Page 153 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

biosynthesis and/or regulatory pathways from Arabidopsis (AtWRI1 and AtDGAT1) and Sesame
(SiOLEOSIN) into the oat cultivar ‘Park’ to modify the fatty acid composition. Four homozygous transgenic
lines were generated with a transformation frequency of 7%. The expression of these introduced genes
initiated a comprehensive transcriptional reprogramming in oat grains and leaves. Notably, endogenous
DGAT, WRI1, and OLEOSIN genes experienced upregulation, while genes associated with fatty acid
biosynthesis, such as KASII, SACPD, and FAD2, displayed antagonistic expression patterns between oat
grains and leaves. Transcriptomic analyses highlighted significant differential gene expression,
particularly enriched in lipid metabolism. Comparing the transgenic oat plants with the wild type, we
observed a remarkable increase of up to 34% in oleic acid content in oat grains. Furthermore, there were
marked improvements in the total oil content in oat leaves, as well as primary metabolites changes in
both oat grains and leaves, while maintaining homeostasis in the transgenic oat plants. These findings
underscore the effectiveness of genetic engineering in manipulating oat oil composition and content,
offering promising implications for human consumption and animal feeding through oat crop improvement
programs.

*[O102] THE RELATIONSHIPS AMONG PHYTOHORMONES AND BENZYLISOQUINOLINE
1
ALKALOIDS DURING EARLY DEVELOPMENT OF PAPAVER RHOEAS L. Zeynab Azimychetabi ,
1
1
Anna B. Kisiala , Scott C. Farrow , and R. J. Neil Emery . Biology Department, Trent University,
1
Peterborough, ON, Canada, K9L 0G2
Correspondence to: zeynazimychetabi@trentu.ca

Benzylisoquinoline alkaloids (BIAs) are widely distributed in the plant kingdom, playing essential roles in
defense against pathogens and herbivores. These compounds are of great interest for both ecological
and pharmaceutical research. The biosynthetic pathways of several BIAs in opium poppy (Papaver
somniferum) have been well-characterized, however, how individual genes within these pathways are
regulated remains largely unknown. Phytohormones are a class of naturally occurring, small organic
molecules that coordinate a comprehensive suite of physiological processes in plants at very low
concentrations. Because phytohormones may alter production of secondary metabolite defense
compounds, we hypothesize that phytohormones regulate BIA metabolism. To date, phytohormones and
BIA profiles have not been investigated simultaneously during ontogenesis in any member of the
Papaveraceae family. Therefore, we investigated phytohormone and BIA profiles of Field poppy (Papaver
rhoeas L.) during the first 5-days of in vitro culture. Our data clearly showed that the production of BIAs
depends on the developmental stage and starts between days three and four at shoot emergence.
Phytohormone profiles changed during this time simultaneously, and directly correlated with changes
observed in BIA levels. In addition, for the functional investigation of phytohormones that control the BIA
pathway, silencing their biosynthesis, degradation, and response factor genes will help confirm their
function. To knock down the genes related to phytohormones and BIA biosynthesis and/or regulation, we
used virus-induced gene silencing (VIGS). The results from the VIGS experiment demonstrated that
modifying the expression of genes associated with a class of phytohormones, Cytokinins, leads to
variations in the production of compounds across various branches of the BIA pathway.

[O103] PROANTHOCYANIDINS IN POPLAR ROOTS: EFFECTS ON MYCORRHIZAL COLONIZATION
AND NITROGEN UPTAKE. Daisuke Yamakawa, C. Peter Constabel, and Barbara J. Hawkins. Centre for
Forest Biology & Department of Biology, University of Victoria, PO Box 3020 STN CSC, Victoria, BC,
Canada, V8W 2Y2
Correspondence to: bhawkins@uvic.ca

Proanthocyanidins (PAs), also known as condensed tannins, are plant secondary metabolites commonly
found in trees. PAs are known for their roles in plant defense, soil nutrient cycling, and applications in
human medicine and diet. Although much research has focused on the roles of PAs in plant shoots, few
studies address the functions of PAs in roots. Evidence from in vitro studies suggests that PAs act as
anti-microbial and anti-fungal compounds. In roots, anti-fungal properties of PAs could negatively affect
colonization by mutualistic mycorrhizal fungi. We aimed to evaluate the effects of PAs on mycorrhizal
colonization in poplar roots, as well as on N uptake by colonized roots.

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