Environmental Engineering Reference
In-Depth Information
and enzymes [28]. The Significant increase of proline under salt stress obviously showed its
powerful ability to help plant to resist osmotic stress. The results of our study also support
this point clearly. The significant decreases of ψ
w
(Figure. 5A) and RWC (Figure. 5B) after
salt treatment clearly indicated the absorption of water was greatly inhibited. Compared with
ZH13, decreases of ψ
w
and RWC in BB52 were much less. This might be explained by the
higher accumulation of proline in BB52.
Under salt stress, the accumulations of Na
+
and Cl
-
perturb the ion homeostasis in plants
[30-32]. Duo to the similar structure, Na
+
competes in absorption and transport with K
+
,
which is essential in physiological metabolism. Moreover, physiological functions of Ca
2+
,
Mg
2+
and HPO
4
-
can also be inhibited by Na
+
and Cl
-
. Hence, the capacity to maintain higher
K
+
and lower Na
+
, Cl
-
is critical for plant salt adaptation [33]. In this study, the contents of
Na
+
and Cl
-
in the leaves increased significantly after salt stress, and the augment in BB52
was much less than in ZH13. Furthermore, in BB52 most of the absorbed Na
+
and Cl
-
were
mainly accumulated in their roots, and the transportation to the above-ground parts such as
leaves was firmly restricted. Compared with ZH13, BB52 maintained a significantly higher
K
+
/Na
+
ratio, especially in leaves. This kind of distribution would reduce the toxic injury to
the major part of the whole plant. Similar conclusion has been reported by White and
Broadley [34].
In summary, when exposed to salt stress, both of cultivated soybean ZH13 and wild
soybean BB52 exhibited a certain tolerance through many kinds of physiological regulations.
Compared to ZH13, BB52 appeared to have higher salt tolerance and this was mainly
attributed to its better abilities to maintain photosynthesis rate, osmotic adjustment and ion
homeostasis.
A
CKNOWLEDGMENTS
This work was jointly supported by the National Natural Science Foundation of China
(No. 41201292; 41171216), One Hundred-Talent Plan of Chinese Academy of Sciences
(CAS), the Chinese Academy of Sciences (CAS) Visiting Professorship for Senior
International Scientists (2012T1Z0010), the Science & Technology Development Plan of
Shandong Province (2010GSF10208), the Science & Technology Development Plan of
Yantai City (2011016; 20102450), Yantai Double-hundred High-end Talent Plan (XY-003-
02) and 135 Development Plan of YIC-CAS.
R
EFERENCES
[1]
Munns R, Tester M (2008) Mechanisms of salinity tolerance.
Annu. Rev. Plant Biol.
59:
651-681.
[2]
Bhatnagar-Mathur P, Vadez V, Sharma KK (2008) Transgenic approaches for abiotic
stress tolerance in plants: retrospect and prospects.
Plant Cell Rep
. 27: 411-424.
[3]
Yang J (2008) Development and prospect of the research on salt-affected soils in China.
Acta Pedol. Sin
. 45: 837-845 (in Chinese).
