Comparison of essential and non-essential element distribution in leaves of the Cd/Zn hyperaccumulator Thlaspi praecox as revealed by micro-PIXE

• Published in: Plant, cell and environment cell and environment, 2008-10, Vol.31 (10), p.1484-1496
• Main Authors: VOGEL-MIKUŠ, KATARINA, SIMČIČ, JURE, PELICON, PRIMOŽ, BUDNAR, MILOŠ, KUMP, PETER, NEČEMER, MARIJAN, MESJASZ-PRZYBYŁOWICZ, JOLANTA, PRZYBYŁOWICZ, WOJCIECH J, REGVAR, MARJANA
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biodegradation, Environmental; Biological and medical sciences; Cadmium - analysis; Cell Compartmentation; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; hyperaccumulation; Lead - analysis; Microbiology; nuclear microprobe; Physics, chemistry, biochemistry and biology of agricultural and forest soils; phytoremediation; Plant Leaves - anatomy & histology; Plant Leaves - chemistry; Soil Pollutants - analysis; Soil science; Spectrometry, X-Ray Emission - methods; STIM; Thlaspi; Thlaspi - anatomy & histology; Thlaspi - chemistry; X‐ray microanalysis; Zinc - analysis
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.2008.01858.x

A detailed localization of elements in leaf tissues of the field-collected Cd/Zn hyperaccumulator Thlaspi praecox (Brassicaceae) growing at a highly metal-polluted site was determined by micro-proton-induced X-ray emission (micro-PIXE) in order to reveal and compare nutrient and non-essential element accumulation patterns in the case of multiple metal accumulation within particular leaf tissues, including the detailed distribution between apoplast and symplast regions. On the larger scans, the highest concentrations of metals were observed in the epidermis, S and Ca in the palisade mesophyll, Cl in the spongy mesophyll and vascular bundles, and P and K in the vascular bundles. On the more detailed scans, the highest Cd, Pb, Cl and K concentrations were observed in vascular bundle collenchyma. The relative element distribution (%) was calculated based on concentrations of elements in particular leaf tissues and their relative weight portions, indicating that most of the accumulated Zn was located in epidermises, while the majority of Cd and Pb was distributed within the mesophyll. Detailed scans of epidermal/mesophyll tissues revealed that Zn was mainly accumulated and detoxified in the symplast of large vacuolated epidermal cells, Cd in the mesophyll symplast, and Pb in the mesophyll symplast and apoplast.