Efectos fisiológicos y compartimentación radicular en plantas de Zea mays L. expuestas a la toxicidad por plomo
Garcia Vargas, Diana
Barceló Coll, Juan, dir. (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)
Gunsé Forcadell, Benito, dir. (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)

Publicació: Bellaterra : Universitat Autònoma de Barcelona, 2007
Resum: Lead (Pb) is a highly toxic metal even at low concentrations and is present in a great variety of soils both naturally and as a result of industrial activity. For this reason, knowing the actuation and tolerance or resistance mechanisms is of great importance to farming practices. In order to advance in this field of knowledge a series of experiments have been set up. From the results obtained, it is important to highlight that this metal, as well as other heavy metals, presents a barrier to translocation towards aerial parts that may be attributed to multiple causes such as lead binding to mucilage, its retention in cellular walls, its accumulation in the root's apoplast and simplast or in both radicular transportation ways. As was observed by root tip dying (fluorescent dyes). In our conditions of growth we have found that lead manifests itself in the length of the radicles even before the metal acts on the accumulation of dry matter. Its effects upon the length of the radicles could probably be a consequence of the effects upon cellular division in combination with effects on cellular wall extensibility. Many a dysfunction created by lead may be due to effects upon the integrity of the plasmatic membrane, as was observed by root tip dying (vital staining). By determining the hydraulic parameters through pressure probe techniques we were able to show that the mechanisms that govern the hydric behavior of this organ are complex and respond to many factors and that they do not obey to action upon the aquaporins. Exposing the root to different divalent metals makes it more vulnerable to attack by other heavy metals, as has been shown by the effects added by exposing the roots to HgCl2 By using IRGA (infrared gas analyzer) techniques we have been able to show that lead at low concentrations may attack important physiological processes such as the photosynthetic activity of the plant, directly and or indirectly. By analyzing the contents of Pb in the plant, through the exude of xylem and the nutritive solution we were able to verify that the chelating agent EDTA may effectively reduce the toxicity of lead, while at the same time finding a mechanisms of Pb detoxification through the formation of a Pb complexes probably exuded by the roots that was also present in the translocated xylem solution. These results show that there are complex Pb detoxification mechanisms at different levels and in different plant physiological processes that need to be researched in greater depth the knowledge of which would be of great use in possible phytoremediation effects and in obtaining plant species capable of growing in Pb contaminated soils. Key words:detoxification, lead, root, phytotoxicity, fluorescent dyes, translocation, exude of xylem, pressure probe, compartimentation, vital staining, calcium.
Nota: Consultable des del TDX
Nota: Títol obtingut de la portada digitalitzada
Nota: Tesi doctoral - Universitat Autònoma de Barcelona. Facultat de Ciències, Departament de Biologia Animal, Biologia Vegetal i Ecologia, 2006
Nota: Bibliografia
Drets: ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs.
Llengua: Castellà
Document: Tesi doctoral
Matèria: Blat de moro ; Fisiologia ; Plantes ; Efectes dels metalls pesants sobre ; Fitotoxines ; Plom ; Toxicologia ; Arrels (Botànica)
ISBN: 8469022075

Adreça alternativa:: https://hdl.handle.net/10803/3676

129 p, 743.2 KB

El registre apareix a les col·leccions:
Documents de recerca > Tesis doctorals

 Registre creat el 2009-05-07, darrera modificació el 2022-05-08

   Favorit i Compartir