DROUGHT SIGNAL-TRANSDUCTION IN PLANTS

Water deficit is one of the most common environmental limitations of c rop productivity by affecting growth through alterations in metabolism and gene expression. The mechanisms involved in drought perception an d signal transduction pathways are poorly understood. The participatio n of the plant hormone abscisic acid (ABA) has been well established. ABA levels increase when there are changes in the environment that res ult in cellular dehydration. Different approaches have been taken to u nderstanding the molecular responses to desiccation and how ABA regula tes gene expression. Recent efforts have identified particular topics of importance in the dissection of the signal transduction pathway whi ch are summarized as follows: physiological approaches: identification of signalling molecules. Genetic approaches: the use of mutants, and Molecular approaches: promoter analysis.