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- Rheological and microstructural features of plant culture media doped with biopolymers: Influence on the growth and physiological responses of in Vitro-Grown Shoots of Thymus lotocephalusPublication . Coelho, Natacha; Filipe, Alexandra; Medronho, Bruno; Magalhães, Solange; Vitorino, Carla; Alves, Luís; Gonçalves, Sandra; Romano, AnabelaIn vitro culture is an important biotechnological tool in plant research and an appropriate culture media is a key for a successful plant development under in vitro conditions. The use of natural compounds to improve culture media has been growing and biopolymers are interesting alternatives to synthetic compounds due to their low toxicity, biodegradability, renewability, and availability. In the present study, different culture media containing one biopolymer (chitosan, gum arabic) or a biopolymer derivative [hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC)], at 100 or 1000 mg L−1, were tested regarding their influence on the growth and physiological responses of Thymus lotocephalus in vitro culture. Cellulose-based biopolymers (HEC and CMC) and gum arabic were used for the first time in plant culture media. The results showed that CMC at 100 mg L−1 significantly improved shoot elongation while chitosan, at the highest concentration, was detrimental to T. lotocephalus. Concerning only the evaluated physiological parameters, all tested biopolymers and biopolymer derivatives are safe to plants as there was no evidence of stress-induced changes on T. lotocephalus. The rheological and microstructural features of the culture media were assessed to understand how the biopolymers and biopolymer derivatives added to the culture medium could influence shoot growth. As expected, all media presented a gel-like behaviour with minor differences in the complex viscosity at the beginning of the culture period. Most media showed increased viscosity overtime. The surface area increased with the addition of biopolymers and biopolymer derivatives to the culture media and the average pore size was considerably lower for CMC at 100 mg L−1. The smaller pores of this medium might be related to a more efficient nutrients and water uptake by T. lotocephalus shoots, leading to a significant improvement in shoot elongation. In short, this study demonstrated that the different types of biopolymers and biopolymer derivatives added to culture medium can modify their microstructure and at the right concentrations, are harmless to T. lotocephalus shoots growing in vitro, and that CMC improves shoot length.
- Impact of chitosan on plant tissue culture: recent applicationsPublication . Coelho, N.; Romano, A.Chitosan is a very versatile biomaterial with countless applications in different fields. Due to its biodegradability, non-toxicity, and biocompatibility, the use of chitosan is associated with sustainable practices. When applied to plants, in an agricultural context, chitosan induces defense mechanisms, stress resistance, and increased productivity and it has proven to be a feasible alternative to harmful agrochemicals. For in vitro plant culture, chitosan has been also applied to crops and other economically important species, with promising results. In this review, we discuss the recent applications of chitosan on plant tissue culture. Chitosan has been mainly used for the improvement of several growth parameters, but it has been also applied to enhance in vitro seed germination and accumulation of secondary metabolites. The plant material used, the concentrations and forms of chitosan employed, and the influence of chitosan on other plant parameters during in vitro culture are revised. We anticipate that chitosan applications will increase in a near future because of its potential and the increasing demand for more eco-friendly procedures.
- The Mediterranean diet: fostering a common vision through a multidisciplinary approachPublication . Delgado, Amélia; Cruz, Ana Lúcia; Coelho, Natacha; Romano, AnabelaInscribed in the UN’s Representative List of the Intangible Cultural Heritage of Humanity, the Mediterranean Diet (MD) is intrinsic to the Mediterranean identity. It involves a set of skills, knowledge, rituals, symbols and traditions related to cultures, landscape and lifestyle. Nevertheless, some Mediterranean rural regions seem to have natural and demographic handicaps resulting from ignorance of the economic potential of the Mediterranean cultural identity. The MD.net Project addressed the problems of currently neglected and undeveloped opportunities of the Mediterranean Diet concept. The main objective of the project was to improve the valuation of this concept according to the United Nations Educational, Scientific and Cultural Organization (UNESCO) Mediterranean Diet Convention, blending comprehensive Mediterranean Diet concepts with innovative tools. The project used both traditional and creative actions, underpinned in the quadruple helix methodology 1 that aims at bringing together stakeholders (government, industry, academia and civil society) in open innovation generation processes, in order to drive structural changes in favour of regional development, far beyond what any single organization could do, thus lifting the MD economy to new quality levels