Intensive cultivation of kiwifruit alters the detrital foodweb and accelerates soil C and N losses

The detrital food web plays an important role in the functioning of agro-ecosystems due to their positive effect on organic matter transformations and nutrient supply to the growing crops, however, the activities of the organisms involved are strongly influenced by agricultural practices. In NW Spain, commercial Hayward kiwifruit (Actinidia chinensis var. deliciosa) is intensively produced using conventional techniques (CONV), however, more sustainable methods, such as integrated (INT) and organic (ORG), have been increasingly adopted to decrease the negative impacts on the environment. We investigated the effects of these agricultural managements on earthworm abundance and functional diversity as well as microbial biomass and enzyme activity and evaluated the potential implications for nutrient retention and runoff in kiwifruit orchards. Our results showed that the CONV soils significantly contained fewer earthworms (ca. 80% less individuals than the INT and ORG systems), with their communities being mainly dominated by small epigeics, but a higher microbial biomass (0.53 ± 0.06 mg C g-1 dw soil compared to 37% more CO2, and five times more DIN) than from the less intensively managed soils. In contrast, the INT and ORG systems sustained a more complex and functionally diverse soil food web that lead to higher soil C and N retention. Therefore, agriculture management (i.e., intensive vs. less intensive) and its effects on the structure of the below-ground communities (i.e., microorganisms plus surface detritivores vs. deep burrowers plus geophagous forms) determine the nutrient sink/source function of these agro-ecosystems. These findings highlight the importance of including the contribution of soil biota to soil processes when optimizing fertilization loads and mitigating environmental impacts of agricultural practices.Xunta de Galicia | Ref. 10 PXIB 310 142 PRMinisterio de Educación, Cultura y Deporte | Ref. AP2009-203

Artificial intelligence tools to better understand seed dormancy and germination

Despite a large number of publications available, the control mechanisms of seed dormancy and germination are far to be fully understood. Seed dormancy and germination are very complex biological processes and because they involve multiple factors (physiological, mechanical, and environmental) and their nonlinear interactions. This explains why extremely little variations on some of those factors and in the way they interact caused enormous variation in the obtained results. Multifactorial process like these can be modeled using computer-based tools to predict better results. In this chapter, some basic concepts relative to seed dormancy and germination and the main factors (physiological, involved in seed dormancy, particularly dormancy-inducers and dormancy-breakers, and seed germination) are reviewed. In the next two, we describe the use of artificial intelligence computer-based models to better understand the physiological mechanisms of seed dormancy (how dormancy is controlled and how can be released) and seed germination. Finally, some applications of artificial neural networks, fuzzy logic, and genetic algorithms to elucidate critical factors and predict optimal condition for seed dormancy-breaking and germination are given as examples of the utility of this powerful computer-based tools

Adsorption of gallic acid, propyl gallate and polyphenols from Bryophyllum extracts on activated carbon

The adsorption of gallic acid (GA) and propyl gallate (PG) on activated carbon (AC) was studied as a function of the AC mass and temperature. Clean first order behavior was obtained for at least three half-lives and the equilibrium was reached after ∼4 h contact time. An increase in the temperature (T = 20–40 °C) increases their adsorption rate constant values (k1) by 2.5 fold but has a negligible effect on the amount of antioxidant adsorbed per mass of AC at equilibrium. We also analyzed the adsorption process of polyphenols from Bryophyllum extracts and ca 100% of the total amount of the polyphenols in the extract were adsorbed when using 7 mg of AC. Results can be explained on the basis of the Freundlich isotherm but do not fit the Langmuir model. Results suggest that the combination of emerging in vitro plant culture technologies with adsorption on activated carbon can be successfully employed to remove important amounts of bioactive compounds from plant extracts by employing effective, sustainable and environmental friendly proceduresXunta de Galicia | Ref. ED431D 2017/18Xunta de Galicia | Ref. ED431E 2018/07Ministerio de Educación, Cultura y Deporte | Ref. FPU15/04849Xunta de Galicia | Ref. POS-B/2016/01

Plant antioxidants in food emulsions

Addition of free radical scavenging antioxidants (AOs) is one of practical strategies controlling the oxidative stability in food emulsions. Attention has been directed toward AOs derived from natural plant extracts with the capacity to improve health and well-being due to lack of consumers’ trust toward synthetic antioxidant in food. Nevertheless, antioxidant efficiency varies widely from one compound to another and the most abundant AOs in our diet are not necessarily those that have the best availability profile at the reaction place with free radicals. In this book chapter, we will provide a state-of-the-art summary of the uses of plant AOs in colloidal systems, ranging from their main structural features to their benefits for the human health and their antioxidant role in controlling the oxidative stress and, particularly, the oxidation of lipid-based food emulsions.Xunta de Galicia | Ref. ED431D-2017/18Ministerio de Educación y Ciencia | Ref. CTQ2006-13969-BQUMinisterio de Educación, Cultura y Deporte | Ref. FPU15/04849Xunta de Galicia | Ref. POS-B/2016/01

Constitutive expression of SlMX1 gene improves fruit yield and quality, health-promoting compounds, fungal resistance and delays ripening in transgenic tomato plants

Tomato is one of the major economically domesticated crops, and it is extensively used in different ways and purposes worldwide. Cell metabolism is the central core of all the biological processes to sustain life including cell growth, differentiation, maintenance, and response to environmental stress. To evaluate how genetic engineering can improve tomato fruit metabolome, the transcriptomic and metabolomic datasets of two transgenic tomatoes (SlMX1 overexpression and RNAi lines) have been compared with wild-type. The combined results demonstrated that the constitutive expression of SlMX1 not only increased trichome formation, carotenoids, and terpenoids as has been stated in several studies, but has also up- and down-regulated the expression of multiple genes related to cell growth (cell wall turnover), primary (carbohydrates, vitamins, and phytohormones), and secondary (phenylpropanoids, carotenoids, and terpenoids) metabolism, cell signaling, and stress responses. These changes in gene expression due to the constitutive expression of SlMX1 promote the most important agroeconomic traits such as fruit yield and quality, biosynthesis of health-promoting phytochemicals (including phenolic acids, flavonoids, and anthocyanins), and finally, activate resistance to Botrytis cinerea and repress the expression of over-ripening-related genes, thus extending the fruit shelf-life. In conclusion, the traits improvement achieved by SlMX1 overexpression can be harnessed in molecular breeding programs to engineer fruit size and yield, induce health-promoting secondary metabolites, promote fungal resistance, and finally extend the fruit shelf-life.Xunta de Galicia | Ref. ED431E 2018/07Xunta de Galicia | Ref. ED431D2017/18Agencia Estatal de Investigación | Ref. EQC2019-006178-

Plant phenolics as dietary antioxidants: insights on their biosynthesis, sources, health-promoting effects, sustainable production, and effects on lipid oxidation

Plants have been used by humanity from ancient times with different purposes, including nutritional and therapeutical uses. Nowadays, it is well-known that the health-enhancing properties attributed to plants are a consequence of the production of bioactive compounds, as a result of their secondary metabolism. Among the different families of secondary metabolites, phenolic compounds (PCs) constitute the highest number of compounds, ubiquitously found in the plant kingdom. PCs play a relevant role in plant physiology, contributing to the general plant response to different stresses, either abiotic (related to the environmental, physicochemical threads) or biotic (infections and relations with other living beings). Furthermore, PCs show a plethora of associated bioactivities, including antioxidant, antimicrobial, anticancer, anti-inflammatory, immunomodulatory, cardioprotective, neuroprotective and hepatoprotective properties. Consequently, these multifaceted compounds have gained much attention due to their countless applications in different fields, including the production of foods for healthier human diets. In this review, the state-of-art of the most relevant PCs found in plant dietary sources has been updated, with the aim of providing a current perspective on the sustainable production, extraction and applications of PCs, as preservatives of the oxidation of lipids in food and as health-promoting agents in humans.Universidade de Vig

Machine learning technology reveals the concealed interactions of phytohormones on medicinal plant In vitro organogenesis

Organogenesis constitutes the biological feature driving plant in vitro regeneration, in which the role of plant hormones is crucial. The use of machine learning (ML) technology stands out as a novel approach to characterize the combined role of two phytohormones, the auxin indoleacetic acid (IAA) and the cytokinin 6-benzylaminopurine (BAP), on the in vitro organogenesis of unexploited medicinal plants from the Bryophyllum subgenus. The predictive model generated by neurofuzzy logic, a combination of artificial neural networks (ANNs) and fuzzy logic algorithms, was able to reveal the critical factors affecting such multifactorial process over the experimental dataset collected. The rules obtained along with the model allowed to decipher that BAP had a pleiotropic effect on the Bryophyllum spp., as it caused different organogenetic responses depending on its concentration and the genotype, including direct and indirect shoot organogenesis and callus formation. On the contrary, IAA showed an inhibiting role, restricted to indirect shoot regeneration. In this work, neurofuzzy logic emerged as a cutting-edge method to characterize the mechanism of action of two phytohormones, leading to the optimization of plant tissue culture protocols with high large-scale biotechnological applicability.Xunta de Galicia | Ref. REDUSO, ED431D 2017/18Clúster de Investigación y Desarrollo Agropecuario | Ref. CITACA, ED431E 2018/0

From ethnomedicine to plant biotechnology and machine learning: the valorization of the medicinal plant Bryophyllum sp.

The subgenus Bryophyllum includes about 25 plant species native to Madagascar, and is widely used in traditional medicine worldwide. Different formulations from Bryophyllum have been employed for the treatment of several ailments, including infections, gynecological disorders, and chronic diseases, such as diabetes, neurological and neoplastic diseases. Two major families of secondary metabolites have been reported as responsible for these bioactivities: phenolic compounds and bufadienolides. These compounds are found in limited amounts in plants because they are biosynthesized in response to different biotic and abiotic stresses. Therefore, novel approaches should be undertaken with the aim of achieving the phytochemical valorization of Bryophyllum sp., allowing a sustainable production that prevents from a massive exploitation of wild plant resources. This review focuses on the study of phytoconstituents reported on Bryophyllum sp.; the application of plant tissue culture methodology as a reliable tool for the valorization of bioactive compounds; and the application of machine learning technology to model and optimize the full phytochemical potential of Bryophyllum sp. As a result, Bryophyllum species can be considered as a promising source of plant bioactive compounds, with enormous antioxidant and anticancer potential, which could be used for their large-scale biotechnological exploitation in cosmetic, food, and pharmaceutical industries.Xunta de Galicia | Ref. ED431D 2017/18Xunta de Galicia | Ref. ED431E 2018/07Ministerio de Educación y Formación Profesional | Ref. FPU15 / 0484

Machine learning unmasked nutritional imbalances on the medicinal plant Bryophyllum sp. cultured in vitro

Plant nutrition is a crucial factor that is usually underestimated when designing plant in vitro culture protocols of unexploited plants. As a complex multifactorial process, the study of nutritional imbalances requires the use of time-consuming experimental designs and appropriate statistical and multiple regression analysis for the determination of critical parameters, whose results may be difficult to interpret when the number of variables is large. The use of machine learning (ML) supposes a cutting-edge approach to investigate multifactorial processes, with the aim of detecting non-linear relationships and critical factors affecting a determined response and their concealed interactions. Thus, in this work we applied artificial neural networks coupled to fuzzy logic, known as neurofuzzy logic, to determine the critical factors affecting the mineral nutrition of medicinal plants belonging to Bryophyllum subgenus cultured in vitro. The application of neurofuzzy logic algorithms facilitate the interpretation of the results, as the technology is able to generate useful and understandable “IF-THEN” rules, that provide information about the factor(s) involved in a certain response. In this sense, ammonium, sulfate, molybdenum, copper and sodium were the most important nutrients that explain the variation in the in vitro culture establishment of the medicinal plants in a species-dependent manner. Thus, our results indicate that Bryophyllum spp. display a fine-tuning regulation of mineral nutrition, that was reported for the first time under in vitro conditions. Overall, neurofuzzy model was able to predict and identify masked interactions among such factors, providing a source of knowledge (helpful information) from the experimental data (non-informative per se), in order to make the exploitation and valorization of medicinal plants with high phytochemical potential easier.Ministerio de Educación, Cultura y Deporte | Ref. FPU15/0484