Whole genome transcriptome profiling of Arabidopsis thaliana guard cells under saline growth conditions

The overall objective was to document transcriptomic changes in the guard cells of Arabidopsis thaliana under short (1x) - and long-term (3x) saline growth conditions. Guard cells of Arabidopsis responded also to the intensity of the salt management by the microarray datasets clearly clustering in (-) salt, 1x salt and 3x salt. Similarly, more GO terms were significantly enriched in differentially expressed guard cell genes of 1 x salt than 3x salt treated plants. Salt induced gene expression studies in the guard cells of glycophyte Arabidopsis thaliana was conducted. For that, guard cells enriched samples were collected from light adapted plants grown under provided saline growth conditions. Two different salt treatment protocols, a short- and long-term, were applied to 4 to 5 weeks old Arabidopsis plants by soaking the soil pots in salt solutions each time for two hours. In the long-term salt stress experiment plants were treated three times : (i) On day 1 and 2 (75 mM NaCl), (ii) on day 7 and 8 (150 mM NaCl), and (iii) on day 13 and 14 (200 mM NaCl) named as 3x salt. In the short-term salt stress experiment plants were treated with 200mM NaCl on day 13 and 14 (named as 1x salt) while the control group faced tap water (named as (-) salt). All samples were collected at the end of the salt experiments on day 15 to ensure that plants have the same plant age and developmental stage. Four samples were collected from each group except for 1x salt where 3 samples were analyzed for gene expression studies.