Physiological Responses of Wild and Cultivated Barley to the Interactive Effect of Salinity and Iron Deficiency

الملخص EN

Literature on the separate effects of salinity and inadequate Fe supply on plant growth and nutrient uptake, concentration, and distribution is abundant but little is known about the interactive effects of these two abiotic constraints.

Here, we investigated the interactive effect of iron availability and salinity on physiological responses of cultivated and wild barley (Hordeum vulgare and H.

maritimum resp.).

Seedlings of both species were grown for 9 days, under complete nutrient solution with or without iron supply.

Then, NaCl treatment was applied at different concentrations (0, 100, 200, and 300 mM) for 60 hours.

After salt exposure, shoot water content of H.

vulgare was significantly reduced as compared to H.

maritimum.

Furthermore, Na+ accumulation in shoots increased parallel to increasing NaCl concentration in the medium.

However, the increase was significantly higher in H.

vulgare than in H.

maritimum.

These responses were associated with lower Fe absorption efficiency photosynthetic parameters in both species.

The reduction was significantly higher in cultivated than in wild barley.

Moreover, phytosiderophore exudation was enhanced in both species by direct (iron free medium) or indirect iron limitation (salt-induced iron limitation).

Such a stimulation of phytosiderophore release was genotype and salt level dependant.