Page 264 - PC2019 Program & Proceedings

PLANT CANADA 2019

P101. Investigating the systematic regulation and function of cyclic nucleotide-gated channels in
arabidopsis
*
Miraples, A. ; W. Moeder; Y. Keiko
University of Toronto

2+
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Despite the importance of Ca signals, Ca channels in plants are still not well understood. Cyclic
nucleotide-gated channels (CNGCs), one of the largest cation channel families in plants, are involved in
2+
Ca signaling and have been shown to be involved in a diverse array of physiological processes in plants
through their Ca channel activity. So far, genetic approaches have not been able to reveal the specific
2+
role of most individual CNGCs probably due to redundancies in their function. We have shown roles for
several clade I CNGCs in pathogen resistance, senescence and programmed cell death. However, most
single mutant phenotypes are very subtle. Therefore, we used a bioinformatics approach to investigate
stimulus induced co-expression patterns of the 6 members of clade I to create higher order knockouts
using a combination of T-DNA insertion lines and CRISPR/Cas9 technology. These mutants will be
tested in conditions where they have been reported to be involved in, and where they show similar
expression patterns. These conditions include pathogen resistance, salt and osmotic stress as well as
hormone induced senescence.

Angelica Miraples (angelica.miraples@mail.utoronto.ca)

P102. Identification and characterization of new lipid droplet proteins in Arabidopsis thaliana
3
2
2
4
*1
Doner, N. ; F. Kretzschmar ; T. Ischebeck ; K. Chapman ; J. Dyer ; R. Mullen
1
1 University of Guelph
2 University of Goettingen
3 University of North Texas
4 U.S. Department of Agriculture–Agricultural Research Service
Cytoplasmic lipid droplets (LDs) are evolutionarily-conserved organelles that function not only in neutral
lipid storage, but also in several cellular processes, such as membrane remodeling, stress responses, and
protein turnover. While LDs are known to form at the endoplasmic reticulum (ER), the molecular
mechanisms underlying their biogenesis, maintenance, and breakdown are largely unknown, particularly
in plants, where relatively few LD proteins have been studied. To help address the limited information,
recent proteomics surveys of isolated LDs from Arabidopsis thaliana seedlings and protein-protein
interactomes with known plant LD proteins serving as ‘bait’ were analyzed for new, putative LD proteins.
Using cell biology and reverse genetics approaches, selected proteins were investigated further in terms of
their localization to LDs or other intracellular compartments associated with LDs (e.g., ER). In addition,
alterations in expression were generated to examine changes in LD phenotype(s) such as changes in LD
size and/or number. Results from preliminary studies involving several candidate LD proteins will be
presented, including those for a previously uncharacterized plant-specific protein that localizes to the
surface of LDs and increases LD numbers when ectopically overexpressed in leaves. How these and other
newly-identified LD proteins may function in LD biology will be discussed, as well as their potential as
targets for bioengineering strategies directed at increasing storage oil content in seeds and vegetative
tissues of food and bioenergy crops.

Nathan Doner (donern@uoguelph.ca)

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