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For this study, the diversity of some effects of salinity on rosette growth, seed production, and seed viability in Arabidopsis thaliana was explored. Plants from 5 accessions (“ecotypes”) were grown on a sand-peat mixture irrigated with nutritive medium. At the emergence of inflorescence axis, 35 mM NaCl was added to the solution. Several morphological parameters of the rosette were measured at the beginning of silique opening, irrigation was interrupted and the substrate was allowed to dry. The siliques and the mature seeds were harvested, and assayed for K+, Na+ and Cl−. Seeds were sown on pure water and germination kinetics were determined. There was a large inter-ecotype variability of the effect of salt on the rosette growth and on all factors contribution to reproduction (number of inflorescence axes, number of flower per axis, flower fertility, and seed viability). Among the five ecotypes, those with highest levels of Na+ and Cl− in the silique valves produced the less viable seeds. This comparison, (i) suggests that salt accumulation in the former organs has detrimental effect on seed maturation, and (ii) indicates that there is a natural variability for control of ion transport to fruits in A. thaliana. [ABSTRACT FROM AUTHOR]

The variability of the sensitivity to sodium chloride (NaCl) in relation with leaf ionic content has been explored in Arabidopsis thaliana. Seedlings of eight ecotypes (WS, COL, LER, NOK0, NOK1, NOK2, NW40, and N273) were grown on a peat substrate mixed or not with 50 mM NaCl. The effect of NaCl treatment on rosette leaf dry weight after 18 days (vegetative stage) was used to establish a scale of sensitivity to salt, where COL was the most sensitive ecotype and NOK2 the more tolerant one. The tolerance to NaCl was associated to a better growth of plants, responsible for a dilution of Na+ in leaf tissues, and to a better supply of K+ to leaves. These two characteristics were responsible for maintenance of a high K/Na ratio in leaves of to the most tolerant ecotypes (NOK1, NOK2), as compared to the other ones. Responses of leaf peroxidase activity to a five-day treatment with NaCl in light and darkness conditions suggest that oxidative status is changed only in the sensitive ecotypes. [ABSTRACT FROM AUTHOR]