Gene cloning and characterization of a nonspecific lipid transfer protein from sheep grass, Aneurolepidium chinense, grown in semiarid area

Abstract

Higher plants growing in a natural environment experience various abiotic stresses. Excessive environmental stress is a limiting factor of plant growth, development and agricultural productivity. Sheep Grass (Aneurolepidium chinense) is a pasture, which grows in semiarid area like in inland China and Mongolia. Sheep Grass can be alive on the severe environmental conditions like drought, high temperature at 42° (day) and low temperature at near 0° (night) in summer season. So we use it as a material for elucidating mechanism of stress-tolerance in higher plants. Nonspecific lipid-transfer proteins (nsLTP) consist of a family of proteins in yeasts, bacteria, animals and plants. So far, it has been thought that these nsLTPs bind with fatty acids and acyl-coenzyme A and thus transfer lipids between membranes. It is suggested that they seem to play a role in many different functions through their ability to bind and/or carry lipophilic compounds such as in cutin biosynthesis, pathogen-defence reactions and response to environmental stresses. We cloned a salt-induced nsLTP gene from Sheep Grass leaves by the differential display method. The gene was homologous to that of barely nsLTP previously reported. Southern blot analysis showed the existence of many nsLTP genes. We also did northern blot analysis. It appeared that the gene is sensitive to the high temperature treatment at 42°. We are now characterizing the gene expression on other abiotic stresses, of the developmental stages, and the localization of its gene product.