Transcriptome characterization of genotype-dependent effects of CaCl2 treatment on drought adaptation in barley (Hordeum vulgare L.).. Hordeum vulgare

The hypothesis whether CaCl2 seed treatment prior to sowing (osmopriming) can enhance drought stress tolerance, and/or alleviate the effect on plant growth was tested. Here we elucidate whether seed treatment prior to sowing (osmopriming) with CaCl2 can improve the drought stress tolerance, as it was previously reported for salt stress on wheat. Thus the effect of 50 mM CaCl2, previously chosen based on pilot experiment, versus water-treated control exposed to drought stress was investigated. Overall design: The experiment was carried out with two spring barley genotypes differing in the response to drought stress: Sebastian and Georgia. A pot experiment was arranged with two seeds treatments (50 mM CaCl2 versus water), two plants treatments at the stage of three-week old plants (drought stress and control) and three replications (10 plants/replication) under controlled conditions in a growth chamber, with the following parameters maintained: 22/18°C day/night, 30% RH and the photoperiod of 16h. The youngest leaves were taken at three selected time points, corresponding to field water capacity (pF) of 3.2, 3.6, and 4.2 in the following days, for RNA extraction and hybridization with Affymetrix microarrays.