Papers by RALUCA ALEXANDRA MIHAI
Toxics
Agriculture is an important economic sector for Ecuador, sustained by food crops like maize, pota... more Agriculture is an important economic sector for Ecuador, sustained by food crops like maize, potatoes, and vegetables cultivated in the highlands while cash crops such as coffee, bananas, cacao, and palm oil are grown on the coastal plains. But, Ecuador is also a country under the influence of several natural hazards due to its geographical location, atmospheric dynamics, and geological characteristics. One of the main risks to food security is the presence of a large number of active volcanoes scattered all over the country with the most representative enemy, the falling volcanic ash. The bibliography in general highlights the potential toxicity of volcanic ash from a human health perspective, but it also negatively influences plant development at the seed’s germination, as well as low crop pollination, damaged fruits, reduced leaf respiration depending on the type of crop, the developmental stage, the ash layer, and the climate. The mineral composition of the volcanic ash can also...
Buletinul Academiei de Ştiinţe a Moldovei. Ştiinţele vieţii, Sep 2, 2013
Electronic Journal of Biology, 2007
The aim of our researches was to follow the establishment of the symbiotic associations in "in vi... more The aim of our researches was to follow the establishment of the symbiotic associations in "in vitro" dual cultures. The partners consisted in root cultures with continuous growth and calli derived from the root tissues in Ipomoea batatas, Zea mays, and Cucumis sativus and spores of the VAM fungus Glomus intraradices. Our results highlighted that following the processes of dedifferentiation in other cell types, specific to cells and tissue culturing in artificial conditions, the plant cells preserve not only their intrinsic capacity of morphogenetic capacity, but also the capacity of biochemical totipotency. This is expressed by signal exchanges and recognition between the plant cells and the VAM fungus, thus permitting the establishment of the symbiosis.
Pharmaceutics, Jun 8, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
The aim of our researches was to follow the establishment of the symbiotic associations in "in vi... more The aim of our researches was to follow the establishment of the symbiotic associations in "in vitro" dual cultures. The partners consisted in root cultures with continuous growth and calli derived from the root tissues in Ipomoea batatas, Zea mays, and Cucumis sativus and spores of the VAM fungus Glomus intraradices. Our results highlighted that following the processes of dedifferentiation in other cell types, specific to cells and tissue culturing in artificial conditions, the plant cells preserve not only their intrinsic capacity of morphogenetic capacity, but also the capacity of biochemical totipotency. This is expressed by signal exchanges and recognition between the plant cells and the VAM fungus, thus permitting the establishment of the symbiosis.
Journal of Fungi
The oil palm Elaeis guineensis represents one of the most important crops in Ecuador. Considering... more The oil palm Elaeis guineensis represents one of the most important crops in Ecuador. Considering that bud rot disease is deadly in Ecuador, more attention has been given to identifying possible causes for palm debility from this disease. We studied the involvement of fungi and nutrients in triggering bud rot disease in E. guineensis. Special emphasis was given to the molecules synthesized by the plant to protect against this devastating disease. Techniques like Diagnosis and Recommendation Integrated System (DRIS) and metagenomic analysis were used to understand the possible implications of biotic and abiotic factors in the development of bud rot disease in oil palm in Ecuador. Liquid chromatography-mass spectrometry (LC-MS) analysis was used to identify the phenolic protection barrier of the palm facing the disease. Our results indicate that fungi from Ascomyceta phylum were found in the tested samples. The species directly involved are different in soil compared with plants. The ...
Sustainability
Urban areas face numerous provocations, such as air, water, and soil contamination. Additionally,... more Urban areas face numerous provocations, such as air, water, and soil contamination. Additionally, urban lakes have numerous beneficial services that contribute to urban sustainability. In urban aquatic ecosystems, X-ray fluorescence can provide complex answers regarding the presence of elements associated with environmental risk. The study aimed to screen the elements with different potentials (critical raw materials—CRMs; toxic; potentially toxic) from Phragmites australis leaves along the Colentina urban river. The samples from the peri-urban and urban river courses highlighted the presence of elements with different potentials for ecosystems and human health. The investigated stations were influenced by regional anthropogenic pressures, where P. australis highlighted the absorption of the dominant elements found in the environment. From the total of 56 elements present in the samples, some have structural roles (K, Si, Ca, and Cl), some are from the CRM category, and some are air...
Molecules, Oct 27, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Forests
Human society is currently facing a growing demand for forest resources, which causes overexploit... more Human society is currently facing a growing demand for forest resources, which causes overexploitation and endangers biodiversity. In this regard, it is important to be aware that 10% of trees across the world are used in traditional and modern medicine. South America has the greatest diversity, with 40% of tree species in the world. The aim of our review consists of the assessment of the state of the art of micropropagation through somatic embryogenesis of representative medicinal trees in South America and of targeting the tree species that should be prioritized for conservation plans. From a total of 23,631 tree species from Central and South America, 31 are extinct, 7047 are threatened, and 1434 are possibly threatened. In this sense, in order to conserve them, various strategies are applied both in situ and ex situ. The application of in vitro multiplication protocols represents effective ways both in conservation and in the sustainable use of resources in order to obtain secon...
Pharmaceutics
The present study aims to provide information about the antioxidant capacity and secondary metabo... more The present study aims to provide information about the antioxidant capacity and secondary metabolites from different plant parts of two species that are grown in Ecuador: Chionanthus pubescens (the Ecuadorian national tree), and Chionanthus virginicus (the fringe tree—endemic to the United States of America and adapted to Ecuador’s physiographical and ecological conditions). These two species have still not been investigated for these characteristics. A comparative estimation of the antioxidant activities between the leaf, fruit, and inflorescence extracts was performed. In the quest for new medicines, the extracts were analyzed for phenolic, anthocyanin, and flavonoid content. A slight difference was observed between C. pubescens and C. virginicus flowers, the highest antioxidant activity being found in the C. pubescens leaf (DPPH IC50 = 62.8866 mg/mL, ABTS IC50 = 55.852 mg/mL, and FRAP IC50 = 2.8466 g/mL). Our results showed correlations between antioxidant activity, total phenol...
Toxics
Soil nutrients influence all stages (reproduction, growth, and development) of a plant species’ l... more Soil nutrients influence all stages (reproduction, growth, and development) of a plant species’ life, and it is known that the deficit and/or toxicity of one or more nutrients has negative effects on the production of crops of commercial interest. Ecuador represents one of the “mega-diverse” countries in the world, with an agricultural sector of great importance, due to its contribution to the country’s economy. This review provides a panoramic view of soil nutrients from different climatic regions of Ecuador and revises the importance of knowledge about the possible influence of nutrients from the soil on the plant metabolism able to influence the crop resistance against pathogens or to enrich the biological characteristics of these crops.
Toxics
Moringa oleifera Lam. contains numerous essential constituents found in all plant parts (leaves, ... more Moringa oleifera Lam. contains numerous essential constituents found in all plant parts (leaves, pods, and seeds). From all its edible parts, the leaf represents an effective remedy with high potential for medicinal applications. Ecuador is part of the new promising cultivation areas for Moringa, and therefore our study is emphasized to determine the influence of soil nutrition, toxicity (excess), and deficiency, from three main areas of this country, correlated with its climatic characteristics, on the mineral components, bioactive compounds’ synthesis, and antioxidant capacity of Moringa. Different analyses were performed in soil and especially leaf samples for phytochemical content, antioxidant activity, calcium, protein, and vitamin C determination to identify the relationship between soil nutrients, abiotic conditions, and the therapeutic potential of this species cultivated in Ecuador. The obtained values using methods such as DPPH, FRAP, and ABTS showed a high antioxidant cap...
Plants
Fine flavor cocoa is a unique category of cocoa that produces almonds with high aromatic potentia... more Fine flavor cocoa is a unique category of cocoa that produces almonds with high aromatic potential and several sensory benefits that make it different from the basic or ordinary cocoas. Ecuador is the world’s leader in the production and export of fine flavor cocoa, responsible for 63% of the world’s total production due to the commercialization of the Arriba Nacional variety, known to possess an intense aroma that is unique in the cocoa world market. Besides its organoleptic specificity, this variety represents a source of important bioactive compounds associated with both sensory and health properties. This study evaluates the influence of an abiotic factor, nutritional soil status, on the phytochemical composition (methylxantines and phenolic compounds), and antioxidant and sensory properties of Arriba variety cocoa beans originating from three different geographical regions of Ecuador. We used the Diagnosis and Recommendation Integrated System (DRIS), Folin–Ciocalteau, high-perf...
Journal of Fungi, 2022
Nowadays, climate change is not the only threat facing our planet. There are also other types of ... more Nowadays, climate change is not the only threat facing our planet. There are also other types of pollution such as waste that poisons soils and water and kills plants, harming humans and animals. Sustainability represents a key issue for the actual Global Citizen. For this reason, our article is dedicated to offering biofriendly solutions to decrease wastes, give them a positive meaning, such as a substrate for an edible oyster fungus with nutritive and biological properties usefully for humans. Three types of wastes such as coconut coir, pine sawdust, and paper waste—representative symbols of pollution in Ecuador—have been tested as suitable growing substrate for the edible fungi Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm by analyzing parameters such as Biological Efficiency, Mushroom Yield, and Productive Rate. The influence of these “waste” substrates on the nutritive (protein content), biological characteristic (antioxidant activity), and the content of human-health-sustaining c...
The Andean Paramo is an important component of biodiversity, affected by the species inhabiting i... more The Andean Paramo is an important component of biodiversity, affected by the species inhabiting it and by the human activities. For these reasons the biotechnological technique represents an important tool for helping the conservation of this ecosystem, one of the alternatives being represented by the in vitro culture. This research aims to establish a protocol for in vitro micro propagation of Paramostraw (Calamagrostis intermedia) represented by the disinfection method and choose of the introduction, multiplication and rooting media, for short term conservative issues. For the disinfection phase were tested three concentrations of sodium hypochlorite(0.5%, 1%, 1.5%)(v/v) with different immersion time(10 to 15 minutes).The introduction media was represented by seven MS media with different concentration of vitamins: 0%, 15%, 30%, 45%, 60%, 85% and 100% (v/v). In multiplication and rootingphase was tested the influence of phytohormones such BAP (0.15 and 0.2 mg/L), BRA (2 and 3 mg/L...
The present study investigated the effect of some biotic (fungal extract of Fusarium oxysporum) a... more The present study investigated the effect of some biotic (fungal extract of Fusarium oxysporum) and abiotic elicitors (mannitol, abscisic acid, jasmonic acid) at different concentrations and combined treatments on the accumulation of resveratrol in a long-term Vitis vinifera callus culture. The application of a two- stage culture system with a combined treatment of mannitol (2mM) and jasmonic acid (40µM) resulted in the optimum accumulation of resveratrol in the callus biomass. Some preliminary investigations on the antitumoral properties of the treated callus extracts on a hepatocellular carcinoma HepG2 cell lines revealed that a high activity was achieved by the extracts from the treated callus with the combined elicitors mannitol (2mM) and jasmonic acid (40µM). The obtained data are sustained by the high accumulation of resveratrol in the callus biomass. This stilbene-type compound is recognized as a remarkable compound with diverse biological effects, having tremendous potential...
Anthocyanin biosynthesis has been extensively studied based on its large biotechnological applica... more Anthocyanin biosynthesis has been extensively studied based on its large biotechnological applicability. Plant cell culture proved to be a feasible experimental
Tomato is one of the most important crops of Solanaceae familyand one of the largest products con... more Tomato is one of the most important crops of Solanaceae familyand one of the largest products consumed in Ecuador. The productivity of this important crop has been affected due to the involvement of some abiotic and biotic factors. For this crop the application of genetic improvement techniquesinvolves as a first step the production of dedifferentiated in vitrotissue culture. The objective of this research is to generate callus formation from tomato leaves, and a protocol for the analysis of GUSgene expression by histochemical tests for further investigation regarding the genetic transformation with various applications for this important crop. The sterilization procedure consisted in using 15% w/v detergent and sodium hypochlorite (0.5% v/v and 0.8% v/v) and for the callus induction the explants were inoculated on MS medium with 2,4-D (0.25 to 3 mgL -1 ) and KIN (0.25 and 0.5 mgL -1 ). The transfer of the reporter gene was performed through tomato callus co-culture with Agrobacteri...
Agriculture and Agricultural Science Procedia, 2016
Romanian …, 2010
Polyphenols, including anthocyanins, are an essential part of human diet and constitute one of th... more Polyphenols, including anthocyanins, are an essential part of human diet and constitute one of the most abundant and ubiquitous group of plant secondary metabolites. Their level is inducible by different types of stress such as fungal infections, but in the in vitro conditions the accumulation of the polyphenols can be stimulated by biotic and abiotic elicitors. In the present study an attempt has been made to maximize the long-term Vitis vinifera L. callus culture growth and anthocyanin biosynthetic capacity by optimizing the hormonal combinations in the growth medium in a two stage culture system. Different concentrations and combinations of elicitors such as: salycilic acid (SA), abscisic acid (ABA), jasmonic acid (JA) and manitol (MAN) were used. Anthocyanin accumulation was greatly enhanced by using medium variants SA-ABA (SA 10µm, ABA 10 µm), JA5-JA5 (5 µm) and JA20-JA20 (20 µm). Two of these medium variants, respectively JA5-JA5 and JA20-JA20, proved to determine the highest accumulation of browning anthocyanins in the callus cultures, while the medium containing SA-ABA determined the lowest one. In conclusion, the medium variant SA-ABA in a two stage culture system could be used as an effective strategy for enhancing the anthocyanin productivity of the long-term Vitis vinifera callus culture.
Uploads
Papers by RALUCA ALEXANDRA MIHAI