Differential cadmium and zinc distribution in relation to their physiological impact in the leaves of the accumulating Zygophyllum fabago L.
Cadmium and zinc share many similar physiochemical properties, but their compartmentation, complexation and impact on other mineral element distribution in plant tissues may drastically differ. In this study, we address the impact of 10 μm Cd or 50 μm Zn treatments on ion distribution in leaves of a metallicolous population of the non-hyperaccumulating species Zygophyllum fabago at tissue and cell level, and the consequences on the plant response through a combined physiological, proteomic and metabolite approach. Micro-proton-induced X-ray emission and laser ablation inductively coupled mass spectrometry analyses indicated hot spots of Cd concentrations in the vicinity of vascular bundles in response to Cd treatment, essentially bound to S-containing compounds as revealed by extended X-ray absorption fine structure and non-protein thiol compounds analyses. A preferential accumulation of Zn occurred in vascular bundle and spongy mesophyll in response to Zn treatment, and was mainly bound to O/N-ligands. Leaf proteomics and physiological status evidenced a protection of photosynthetically active tissues and the maintenance of cell turgor through specific distribution and complexation of toxic ions, reallocation of some essential elements, synthesis of proteins involved in photosynthetic apparatus or C-metabolism, and metabolite synthesis with some specificities regarding the considered heavy metal treatment.
Groupe de Recherche en Physiologie végétale (GRPV), Earth and Life Institute - Agronomy (ELI-A), Université catholique de Louvain, Croix du Sud 4-5, bte L7.07.13, 1348, Louvain-la-Neuve, Belgium.
Isabelle
I
Lefèvre
Katarina
K
Vogel-Mikuš
Luka
L
Jeromel
Primož
P
Vavpetič
Sébastien
S
Planchon
Iztok
I
Arčon
Johannes T
JT
Van Elteren
Gilles
G
Lepoint
Sylvie
S
Gobert
Jenny
J
Renaut
Primož
P
Pelicon
Stanley
S
Lutts
D001692:Biological Transport; D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D053685:Laser Therapy; D013058:Mass Spectrometry; D010788:Photosynthesis; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D020543:Proteome; D013052:Spectrometry, X-Ray Emission; D015032:Zinc / Q000032:analysis / Q000378:metabolism*; D032445:Zygophyllum / Q000378:metabolism*
D010940:Plant Proteins; D020543:Proteome; D002104:Cadmium; D002734:Chlorophyll; D015032:Zinc
EXAFS; LA-ICP-MS; carbohydrates; heavy metals; micro-PIXE; non-protein thiols; photosynthetic-related parameters; plant proteomics; proline; water relations