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Comparative expression analysis of three genes from the Arabidopsis vacuolar Na+/H+ antiporter (AtNHX) family in relation to abiotic stresses.
- Source :
-
Chinese Science Bulletin . Jul2007, Vol. 52 Issue 13, p1754-1763. 10p. 1 Diagram, 1 Chart, 3 Graphs. - Publication Year :
- 2007
-
Abstract
- Na~/H~ antiporters (NHX) are ubiquitous transmembrane proteins that play a key role in salt tolerance of plants. In this study, the sequence of 3 Arabidopsis NHX genes (AtNHX2-4) were compared with other AtNHX members. Putative cis-elements analysis identified elements that have been associated with stress responses. The activities of the promoters AtNHX2-4 were studied in transgenic plants carrying corresponding promoter-~-glucuronidase (GUS) fusions. The AtNHX2 promoter-GUS analysis indicated that AtNHX2 was expressed in constitutive pattern with high GUS activity in roots and leaves. AtNHX2 promoter activity was not up-regulated by NaCI or abscisic acid (ABA), in contrast to the AtNHX1 promoter which was previously studied. The AtNHX3 and AtNHX4 promoters showed tissue-specific activities. Strong GUS activity was detected in roots and vascular bundles of the stele in plants carrying an AtNHX4 promoter-GUS fusion, and GUS activity increased under salt stress suggesting a function related to salt tolerance. Transgenic plants carrying the AtNHX3 promoter-GUS fusion showed strong GUS activity in petals, stamens and tops of siliques, suggesting a possible role of AtNHX3 in flower and seed development. Results of histochemical analysis suggested that AtNHX2-4 are involved in divergent functions and are differentially regulated under abiotic stress. The structure of AtNHX4 was predicted to include 12 transmembrane regions and a NHX domain. Overexpression of AtNHX4 in Arabidopsis transgenic lines confers greater salt tolerance than in wild type plants. These results suggest that AtNHX4 may encode a putative vacuolar NHX that plays an important role in salt tolerance. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10016538
- Volume :
- 52
- Issue :
- 13
- Database :
- Academic Search Index
- Journal :
- Chinese Science Bulletin
- Publication Type :
- Academic Journal
- Accession number :
- 31990027
- Full Text :
- https://doi.org/10.1007/s11434-007-0278-x