Genome-wide identification and functional analysis of GRAS transcription factors in Perilla frutescens reveals the positive role of PfGRAS70 in regulating rosmarinic acid biosynthesis

Perilla frutescens (L.) Britt., an important medicinal and aromatic plant, is widely utilized in traditional Chinese medicine and health food products. GRAS transcription factors vitally drive plants’ growth, development, and environmental stress responses. Nevertheless, the functional role of GRAS transcription factors in P. frutescens remains unexplored. This study identified 83 PfGRAS genes in total from the P. frutescens genome and divided them into nine subfamilies by phylogenetic analysis. According to conserved motif analysis, genes within the same subfamily demonstrated comparable conserved motifs. Most PfGRAS genes lacked introns and their promoters contained multiple cis-acting elements that regulate plant hormone and stress responses. PfGRAS70 was localized to the nucleus and plasma membrane and possessed transcriptional activation function. Overexpression of PfGRAS70 in P. frutescens hairy roots increased rosmarinic acid content, suggesting that PfGRAS70 may positively regulate rosmarinic acid biosynthesis. qRT-PCR and yeast one-hybrid assays indicated that PfGRAS70 may promote PfC4H4 expression by binding to the TTTCATGT motif, accordingly benefiting the rosmarinic acid biosynthesis. Collectively, these findings highlight the potential value of PfGRAS70 in molecular breeding and provide a basis for further functional exploration. • Rosmarinic acid is the key compound determining the quality of Perilla frutescens. • Overexpression of PfGRAS70 enhanced rosmarinic acid accumulation by 1.6-1.76 fold. • PfGRAS70 specifically binds to the TTTCATGT motif. • PfGRAS70 may regulate rosmarinic acid biosynthesis via interaction with PfC4H4.