CHANGES OF LOW-MOLECULAR-WEIGHT SUBSTANCES IN BOEA-HYGROSCOPICA IN RESPONSE TO DESICCATION AND REHYDRATION

Boea hygroscopica is a poikilohydrous plant. This and similar species are also called desiccation-tolerant or resurrection plants. They have the unique ability to revive from an extreme air-dry condition. Samples of fresh, dried and rehydrated leaves were analysed for the major classes of organic substances like sugars, alditols, inositols, fatty acids, amino acids, betaines, phytosterols and others. The compounds which accumulated in desiccated leaves were sucrose and polyunsaturated C18 acids. Abietanes and pimaranes were also detected. Monosaccharides, which are present in fresh leaves, disappeared, whilst phytosterols, stearic and oleic acids decreased to low levels; palmitic acid was unchanged. Rehydration of dried leaves seemed to restore the chemical composition of unstressed leaves. Betaines were not detected in any of the plant samples examined.