Poster Presentation 2014 International Biophysics Congress

How does isoprene protect plants from heat stress? Investigation using model lipid membranes (#309)

Uzma M. Malik 1 , Neville T. Charles 1 2 , Thomas Lenné 2 , Marilyn C. Ball 2 , Gary Bryant 1
  1. Centre for Molecular and Nanoscale Physics, RMIT University, Melbourne, VIC, Australia
  2. Research School of Biology, Australian National University, Canberra, ACT, Australia

Isoprene is a volatile hydrocarbon emitted by many species of plants and has a significant effect on atmospheric chemistry. The incidence and rate of isoprene emission in plants is dependent on local climate, light and temperature, and the taxonomy of isoprene emitting species is well established. Exogenous and endogenous isoprene has been shown to protect plants from damage due to rapid heat spikes and to reactive oxygen species (ROS). However, the mechanism by which isoprene protects plants is still unknown.

In this paper we present the results of Small and Wide angle X-ray scattering (SAXS/WAXS) and differential scanning calorimetry (DSC) studies of the effects of isoprene on model DPPC (dipalmitoylphosphatidylcholine) membranes. We present results showing that isoprene significantly affects the structure and phase transition behavior of the membrane, and conduct a quantitative study as functions of temperature, hydration and isoprene:lipid ratio.

Using these results, we present a possible mechanism to explain the role of isoprene in protecting plants from heat stress.