Year: 2010
Type: dissertation
Abstract: Salinity and drought are two major environmental stresses that affect agricultural productivity. To meet the food demand of an increasing population and a warming environment, the need to generate salt and drought tolerant crops is apparent. High salinity in the soil makes it harder for plant roots to extract water, and high concentration of salts within plant cells can be toxic to the cellular enzymes. One approach to improve salt tolerance in crops is to sequester excess sodium ion (Na+) into the large intracellular vacuoles via the tonoplast membrane. Consequently, there is reduction of Na+ in cytoplasm with the accumulation of compatible solutes that restore the correct osmolarity to the intracellular milieu, which favors water uptake by plant root cells and improves water retention in tissues under high soil salinity. This approach was successfully demonstrated in several plants, where overexpression of the Arabidopsis gene AtNHX1 that encodes a vacuolar sodium/proton (Na+/H+) antiporter resulted in a higher salt tolerance phenotype. \nPeanut (Arachis hypogaea L.) is an important crop of tropical and sub-tropical regions of the world. To improve yield and quality under salinity stress conditions, the Arabidopsis gene AtNHX1 was introduced into peanut through Agrobacterium-mediated transformation. The AtNHX1-expressing peanut plants produced more biomass when grown on up to 150 mM NaCl in greenhouse conditions. The increased growth of AtNHX1-expressing peanut plants is likely due to the consequence of higher photosynthetic rates in the transgenic plants compared to wild-type plants under saline conditions. The better performance of AtNHX1-expressing peanut lines compared to wild-type plants under high salinity indicates that AtNHX1 can be used to enhance salt tolerance in peanut.
Author: Manoj Banjara
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1667219329