactorial bioinformatic strategy was applied to search for putative PPR genes in the foliar and meristematic tissues of green and albino plantlets of the non-model plant Agave angustifolia Haw. RESULTS: A total of 1581 PPR transcripts were identified, of which 282 were chloroplastic. Leaf tissue in the albino plantlets showed the highest levels of expression of chloroplastic PPRs. The search for hypothetical targets of 12 PPR sequences in the chloroplast genes of A. angustifolia revealed their action on transcripts related to ribosomes and translation, photosystems, ATP synthase, plastid-encoded RNA polymerase and RuBisCO. CONCLUSIONS: Our results suggest that the expression of PPR genes depends on the state of cell differentiation and plastid development. In the case of the albino leaf tissue, which lacks functional chloroplasts, it is possible that anterograde and retrograde signaling networks are severely compromised, leading to a compensatory anterograde response characterized by an increase in the expression of PPR genes.
Assuntos
Agave , Proteínas de Cloroplastos , Agave/metabolismo , Proteínas de Cloroplastos/genética , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismoRESUMO
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.
Assuntos
Agave/química , Agave/metabolismo , Extratos Vegetais/farmacologia , Flavonoides , México , Fenóis , Folhas de Planta/química , Saponinas , Metabolismo Secundário/fisiologia , Resíduos/análiseRESUMO
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⯵g), flavanone (291.51⯵g), hesperidin (34.23⯵g), delphinidin (24.23⯵g), quercetin (15.57⯵g), kaempferol (13.71⯵g), cyanidin (12.32⯵g), apigenin (9.70⯵g) and catechin (7.91⯵g) 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.
Assuntos
Agave/química , Agave/genética , Agave/metabolismo , Biomassa , Flavonoides/metabolismo , Extratos Vegetais/química , Resíduos/análise , Perfilação da Expressão Gênica , MéxicoRESUMO
While terahertz imaging has been used before for the determination of water content in vegetative tissue, most studies have either presented measurements of the temporal evolution of water content at a single-point of the plant or have presented two-dimensional images of leaves, demonstrating the potential of the technique, but relatively little of such information has been used to support biologically relevant conclusions. In this article we introduce terahertz time-domain spectroscopic imaging as a technique for the determination of the three-dimensional distribution of water in succulent plant tissues. We present the first three-dimensional water mapping of an agave leaf, which demonstrates an unprecedented capability to study the water retention mechanisms within succulent plants. We found that agave leaves are composed of a low-hydration outer tissue layer, defined by the outermost layer of vascular tissue that surrounds a high-hydration tissue, the carbohydrate rich hydrenchyma. The findings are supported by histological images and the correlation between the water content and carbohydrate presence is consistent with recently published findings of a remarkably large hydration shell associated with agave fructans.
Assuntos
Agave/química , Imageamento Tridimensional , Folhas de Planta/química , Imagem Terahertz/métodos , Água/análise , Aclimatação , Agave/metabolismo , Secas , Frutanos/metabolismo , Folhas de Planta/metabolismo , Espectroscopia Terahertz/métodos , Água/metabolismoRESUMO
BACKGROUND: Pulque bread is a traditional Mexican product obtained by fermentation using microflora present only in pulque. In this study, the possibility of creating a pulque microbial consortium under laboratory conditions and its applications were evaluated. A laboratory-made consortium was compared with a consortium originating in Mexico in bread and pulque production. They were tested in various growth medium systems: pulque made from agave sap and malt extract, Mexican wheat and rye pulque bread, and European wheat and rye bread. RESULTS: Depending on the growth medium, consortiums showed differing influence on many factors, such as specific volume, weight loss after baking, soluble proteins, and crust and crumb color. Indigenous starters increased sensorial acceptance of pulque and Mexican rye bread, decreased pH, and increased titratable acidity of the breads at the highest level whereas laboratory consortia improved sensory acceptance of wheat breads. The laboratory-prepared starter in some cases improved antiradical activity. All pulques received similar consumer evaluations. However, malt pulque was the least appreciated beverage. CONCLUSION: The results show the possibility of creating a pulque microbial consortium under laboratory conditions. Depending on the flour type and the breadmaking technique, the use of a particular microbial consortium allowed modification of certain physicochemical parameters. In conclusion, it is feasible to modify bread parameters to obtain features corresponding to consumer demands by using an appropriate microflora, pulque, or flour type. Moreover, this research describes, for the first time, the use of rye malt for pulque and rye flour for pulque bread preparation as raw materials. © 2019 Society of Chemical Industry.
Assuntos
Bactérias/metabolismo , Pão/microbiologia , Consórcios Microbianos , Agave/metabolismo , Agave/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Pão/análise , Fermentação , Farinha/análise , Farinha/microbiologia , Manipulação de Alimentos , Humanos , México , Secale/metabolismo , Secale/microbiologia , Paladar , Triticum/metabolismo , Triticum/microbiologiaRESUMO
BACKGROUND: Phosphate-solubilizing bacteria (PSB) can be an environment-friendly strategy to improve crop production in low-phosphorus (P) or P-deficient soils. The effect of indigenous mixed inocula of PSB on Agave angustifolia Haw. growth was assessed. The four treatments evaluated were T1 (Pseudomonas luteola + Enterobacter sp.), T2 (Pseudomonas luteola + Bacillus sp.), T3 (Pseudomonas luteola + Acinetobacter sp.), and T4 (control); each was replicated 25 times using a completely randomized design during 12 months under rain-fed conditions. Additionally, P solubilization in vitro of the mixed inocula with three different sources of inorganic P was tested. RESULTS: The mixed inocula were able to solubilize more P from tricalcium phosphate Ca3 (PO4 )2 than from aluminum phosphate (AlPO4 ) and iron phosphate (FePO4 ). Relative to the control, T2 increased plant height by 22.9%, leaf dry weight by 391.4%, plant stem diameter by 49.6%, and root dry weight by 193.9%. The stem solid soluble content increased 50.0% with T1. Plant-available soil P increased 94.6% with T3 and 77.3% with T1. Soil alkaline phosphatase activity increased 85.9% with T1. CONCLUSION: T2 was the mixed inoculum that most improved Agave angustifolia plant growth. The indigenous mixed inocula of PSB evaluated appears to be a practical and efficient option for promoting field growth of Agave angustifolia plants. However, further research is necessary to achieve a deeper understanding of the relationships between different PSB species and their effects on agave, which may reveal some of the mechanisms of the synergistic interactions that are involved in the promotion of plant growth. © 2019 Society of Chemical Industry.