A review of extraction and analysis: Methods for studying osmoregulants in plants
School of Science / Centre for Ecosystem Management
Compatible osmolytes are substances produced by plants exposed to stressful environmental conditions. These protect plants during stress by performing several functions including scavenging of free radicals and maintenance of osmotic balance. The three most commonly examined include proline, mannitol and glycine betaine. Extraction and analysis of osmolytes are essential steps for a number of applications including estimation of the potential of new breeds, genetically engineered plants, and plants exposed to extreme environmental conditions. A wide range of extracting solvents have been used for the three key osmoregulants, and rarely is the selection of the extracting solvent experimentally determined. Furthermore, in many studies involving two or more osmolytes each is extracted individually. Similarly, there are a variety of methods reported for the quantification of these compounds. As with extraction, a separate method is often applied in quantifying each osmoregulant. Therefore, the aim of this review is to provide a detailed overview of the available methods for extraction and quantification of compatible osmolytes for the study of plant stress. Furthermore, the methods available for simultaneous extraction and quantification of key osmoregulants have been described.