Abstract Detail

Biotic and abiotic stress

Hiiback, Katrina [1], Stokes, Michael [2], Mahtani, Trisha [3], Campbell, Malcolm M. [1].

Chemical priming can attenuate chilling-induced anthocyanin accumulation.

As sessile organisms, plants must contend with frequent fluctuations in environmental conditions. Priming is a mechanism in which early exposure to an environmental stimulus results in more rapid or vigorous response when the plant is exposed to subsequent challenges. Priming can thereby pre-condition plants for later fluctuations in environmental conditions. Although priming is understood for biotic stress conditions, under the name ‘systemic acquired resistance’, priming for abiotic stimuli is not well characterised. Using a high-throughput approach, a library of chemicals was tested to identify compounds that altered the response of Arabidopsis thaliana to a cold stimulus well after removal of the compound. Starting with thousands of small molecules, eight compounds from three structural categories were identified that had the ability to reduce the intensity of a visible phenotype in response to chilling, anthocyanin accumulation. Chilling-induced anthocyanin accumulation was markedly reduced in seedlings that had been exposed to the compounds, even though chemical exposure was limited to seed germination. There was a statistically-significant correlation between increased compound dose and decreased anthocyanin accumulation. The priming effect varied temporally, with significant differences observed between treatment regimes at different early developmental stages. Current research aims to determine if the observed anthocyanin response represents a primed relief from chilling specifically, or a persistent perturbation in the anthocyanin biosynthetic pathway. Concomitant alterations to seedling root architecture, overall biomass, and the timing of key developmental milestones suggests that different pathways may be affected by each class of the specific priming compounds. The duration of the persistence of compound treatment effects on anthocyanin accumulation is also under investigation. Further studies aim to illuminate the molecular basis of the chemically-induced phenotypes, with an emphasis on those that persist long after chemical exposure. It is hoped that these will begin to provide insights into abiotic priming.

1 - University of Toronto , Cell and Systems Biology , 25 Harbord Street, Toronto , Ontario, M5S 3G5, Canada
2 - Columbia University, Department of Biological Sciences, 550 West 120th St, New York, NY, 10027, USA
3 - University of Toronto Scarborough, Department of Biological Sciences, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada

Keywords:
Abiotic stress
priming
chemical genomics
Anthocyanin
chilling response
Arabidopsis thaliana.

Presentation Type: Oral Paper:Papers for Topics
Session: 7
Location: Salon 13/14/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 11:45 AM
Number: 7015
Abstract ID:540
Candidate for Awards:CSPB President's Award for Best Student Presentation