The Role of SCARECROW-LIKE 3 in Salt Tolerance During Germination and Seedling Development in Arabidopsis thaliana

Abstract

Salinity is a stress factor that results in reduced crop productivity. As much as three hectares of arable land is lost due to salinity per minute. With an increasing world population and shrinking arable land, world crop production must increase by at least 20% in the next two decades to avoid global food crisis according to the Food and Agriculture Organization. It is imperative to investigate and develop salt tolerance in plants so that saline land can be reclaimed for agricultural use. Much study has been done to understand the mechanism of salt stress response in plants; however, most of the intermediates involved in the stress signaling process have not been identified. We investigated the role of a GRAS family member called SCARECROW-LIKE 3 (SCL3) in salt tolerance in Arabidopsis thaliana. We used mutant alleles of SCL3, each having a T-DNA insertion at different positions of the gene to investigate the mutant phenotype and RNA expression pattern. By exposing mutants to high NaCl concentrations, we demonstrated that the mutants exhibited a delay in germination and stunted root length phenotype when compared to wild-type. Using reverse transcription PCR (RT-PCR), we observed a change in the transcription levels of the mutant alleles when compared to WT during salt stress. We also observed an absence of the C terminal of the RNA transcript in two mutants which correlated with the severity of the mutant phenotypes. Our work indicates that SCL3 is involved in salt tolerance during both germination and during seedling development.