Abstract:GNOM is a kind of guanine nucleotide exchange factor (GEF) of ADP ribosylation factor (ARF). In order to explore the function of GNOM in stress resistance of Dryopteris fragrans, we cloned DfGNOM and analyzed by bioinformatics. The expression pattern of DfGNOM gene under different plant hormones and stress was analyzed by realtime fluorescent quantitative PCR (qRTPCR). The results provide a basis for further exploring the function of the gene and the stress resistance mechanism of D. fragrans. The results showed that: (1) DfGNOM was obtained with a total length of 4 338 bp. Multiple protein sequence alignment and phylogenetic tree analysis showed that DfGNOM was closely related to Selaginella moellendorffii SmGNOM, and motif analysis showed that the protein contained the sec7 conserved domain. (2) qRTPCR analysis showed that: DfGNOM was expressed in the roots, petioles and leaves of D. fragrans, but the highest expression was in the leaves; the relative expression of DfGNOM was upregulated after IAA treatment; abscisic acid (ABA) treatment decreased the expression level; under NaCl treatment, the trend was “downupdown”; under high temperature and low temperature treatment, the trend was “updownup”. The relative expression patterns of DfGNOM were also different under the treatments of MeJA, ETH and PEG. The results showed that DfGNOM played a regulatory role in the abiotic stress response of D. fragrans.