Abstract Detail

Bryology and Lichenology

Herath, Hansika [1], McLetchie, Nicholas [2].

Testing for long-term acquired thermotolerance in the tropical plant Marchantia inflexa.

Climate change and increasing temperature causes a great threat to plant productivity and their ecological stability. The rise in temperature by 10-15 ⁰C over the ambient temperature is considered a heat stress. Depending on the intensity, duration and the frequency of heat stress, plants may show complex and variable cellular responses. One such response is acquired thermotolerance (due to a mild priming heat stress event), which can be short- and long-term. Short-term acquired thermotolerance last for minutes to a few hours while long-term acquired thermotolerance last for a longer period (> 48 hours) after the priming event. Many plant species, including crop plants, have been well studied for short-term acquired thermotolerance. However, long-term acquired thermotolerance has only been studied in Arabidopsis and is predicted to decline overtime. Here, we used Marchantia inflexa to test for the presence of long-term acquired thermotolerance and the gradual decline with the length of time between priming and the subsequent heating event. Thallus tips were collected from plants growing in the growth chamber and then subjected to heat treatment assays with one-, two-, four-, and eight-days between an initial mild heat stress and the high temperature challenge. Percent recovery was calculated by measuring quantum efficiency of photosystem II. After the heat challenge, we detected higher recovery of plants subjected to the initial heat stress (or priming) than those without the initial heat stress. Further, we observed a variable pattern of recovery for the one-, two-, four-, and eight-days intervening periods rather than a consistent, gradual decrease in thermotolerance. A comprehensive understanding of plants' responses of long-term acquired thermotolerance requires additional studies. The information obtained from such phenotypic studies can be used to elucidate underlying molecular mechanisms that can be useful in improving crop thermotolerance and for purposes of species conservation in a broader sense.

1 - University Of Kentucky, Department Of Biology, 101 T. H. Morgan Building, Lexington, KY, 40506, United States
2 - University Of Kentucky, Department Of Biology, 101 Morgan Build., Lexington, KY, 40506, United States

Keywords:
Marchantia inflexa
Heat stress
Acquired thermotolerance
Acclimation
Chlorophyll fluorescence.

Presentation Type: Poster
Number: PBL001
Abstract ID:158
Candidate for Awards:None