Studio della relazione tra la nutrizione solfatica e ferrica in piante a strategia I e a strategia II
Author(s)
Zuchi, Sabrina
Date Issued
October 22, 2008
Type
Doctoral Thesis
Abstract
The ability of plants to develop strategies for adaptation to environmental changes is the characteristic that allows plants to optimize the use of available resources. Among the most frequent environmental stresses, the deficiency in micronutrient, such as Fe, is of particular concern. Indeed, although Fe is commonly present in soil, it is generally not available to plants due to its predominating insoluble form in the soil. Plants have developed two distinct strategies to uptake Fe from soil, Strategy I and Strategy II. Both strategies share a common element, the methionine, which is the precursor of nicotianammine, ethylene and phytosiderophores (PS). So, it is rather likely that Fe-deficiency can cause changes in sulphate fluxes as well as in methionine metabolic pathway and, on the other hand, that availability of sulphate could be relevant to the Fe-deficiency responses in both strategies.
Aim of this work was to study the relationship between S and Fe nutrition in Strategy I and Strategy II plants. The importance of this study is stressed by the recent increase of the incidence of S-deficiency in soils caused by the recent strong decrease in atmospheric SO2 emissions and the use of high-analysis, low-S-fertilisers.
In the first part of this work, maize and barley have been used as Strategy II model plants. Data suggest that S-deficiency affects plant ability to take up Fe from soil by limiting the release of PS in the rhizosphere and the acquisition rate of the Fe/PS complexes. Moreover, Fe-deficiency induces the redistribution of reduced sulphur pool in plants in order to sustain PS synthesis in roots.
In the second part of this work, tomato have been used as Strategy I model plant. Results indicate that also in Strategy I plants S-deficiency negatively affect the capability of plant to cope with Fe-shortage.
Additional information
Dottorato di ricerca in Scienze ambientali
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