Modulated fatty acid desaturation via overexpression of two distinct ω-3 desaturases differentially alters tolerance to various abiotic stresses in transgenic tobacco cells and plants
Article first published online: 16 SEP 2005
The Plant Journal
Volume 44, Issue 3, pages 361–371, November 2005
How to Cite
Zhang, M., Barg, R., Yin, M., Gueta-Dahan, Y., Leikin-Frenkel, A., Salts, Y., Shabtai, S. and Ben-Hayyim, G. (2005), Modulated fatty acid desaturation via overexpression of two distinct ω-3 desaturases differentially alters tolerance to various abiotic stresses in transgenic tobacco cells and plants. The Plant Journal, 44: 361–371. doi: 10.1111/j.1365-313X.2005.02536.x
- Issue published online: 7 OCT 2005
- Article first published online: 16 SEP 2005
- Received 28 June 2005; accepted 15 July 2005.
- fatty acids;
- osmotic stress;
- heat stress;
Changes in the degree of fatty acid (FA) desaturation are implicated in plant responses to various abiotic stresses, including heat, salt and drought. However, it is still not known whether decreased levels of linolenic acid, found in many plants subjected to salt and drought stress, reflect a mechanism of defence or damage. We addressed this question by generating tobacco cells and plants ectopically overexpressing two FA desaturases: the cytosolic FAD3 or the plastidic FAD8. A remarkable increase in the ratio of total linolenic to linoleic acids resulted from overexpression of FAD3, whereas ectopic overexpression of FAD8 induced an increased ratio mainly in the plastidic lipids. Here we present evidence that overexpressing FAD8 imposes much greater heat sensitivity than does FAD3 overexpression, in both cultured cells and whole plants. Overexpression of either FAD3 or FAD8 increases tolerance to drought in tobacco plants and to osmotic stress in cultured cells. These findings suggest that a drought-induced decreased level of linolenic acid reflects damage. Our results point to the potential of exploiting FAD overexpression as a tool to ameliorate drought tolerance.