DIFFERENCES IN CELL WALL BINDING CAPACITY OF GRAPEVINE CULTIVARS

Calcium compartmentalization in the root and in the leaf blades of "Ca²⁺ accumulator" varieties (Leányka and Georgikon 28) and "Ca²⁺ excluder" varieties (Chasselas x Berlandieri 41 B, Rupestris du Lot) were studied under Ca²⁺ excess.
One node cuttings were rooted hydroponically for about 4 weeks in 1/10 Hoagland solution and than treated with 25 mM Ca(NO₃)₂ for two weeks.
Ca²⁺ concentration of the roots and leaves and the purified cell wall fractions were measured.
Varietal differences in Ca²⁺ accumulation of the roots could not be observed.
Nearly the same Ca²⁺ levels were measured in control and treated plants.
About 50 % of the Ca²⁺ content of roots could be mobilized during the cell wall purification process, the residue was fixed in the cell wall fraction.
Accumulator varieties bound more Ca²⁺ in their leaves already under control condition, than the excluder ones.
Ca²⁺ treatment resulted about the same increase (in %) in leaf Ca²⁺ content in each variety.
In the leaves, 90 % of Ca²⁺ was deposited in the cell wall fraction.
Under control condition Ca²⁺ concentration in the intact leaf blades and in their cell wall was similar.
Under Ca²⁺ excess the accumulator varieties bound the surplus in the cell wall showed by the increased cell wall concentration compared to the intact leaves.
In the excluder varieties this increase could not be observed.
Contrary, Ca²⁺ level in the intact leaves was the same (Rupestris du Lot) or higher (Chasselas x Berlandieri 41 B) than in their cell wall.
This phenomena can be explained by the difference in the genetically determined polygalacturonic-acid content of the cell wall of the varieties, which has an important role in the Ca²⁺ binding capacity.

V International Symposium on Grapevine Physiology

E. Miklós, L. Szõke, P. Kozma, L. Erdei

rootstock, calcium, compartmentalization

https://doi.org/10.17660/ActaHortic.2000.526.16