Arabidopsis non-TZF gene AtC3H17 functions as a positive regulator in salt stress response.

Functional studies of CCCH-type zinc finger proteins in abiotic stress responses have largely focused on tandem CCCH-type zinc finger (TZF) genes, whereas the study of functional roles of non-TZF genes in abiotic stress responses has largely been neglected. Here, we investigated the functional roles of AtC3H17, a non-TZF gene of Arabidopsis, in salt stress responses. AtC3H17 expression significantly increased under NaCl, mannitol, and ABA treatments. AtC3H17-overexpressing transgenic plants (OXs) were more tolerant under NaCl and MV treatment conditions than the wild type (WT). atc3h17 mutants were more sensitive under NaCl and MV treatment conditions compared with the WT. The transcription of the salt stress-responsive genes in ABA-dependent pathway, such as RAB18, COR15A, and RD22, was significantly higher in AtC3H17 OXs than in WT both under NaCl-free condition and after NaCl treatment. Our results demonstrate that AtC3H17 functions as a positive regulator in salt stress response, via the up-regulation of ABA-dependent salt stress-response pathway.