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Open Access item Increasing Omega-3 Desaturase Expression In Tomato Results In Altered Aroma Profile And Enhanced Resistance To Cold Stress
Hernández, M. Luisa
Pennycooke, Joyce C.
Martínez-Rivas, José Manuel
Stockinger, Eric J.
Sánchez Serrano, José J.
|Keywords:||Omega-3 desaturase, Oxylipins, Hexanal, (Z)-hex-3-enal, Aroma, Solanum lycopersicum, Cold stress, Linoleic acid, Linolenic acid|
|Publisher:||American Society of Plant Biologists|
|Citation:||Plant Physiology (Preview): (2010)|
|Abstract:||One of the drawbacks in improving the aroma properties of tomato fruit is the complexity
of this organoleptic trait with a great variety of volatiles contributing to determine specific
quality features. It is well established that the oxylipins hexanal and (Z)-hex-3-enal,
synthesized through the lipoxygenase pathway, are among the most important aroma
compounds and impart in a correct proportion some of the unique fresh notes in tomato.
Here, we confirm that all enzymes responsible for the synthesis of these C6 compounds
are present and active in tomato fruit. Moreover, due to the low odor threshold of (Z)-hex-
3-enal, small changes in the concentration of this compound could modify the properties
of the tomato fruit aroma. To address this possibility, we have over-expressed the ω-3
fatty acid desaturases FAD3 and FAD7 that catalyzed the conversion of linoleic (18:2) to
linolenic acid (18:3), the precursor of hexenals and its derived alcohols. Transgenic OEFAD
tomato plants exhibit altered fatty acid composition with an increase in the 18:3/18:2
ratio in leaves and fruits. These changes provoke a clear variation in the C6 content that
results in a significant alteration of the (Z)-hex-3-enal/hexanal ratio that is particularly
important in ripe OE-FAD3FAD7 fruits. In addition to this effect on tomato volatile
profile, OE-FAD tomato plants are more tolerant to chilling. However, the different
behavior of OE-FAD plants underscores the existence of separate FA fluxes to ensure
plant survival under adverse conditions.|
|Description:||37 pages, 5 figures, 3 tables.-- PDF pre-print.-- PMID: 20382895 [PubMed]|
|Publisher version (URL):||http://dx.doi.org/10.1104/pp.110.154815|
|Appears in Collections:||(CNB) Artículos|
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