Agriculture Reference
In-Depth Information
phylogenically distant halophyte plants have developed similarly high levels
of salt tolerance. Further analysis of gene suppression in halophytes and
glycophytes under salt stress will test this hypothesis.
C
ONCLUSION AND
F
UTURE
D
IRECTIONS
There has been some progress toward understanding the mechanisms
underlying salt tolerance in mangroves at a molecular level. Osmoregulation is
achieved by producing compatible solutes and/or Na
+
sequestration, and the
production of antioxidant enzymes is also an important feature of salt
tolerance mechanisms in mangroves. EST and microarray analyses have been
complemented by functional screening of cDNAs from several mangrove
species, revealing the involvement of novel mangrove-specific genes in
tolerance to salinity stress [58, 59, 61, 62].
Despite the advances made in the research reviewed here, we still do not
have a comprehensive understanding of the molecular mechanisms that
mediate salt tolerance in mangrove plants. Although the genes listed in this
review likely play a role in the molecular mechanisms of salt tolerance in
mangroves, it is likely that there are other unknown mechanisms, which might
be common to all mangroves or specific to certain mangroves, which remain
to be clarified. The study of mangrove salt tolerance is still in its infancy
compared to model plants, such as
Arabidopsis
and rice.
Intensive studies will be needed to clarify these mechanisms in mangroves
and utilize this information for molecular breeding of salt-tolerant plants. The
involvement of repression or silencing of genes in salt tolerance in
glycophytes may be the key to developing novel strategies to uncover these
mechanisms.
In addition, new approaches are being developed to aid in the analysis of
several important features of metabolic regulation during salinity stress
management, such as the rapidly developing technology of metabolomics [91].
Metabolite profiling in combination with different ―omics‖ platforms appears
to be a promising approach to further our understanding of the dynamics of
salinity tolerance.
