Genes and salt tolerance: bringing them together

Summary Salinity tolerance comes from genes that limit the rate of salt uptake from the soil and the transport of salt throughout the plant, adjust the ionic and osmotic balance of cells in roots and shoots, and regulate leaf development and the onset of senescence. This review lists some candidate genes for salinity tolerance, and draws together hypotheses about the functions of these genes and the specific tissues in which they might operate. Little has been revealed by gene expression studies so far, perhaps because the studies are not tissue‐specific, and because the treatments are often traumatic and unnatural. Suggestions are made to increase the value of molecular studies in identifying genes that are important for salinity tolerance. Contents Summary 645 I. Introduction 645 II. Physiological mechanisms of salt tolerance 646 III. Candidate genes for salt tolerance and results of transformation experiments 650 IV. Gene activity expected in roots, leaves and growing tissues of plants exposed to salinity, and results of gene expression studies 655 V. Conclusions 660 Acknowledgements 660 References 660