A plant’s adaptation to its environment is one of the most important issues in evolutionary biology.
Mangroves are trees that inhabit the intertidal zones with high salinity, while salt tolerance competence
of different species varies. Even congeneric species usually occupy distinct positions of intertidal
zones due to differential ability of salt tolerance. Some species have different ecotypes that adapt well
to littoral and terrestrial environments, respectively. These characteristics of mangroves make them
ideal ecological models to study adaptation of mangroves to salinity. Here, we briefly depict adaptive
traits of salt tolerance in mangroves with respect to anatomy, physiology and biochemistry, and review
the major advances recently made on both the genetic and genomic levels. Results from studies on
individual genes or whole genomes of mangroves have confirmed conclusions drawn from studies on
anatomy, physiology and biochemistry, and have further indicated that specific patterns of gene expression
might contribute to adaptive evolution of mangroves under high salinity. By integrating all
information from mangroves and performing comparisons among species of mangroves and
non-mangroves, we could give a general picture of adaptation of mangroves to salinity, thus providing
a new avenue for further studies on a molecular basis of adaptive evolution of mangroves.