AtPPRT1 negatively regulates salt stress response in Arabidopsis seedlings.

Salt stress is one of the environmental factors that negatively affect plant growth and development. We have previously reported a putative C3HC4 zinc-finger ubiquitin E3 ligase (AtPPRT1) negatively regulates Abscisic acid (ABA) and drought stress response. According to previous studies, the accumulation of ABA in plants can further regulate the salt stress response. Therefore, in this study, we further analyzed whether AtPPRT1 negatively regulates the salt stress response. The results showed that expression was induced by salt stress. Furthermore, under salt stress, the β-glucuronidase () gene driven by the promoter has shown increased activity in the hypocotyl and petioles of Arabidopsis seedlings. Additionally, seedlings of the T-DNA insertion mutant showed significant growth advantage under salt stress, whereas overexpressing (OE lines) in Arabidopsis seedlings displayed hypersensitive under salt stress. Etiolated seedlings also demonstrated significantly elongated hypocotyl lengths in salt stress. The elevated or reduced salt tolerance of and overexpressing lines was confirmed by the changes in chlorophyll content and 3,3'-Diaminobenzidine (DAB) staining. The above data suggest that AtPPRT1 has a negative effect on salt tolerance in Arabidopsis seedlings.