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Climate change induces unexpected weather and causes abiotic and biotic stresses in plants. These stresses negatively affect crop growth and production. Additionally, a steady increase in the world population has been leading to higher food demand. Therefore, the development of more stress-resilient crops is essential to combat these problems. One such stress is a salinity that affects crop production. Almond is a salt-sensitive crop, so there is a need to identify salt-tolerant almond rootstocks. AtGCN4 is a novel gene that was identified in Arabidopsis thaliana to play a significant role in host-pathogen interaction and drought tolerance when overexpressed. The preliminary results show that GCN4 imparts salt tolerance too. Similarly, AtNHX2, codes for a sodium/hydrogen exchanger and is very well characterized in A. thaliana to play a significant role in salt tolerance. However, these genes have not been studied in almonds. In this study, we are amplifying both of these genes from Almond rootstock Nemagaurd. We have developed transgenic lines of PpNHX2 in the atnhx2 knockout mutant of A. thaliana for overexpression and endogenous level expression by floral dip transformations. We are selecting for the homozygous lines. We are checking the transgenic line by qRT-PCR for gene expression and genotyping. As GCN4 is an essential gene and complete deletion causes the death of the plant, we are expressing this gene in wildtype A. thaliana under 2X35S promoter for overexpression and under the native PpGCN4 promoter for endogenous expression using gateway technology. Once we select the homozygous lines, we will test them for salt tolerance at different levels of salt concentrations ranging from 50 mM to 150 mM NaCl. If almond PpGCN4 and PpNHX2 genes have the same function as Arabidopsis AtGCN4 and AtNHX2 genes, these genes can be used as a genetic marker in almond rootstocks to develop salt tolerance.
Utah State University
Moravek, Amanda, "Functional Complementation of the PpGCN4 and PpNHX2 Genes in Arabidopsis thaliana to Study Salt Tolerance" (2020). Fall Student Research Symposium 2020. 53.