1. Abdelali Hannoufa (PI) (Abdelali.Hannoufa@agr.gc.ca) and Lisa Amyot (technician)
A major goal of our research is to improve the
quality and yield of plant biomass by identifying and
characterizing factors that regulate cell wall
development and biomass production.
Genomics of Value-Added Traits in Canadian Crops
We are exploring the role of the miR156 regulatory
network in determining flowering time and plant
biomass (Fig. 2), and investigating the relationship
between miR156 and its target genes on
strigolactone biosynthesis, and subsequently root-
rhizobia symbiosis. These traits are all important for
maximizing forage and bioenergy crop production.
Camelina sativa is a new oilseed crop in Canada.
We are working with other scientists to improve
seed quality. Our goal is to reduce the undesirable,
anti-nutritional components in the seed, such as
phytate and sinapine, to allow for use in livestock
and fish feed.
Forage enhancement
miR156, a novel regulator of
plant biomass production
Improving canola seed Camelina, a new oil seed for Canada
Enhancing plant biomass
To improve the digestibility of plant biomass,
including forages, bioenergy crops, and agricultural
by-products, we are looking at ways to modify the
chemical composition of the rigid secondary plant
cell walls. Several key regulators of lignin
biosynthesis have been characterized in our
laboratory, including Diminuto1 (Fig. 1) and
Elongation Factor eEF1Bβ1.
DIM-RNAiWT DIM-OE
Figure 1. Phloroglucinol (lignin) staining of stem cross
sections from control (WT), and Dimunto1 over-
expression (DIM-OE) and knockout (DIM-RNAi) lines.
Owing to its high protein quality, canola seed is a
potential source of ingredients for fish and livestock
feed formulations. We have boosted its nutritional
value by reducing levels of anti-nutritional factors
and enhancing desirable metabolites.
To increase carotenoid production in canola seed,
we targeted lycopene Ɛ-cyclase (Ɛ-CYC). Silencing
of Ɛ-CYC resulted in an over 50-fold increase in
total carotenoids (Fig. 3).
Enhancing carotenoid content
Sinapine is an alkaloid compound that imparts a
pungent taste to the seed meal thereby reducing
feed palatability. We have targeted key regulatory
steps in the sinapine biosynthesis pathway to
reduce sinapine levels in camelina seed. We
previously used a similar approach to reduce
sinapine by 90% in canola seed.
Reducing sinapine levels
Figure 3. Carotenoid extracts from seeds showing the
increased levels of pigments in Ɛ-CYC-silenced lines
Control Ɛ-CYC-silenced lines
Reducing phytate levels
Figure 4. Total seed carotenoids levels increased 5-fold in
the TILLING splice mutant relative to the control.
Producing novel carotenoids
A goal of ours is to engineer lines containing high
levels of carotenoids with β-carotene ketolase in
order to produce astaxanthin. Astaxanthin is a
highly valuable pigment used in the aquaculture
and nutraceutical industries.
Phytate is an indigestible phosphorus compound
that interferes with nutrient absorption and causes
environmental problems in water systems. We
have developed a strategy to greatly reduce levels
of phytate in camleina seed.
Acknowledgements
The team (from left): Shailu Lakshminarayan, Spencer Jones, Saoussen Ben Abdallah, Lisa
Amyot, Banyar Aung, Ying Wang, Ali Hannoufa, Davood Emami
miR156 overexpressioncontrol
Figure 2. Over-expression of miR156 in alfalfa imparts a
“bushy”, late flowering phenotype.
We used the non-GMO TILLING (Targeting
Induced Local Lesions IN Genomes) approach to
generate canola lines with defective Ɛ-CYC. A total
of 24 mutants were identified with mutations in the
Ɛ-CYC gene, some of which had increased seed
carotenoid levels (Fig. 4). These seeds can be
incorporated into breeding programs to develop
alternative poultry and fish feed ingredients.