Article

Expression of a fungal sterol desaturase improves tomato drought tolerance, pathogen resistance and nutritional quality

National Institute of Plant Genome Research , New Delhi, India.
Scientific Reports (Impact Factor: 5.58). 12/2012; 2:951. DOI: 10.1038/srep00951
Source: PubMed

ABSTRACT Crop genetic engineering mostly aims at improving environmental stress (biotic and abiotic) tolerance as well as nutritional quality. Empowering a single crop with multiple traits is highly demanding and requires manipulation of more than one gene. However, we report improved drought tolerance and fungal resistance along with the increased iron and polyunsaturated fatty acid content in tomato by expressing a single gene encoding C-5 sterol desaturase (FvC5SD) from an edible fungus Flammulina velutipes. FvC5SD is an iron binding protein involved in ergosterol biosynthesis. Morphological and biochemical analyses indicated ≈23% more epicuticular wax deposition in leaves of transgenic plants that provides an effective waterproof barrier resulting in improved protection from drought and infection by phytopathogenic fungus Sclerotinia
sclerotiorum. Furthermore, the transgenic fruits have improved nutritional value attributed to enhanced level of beneficial PUFA and 2-3 fold increase in total iron content. This strategy can be extended to other economically important crops.

Download full-text

Full-text

Available from: Mohammad Azam, Aug 24, 2015
0 Followers
 · 
172 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The importance of optimal nutrition for human health and development is well recognised. Adverse environmental conditions, such as drought, flooding, extreme heat and so on, affect crop yields more than pests and diseases. Thus, a major goal of plant scientists is to find ways to maintain high productivity under stress as well as developing crops with enhanced nutritional value. Genetically-modified (GM) crops can prove to be powerful complements to those produced by conventional methods for meeting the worldwide demand for quality foods. Crops developed by genetic engineering can not only be used to enhance yields and nutritional quality but also for increased tolerance to various biotic and abiotic stresses. Although there have been some expressions of concern about biosafety and health hazards associated with GM crops, there is no reason to hesitate in consuming genetically-engineered food crops that have been thoughtfully developed and carefully tested. Integration of modern biotechnology, with conventional agricultural practices in a sustainable manner, can fulfil the goal of attaining food security for present as well as future generations.
    Agriculture and Food Security 01/2013; 2(1):15. DOI:10.1186/2048-7010-2-15
  • [Show abstract] [Hide abstract]
    ABSTRACT: Interest in use of flax (Linum usitatissimum L.) as cadmium (Cd)-accumulating plant for phytoextraction of contaminated soils opened up a new and promising avenue toward improving tolerance of its varieties and cultivars to Cd stress. The aim of this study is to get insights into the mechanisms of Cd detoxification in cell membranes, by exploring the effects of salicylic acid (SA)-induced priming on fatty acids and lipid composition of flax plantlets, grown for 10 days with 50 and 100 μM Cd. At leaf level, levels of monogalactosyldiacylglycerol (MGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG), and neutral lipids (NL) have shifted significantly in flax plantlets exposed to toxic CdCl2 concentrations, as compared to that of the control. At 100 μM Cd, the linoleic acid (C18:2) decreases mainly in digalactosyldiacylglycerol (DGDG) and all phospholipid species, while linolenic acid (C18:3) declines mostly in MGDG and NL. Conversely, at the highest concentration of the metal, SA significantly enhances the levels of MGDG, PG and phosphatidic acid (PA), and polyunsaturated fatty acids mainly C18:2 and C18:3. Furthermore, SA pretreatment seems to reduce the Cd-induced alterations in both plastidial and extraplastidial lipid classes, but preferentially preserves the plastidial lipids by acquiring higher levels of polyunsaturated fatty acids. These results suggest that flax plantlets pretreated with SA exhibits more stability of their membranes under Cd-stress conditions.
    Environmental Science and Pollution Research 08/2014; 22(2). DOI:10.1007/s11356-014-3475-6 · 2.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Alpha linolenic acid and linoleic acid are essential fatty acids (EFAs) for humans and required for maintenance of optimal health, but they can not be synthesized by the human body and must be obtained from dietary sources. Using TomloxC fragment, TomloxD fragment and partial TomloxA sequence that is high identical with TomloxB and TomloxE, an RNAi expression vector was constructed. The construct was used to transform tomato cotyledon explants with the Agrobacterium-mediated cocultivation method. The real time RT-PCR analysis showed that the expression of TomloxA, TomloxB, TomloxC, TomloxD and TomloxE in transgenic tomato plants was drastically repressed, which led to a marked decrease in the levels of lipoxygenase activity. Finally, higher accumulations of the endogenous alpha linolenic acid and linoleic acid were detected in the transgenic tomato fruits, which were 1.65-3.99 times and 2.91-4.98 times that of the non-transformed tomato fruits, respectively.
    Journal of Agricultural and Food Chemistry 11/2014; 62(49). DOI:10.1021/jf503801u · 3.11 Impact Factor