Dissection of Genomic Regions for Ion Homeostasis under Sodic Salt Stress in MAGIC Rice Population

Salt tolerance mechanisms are regulated by balance in cell ionic concentrations such as K+, Na+, H+, Ca2+, and Mg2+. In this study, we examined major QTLs for the traits K+/Na+ homeostasis, shoot magnesium content (Mg2+), shoot calcium content (Ca2+), and shoot length. The QTLs for K+/Na+ homeostasis Sod K/Na.1 are associated with three candidate genes: LOC_Os02g48290, LOC_Os02g48340, and LOC_Os02g48350, and Sod_Ca.1 is associated with the gene LOC_Os08g15020. Three significant candidate gene haplotypes for shoot length, Sod_SL.1 (LOC_Os10g36690), sodium content Sod_Na.1 (LOC_Os01g41770), and magnesium content Sod_Mg.1 (LOC_Os10g31040) were identified. The identified candidate genes encode dehydration response proteins, leucine rich repeat proteins, citrate transporter proteins, and diacylglycerol O-acyltransferase (DGATs), and play a key role in salt and abiotic stress tolerance. The identified novel QTLs and potential candidate genes could be used for functional characterization to help further supplement our understanding of the genetic makeup of sodicity stress tolerance in rice.