Page 276 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

[P144] ASSESSING AMMONIA VOLATILIZATION LOSSES WITH DIFFERENT NITROGEN SOURCE,
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TIMING, AND PLACEMENT. Jongwon Kang , Jason DeBruin , Rebecca Hensley , and Joshua
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Nasielski . Department of Plant Agriculture, University of Guelph, Guelph, Ontario, N1G 2W1, Canada;
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2 Corteva Agriscience, Johnston, Iowa, USA, Johnston, Iowa, IA 50131, USA; and Corteva Agriscience,
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Windfall, Indiana, IN 46076, USA
Correspondence to: jkang18@uoguelph.ca

Given the economic and environmental costs associated with ammonia (NH3) losses from nitrogen (N)
fertilizer applications, there is significant interest in evaluating various N management practices to reduce
NH3 volatilization. The aim of this study was to provide N management recommendations to enhance N
use efficiency and minimize ammonia losses. A three-year field study (2021-2023) was conducted at five
locations in Canada and the US to measure NH3 volatilization from different N sources (urea and UAN
with/without urease inhibitor), placements (broadcast and injection), and application timings (V5 and V13)
in corn fields, using the dositube method. Both urease inhibitors and tillage were found to reduce
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volatilization losses for urea (average 39.2 kg N ha ) and UAN (average 5.6 kg N ha ), although losses
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with UAN were already low even when applied on the surface. Application timing (V5 or V13) did not
significantly affect total NH3 loss, except in the case of surface-applied urea, which had higher losses at
V13 than at V5. Soil texture was a significant factor in that soils with high sand content were more prone
to N losses due to rapid downward movement of N following rainfall events. However, this can raise the
potential risk of increasing other N losses, such as N leaching (pollution swapping).

*[P145] METABOLOMICS TO INVESTIGATE PLANT ADAPTATATIONS TO CLIMATE CHANGE: AN
EXAMPLE FROM THE ARTIC. Daniel A. Gaudet , Susan J. Murch , and Lauren A.E. Erland ,
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1,2
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1 University of British Columbia, Okanagan, 3247 University Way, Syilx Okanagan Nation Territory,
Kelowna, BC, Canada V1V 1V7; and University of the Fraser Valley, Stó:lō Temexw, Chilliwack, BC,
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Canada, V2S 7M8
Correspondence to: Lauren.erland@ufv.ca

Inuit Nunangat and Canada’s Arctic are experiencing warming at up to 4X the rate of Southern regions in
a phenomenon known as Artic amplification. Plant species growing in these regions are highly adapted to
growth at low temperatures and long day-lengths and are experiencing relatively rapid changes in their
environments. To better understand the metabolomic changes occurring in Artic plant species, field
samples of aerial tissues of Cerastium regelii (Ostenf.) and Stellaria longipes (L.) were collected in
Qausuittuq, Nunavut. We hypothesized that plants collected from northern regions respond to changing
temperatures by activation of specific metabolic pathways. Metabolomics is the untargeted analysis of
any biological sample. We used an untargeted metabolomics approach to detect and identify metabolites
in C. regelii and S. longipipes seedlings grown in tissue culture in controlled environment chambers with
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three climate setting (12 C, 24 C or 28 C). Data on physiological responses was collected after three
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weeks. In vitro-grown tissues were collected, flash frozen and extracted in a stabilizing buffer. Metabolites
were separated by reverse phase chromatography (Thermo UHPLC; BEH C18 column; gradient elution)
and high-resolution mass spectrometry (Q-Exactive orbitrap). A set of 50 known plant growth regulators
was used as a standard mixture to ensure data quality. Data were exported, aligned, and verified through
MZMine version 3.0. Multivariate statistical approaches and data visualization algorithms including PCA,
PLSDA and SAM were used to determine significant differences and eliminate false discoveries in the
data. Compound ID, HormonomicsDB, and pathway deconvolution algorithms were used to predict
specific compounds and mechanisms. Growing temperature significantly affected 222 features in C.
regelii and 110 features in S. longipes. Important biosynthetic pathways that are responsive to
temperature in these species include the GOGAT pathways, shikimic acid biosynthesis pathways,
polyamine metabolism and cytokinin biosynthesis. Interestingly, dihydrozeatin-O-glucoside and meta-
topolin metabolism were induced by temperature increases and associated with increased growth. The
data proposes several new hypotheses for plant adaptation mechanisms that may be important factors in
plant resiliency or vulnerability to climate change.

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