Thermotolerance of Populus euphratica cell suspensions

Abstract

Abiotic stresses, such as extreme temperatures, drought, salinity, chemical toxicity and oxidative stress are serious threats to agriculture and result in the deterioration of the environment. Abiotic stress leads to a series of morphological, physiological, biochemical and molecular changes that adversely affect plant growth and productivity. Populus euphratica Olive, is the only arborescent species naturally distributed at the limit of barren desert or semi-barren desert worldwide (being native to northwest China, middle and west Asia and some areas in Europe), and is well known for its natural tolerance to extreme temperatures (-40ºC to +45ºC). Its relatively small genome and easy manipulation in vitro made it an excellent model to the study of thermotolerance mechanisms among trees. Studies on physiological characterization of heterotrophic cell suspensions of Populus euphratica were attempted subjecting cells to different temperatures. Cells collected at exponential growth phase were subjected to temperatures within the range +5ºC to +75ºC, and allowed to recover at 25ºC. The evaluation of biomass and cell viability before and after the thermal shock revealed the array of temperatures non-lethal to this species (+5ºC to +45ºC). Furthermore, assessment of reactive oxygen species (ROS) after thermal shock and during recovery is in progress.