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Rice Genomics and Genetics 2012, Vol.3, No.7, 39
-
49
http://rgg.sophiapublisher.com
39
Research Report Open Access
Genetics and Molecular Breeding for Salt-Tolerance in Rice
Shikai Hu , Hongjian Tao , Qian Qian , Longbiao Guo
State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006, P. R. China
Corresponding author email:
guolongb@mail.hz.zj.cn; qianqian188@hotmail.com;
Authors
Rice Genomics and Genetics, 2012, Vol.3, No.7 doi: 10.5376/rgg.2012.03.0007
Received: 21 May, 2012
Accepted: 27 Jun., 2012
Published: 29 Jun., 2012
This article was first published in Molecular Plant Breeding (2010, Vol.8, No.4, 629-640) in Chinese, and here was authorized to translate and publish the paper
in English under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided
the original work is properly cited.
Preferred citation for this article:
Hu et al., 2012, Genetics and Molecular Breeding for Salt-Tolerance in Rice, Vol.3, No.7 39
-
49 (doi: 10.5376/rgg.2012.03.0007)
Abstract
Salt stress is one of the main environmental constraints for the losses of rice yield. In this paper, we introduced the
mechanisms of rice salt-tolerance by the following three aspects: the integrity of membrane systems, ionic compartmentation, and
osmotic adjustment. We also briefly presented the three methods for identifying rice salt-tolerance, which specifically refer to
biological and agronomic salt resistance, as well as the response of in vitro cells to salt stress. Then we summarized the progresses of
mining salt-resistance rice germplasm resources, mapping the QTLs conferring salt-tolerance, cloning slat-tolerant genes of
importance and breeding salt-tolerant rice varieties. Through a long-term evaluation of this trait, some rice germplasm involved in
salt tolerance have been identified. More than 70 QTLs controlling the salt-related traits of Na
+
/K
+
contents and survival days in rice
have been identified. Two salt-tolerance genes
SKC1
and
DST
have been cloned. A series of transgenic lines with salt-tolerance and
polymerization lines of two salt-resistant genes (
SKC1
and
BADH
) in rice have been developed in our lab. Finally, we discussed the
prospects of rice salt-tolerant mechanism research and their applications in practice, which might provide an important reference for
further studies of salt-tolerance in rice.
Keywords
Rice; Salt-tolerance; Germplasm; QTL; Genetics and breeding
Background
Salt-stress damage is one of the crucial factors
contributing to unfavorable rice-production while soil
salinization is the main limiting factor for
directly
influence its production (Li et al., 2005). Rice, planted
in this kind of poor soil, often cut the production or
even can not complete its life cycle when serious.
Among 960 million hectares of saline-alkali soil
worldwide, about 100 million hectares have existed in
China. Rice fields suffering salt damage account for
one fifth of all cultivated area in the continent.
This
salt damage
can be reduced via managing soil and
water, as well as modified chemical. However, it’s
hard to come true for the high cost and its
ineffectiveness. Therefore, it is one of the effective
ways to ensure the food safety production of the
salinization rice area and improve the ecological
environment to cultivate salt-tolerant rice variety and
do the salt tolerance research deeply in rice. By
following those, it was done by the most botanists in
China for a long time to protect the security of food
and the environment (Zhang, 2005). In this paper, we
summarized and prospected the germplasm resource,
mechanism of salt-tolerance and corresponding
molecular mechanism in rice, which might provide an
important reference for further studies of salt-
tolerance in rice.
1 The mechanism of salt-tolerance in rice
Salt tolerance refers to the ability of surviving and
yielding while rice varieties cultivated in saline soil.
When exposure to high-salt environment, plants
cannot absorb water effectively, leading to a
growth-delay, which is called the osmotic effect of salt
stress. On the other hand, NaCl enters the respiratory
chain so that the leaf cells accumulate large amount of
Na
+
which further impedes the growth of rice, which
is called the ion effect of salt stress (Yang et al., 2008).
The response of rice under salt-stress is as followings:
maintaining the integrity of membrane system, ionic
compartmentation, osmotic adjustment and accumulation
of macromolecular protein etc.