Up-regulation of plasma membrane H+-ATPase under salt stress may enable Aeluropus littoralis to cope with stress

Abstract

Most plants encounter stress such as drought and salinity that adversely affect growth, development and crop productivity. The expression of the gene glutathione-s-transferases (GST) extends throughout various protective mechanisms in plants and allows them to adapt to unfavorable environmental conditions. GSTF1 (the first phi GSTFs class) gene expression patterns in the wheat cultivars Mahuti and Alamut were studied under salt and ABA treatments using a qRT-PCR technique. Results showed that gene expression patterns were significantly different in these two cultivars. Data showed that in Mahuti, there was an increase of transcript accumulation under salt and ABA treatments at 3h, 10h and 72h respectively. In Alamut, however, the pattern of transcript accumulation was different; the maximum was at 3h. In contrast, there were no significant differences observed between the cultivars for GSTF1 gene expression profiles at three levels of NaCl concentration (50, 100, and 200 mM) or in ABA (Abscisic Acid) treatment. It is likely that difference of gene expression patterns between the cultivars (Mahuti as a salt tolerant cultivar and Alamut as a salt sensitive cultivar) is due to distinct signaling pathways which activate GSTF1 expression. Lack of a significant difference between the GSTF1 gene expression profile under salt and ABA treatments suggests that the GSTF1 gene is not induced by stress stimuli. Of course it is possible that other levels of NaCl and ABA treatments cause a change in the GSTF1 gene.

Keywords: ABA; GSTF1; qRT-PCR; salinity; wheat.

Figure 1

Total RNA extracted from leaves of A. littoralis was separated by 1% agarose gel electrophoresis and stained with ethidium bromide. 1) Total RNA extracted from sample and 2) size marker λ/StyI.

Figure 2

Agarose gel electrophoretic analysis of RT-PCR-amplified cDNA of a plasma membrane proton pump gene. 1) Size marker λ/StyI and 2) A 259 bp fragment was amplified from cDNAs prepared from RNA of leaves

Figure 3

A. littoralis plants were treated by different concentrations of NaCl (control, 50, 100, 150, 200, 250, 500, 1nd 1000 mM

Figure 4

Quantitative Real-time PCR analysis. The relative expression level of a gene encoding plasma membrane proton pump in leaves of A. littoralis (normalized by the level of actin gene, as a housekeeping gene) is shown