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- The role of grapevine leaf morphoanatomical traits in determining capacity for coping with abiotic stresses: a reviewPublication . MacMillan, Phoebe; Teixeira, Generosa; Lopes, Carlos M.; Monteiro, AnaWorldwide, there are thousands of Vitis vinifera grape cultivars used for wine production, creating a large morphological, anatomical, physiological and molecular diversity that needs to be further characterised and explored, with a focus on their capacity to withstand biotic and abiotic stresses. This knowledge can then be used to select better adapted genotypes in order to help face the challenges of the expected climate changes in the near future. It will also assist grape growers in choosing the most suitable cultivar(s) for each terroir; with adaptation to drought and heat stresses being a fundamental characteristic. The leaf blade of grapevines is the most exposed organ to abiotic stresses, therefore its study regarding the tolerance to water and heat stress is becoming particularly important, mainly in Mediterranean viticulture. This review focuses on grapevine leaf morphoanatomy - leaf blade form, leaf epidermis characteristics (cuticle, indumentum, pavement cells and stomata) and anatomy of mesophyll - and their adaptation to abiotic stresses. V. vinifera xylem architecture and its adaptation capacity when the grapevine is subjected to water stress is also highlighted since grapevines have been observed to exhibit a large variability in responses to water availability. The hydraulic properties of the petiole, shoot and trunk are also reviewed. Summarising, this paper reviews recent advances related to the adaptation of grapevine leaf morphoanatomical features and hydraulic architecture to abiotic stresses, mainly water and heat stress, induced primarily by an ever-changing global climate.
- Pharmacognostic Survey on Paeonia Broteri – An Iberian EndemismPublication . Pereira, Joel; Teixeira, GenerosaThe genus Paeonia (Paeoniaceae) includes perennial plants distributed throughout the northern hemisphere and some of these are used in traditional medicine and cultivated as ornamental species. Paeonia broteri is endemic to Iberian Peninsula and the current paper is the first report on a pharmacognostic survey on its roots, leaves and corresponding powders. Using light and scanning electron microscopy, simple and compound polyhedral starch grains, with a fissure-type hilum and no striae, are recorded in the root phelloderm cells and the presence of idioblasts with druse-type calcium oxalate crystals, in addition to isolated stone cells, are also common. Irregular and sinuous epidermal cells can be detected on both leaf surfaces and anomocytic stomata, with an elliptical-rounded shape, are only on the abaxial face. In leaves, druse-type calcium oxalate crystals appear along the vascular tissues. The histochemical tests allowed the in situ localization of some chemical groups and the most relevant detected were polyphenols and terpenoids.
- Harnessing sediments of coastal aquaculture ponds through technosols construction for halophyte cultivation using saline water irrigationPublication . Cortinhas, Ana; Caperta, Ana D.; Teixeira, Generosa; Carvalho, Luísa; Abreu, Maria ManuelaThe Mediterranean aquaculture has been developed mostly in brackish environment in inactive coastal salt production areas. This study aims to utilise Technosols made with aquaculture sediments for Limonium algarvense Erben cultivation. This species that has nutraceutical potential thrives in halophilic environments in the southwest of the Iberian Peninsula and in Morocco. A microcosm assay was set up with plants grown in bottom sediments (C+), commercial substrate (C-), and Technosols with amendments mixture application at 180 g/kg (Tec180) or at 360 g/kg (Tec360). These plants were irrigated with saline (assay 1) and/or with deionised water (assay 2). The bottom pond sediments, coffee wastes and the estuarine water were evaluated for diverse physicochemical parameters. Plant growth was characterised through a combined methodology using morphometric, SEM and physiological analysis. The Technosols were constructed with bottom sediments and a mixture of organic wastes used as amendments. Results revealed that the bottom sediments had low pH 3.2, Corg and extractable P and K contents, and high electroconductivity (EC) and N-NH4 concentration. The estuarine water had a neutral pH, high EC and high Cl-, HCO3-, Na+, Mg2+ and Ca2+ but low N-NO3- content. The Technosols showed a significant increase of pH, Corg, K and P and a decrease in N-NH4 and EC in comparison with sediments. Principal component analysis separated the different experiments in three groups: C-, A1 and A2 assays. The C- was highly correlated with Corg, P, K, N-NO3 parameters and total ascorbate. The A1 assay showed a strong association with Na, Ca and EC parameters, whereas the A2 assay presented a strongly correlation with plant growth. Plants from Technosols had greater development when irrigated with deionised water than under salty irrigation as opposed to plants cultivated in unamend sediments. In conclusion, these results support that highly saline sediments could be valorised through Technosols construction to cultivate plants with saline water, with potential application in the agro-food and pharmaceutical industry.
- Secretory structures in plants: Lessons from the Plumbaginaceae on their origin, evolution and roles in stress tolerancePublication . Caperta, Ana D.; Róis, Ana S.; Teixeira, Generosa; Garcia‐Caparros, Pedro; Flowers, Timothy J.The Plumbaginaceae (non-core Caryophyllales) is a family well known for species adapted to a wide range of arid and saline habitats. Of its salt-tolerant species, at least 45 are in the genus Limonium; two in each of Aegialitis, Limoniastrum and Myriolimon, and one each in Psylliostachys, Armeria, Ceratostigma, Goniolimon and Plumbago. All the halophytic members of the family have salt glands and salt glands are also common in the closely related Tamaricaceae and Frankeniaceae. The halophytic species of the three families can secrete a range of ions (Na+ , K+ , Ca2+ , Mg2+ , Cl- , HCO3- , SO42- ) and other elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Salt glands are, however, absent in salt-tolerant members of the sister family Polygonaceae. We describe the structure of the salt glands in the three families and consider whether glands might have arisen as a means to avoid the toxicity of Na+ and/or Cl- or to regulate Ca2+ concentrations with the leaves. We conclude that the establishment of lineages with salt glands took place after the split between the Polygonaceae and its sister group the Plumbaginaceae.