Tissue-specific calcium and magnesium allocation to explain differences in bulk concentration in leaves of one-year-old seedlings of two olive (Olea europaea L.) cultivars

• Published in: Plant physiology and biochemistry Vol. 194; pp. 619 - 626
• Main Authors: Pongrac, Paula, Kelemen, Mitja, Vogel-Mikuš, Katarina, Vavpetič, Primož, Pelicon, Primož, Žurga, Paula, Vidović, Nikolina, Polić Pasković, Marija, Smiljana, Goreta Ban, Lukić, Igor, Pasković, Igor
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01-01-2023
• Subjects: Boron; Calcium; Magnesium; Mineral nutrition; Molybdenum; Olea; Plant Leaves; Potassium; Seedlings; Sodium; X-ray fluorescence; Mineral nutrition; X-ray fluorescence; Magnesium; Calcium; Potassium; Seedlings
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2022.11.040

Olive tree (Olea europaea L.) leaves have recently been recognised as a valuable source in cosmetic and pharmaceutical industry as well as in preparation of health-supporting beverages. Little is known about the element composition of olive leaves and almost nothing about tissue-specific allocation of elements. Element composition and tissue-specific distribution were determined in leaves of two olive cultivars, Leccino and Istarska bjelica using micro-particle induced X-ray emission (micro-PIXE). In leaves of the Istarska bjelica cultivar larger bulk concentrations of potassium, sodium, molybdenum and boron, but smaller concentrations of calcium and magnesium were found than in leaves of the Leccino cultivar. Tissue-specific investigation revealed that larger concentration of calcium in epidermis and in leaf blade tissues (secondary veins, palisade and spongy mesophyll) contributed to the larger leaf bulk calcium concentration in the Leccino cultivar. For magnesium, all leaf tissues, except the bundle sheath cells and consequently the main vascular bundle, contributed to the larger bulk concentration in the Leccino cultivar. Potassium was not predominant in any of the leaf tissues examined, while sodium and molybdenum were below the limit of detection, and boron not detectable by micro-PIXE. The results indicate that sinks for calcium and magnesium are stronger in specific leaf tissues of the Leccino than of the Istarska bjelica cultivar. The new understanding of tissue-specific allocation of elements in leaves of olive will serve as a basis for detailed studies into the effects of foliar and/or soil fertilisers in olive.
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•Element composition of Istarska bjelica (Ib) and Leccino (Lec) cultivars was compared.•Bulk element profiles in leaves of Ib and Lec cultivars differed.•At tissue level there was similar allocation of elements in the leaves of Ib and Lec.•Higher bulk Ca in Lec was due to more Ca in epidermis and leaf blade than in Ib.•All leaf tissues, except the bundle sheath cells, had more Mg in Lec than in Ib.