Pecan is a North American native tree that produces a stone fruit or kernel, commonly known as pecan nut,which is highly valuable worldwide due to its sensory quality, and health promoting properties derived from the presence of mono- and polyunsaturated fatty acids, tocopherols and monomeric and polymeric polyphenolic compounds. The increase in the demand for pecan nut leads to an increase in by-products such as leaves, cake and principally nutshell, which have high contents of bioactive components, making them interesting raw materials to produce nutraceuticals with health benefits. The phytochemical content of pecan oil and kernel, as well as that of the main pecan by-products is discussed in detail, paying special attention to the presence of individual polyphenols with monomeric and polymeric structures. Finally, studies regarding the biological activity and potential use of pecan oil, kernel and by-products are summarized and discussed.

One of the initial and critical procedures for the analysis of metabolomics data using liquid chromatography and mass spectrometry is feature detection. Feature detection is the process to detect boundaries of the mass surface from raw data. It consists of detected abundances arranged in a two-dimensional (2D) matrix of mass/charge and elution time. MZmine 2 is one of the leading software environments that provide a full analysis pipeline for these data. However, the feature detection algorithms provided in MZmine 2 are based mainly on the analysis of one-dimension at a time. We propose GridMass, an efficient algorithm for 2D feature detection. The algorithm is based on landing probes across the chromatographic space that are moved to find local maxima providing accurate boundary estimations. We tested GridMass on a controlled marker experiment, on plasma samples, on plant fruits, and in a proteome sample. Compared with other algorithms, GridMass is faster and may achieve comparable or better sensitivity and specificity. As a proof of concept, GridMass has been implemented in Java under the MZmine 2 environment and is available at http://www.bioinformatica.mty.itesm.mx/GridMass and MASSyPup. It has also been submitted to the MZmine 2 developing community.

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Although habanero peppers (Capsicum chinense, Jacq.) are highly appreciated as a result of their organoleptic and pungency properties, the crop faces edaphic stresses throughout Mexico. A study was conducted to determine how the photosynthetic parameters, vegetative growth, yield, and fruit quality of the plant change in response to suboptimal conditions in the substrate. Habanero plants were grown in an inert substrate (perlite) and exposed to increased salinity levels (4 and 7 dS·m−1) and reduced nitrogen and phosphorus conditions. Plants grown with a Hoagland-based solution were used as controls. High salinity conditions reduced the light-saturated photosynthetic rates (64% of the control) but did not compromise yield or fruit quality. This effect was possibly the result of the addition of Ca2+, which reduced salinity-induced calcium deficiency. Although comparable low nitrogen levels in previous studies were shown to cause a severe reduction in plant viability, in our study, low nitrogen reduced the light-saturated photosynthetic rates (47% of the control) and shoot:root ratio (67% of the control) but did not significantly affect yield or fruit quality. Low nitrogen and 7-dS·m−1 treatments increased fructose and glucose content (increases of 27% and 21%, respectively). Low phosphorus significantly affected plant growth and yield and reduced fructose content (73% of the control). Plants were not sensitive to low nitrogen and high salinity, possibly as a result of the use of nitrate-based fertilizers and the addition of calcium, respectively. These results provide guidelines for habanero pepper production under suboptimal edaphic conditions.

Habanero (Capsicum chinense) is appreciated for its aroma and pungency; however, little is known of the stress effects on Habanero fruits. This work, through untargeted metabolomics, measures changes in the Habanero fruit pericarp under increased salinity and nitrogen and phosphorus deficiency at three ripening stages. Responses to salinity and macronutrient deficiency are stress-and ripening stage-specific, with a few features (<1% in N and P deficit; ca. 1.5% in salinity) being consistently affected through maturation, with the most evident changes in ripe fruit. Results point to a threshold in salinity, between 4 and 7 dS•m −1 , above which a measurable response is seen. Nitrogen deficiency has a symmetric effect on feature abundance, pointing at a metabolite substitution in the pericarp; in contrast, phosphorus deficiency leads to an overall reduction in metabolite diversity, which could negatively affect the postharvest shelf-life. This work shows that untargeted approaches help to improve our understanding of Habanero fruit metabolism under stress conditions beyond traditional metrics.

A.C. Unidad Noreste. México. Correo-e: rafaelurrea80@yahoo.es ResumenLos bosques y selvas enfrentan el reto de satisfacer la demanda por recursos de una población en crecimiento, así como la amenaza del rápido cambio climático que exacerba la magnitud y frecuencia de estreses bióticos y abióticos. Para ello, es urgente acelerar el mejoramiento genético de especies forestales. Sin embargo, sus largas etapas juveniles y asincronía floral retrasan peligrosamente este proceso. El presente ensayo explora los adelantos biotecnológicos en inducción floral y su potencial aplicación en especies forestales. Entre los genes identificados y caracterizados que participan en la ruta de señalización de la floración, especial atención se destina al gen FLOWERING LOCUS T, considerado un integrador de rutas de señalización altamente conservado entre las angiospermas, que, al sobre-expresarse por ingeniería genética, es capaz de inducir la floración de forma eficiente. Esta novedosa estrategia biotecnológica se ha utilizado, recientemente, para segregar genes de resistencia a enfermedades, en un menor tiempo, en germoplasma comercial de manzana y ciruela. Permite soslayar barreras naturales que por mucho tiempo han restringido a las especies forestales al mejoramiento por selección, principalmente. Entre sus ventajas está la de poder restringirla al proceso y no al producto, para acelerar las cruzas sexuales sin modificar genéticamente la progenie; se aleja así de la controversia alrededor de la liberación y consumo de organismos genéticamente modificados, y de los costos y trámites obligatorios para los OGM para monitoreo de posibles riesgos. Se proyecta como una tecnología que puede acelerar, significativamente, el mejoramiento de especies forestales.Palabras clave: Biotecnología forestal, FLOWERING LOCUS T, ingeniería genética vegetal, mejoramiento acelerado de perennes, mejoramiento de árboles, inducción de floración.

Avocado, Persea americana Mill, is one of the most traded tropical fruits in the international market. Here, we report transient transformation of avocado leaves via agroinfiltration with the LBA4404 strain of Agrobacterium tumefaciens and constructs encoding the synthetic betalain gene biosynthesis cassette, RUBY, or GFP. The efficiency of transformation was dependent on leaf age, whilst microwounding and jasmonic acid treatments significantly enhanced transformation, acting synergistically to improve avocado transformation. This is the first report on Agrobacterium-mediated transient transformation on avocado leaves. It provides a useful tool in plant molecular and cellular biology research and has the potential to facilitate new capabilities to the genomics research community of this ancestral angiosperm.

Avocado, Persea americana Mill, is one of the most traded tropical fruits in the international market. To date, stable and transient transformation has only been achieved for of zygotic embryos and not of adult plant tissue, which limits functional genomics research. We provide the first transient Agrobacterium-mediated transformation methodology in avocado leaves that overcomes the recalcitrance to transformation of this species. We investigated the effect of Agrobacterium strain, leaf stage, wounding pre-treatment, the phytohormone jasmonic acid, and vacuum infiltration on transient transformation of avocado leaves. Using the Agrobacterium strain LBA4404 and the RUBY reporter a transformation frequency of up to 27% was obtained for avocado detached leaves. The transformation efficiency depended on the age of the leaf, with an intermediate stage of leaf development showing the highest efficiency of transient reporter gene expression. Microwounding pre-treatment facilitates agroinfiltration and coupled with leaf age are the primary factors influencing competence for transient transformation. Jasmonic acid did not significantly affect transient transformation in the absence of microwounding. However, microwounding and 250 µM of jasmonic acid acted synergistically to significantly enhance transient expression. Using this methodology with localized vacuum agroinfiltration, transient transformation of attached avocado leaves was achieved. This method unlocks the use of Agrobacterium-mediated transient transformation as a tool for explore gene function and metabolic pathways in both, detached and attached avocado leaves.