Title: The nature of the progression of drought stress drives differential metabolomic responses in Populus deltoides

Abstract

Background and Aims: The use of woody crops for Quad-level (approx. 1 × 10¹⁸ J) energy production will require marginal agricultural lands that experience recurrent periods of water stress. Populus species have the capacity to increase dehydration tolerance by lowering osmotic potential via osmotic adjustment. The aim of this study was to investigate how the inherent genetic potential of a Populus clone to respond to drought interacts with the nature of the drought to determine the degree of biochemical response. Methods: A greenhouse drought stress study was conducted on Populus deltoides ‘WV94’ and the resulting metabolite profiles of leaves were determined by gas chromatography–mass spectrometry following trimethylsilylation for plants subjected to cyclic mild (–0.5 MPa pre-dawn leaf water potential) drought vs. cyclic severe (–1.26 MPa) drought in contrast to well-watered controls (–0.1 MPa) after two or four drought cycles, and in contrast to plants subjected to acute drought, where plants were desiccated for up to 8 d.Key Results: The nature of drought (cyclic vs. acute), frequency of drought (number of cycles) and the severity of drought (mild vs. severe) all dictated the degree of osmotic adjustment and the nature of the organic solutes that accumulated. Whereas cyclic drought induced themore » largest responses in primary metabolism (soluble sugars, organic acids and amino acids), acute onset of prolonged drought induced the greatest osmotic adjustment and largest responses in secondary metabolism, especially populosides (hydroxycinnamic acid conjugates of salicin). Conclusions: The differential adaptive metabolite responses in cyclic vs. acute drought suggest that stress acclimation occurs via primary metabolism in response to cyclic drought, whereas expanded metabolic plasticity occurs via secondary metabolism following severe, acute drought. Here, the shift in carbon partitioning to aromatic metabolism with the production of a diverse suite of higher order salicylates lowers osmotic potential and increases the probability of post-stress recovery.« less

Authors:

Tschaplinski, Timothy James  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-9540-6622"

Abraham, Paul E.  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-2685-9123"

Jawdy, Sara S. ^[1]; Gunter, Lee E.  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-1211-7532"

Martin, Madhavi Z.  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-6677-2180"

Engle, Nancy L.  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0290-7987"

Yang, Xiaohan  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-5207-4210"

Tuskan, Gerald A.  ^[1]

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• Search DOE PAGES for ORCID "0000-0003-0106-1289"

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Wed Jan 23 00:00:00 EST 2019

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1545241

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Annals of Botany

Additional Journal Information:

Journal Volume: 124; Journal Issue: 4; Journal ID: ISSN 0305-7364

Publisher:

Oxford University Press

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; Populus deltoides ‘WV94’; cyclic drought; acute drought; gas chromatography–mass spectrometry; metabolite profiles; osmotic adjustment; acclimation; metabolic perturbation