Membrane Transporters in Oxidative Stress

One of my Discovery projects deals with the role of membrane transporters in oxidative stress signalling and tolerance in plants. Reactive oxygen species (ROS) are ubiquitous second messengers in plants. At the same time, stress-induced elevation in ROS production is detrimental to crop performance. Thus, the ability of a plant to maintain the fine balance between ROS production and scavenging is critical to growth, development and adaptation. Specific physiological mechanisms controlling this balance remain obscure.

This project will reveal the identity of key membrane transporters mediating ROS signalling and tolerance in plants, and link them with plant adaptive responses to salinity and drought. The obtained results will be used by plant breeders to improve plant stress tolerance and minimise detrimental effects of salinity and drought on crop production.

The project aims to:

  1. reveal the stress specificity of ROS production in plants under drought and salinity;
  2. quantify the effects of various ROS species (H2O2 and •OH–) on activity of the key membrane transporters potentially contributing to cytosolic K+, Na+, and Ca2+ homeostasis; and (iii) to reveal the molecular identity of Ca2+ efflux systems contributing to cytosolic Ca2+ homeostasis, and their role in ROS stress signalling and adaptation.

Understanding mechanisms of Na+ uptake, transport and compartmentation between various plant tissues and organelles is paramount to overcoming salinity problem and breeding plants for salinity tolerance.

Until now, the progress in the area was significantly handicapped by the lack of appropriate techniques allowing in planta measurements of rapid Na+ flux kinetics across plant membranes.

The very poor selectivity of all existing Na+ liquid ion exchangers prevents the application of Na+-sensing microelectrodes in salinity research My another Discovery project is aimed to resolved this issue. Two major pathways are currently being explored:

  1. by using a lab-on-a-chip and
  2. by designing the new (more selective) Na+ ionophore.

The project utilises most recent advances in microtechnology and separation science and is aimed to produce a highly selective system for Na+ measurements with high spatial and temporal resolution, which then can be applied to address a range of fundamental physiological questions related to mechanisms of salt tolerance in plants.

Large volumes of saline wastewater are generated by industry and municipal water treatment processes every year. To be used for conventional crop irrigation, this water needs to be desalinised, at a very high cost. An economically viable alternative is to use (naturally salt tolerant) halophytes as an alternative cash crop species