Effect of osmotic stress on abscisic acid efflux and compartmentation in the roots of two maize lines differing in drought susceptibility
2000
Jovanovic, L. (Agricultural Research Inst. Serbia, Belgrade (Yugoslavia). Pesticides and Environmental Research Centre) | Stikic, R. | Hartung, W.
Roots of two Zea maize lines (drought-resistant Polj 17, and drought-susceptible F-2) were exposed to osmotic stress induced by sorbitol (osmotic potential -1,0 MPa). The following parameters were determined in cortex cells: membrane permeability for abscisic acid (ABA), ABA fluxes across membranes, pH values and ABA content in cytoplasm and vacuole. Osmotic stress induced different distribution of ABA within cell compartments in the investigated lines. ABA transport in the F-2 line occurred according to the intracellular pH gradient and the anion trap concept. In Polj 17, however, osmotic stress did not cause any significant effect on pH gradient and compartmental ABA content, but had a stimulating effect on ABA efflux from cytoplasm to apoplast and than via xylem to the leaf. These findings indicate different mechanisms of ABA transport between the investigated lines in response to osmotic stress.
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