Distribution of aluminium in hydrated leaves of tea (Camellia sinensis) using synchrotron- and laboratory-based X-ray fluorescence microscopy.

Autor: van der Ent A; The University of Queensland, Sustainable Minerals Institute, St Lucia, Queensland 4072, Australia. a.vanderent@uq.edu.au., Kopittke PM, Paterson DJ, Casey LW, Nkrumah PN
Jazyk: angličtina
Zdroj: Metallomics : integrated biometal science [Metallomics] 2020 Jul 01; Vol. 12 (7), pp. 1062-1069. Date of Electronic Publication: 2020 Apr 08.
DOI: 10.1039/c9mt00300b
Abstrakt: Aluminium (Al) is highly toxic to plant growth, with soluble concentrations being elevated in the ∼40% of arable soils worldwide that are acidic. Determining the distribution of Al in plant tissues is important for understanding the mechanisms by which it is toxic and how some plants tolerate high concentrations. Synchrotron- and laboratory-based X-ray fluorescence microscopy (XFM) is a powerful technique to quantitatively analyse the distribution of elements, including in hydrated and living plants. However, analysis of light elements (z < phosphorus) is extremely challenging due to signal losses in air, and the unsuitability of vacuum environments for (fresh) hydrated plant tissues. This study uses XFM in a helium environment to avoid Al signal loss to reveal the distribution of Al in hydrated plant tissues of Tea (Camellia sinensis). The results show that Al occurs in localised areas across the foliar surface, whereas in cross-sections Al is almost exclusively concentrated in the apoplastic space above and in between adaxial epidermal cells. This distribution of Al is related to the Al tolerance of this species, and accumulation of phytotoxic elements in the apoplastic space, away from sensitive processes such as photosynthesis in the palisade mesophyll cells, is a common tolerance mechanism reported in many different plant species. This study develops an XFM method on both synchrotron and laboratory sources that overcomes the drawbacks of existing analytical techniques, permitting measurement of light elements down to Al in (fresh) hydrated plant tissues.
Databáze: MEDLINE