Rhizobacteria emit bioactive metabolites with antifungal properties that could be used for biocontrol of fungal diseases. In this study, we evaluated the potential of diffusible and volatile organic compounds (VOCs) emitted by avocado rhizobacteria to inhibit the growth of Fusarium kuroshium, one of the causal agents of Fusarium dieback (FD) in avocado. Three bacterial isolates (INECOL-6004, INECOL-6005, and INECOL-6006), belonging to the Bacillus genus, were selected based on their capacity to inhibit several avocado fungal pathogens, and tested in antagonism assays against F. kuroshium. The three bacterial isolates significantly inhibited F. kuroshium mycelial growth by up to 48%. The composition of bacterial diffusible compounds was characterized by the analysis of EtOAc and n-BuOH extracts by using ultra-performance liquid chromatography (UPLC) coupled to high-resolution mass spectrometry (HRMS). The three bacterial isolates produced cyclo-lipopeptides belonging to the iturin, fengycin, and surfactin families. The antifungal activity of n-BuOH extracts was larger than that of EtOAc extracts, probably due to the greater relative abundance of fengycin in the former than in the latter. In addition, isolates INECOL-6004 and INECOL-6006 significantly inhibited F. kuroshium mycelial growth through VOC emission by up to 69.88%. The analysis of their VOC profiles by solid phase micro-extraction (SPME) coupled to gas chromatography and mass spectrometry (GC-MS) revealed the presence of ketones and pyrazine compounds, particularly of 2-nonanone, which was not detected in the VOC profile of isolate INECOL-6005. These results emphasize the need to further investigate the antifungal activity of each bioactive compound for the development of new formulations against fungal phytopathogens.

This investigation cultured Cecropia obtusifolia cells in suspension to evaluate the effect of nitrate deficiency on the growth and production of chlorogenic acid (CGA), a secondary metabolite with hypoglycemic and hypolipidemic activity that acts directly on type 2 diabetes mellitus. Using cell cultures in suspension, a kinetics time course was established with six time points and four total nitrate concentrations. The metabolites of interest were quantified by high-performance liquid chromatography (HPLC), and the metabolome was analyzed using directed and nondirected approaches. Finally, using RNA-seq methodology, the first transcript collection for C. obtusifolia was generated. HPLC analysis detected CGA at all sampling points, while metabolomic analysis confirmed the identity of CGA and of precursors involved in its biosynthesis. Transcriptome analysis identified differentially expressed genes and enzymes involved in the biosynthetic pathway of CGA. C. obtusifolia probably expresses a key enzyme with bifunctional activity, the hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase and hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HQT/HCT), which recognizes shikimic acid or quinic acid as a substrate and incorporates either into one of the two routes responsible for CGA biosynthesis.

Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogenesis and a tool for the mass production of plants. However, establishing SE in avocado has been complicated due to the very low efficiency of embryo induction and plant regeneration. To understand the molecular foundation of the SE induction and development in avocado, we compared embryogenic (EC) and non-embryogenic (NEC) cultures of two avocado varieties using proteomic and metabolomic approaches. Although Criollo and Hass EC exhibited similarities in the proteome and metabolome profile, in general, we observed a more active phenylpropanoid pathway in EC than NEC. This pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall and flavonoid production. We could corroborate that particular polyphenolics compounds, including p-coumaric acid and t-ferulic acid, stimulated the production of somatic embryos in avocado. Exogen phenolic compounds were associated with the modification of the content of endogenous polyphenolic and the induction of the production of the putative auxin-a, adenosine, cellulose and 1,26-hexacosanediol-diferulate. We suggest that in EC of avocado, there is an enhanced phenylpropanoid metabolism for the production of the building blocks of lignin and flavonoid compounds having a role in cell wall reinforcement for tolerating stress response. Data are available at ProteomeXchange with the identifier PXD019705.

Antecedentes y Objetivos: Los ambientes de los litorales rocosos del estado de Veracruz, México, son sitios únicos en los que la riqueza específica macroalgal ha sido poco estudiada, ya que se carece de listados florísticos completos y de un seguimiento a los cambios en las poblaciones algales. El objetivo de este trabajo fue contribuir al conocimiento de algas de los ambientes rocosos veracruzanos ubicados en Playa Paraíso, Playa Villa Rica y Playa Muñecos, los cuales están influenciados por las estribaciones del Eje Neovolcánico.Métodos: Las algas se recolectaron durante la época de lluvias (septiembre 2016) y de secas (mayo 2017) en Playa Paraíso (PP), Playa Villa Rica (PVR) y Playa Muñecos (PM). Las muestras se preservaron en una solución de agua de mar y formol al 4%. Se realizaron observaciones morfométricas externas e internas de los talos y se determinaron las especies de acuerdo con literatura taxonómica especializada.Resultados clave: Se determinaron un total de 45 especies, de las cuales 18 fueron Chlorophyta, 16 Rhodophyta y 11 Ochrophyta. Las familias mejor representadas fueron Corallinaceae, Rhodomelaceae, Cladophoraceae y Dictyotaceae. La mayor riqueza de especies se observó en PP durante la época de secas. Se mencionan nuevos registros para las localidades de estudio; de éstos, Centroceras gasparrinii, Gracilaria apiculata y G. flabelliformis son nuevos registros para el estado de Veracruz.Conclusiones: La flora algal del litoral rocoso Neovolcánico de Veracruz es de tipo tropical y alberga 31% de la flora algal regional del estado de Veracruz. Los nuevos registros en cada una de las localidades reflejan que aún prevalece una brecha en el conocimiento de la riqueza algal de esta región. Por lo tanto, se sugiere continuar con el registro de especies en la zona con la finalidad de integrar los listados florísticos correspondientes.

ResumenVitis tiliifolia es una uva silvestre que se consume generalmente en forma de vino, pero las semillas son desechadas, por lo que en este trabajo las propiedades fisicoquímicas de la harina y el aceite de las semillas de uvas de Vitis tiliifolia fueron evaluadas, se identificaron y cuantificaron los compuestos fenólicos mediante UPLC-ESI-MS. La harina de la semilla tuvo 75% de humedad, 0.23% de proteínas, 1.43% de cenizas, 3.15% de fibra total dietaria y 17.5% de aceite. La caracterización de polifenoles en la harina reveló la presencia de (-)-epicatequina (1318.66 µg g -1 ), (+)-catequina (703.12 µg g -1 ) y trans-resveratrol (32.88 µg g -1 ) como los polifenoles mayoritarios. El aceite presentó compuestos bioactivos como carotenoides y polifenoles. Los ácidos grasos que predominaron en el aceite fueron el ácido linoleico (Ω-6, 84.73%), oleico (Ω-9, 5.83%) y esteárico (2.21%) Adicionalmente los extractos, etanol: agua (3:1; v: v) y metanol: HCl (0.01%) del aceite, resultaron tener una alta concentración de polifenoles (125 mg GAE g -1 ) y una alta actividad antioxidante. El índice de yodo fue de 68.56 g I2/100 g aceite y el índice de peróxidos fue de 20 meqO2 kg -1 aceite. Las semillas tuvieron una AbstractVitis tiliifolia is a wild grape that is usually consumed as wine, but the seeds are discarded, so in this paper the physicochemical properties of flour and oil of grapes seeds Vitis tiliifolia were evaluated, the phenolic compounds were identified and quantified by UPLC-ESI-MS. Seed meal had 75% moisture, 0.23% protein, 1.43% ash, 3.15% total dietary fiber and 17.5% oil.The characterization of polyphenols in flour revealed the presence of (-)-epicatechin (1318.66 ug g -1 ), (+)-catechin (703.12 µg g -1 ) and transresveratrol (32.88 µg g -1 ) as the major polyphenols. The oil featured bioactive compounds such as carotenoids and polyphenols. The fatty acids that predominated in the oil were linoleic (Ω-6, 84.73%), oleic (Ω-9, 5.83%) and stearic acid (2.21%). In addition the extracts, ethanol: water (3:1; v: v) and methanol: HCl (0.01%) of the oil, resulted in a high concentration of polyphenols (125 mg GAE g -1 ) and a high antioxidant activity. The iodine value was 68.56 g I2/100 g oil and the peroxide was 20.0 meq O2 kg -1 oil. The seeds had a considerable amount of polyphenols and linoleic acid that confers a high antioxidant activity, so it could be suitable for use in food and industrial applications and encourage 1114 Rev. Mex. Cienc. Agríc. Vol.8 Núm. 5 30 de junio -13 de agosto, 2017 Nadia Juárez Trujillo et al.cantidad considerable de polifenoles y ácido linoleico que le confieren una alta actividad antioxidante, por lo cual podría ser adecuada para su uso en aplicaciones alimentarias e industriales y fomentar la producción y consumo de esta uva como fuente de nutrientes y compuestos fenólicos adecuados para su incorporación en alimentos funcionales.