Ultrasound-assisted extraction of fructans from agave (Agave tequilana Weber var. azul) at different ultrasound powers and solid-liquid ratios

Abstract The effects of ultrasound-assisted extraction (UAE) at different ultrasound power densities (UPDs; 40, 80, and 120 mW/mL) and solid:liquid (S:L) ratio (1:2, 1:3, and 1:6) on the extraction of carbohydrates from Agave tequilana plant of different ages were evaluated. Extracts obtained (6- and 7-year-old plant) were analyzed in the yield of carbohydrates (YC), fructan (FRU) content, simple sugars, fructan profile and the average degree of polymerization (DPn). UPD, S:L ratio, and plant age all affected YC, FRU, and DPn. Maximum YC and FRU were obtained from the older agave with UPD and S:L ratio of 120 mW/mL and 1:6, respectively; while glucose, fructose, and sucrose were highly released from the younger plant. Agave of 7-year-old presented the highest DPn. Fructan degradation occurred at high UPD, increasing the simple sugars and decreasing the DPn. Thermal-traditional extraction without sonication caused more fructan degradation; and overall, ultrasound enhanced fructan extraction and minimized fructan damage, representing a technological alternative for fructan extraction from agave. Keywords: agave; fructans; ultrasound; power density; solid:liquid ratio; plant age. Practical Application: Agave tequilana Weber var. azul plants have significant amounts of fructans. Extraction of these components by alternative methods such as ultrasound could represent advantages, improving the extraction and product quality. This research presents an alternative for the extraction of fructans assisted with ultrasound, evaluating different powers and solid-liquid ratios from agave heads of two different ages. Both variables, as well as age of agave showed a strong effect on fructan extraction. Ultrasound enhanced the extraction and minimized fructan damage, representing a technological alternative

Análisis genético y molecular de propiedades fisicoquímicas del almidón y su asociación con la modificación del endospermo en maíz de calidad proteínica

Quality protein maize (QPM) was created converting the soft opaque-2 endosperm into a vitreous phenotype, but the mechanisms involved in this modification are not completely understood. Recombinant inbred lines (RILs) derived from K0326Y QPM and W64Ao2 were used to identify quantitative trait loci (QTL) associated with starch physicochemical properties. RILs contrasting in vitreousness were also used to evaluate the expression of starch biosynthesis genes. Mapping identified 5-6 QTLs for each trait that explained 66 % of the phenotypic variation. Three QTLs on bins 4.05, 5.04, and 9.03 were found close to the starch biosynthesis genes Brittle-2 (Bt2), Amylose extender-1 (Ae1), and Waxy-1 (Wx1), respectively. The expression of Wx1 was three-fold greater in K0326Y QPM than W64Ao2 and eight-fold higher in vitreous than opaque RILs, which corresponded with the greater accumulation of granule bound starch synthase I (GBSSI) and the higher amylose content observed in the vitreous lines. The increased synthesis of amylose may result in starch granules with more amorphous regions that favor their compaction. These results suggest that endosperm modification in QPM is associated with the synthesis of starch containing more amylose during kernel development, which may facilitate the packing of the starch granules resulting in the vitreous phenotype.El maíz de calidad proteínica (QPM) fue creado convirtiendo el endospermo suave opaco-2 en un fenotipo vítreo, pero los mecanismos involucrados en esta modificación no se conocen por completo. Se utilizaron líneas recombinantes puras derivadas de las líneas K0326Y QPM y W64Ao2 para identificar loci de características cuantitativas (QTL) asociados con propiedades fisicoquímicas del almidón. También se usaron RILs contrastantes en vitrosidad para evaluar la expresión de genes de biosíntesis de almidón. El mapeo identificó 5 o 6 QTL para cada característica que explicaron en promedio el 66 % de la variación fenotípica. Tres de los QTLs en los bins 4.05, 5.04 y 9.03 se encontraron cerca de los genes de síntesis de almidón Brittle 2 (Bt2), Amylose extender 1 (Ae1), y Waxy 1 (Wx1), respectivamente. La expresión de Wx1 fue tres veces mayor en K0326Y QPM que en W64Ao2 y ocho veces mayor en líneas vítreas en comparación con las opacas, lo que correspondió con la mayor acumulación de la enzima almidón sintasa unida al gránulo I (GBSSI) y el mayor contenido de amilosa observado en las líneas vítreas. El incremento en la síntesis de amilosa podría resultar en gránulos de almidón con más regiones amorfas que favorecen su compactación. Estos resultados sugieren que la modificación del endospermo en QPM está asociada con la síntesis de almidón conteniendo más amilosa durante el desarrollo del grano, lo cual podría facilitar el empaquetamiento de los gránulos de almidón resultando en el fenotipo vítreo

Transportability of non-target arthropod field data for the use in environmental risk assessment of genetically modified maize in Northern Mexico

In country, non-target arthropod (NTA) field evaluations are required to comply with the regulatory process for cultivation of genetically modified (GM) maize in Mexico. Two sets of field trials, Experimental Phase and Pilot Phase, were conducted to identify any potential harm of insect-protected and glyphosate-tolerant maize (MON89Ø34-3 × MON-88Ø17-3 and MON-89Ø34-3 × MON-ØØ6Ø3-6) and glyphosatetolerant maize (MON-ØØ6Ø3-6) to local NTAs compared to conventional maize. NTA abundance data were collected at 32 sites, providing high geographic and environmental diversity within maize production areas from four ecological regions (ecoregions) in northern Mexico. The most abundant herbivorous taxa collected included field crickets, corn flea beetles, rootworm beetles, cornsilk flies, aphids, leafhoppers, plant bugs and thrips while the most abundant beneficial taxa captured were soil mites, spiders, predatory ground beetles, rove beetles, springtails (Collembola), predatory earwigs, ladybird beetles, syrphid flies, tachinid flies, minute pirate bugs, parasitic wasps and lacewings. Across the taxa analysed, no statistically significant differences in abundance were detected between GM maize and the conventional maize control for 69 of the 74 comparisons (93.2%) indicating thatthe single or stacked insect-protected and herbicide-tolerant GM traits generally exert no marked adverse effects on the arthropod populations compared with conventional maize. The distribution of taxa observed in this study provides evidence that irrespective of variations in overall biodiversity of a given ecoregion, important herbivore, predatory and parasitic arthropod taxa within the commercial maize agroecosystem are highly similar indicating that relevant data generated in one ecoregion can be transportable for the risk assessment of the same or similar GM crop in another ecoregion

Plant characterization of genetically modified maize hybrids MON-89Ø34-3 × MON-88Ø17-3, MON-89Ø34-3 × MON-ØØ6Ø3-6, and MON-ØØ6Ø3-6: alternatives for maize production in Mexico

Environmental risk assessment (ERA) of genetically modified (GM) crops is a process to evaluate whether the biotechnology trait(s) in a GM crop may result in increased pest potential or harm to the environment. In this analysis, two GM insect-resistant (IR) herbicide-tolerant maize hybrids (MON-89Ø34-3 9 MON-88Ø17-3 and MON-89Ø34-3 9 MON-ØØ6Ø3-6) and one herbicide-tolerant GM hybrid (MON-ØØ6Ø3-6) were compared with conventional maize hybrids of similar genetic backgrounds. Two sets of studies, Experimental Phase and Pilot Phase, were conducted across five ecological regions (ecoregions) in Mexico during 2009–2013, and data were subject to meta-analysis. Results from the Experimental Phase studies, which were used for ERA, indicated that the three GM hybrids were not different from conventional maize for early stand count, days-tosilking, days-to-anthesis, root lodging, stalk lodging, or final stand count. Statistically significant differences were observed for seedling vigor, ear height, plant height, grain moisture, and grain yield, particularly in the IR hybrids; however, none of these phenotypic differences are expected to contribute to a biological or ecological change that would result in an increased pest potential or ecological risk when cultivating these GM hybrids. Overall, results from the Experimental Phase studies are consistent with those from other world regions, confirming that there are no additional risks compared to conventional maize. Results from Pilot Phase studies indicated that, compared to conventional maize hybrids, no differences were detected for the agronomic and phenotypic characteristics measured on the three GM maize hybrids, with the exception of grain moisture and grain yield in the IR hybrids. Since MON-89Ø34- 3 9 MON-88Ø17-3 and MON-89Ø34-3 9 MONØØ6Ø3- 6 confer resistance to target insect pests, they are an alternative for farmers in Mexico to protect the crop from insect damage. Additionally, the herbicide tolerance conferred by all three GM hybrids enables more cost-effective weed management

Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize

Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives

Presencia de "Candidatus Liberibacter solanacearum" en "Bactericera cockerelli" Sulc asociada con enfermedades en tomate, chile y papa

The “permanent tomato”, “spotted tuber”or “zebra chip”in potato and “chlorotic buds”of chili, are three diseases described in Mexico with coincidental signs of flower abortion, obscuration of vascular tissue at the base of the stem and root of the plants. The association between these diseases and the emerging bacterium Candidatus Liberibactersolanacearum(CLs) as well as the psyllid Bactericera cockerelli as its vector has been mentioned. These diseases, which were initially located in three states of Mexico, have spread to the main Solanaceae producing regions, both in field conditions and in the greenhouse. The objective of the study was to know the presence of CLs associated with diseases that affect the tomato, para and chilicrops in Mexico. The bacterium was identified by PCR of the 16S rDNA gene, cloning and sequencing. The alignment of nucleotide sequences was performed with the Clustal W method and the phylogenetic tree was built with the Neighbor-Joining algorithm from distances calculated with the Tajima-Nei method and a Felsenstein index of 1000 replicas, using the software MEGA version 5.05. A total of 167 samples were analyzed, of which 86 were positive, from 14 states of Mexico. Five nucleotide sequences from Guanajuato, San Luis Potosiand Sinaloa corresponding to tomato, potato and chili, adults and eggs of B. cockerelli were obtained. The analysis of the sequences showed an identity of 99.4%when compared between these and up to 99.8% with GenBank accessions described for CLs in the USA, New Zealand and Canada. Keywords: chlorotic buds, tomato permanent, zebra chipEl “permanente del tomate”, “manchado del tubérculo” o “zebra chip” en papa y “brotes cloróticos” del chile, son tres enfermedades descritas en México con signos coincidentes de aborto de flor, oscurecimiento de tejido vascular en la base del tallo y raíz de las plantas. Se ha mencionado la asociación entre estas enfermedades y la bacteria emergente Candidatus Liberibacter solanacearum (CLs) así como al psílido Bactericera cockerelli como su vector. Estas enfermedades, que en inicio se localizaban en tres estados de México se han diseminado a las principales regiones productoras de solanáceas, tanto en condiciones de campo como en invernadero. El objetivo del estudio fue conocer la presencia de CLs asociado a enfermedades que afectan los cultivos de tomate, para y chile en México. La bacteria se identificó por PCR del gen 16S de ADNr, clonación y secuenciación. La alineación de secuencias nucleotídicas se realizó con el método Clustal W y el árbol filogenético se construyó con el algoritmo de Neighbor-Joining a partir de distancias calculadas con el método de Tajima-Nei y un índice de Felsenstein de 1 000 réplicas, utilizando el software MEGA versión 5.05. En total se analizaron 167 muestras, de las cuales 86 resultaron positivas, provenientes de 14 estados de México. Se obtuvieron cinco secuencias nucleotídicas de Guanajuato, San Luis Potosí y Sinaloa correspondientes al tomate, papa y chile, adultos y huevecillos de B. cockerelli. El análisis de las secuencias mostró una identidad de 99.4% al comparase entre estas y hasta 99.8% con accesiones del GenBank descritas para CLs en EUA, Nueva Zelanda y Canadá. Palabras clave: brotes cloróticos, permanente del tomate, zebra chi