11 research outputs found
Orius laevigatus Induces Plant Defenses in Sweet Pepper
Pest management in protected sweet pepper crops primarily relies on biological control
strategies. The release of the phytoseiid Amblyseius swirskii Athias-Henriot (Acari:
Phytoseiidae) and the anthocorid Orius laevigatus Fieber (Hemiptera: Anthocoridae)
provides effective control of the two key pests of this crop, the thrips Frankliniella
occidentalis Pergande (Thysanoptera: Thripidae) and the whitefly Bemisia tabaci
Gennadius (Hemiptera: Aleyrodidae) (Sanchez et al., 2000; Calvo et al., 2009; van der
Blom et al., 2009). A part of their direct effect on pest predation, zoophytophagous
predators may induce defensive plant responses due to their plant feeding behaviour which
involves the release of diverse volatiles through different pathways that are triggered by
phytohormones (De Puysseleyr et al., 2011; Naselli et al., 2016; Pappas et al., 2015, 2016;
Pérez-Hedo et al., 2015a,b). These responses may result in the repellence or attraction of
pests and natural enemies. It is hence hypothesized that O. laevigatus would be able to
induce plant responses in sweet pepper as has been demonstrated in other plantzoophytophage systems. As a first step to better understand the interaction between O.
laevigatus and sweet pepper, the behavior of O. laevigatus on the plants was studied and
plant feeding behaviour quantified to compare general behaviors. Orius laevigatus spends
the majority of its time (38%) feeding on apical meristems and apical fresh leaves, which
were also preferred residence locations (Bouagga et al., 2017)
Untargeted Metabolomics of Rind Essential Oils Allowed to Differentiate Two Closely Related Clementine Varieties
Chemical characterization of clementine varieties (Citrus clementina Hort. ex Tan.) essential oils (EO) can lead to variety identification and valorization of their potential use in food and aroma industries. The goal of this study was the chemometric discrimination between two very closely related and morphologically identical clementine varieties, Clemenules (NL) and Clemenpons (PO), based on their rind EO, to identify the differential volatile organic compounds (VOCs) and to determine their antioxidant capacity. EO rind volatile profile was determined by gas chromatography coupled to mass spectrometry in Citrus fruit at different ripening stages grown two independent years in two different locations. Untargeted metabolomics and multivariate data analysis showed an evolution of EO volatile profiles markedly parallel in both varieties. Although EO qualitative composition was identical in both varieties, PLS-DA allowed the identification of characteristic VOCs, quantitatively discriminating them along all the ripening process. PO showed higher accumulation of several mono- and sesquiterpene compounds such as trans-carveol, while NL showed higher levels of aldehyde and alcohol non-terpenoids like dodecanal. Both varieties evinced identical EO antioxidant
activities, indicating a similar value for food preservation. Hence, untargeted metabolomics approach based on rind EO volatiles was revealed as a powerful technique able to differentiate between morphologically undistinguishable Citrus varieties
Fortification and bioaccessibility of saffron apocarotenoids in potato tubers
Carotenoids are C40 isoprenoids with well-established roles in photosynthesis, pollination, photoprotection, and hormone biosynthesis. The enzymatic or ROS-induced cleavage of carotenoids generates a group of compounds named apocarotenoids, with an increasing interest by virtue of their metabolic, physiological, and ecological activities. Both classes are used industrially in a variety of fields as colorants, supplements, and bio-actives. Crocins and picrocrocin, two saffron apocarotenoids, are examples of high-value pigments utilized in the food, feed, and pharmaceutical industries. In this study, a unique construct was achieved, namely O6, which contains CsCCD2L, UGT74AD1, and UGT709G1 genes responsible for the biosynthesis of saffron apocarotenoids driven by a patatin promoter for the generation of potato tubers producing crocins and picrocrocin. Different tuber potatoes accumulated crocins and picrocrocin ranging from 19.41–360 to 105–800 μg/g DW, respectively, with crocetin, crocin 1 [(crocetin-(β-D-glucosyl)-ester)] and crocin 2 [(crocetin)-(β-D-glucosyl)-(β-D-glucosyl)-ester)] being the main compounds detected. The pattern of carotenoids and apocarotenoids were distinct between wild type and transgenic tubers and were related to changes in the expression of the pathway genes, especially from PSY2, CCD1, and CCD4. In addition, the engineered tubers showed higher antioxidant capacity, up to almost 4-fold more than the wild type, which is a promising sign for the potential health advantages of these lines. In order to better investigate these aspects, different cooking methods were applied, and each process displayed a significant impact on the retention of apocarotenoids. More in detail, the in vitro bioaccessibility of these metabolites was found to be higher in boiled potatoes (97.23%) compared to raw, baked, and fried ones (80.97, 78.96, and 76.18%, respectively). Overall, this work shows that potatoes can be engineered to accumulate saffron apocarotenoids that, when consumed, can potentially offer better health benefits. Moreover, the high bioaccessibility of these compounds revealed that potato is an excellent way to deliver crocins and picrocrocin, while also helping to improve its nutritional value
Headspace-based techniques to identify the principal volatile compounds in red grape cultivars
The control of the raw material has a great influence on the final quality of wine. Nowadays, wineries have practically not incorporated an effective quality control of grape juice on their production process. Although wine aroma has been widely analysed, grape juice aroma for wine-making has been poorly studied. In this study, two headspace-based technique methodologies have been proposed to characterise the aroma of grape juice: static headspace (SHS) and headspace solid phase microextraction (HS-SPME). Both techniques were applied on the samples from three maturation stages of two red grape cultivars: Tempranillo and Bobal, ranked first in Spanish and in Valencian Community cultivars, respectively. This study identifies the principal volatile compounds of grape juice: C(6) compounds, especially alcohols and aldehydes, using both techniques. It was confirmed that SHS and HS-SPME techniques could be incorporated into the process of the grape quality control in wineries as a result of its operational simplicity, low cost and reduced ecological impact compared with other conventional organic solvent-based techniques
Evaluation of Unintended Effects in the Composition of Tomatoes Expressing a Human Immunoglobulin A against Rotavirus
The
production of neutralizing immunoglobulin A (IgA) in edible
fruits as a means of oral passive immunization is a promising strategy
for the inexpensive treatment of mucosal diseases. This approach is
based on the assumption that the edible status remains unaltered in
the immunoglobulin-expressing fruit, and therefore extensive purification
is not required for mucosal delivery. However, unintended effects
associated with IgA expression such as toxic secondary metabolites
and protein allergens cannot be dismissed a priori and need to be
investigated. This paper describes a collection of independent transgenic
tomato lines expressing a neutralizing human IgA against rotavirus,
a mucosal pathogen producing severe diarrhea episodes. This collection
was used to evaluate possible unintended effects associated with recombinant
IgA expression. A comparative analysis of protein and secondary metabolite
profiles using wild type lines and other commercial varieties failed
to find unsafe features significantly associated with IgA expression.
Preliminary, the data indicate that formulations derived from IgA
tomatoes are as safe for consumption as equivalent formulations derived
from wild type tomatoes
Analysis of five gene sets in chimpanzees suggests decoupling between the action of selection on protein-coding and on noncoding elements
We set out to investigate potential differences and similarities between the selective forces acting upon the coding and noncoding regions of five different sets of genes defined according to functional and evolutionary criteria: 1) two reference gene sets presenting accelerated and slow rates of protein evolution (the Complement and Actin pathways); 2) a set of genes with evidence of accelerated evolution in at least one of their introns; and 3) two gene sets related to neurological function (Parkinson's and Alzheimer's diseases). To that effect, we combine human-chimpanzee divergence patterns with polymorphism data obtained from target resequencing 20 central chimpanzees, our closest relatives with largest long-term effective population size. By using the distribution of fitness effect-alpha extension of the McDonald-Kreitman test, we reproduce inferences of rates of evolution previously based only on divergence data on both coding and intronic sequences and also obtain inferences for other classes of genomic elements (untranslated regions, promoters, and conserved noncoding sequences). Our results suggest that 1) the distribution of fitness effect-alpha method successfully helps distinguishing different scenarios of accelerated divergence (adaptation or relaxed selective constraints) and 2) the adaptive history of coding and noncoding sequences within the gene sets analyzed is decoupled