Abstract Detail

Ecology

Gallick, Christina [1], Oakley, Christopher [2].

Natural Variation in Drought Tolerance of Arabidopsis thaliana.

Drought frequency and severity is expected to increase regionally due to climate change, which will have negative consequences for natural plant populations. Arabidopsis thaliana is a widespread winter annual adapted to seasonal droughts coincident with the onset of flowering. Most research on drought tolerance in this species has not imposed drought treatments during flowering, the relevant life cycle stage. We quantified natural variation in late-stage drought tolerance in A. thaliana ecotypes and examined how well the origin climate predicted drought tolerance. We imposed drought treatments of different severities on late-stage plants of ecotypes from Sweden, Italy, and Spain and measured survival, flowering time, fruit production, seed production. To examine transgenerational effects of drought, we then performed a germination assay using seeds produced under drought and control conditions. All plants survived the drought treatments, but there were strong and significant differences in the effects of drought on fruit production among the ecotypes that were dependent on treatment. All ecotypes experienced similar reductions in fitness due to drought in one drought treatment, but reductions in fitness ranged from 10-97% in another. There was evidence of selection for earlier flowering in response to drought stress, but there was no adaptive plasticity in flowering time. This suggests that natural variation in drought tolerance in A. thaliana is more likely to be mediated by changes in physiology than in phenology. Surprisingly, drought tolerance was not significantly related to climate of origin variables like mean precipitation. However, we could not examine temporal variation in climate variables, which is likely important for differential adaptation to drought. Germination rate of seeds produced during a drought was generally lower than that of seeds produced in well-watered conditions, indicating fitness reductions via transgenerational effects compound the fitness consequences of drought on fruit number. By understanding how ecotypes respond to different drought treatments, we can better predict how different A. thaliana will be affected by climate change.

1 - Purdue University, Biological Sciences, 915 W State Street, West Lafayette, IN, 47907, USA
2 - Purdue University, Botany And Plant Pathology, 915 W State Street, West Lafayette, IN, 47907, United States

Keywords:
Drought Tolerance
natural variation
transgenerational effects
Plasticity
flowering time
G x E
abiotic stress.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC013
Abstract ID:659
Candidate for Awards:Phytochemical Best Poster Award