Mª Teresa Martínez

Somatic Embryogenesis in Mature Quercus Robur Trees

Somatic embryo induction and plant regeneration have been obtained in tissues from mature Quercus robur L. trees. Epicormic shoots were forced to flush in branch segments collected from the crown of trees growing in selected stands on different collection dates. Expanding leaves from five genotypes, cultured following a multistage treatment procedure, produced somatic embryos at frequencies ranging from 0.3 to 3.6% of leaf explants, depending on genotype and collection date. After being induced, somatic embryos started a recurrent process by secondary embryogenesis which amplified the 15 embryogenic lines established. Plant recovery was achieved in 60% and 17% of matured embryos from two genotypes.

Peptide-based biomaterials. Linking L-tyrosine and poly L-tyrosine to graphene oxide nanoribbons

Peptide-based biomaterials are being studied actively in a variety of applications in materials science and biointerface engineering. Likewise, there has been ongoing exploration over the last few decades into the potential biological applications of carbon nanomaterials, motivated by their size, shape, structure and their unique physical and chemical properties. In recent years, the functionalization of carbon nanotubes and graphene has led to the preparation of bioactive carbon nanomaterials that are being used in biomedicine as structural elements and in gene therapy and biosensing. The present study proposes different strategies for the bonding of l-tyrosine and the homopolypeptide poly-l-tyrosine to graphene oxide nanoribbons (GONRs). The covalent attachment of l-tyrosine was undertaken by amidation of the α-amine group of tyrosine with the existing carboxylic groups in GONR and by means of esterification through phenol nucleophiles contained in their side chains. In both cases use was made of protective groups to address the functionalization with the desired reactive groups. The linking of GONRs to the PTyr was attempted according to two different strategies: either by ester bonding of commercial PTyr through its phenol side groups or by in situ ring-opening polymerization of an N-carboxyanhydride tyrosine derivative (NCA-Tyr) with Tyr-functionalized GONRs. These biofunctionalized nanomaterials were characterized by Raman and infrared spectroscopies, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission electron microscopy, fluorescence and electrochemical techniques. On the basis of their properties, prospects for the potential utilization of the prepared hybrid nanomaterials in different applications are also given.

Carbon Nanotubes as Suitable Interface for Improving Neural Recordings

In the last decades, system neuroscientists around the world have dedicated their research to understand how neuronal networks work and how they malfunction in various diseases. Furthermore in the last years we have seen a progressively increased interaction of brain networks with external devices either for the use of brain computer interfaces or through the currently extended brain stimulation (e.g. transcranial magnetic stimulation) for therapy. Both techniques have evidenced even more the need for a better understanding of neuronal networks. These studies have resulted in the development of different strategies to under‐ stand the ongoing neuronal activity, such as fluorescence microscopy for genetic labelling and optogenetic techniques, imaging techniques, or the recording/stimulation with increas‐ ingly large numbers of electrodes in the whole brain or in both cell cultured neurons and slice preparations. It is in these last two areas where the technology developed on microelectrode arrays, commonly called multi-electrode arrays (MEAs), has become important over other technologies [1–3].

Holm Oak Quercus ilex L.

The holm oak is an evergreen tree species representative of Mediterranean forests. The largest populations of this species are in the Iberian Peninsula, forming the tree cover of an agro-silvo-pastoral system called “dehesa” in Spain and “montado” in Portugal. The high ecological and economic value of the species is of interest for rural development. The main current product are the acorns used for feeding Iberian black pigs, which are the basis of an important gastronomic industry. In addition, several bioactive compounds with new potential industrial applications in nutrition, pharmacology and cosmetics have been identified in acorns of oak species. Plantations with holm oak seedlings mycorrhized with Tuber melanosporum are been carried out for the production of the highly demanded black truffle. Vegetative propagation can be a main tool in the domestication of this forest species. Cloning plants from tissues of adult donor trees is desirable because selection is more reliable at mature stages. The present chapter deals with plant regeneration protocols by somatic embryogenesis from tissues of adult trees. The induction in male catkins, developing ovules and apexes and expanding leaves from in vitro cultured shoots is described. A description of methods for the cryopreservation of embryogenic lines is also provided.

Application of Thidiazuron in the Micropropagation of Fagaceae

The Fagaceae family consists of 7 genera and around 1000 species of trees and bushes that are mainly distributed in temperate and warm areas of the northern hemisphere, although few cross the equator in Southeast Asia. In terms of forestry, members of the Fagaceae are of most importance in forests in the temperate regions of the northern hemisphere, a dominance shared with the conifers that replace this family in cold areas and mountain tops. The genera Quercus (oaks and holm oaks), Fagus (beeches), and Castanea (chestnut) are commercially important sources of timber; Castanea and Quercus (holm oaks) also provide fruits that are used as human food and as animal feed. Many of these trees are also of ornamental value, mainly due to their attractive color of their leaves in autumn.

Biotechnological Approaches for the Improvement and Conservation of Alnus glutinosa (L.) Gaertner

European alder [Alnus glutinosa (L.) Gaertner], also called black alder or European black alder, is a medium-sized tree that is widely distributed throughout Europe. In the few decades, black alder populations have declined drastically, partly as a result of deforestation and the disappearance of riparian habitats but mainly because of alder blight disease, caused by Phytophthora alni. In order to protect these important genetic resources, the existing conservation methods must be improved and new tools developed.