Genome-wide identification, characterization, and expression profiling of TIFY family members in Panax notoginseng

In plants, TIFY proteins regulate growth, development, and stress response. Although the chromosome-level Panax notoginseng genome has been published, the PnTIFY gene family remains uncharacterized. Here, we conducted a comprehensive bioinformatic analysis of the PnTIFY gene family, including phylogenetic, gene structure, chromosome location, as well as tissue-specific and Fusarium solani-induced gene expression analyses.

A total of 26 PnTIFY genes were identified and distributed on all twelve chromosomes. The TIFY genes of P. notoginseng, Arabidopsis thaliana, and Oryza sativa were divided among the JAZ (further divided into three subgroups), TIFY, ZIM/ZML, and PPD subfamilies. PnTIFY genes belonging to the same subfamily tended to have similar gene structures and conserved domains. Collinearity analysis showed that segmental duplication events played a key role in the expansion of the PnTIFY gene family. Cis-elements related to phytohormones, stress, and light were identified in the PnTIFY gene promoters, suggesting roles in growth and stress adaptation. JAZ I subgroup genes were highly expressed in flowers and leaves, while JAZ II/III and ZIM/ZML members exhibited stable, tissue-wide expression. JAZ II/III genes were prominently upregulated in older roots, implicating their roles in jasmonic acid signaling and secondary metabolism. Finally, qRT-PCR analysis revealed that PnJAZ2/4/6/16/17 were strongly induced in response to F. solani infection.

The results of this study clarify the molecular regulatory network underlying the response of P. notoginseng to soil-borne fungal diseases and will aid in the development of disease-resistant varieties.