Author : Tsuguhiro Hoshino

Summary : Drought, salt and freezing are environmental conditions that dramatically affect the growth of plants and the productivity of crops. Genetic engineering has high potential to improve the stress tolerance of crops using gene transfer technology. Recently, several different approaches to improve the stress tolerance of plants by gene transfer have been attempted. Approaches of partial improvement are the introduction of genes encoding enzymes required for the biosynthesis of various osmoprotectants, such as mannitol, proline and glycine betaine. Other introduced genes encode enzymems for modifying membrane lipid, LEA proteins and detoxification enzymes. In every approach a single protective protein or enzyme is produced in plants, although a number of genes have been shown to function in environmental stress tolerance and response. To develop biotechnology for improving stress tolerance, we analyzed plant responses to environmental stress.