Especially non-model species, are fairly rare to date, mainly due to the difficulties in integrating the analysis of stress-induced responses and the assessment of evolutionary changes. In a previous study, Bressan hypothesized that evolutionary divergence and adaptation to an extreme lifestyle in plants may have led to the appearance of novel gene combinations that support tolerance. Thus, it is intriguing to identify such genes or gene sets that are associated with the stress-related divergence between species that differ strikingly in stress tolerance. Although salt tolerance in model plants has attracted the attention of researchers for years and the knowledge of salt-induced responses has been enriched by exploring physiological and molecular mechanisms, studies emphasizing the loci underlying salt adaptation from an evolutionary perspective are rarely Selumetinib reported. Several comparative studies on the transcriptomes of salt-sensitive and salt-tolerant plants offered some novel insights into this issue, providing a linkage between gene expression differences and salt-tolerance capacities. Mangroves are woody plants that grow along tropical and subtropical coasts and form clumpy stands in intertidal zones. These trees can tolerate high salinity, though the adaptation competencies vary across species. Ceriops tagal is a typical true mangrove species that can form rich stands in fields with salinities up to 35%. In lab-cultured seedlings, Na+ and Cl2 may accumulate in the leaves of C. tagal when subjected to increasing salinity, and also be enriched in the developing propagules. These observations do not fully agree with the ultrafiltration hypothesis and imply that a combined management and regulation of ion contents may operate in this species. In this study, we attempted to use the microarray technique to uncover the connection between salt-induced time-course transcript profiling and the salinity-adaptation capability of C. tagal. We constructed a customized cDNA microarray containing probes derived from a root cDNA library of C. tagal and then monitored the transcript profiles at various time points over a period of salt stress. We identified differentially expressed genes by comparing salt-shocked samples with unstressed controls. Additionally, comparative analyses between C. tagal and Arabidopsis thaliana were conducted to reveal the transcriptional divergence that may be associated with the salt adaptation of C. tagal. The adaptation of mangroves to saline environments is related to transcriptional regulation. In a recent study on the transcriptomes of two mangrove species, Rhizophora mangle and Heritiera littoralis, the authors observed that the distributions of the GO lineages and KEGG pathways of these two mangroves were similar to each other but differed substantially from those of model plants, suggesting a unique mangrove lifestyle. Laguncularia racemosa, also a mangrove species, shows little genetic but large epigenetic differences between populations occurring in naturally contrasting habitats, at a riverside or near a salt marsh. C. tagal is a salt-tolerant species and has many typical features that are associated with the adaptation to saline environments. As stated in the Introduction section, rapid and successful rooting into saline soils is one of the key steps for survival under such challenging environments.