Salt Responsive Alternative Splicing of a RING Finger E3 Ligase Modulates the Salt Stress Tolerance

Increasing evidence points to the tight relationship between alternative splicing (AS) and salt stress response. However, the insights into molecular regulatory mechanisms linking those two factors are limited. Here, we found that Salt Responsive Alternatively Spliced gene 1 (SRAS1), encoding a RING-Type E3 Ligase, generates two splicing variants: SRAS1.1 and SRAS1.2, which showed opposing responses to salt stress. The salt stress-responsive AS event thus resulted in greater accumulation of SRAS1.1 and a lower level of SRAS1.2. The full-length SRAS1.1 protein has E3 ubiquitin ligase activity while the truncated SRAS1.2 lacks E3 ligase activity.