Page 222 - PC2019 Program & Proceedings

PLANT CANADA 2019

P17. Investigating the relationship of HD2 family histone deacetylases in response to drought stress
in Arabidopsis thaliana
*1
1
Tahir, M. ; J. Karagiannis ; L. Tian
2
1 University of Western Ontario
2 Agriculture and Agri-Food Canada
Despite the evidence that plant-specific histone deacetylase 2 (HD2) family plays significant role in the
abiotic stress responses of plants, the relationship of histone deacetylases (HDACs) among HD2 family in
response to environmental stresses remains largely unknown. Objective of this study is to investigate the
relationship of four HD2-type HDACs in Arabidopsis in response to drought stress. In-vitro yeast two-
hybrid assay showed interaction of HD2A, HD2C and HD2D proteins among each other. This indicates
that HD2A, HD2C and HD2D proteins may be related to regulate the abiotic stress response. All HD2
genes demonstrated significant variation in their expression under drought stress. T-DNA insertion
mutant lines of each HD2 gene were screened and expression of all HD2 genes was analysed in each
single hd2 mutant line. To further study the HD2 family relationships, overexpression (OE) lines of each
HD2 gene were developed. Expression of all HD2 genes in each HD2-OE lines will be analysed.
Moreover, effect of OE and knockout of HD2 genes on primary root length, no. of lateral roots, plant total
biomass and plant survival under drought stress will be studied to investigate the relationships of HD2
family members. Knowledge generated from this research will be useful to improve our understanding
about the interactional role of HD2-type HDACs in mediating the plant response toward drought stress.

Muhammad Tahir (mtahir25@uwo.ca)

P18. Genetic variation for yield formation traits affecting drought tolerance in commercial soybean
[Glycine max (L.) Merr.] varieties adapted to Ontario
*
Gebre, M.G. ; H. Earl
University of Guelph

Drought stress significantly limits soybean yields in Ontario, Canada, with demonstrated losses ranging
from 8-24%. In a greenhouse experiment, we compared fifteen Ontario-adapted soybean varieties for
their drought tolerance. Plants were grown in field soil amended with sand in 1 m long, 10-cm diameter
rooting columns. The soil water content was maintained at 100% field capacity by daily weighing and
watering until the R1 developmental stage. From R1 until maturity, columns were maintained at either
100% (control) or 50% (drought stress) capacity. There were significant variety and treatment effects for
seed yield and yield components (pod number, seeds per pod, seed size) and related traits (whole-plant
biomass, water use, and water use efficiency). The drought stress significantly reduced seed yield, pod
number, whole-plant biomass, and plant water use each by about 50%. There were significant variety x
treatment interactions for seed yield, pod number, and water use. Based on their ratio of seed yield
between drought stress and control conditions, we identified two drought-sensitive varieties (Saska and
OAC Drayton) and three drought-tolerant varieties (OAC Lakeview, OAC Champion, and PRO
2715R). Principal component and correlation analyses revealed that high water use efficiency under stress
was strongly associated with high seed yield ratio. Drought-tolerant varieties were also those that
maintained high water use, shoot dry matter, and pod number under stress conditions relative to control
conditions.

Michael G. Gebre (mgebre@uoguelph.ca)

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