Page 132 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

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1 ), straw (by 1.32 Mg ha ) and biomass (by 2.49 Mg ha ) yields of only wheat. Yields of barley, canola
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and soybean weren’t affected by EcoTea seed treatment. Among crops, barley produced the highest
grain (3.59 Mg ha ), straw (6.66 Mg ha ) and biomass (9.80 Mg ha ) yields. Farmers are recommended
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to treat wheat seed with EcoTea for increasing grain, straw and biomass yields of wheat.
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[O61] COVER CROPPING AND NITROUS OXIDE EMISSIONS IN THE RED RIVER VALLEY. Mario
Tenuta, Shannon Mustard, Katie Webb, Junaid Afzal, Rida Sabirova, and Brad Sparling. Department of
Soil Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
Correspondence to: mario.tenuta@umanitoba.ca

Achieving crop production that is net zero for greenhouse gas emissions involves reducing the losses of
nitrous oxide (N2O) from nitrogen fertilizer applied to soils. Nitrification inhibitors, DCD and nitrapyrin with
urea (46-0-0) and UAN (28-0-0) fertilizers, can reduce emissions of N2O by 30-50%. However,
commercial nitrification inhibitors such as pronitridine and DMPP are recently available in commercial
products and if they reduce emissions is not well known. Here we examined in 2023 and 2024 in two farm
studies spring and fall application of a pronitridine (Centuro) product with anhydrous ammonia (82-0-0).
We also conducted four field trials with DMPP and urea applied in spring to canola. 2023 was a dry year
with low emissions. Centuro did not reduce emissions at either farm site and DMPP did not reduce
emissions at all four trial sites. 2024 is off to a much wetter start and results available for one site indicate
Centuro is reducing emissions so far. The laboratory results showed Centuro or DMPP with UAN to also
not reduce emissions though nitrapyrin (eNtrench) and, to a lesser extent, DCD, to reduce emissions.
Here, we discuss some possible reasons why the newer products were not be effective in reducing N2O
emissions.

[O62] MOLECULAR ANALYSES OF DIFFERENTIAL RESISTANCE IN LODGEPOLE AND JACK PINE
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TO CRONARTIUM HARKNESSII, THE CAUSAL AGENT OF WESTERN GALL RUST. Janice Cooke ,
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Samson Osadolor , Rhiannon Peery , Laura Manerus , Marion Mayerhofer , L. Irina Zaharia , and
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Chandra McAllister . Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9,
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Canada; National Research Council of Canada, Aquatic and Crop Resource Development Research
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Centre, Saskatoon, SK S7N 0W9 Canada; Present address: Natural Resources Canada, Canadian
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Forest Service, Pacific Forestry Centre, Victoria BC V8Z 1M5 CANADA; and Present address: Entos
Pharmaceuticals, San Diego CA 92121 UNITED STATES
Correspondence to: janice.cooke@ualberta.ca

Forest health is profoundly impacted by pests and pathogens. In Canada, the forest area affected by
pests and pathogens each year exceeds the annual harves, and is predicted to increase under climate
change [2]. Western gall rust is a disease of pines caused by the fungal pathogen Cronartium harknessii
Meinecke (syn. Endocronartium harknessii (Moore) Hiratsuka). C. harknessii causes tree stunting and
deformation, and can result in seedling mortality. The most economically and environmentally important
hosts for C. harknessii are lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and jack
pine (Pinus banksiana Lambert) [6]. Lodgepole pine is found in the mountain regions of western North
America, while jack pine spans the boreal forest from Alberta to the Maritimes. C. harknessii belongs to
Class Puccinales (Basidiomycota), members of which are considered to be obligate biotrophs. We have
demonstrated that lodgepole pine is more susceptible to C. harknessii than jack pine. RNA-Seq of mock-
inoculated vs. C. harknessii-inoculated lodgepole and jack pine seedlings revealed that jack pine mounts
a quicker, more intense response at the level of gene expression than does lodgepole pine.
Simultaneous quantification of C. harknessii transcripts – sometimes called dual RNA-Seq – indicates
that jack pine’s concerted gene expression defense strategy is more effective at limiting pathogen
colonization than that of lodgepole pine. Mining of functional annotation categories that were significantly
enriched in jack pine but not lodgepole pine suggests that jack pine effectively constrains C. harknessii
colonization via cell wall remodeling together with increased terpenoid and phenolic defense metabolite
synthesis. RNA-Seq data suggested that this response is regulated at the transcriptional level as well as
at the level of post-translational modification. Several transcription factors belonging to families with well-
established roles in plant immunity were upregulated early in jack pine’s response to C. harknessii
inoculation, but not in lodgepole pine. Given that salicylate is canonically implicated in plant responses to
biotrophs, we had predicted that salicylate would be invoked in pine responses to C. harknessii.
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