Comparative Analysis of Gene Expression Related to Salt Tolerance with Sorghum (Sorghum bicolor L. Moench) Mutants L. Moench) Mutants

Sorghum is the fifth most important grain crop worldwide. It is not only used as food and feed, but also as a resource forbiofuel production. In addition, it has potential uses as a model plant for research on adaptation to environmental stress. In this study,mutant sorghum lines were generated by gammy ray irradiation. Ten of the M6 sorghum mutant lines were selected from 28 mutant lineson the basis of agronomic characteristics. These 10 lines, along with their original accessions/cultivar, were evaluated to determine thegermination rate and the shoot and root length under salt treatment. Compared with their original accessions, three mutant lines (B5,SY6, and SY7) showed significant differentiation under saline conditions (150 mM NaCl), with increased shoot length (by 1.3-2.2times) and root length (by 1.5-2.5 times). We determined the transcript levels of 20 abiotic stress-responsive genes in B5 (the mostsalt-tolerant mutant) and its original accession. These genes included those encoding heat shock proteins, aquaporins, ROS scavengingsystem, and transcription factors. In the B5 mutant, 15 genes showed differences in transcript levels between the control and the salttreatment. Salt treatment resulted in significant up-regulation of Sb03g045840 and down-regulation of Sb3g030750 in the B5 mutant. Here, we reported a simple method to identify genes related to salt tolerance in a sorghum mutant.