On the distribution and evaluation of Na, Mg and Cl in leaves of selected halophytesPongrac, Paula (Avtor) Vogel-Mikuš, Katarina (Avtor) Regvar, Marjana (Avtor) Kaligarič, Mitja (Avtor) Vavpetič, Primož (Avtor) Kelemen, Mitja (Avtor) Grlj, Nataša (Avtor) Pelicon, Primož (Avtor) light elementsmicro-PIXEsalinitysalt toleranceDiverse physiological, biochemical and morphological adaptations enable plantsto survive in extreme saline environments where osmotic and ionic stresses limit growth and development. Halophytes are salt-tolerant plants that can withstand extraordinarily high levels of Na and Cl in their leaves. The tissue and cellular distribution patterns of salt ions can be linked to the underlying mechanisms of salt tolerance. Application of fast, reliable, multi-elemental and quantitative techniques such as micro-proton-induced X-rayemission (micro-PIXE) will significantly contribute to and accelerate studies of plant salt tolerance, especially as micro-PIXE also provides spatially resolved quantitative data for light elements, such as Na and Mg. The spatial concentration distributions of Na, Mg, Cl, K, P and S in leaves offour halophytes (Bassia indica, Atriplex prostrata, Spartina maritima and Limonium angustifolium) were determined using micro- PIXE, to study the salt-tolerance strategies of the selected halophytes. Different distribution patterns of the studied elements were seen in the leaves; however, in all fourof these plant species, Na was excluded from photosynthetically active chlorophyl tissues. With the exception of L. angustifolium, Cl, P and S contents (representing chloride, phosphate and sulphate ionic forms, respectively) did not ensure charge balance in the leaves, which suggests other anionic compounds, such as nitrate and organic anions, have crucial roles in maintaining electroneutrality in these halophytes. By increasing soilsalinisation worldwide, the possibility to reliably complement spatial distributions of Na, Mg, Cl, K, P and S with plant structural morphology will contribute significantly to our understanding of plant tolerance mechanisms atthe tissue and cell levels. In addition, these kinds of studies are of particular value for designing crop plants with high salt tolerance and for the development of phytoremediation technologies.20132015-07-10 13:04:31Delo ni kategorizirano37681sl