Effects of salt stress on ion balance and nitrogen metabolism of old and young leaves in rice (Oryza sativa L.)

BMC Plant Biology

Research Article

Rui Guo¹  Meishan Zhang²  Huan Wang³  Decheng Shi³  Bao Liu³  Chunwu Yang³  Xiuyun Lin⁴ 

[1] Chinese Academy of Agricultural Sciences (CAAS), Key Laboratory of Dry land Agriculture, Institute of Environment and Sustainable Development in Agriculture(IEDA), 100081, Beijing, MOA, China;Department of Agronomy, Jilin Agricultural University, 130118, Changchun, Jilin Province, China;Key laboratory of Molecular Epigenetics of MOE, Northeast Normal University, 130024, Changchun, Jilin Province, China;Rice Institute, Jilin Academy of Agricultural Sciences, 130033, Changchun, Jilin Province, China;

关键词: Salt stress;    Rice;    Nitrogen metabolism;    Gene expression;    Old and young leaves;   

DOI  :  10.1186/1471-2229-12-194

 received in 2012-08-02, accepted in 2012-10-17,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundIt is well known that salt stress has different effects on old and young tissues. However, it remains largely unexplored whether old and young tissues have different regulatory mechanism during adaptation of plants to salt stress. The aim of this study was to investigate whether salt stress has different effects on the ion balance and nitrogen metabolism in the old and young leaves of rice, and to compare functions of both organs in rice salt tolerance.ResultsRice protected young leaves from ion harm via the large accumulation of Na+ and Cl− in old leaves. The up-regulation of OsHKT1;1, OsHAK10 and OsHAK16 might contribute to accumulation of Na+ in old leaves under salt stress. In addition, lower expression of OsHKT1;5 and OsSOS1 in old leaves may decrease frequency of retrieving Na+ from old leaf cells. Under salt stress, old leaves showed higher concentration of NO3− content than young leaves. Up-regulation of OsNRT1;2, a gene coding nitrate transporter, might contribute to the accumulation of NO3− in the old leaves of salt stressed-rice. Salt stress clearly up-regulated the expression of OsGDH2 and OsGDH3 in old leaves, while strongly down-regulated expression of OsGS2 and OsFd-GOGAT in old leaves.ConclusionsThe down-regulation of OsGS2 and OsFd-GOGAT in old leaves might be a harmful response to excesses of Na+ and Cl−. Under salt stress, rice might accumulate Na+ and Cl− to toxic levels in old leaves. This might influence photorespiration process, reduce NH4+ production from photorespiration, and immediately down-regulate the expression of OsGS2 and OsFd-GOGAT in old leaves of salt stressed rice. Excesses of Na+ and Cl− also might change the pathway of NH4+ assimilation in old leaves of salt stressed rice plants, weaken GOGAT/GS pathway and elevate GDH pathway.

【 授权许可】

Unknown   
© Wang et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.