A metabolomic study in oats (Avena sativa) highlights a drought tolerance mechanism based on salicylate signalling pathways and the modulation of carbon, antioxidant and photo-oxidative metabolism

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Type Article
Original languageEnglish
Pages (from-to)1434-1452
Number of pages19
JournalPlant, Cell and Environment
Volume38
Issue number7
Early online date23 Dec 2014
DOI
Publication statusPublished - 31 Jul 2015
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Abstract

Although a wealth of information is available on the induction of one or several drought related responses in different species, little is known of how their timing, modulation and crucially integration influence drought tolerance. Based on metabolomic changes in oat (Avena sativa L.) we have defined key processes involved in drought tolerance. During a time course of increasing water deficit, metabolites from leaf samples were profiled using Direct Infusion – Electrospray Mass Spectroscopy (DI-ESI-MS) and HPLC ESI-MS/MS and analysed using Principal Component Analysis and Discriminant Function Anlaysis. The involvement of metabolite pathways was confirmed through targeted assays of key metabolites and physiological experiments. We demonstrate an early accumulation of SA influencing stomatal opening, photorespiration and antioxidant defences before any change in relative water content. These changes are likely to maintain plant water status, with any photoinhibitory effect being counteracted by an efficient antioxidant capacity, thereby representing an integrated mechanism of drought tolerance in oats. We also discuss these changes in relation to those engaged at later points consequence of the different water status in susceptible and resistant genotypes.

Keywords

  • metabolomics, photorespiration, salicylic acid