Agriculture Reference
In-Depth Information
Chapter 3
M
OLECULAR
M
ECHANISMS OF
S
ALT
T
OLERANCE IN
M
ANGROVE
P
LANTS
Yuichi Tada
School of Bioscience and Biotechnology,
Tokyo University of Technology, Tokyo, Japan
A
BSTRACT
In an effort to uncover the molecular mechanisms that underlie
mangrove salt tolerance, studies have focused on the cellular processes
that regulate the production and transport of compatible solutes, the
maintenance of ion homeostasis, and the production and activities of
antioxidative enzymes. As a result of these efforts, the molecular
pathways involved in the production and transport of glycine betaine and
proline have been reported. It has also been suggested that the
sequestration of Na
+
into vacuole by Na
+
/H
+
antiporters play a role in the
salt tolerance. In addition, several reports of the up-regulation of
antioxidative enzymes and their corresponding genes in mangroves under
saline conditions suggest that salt tolerance mechanisms in mangroves
can be partially explained by the scavenging properties of antioxidative
proteins. Recently, a genome-wide approach has been utilized to identify
genes involved in the salt tolerance mechanisms of mangroves. These
studies include transcriptome and proteome analysis, subtractive
screening of cDNAs, and functional screening of cDNAs in
microorganism hosts. Several promising genes, such as
mangrin
in
Bruguiera sexangula
and
Bg70
in
Bruguiera
gymnorhiza,
were identified
