Differentially Expressed Genes Associated with Salt Tolerance in Soybean.

Salt stress causes foliar chlorosis and scorch, plant stunting, and eventually yield reduction in soybean. Soybean plants develop the salt-tolerance mechanisms through maintenance of ion homeostasis, osmotic adjustment, oxidative balance restoration, and metabolic and structural adaptation, while salt tolerance could be contributed to the transcript regulation of stress-related genes. Identification of the genes responsible for salt tolerance in soybean will facilitate understanding the molecular mechanisms of salt tolerance, and also facilitate the genetic improvement of soybean through marker-assisted selection (MAS) or gene transformation. The objectives of this study were to identify the genes differentially expressed between salt-tolerant and salt-sensitive lines using RNA sequencing, and to annotate the function of stress-related genes. Five salt tolerant genotypes and five salt sensitive genotypes were selected from F_4:6 lines derived from RA-452 x Osage, and were treated with 250mM NaCl, 250mM KCl, and tap water for 36 hours. The treatment was imposed beginning at the V1 stage and continued for 36 hours. Total RNA were isolated from the leaves harvested at 0, 12, 24, 36h, respectively. RNA samples representing each group were submitted to Illumina Inc. for sequencing. qRT-PCR were performed to verify the data obtained by Illumina RNA-seq. The results will be summarized and presented when the experiment is completed.