RIG/CAA: Salinity Tolerlance Mechanisms in Ceratopteris Richardii

Clark Atlanta University, Atlanta GA

Investigators

Abstract

C-Fern, Ceratopteris richardii is a model plant for determining the cellular and genetic bases for salt tolerance in plants. Salt tolerance mechanisms in plants are relatively unknown because few salt tolerant mutants exist. C-Fern has several different salt tolerant mutants. Each salt tolerance mutant has different single mutant genes that allow the plant to grow in high levels of salt. These salt tolerance mutant plants are unique in that they are the small, heart-shaped sexual reproductive phase of the ferns, which is separate from the larger fern body. The physiology of salt tolerance in a mutant named stl2 is well characterized, as is the salt response of the normal plant. Unlike the stl2 mutant, calcium treatment counteracts the effects of salt stress in the normal plant by restoring potassium/sodium balance. Calcium treatment has little effect on the growth and potassium/sodium balance of the stl2 mutant under salt stress. Therefore, calcium may have a special role in the salt tolerance of the stl2 mutant. The major goals of this research are the determination of the salt stress response, the mechanism of that response that contributes to salt tolerance, and the role of calcium in both the normal plant and the stl2 mutant. The analysis of existing genetic data in the public domain on salt stress responses in the model plant, Arabidopsis, will provide a foundation for this research on salt tolerance of the C-Fern stl2 mutant. In Arabidopsis the salt stress responses vary among different tissues and stages of development. These responses are confined to a small group of genes that are consistently induced by salt stress in two or more tissues. Some of these genes may also be responsible for the salt tolerance found in the mutant fern. Broader Impacts - Increasing the salt tolerance of food and fiber crops is a major goal for agriculture. This will permit increased growth and commercial yield of plants on marginal lands or irrigated lands where salt concentration is high. This work will complement the salt tolerance research in Arabidopsis as well as provide evolutionary evidence for the development of salt tolerance in vascular plants. Since this research project takes place at Clark Atlanta University, an HBCU, African American undergraduate and graduate students will be trained in current molecular and genomic techniques using a plant model system through classroom experiences, student research projects, and laboratory rotations.