The objective of this research proposal is to develop a cost-effective and reliable method for screening soybean cultivars for drought tolerance. The methodology uses an in vitro system in which the level of water stress applied to the plants can be easily manipulated and adjusted using polyethylene glycol as an osmotic agent.
Commercial soybean lines will be assessed for the ability to tolerate drought stress during germination, and during seedling establishment. Morphological growth parameters, as well as physiological measurements including photosynthetic rate, internal CO2 level and water use efficiency will be utilized to evaluate the response of the soybean cultivars exposed to different levels of water stress. Furthermore, the function of the protein phytoglobin (Pgb) and the possibility to use its expression level as a marker for predicting plant behaviour to water stress will be assessed using available methodologies to measure gene expression, as well as employing plants in which the level of Pgb has been experimentally altered.