Transcription Factor SiDi19-3 Enhances Salt Tolerance of Foxtail Millet and Arabidopsis

Salt stress is an important limiting factor of crop production. Foxtail millet (Setaria italica L.) is an important model crop for studying tolerance to various abiotic stressors. Therefore, examining the response of foxtail millet to salt stress at the molecular level is critical. Herein, we discovered that SiDi19-3 interacts with SiPLATZ12 to control salt tolerance in transgenic Arabidopsis and foxtail millet seedlings. SiDi19-3 overexpression increased the transcript levels of most Na+/H+ antiporter (NHX), salt overly sensitive (SOS), and calcineurin B-like protein (CBL) genes and improved the salt tolerance of foxtail millet and Arabidopsis. Six SiDi19 genes were isolated from foxtail millet. Compared with roots, stems, and leaves, panicles and seeds had higher transcript levels of SiDi19 genes. All of them responded to salt, alkaline, polyethylene glycol, and/or abscisic acid treatments with enhanced expression levels. These findings indicate that SiDi19-3 and other SiDi19 members regulate salt tolerance and other abiotic stress response in foxtail millet.

Automated summary

Salt stress is a significant limiting factor for crop production. In this study, we found that SiDi19-3 interacts with SiPLATZ12 to regulate salt tolerance in transgenic Arabidopsis and foxtail millet seedlings. Overexpression of SiDi19-3 increased the transcript levels of various salt-responsive genes and improved salt tolerance in foxtail millet and Arabidopsis. Our findings suggest that SiDi19-3 and other SiDi19 members play important roles in regulating salt tolerance and other abiotic stress responses in foxtail millet.