Genome-wide identification of AP2/ERF gene family in Coptis Chinensis Franch reveals its role in tissue-specific accumulation of benzylisoquinoline alkaloids

Abstract

Background The Plant-specific AP2/ERF gene family encodes proteins involved in various biological and physiological processes. Although the genome of Coptis chinensis Franch, a plant producing benzylisoquinoline alkaloids (BIAs), has been sequenced at the chromosome level, studies on the AP2/ERF gene family in C. chinensis are lacking. Thus, a genome-wide identification of AP2/ERF gene family in C. chinensis was conducted to explore its role in BIAs biosynthesis. Results A total of 96 CcAP2/ERF genes were identified and categorized into five subfamilies, including 43 ERFs, 32 DREBs, 17 AP2s, 3 RAVs, and 1 Soloist, based on their structural domains. These CcAP2/ERF genes were unevenly distributed across nine chromosomes. Analysis of gene duplication events identified 17 CcAP2/ERF gene pairs in the genome, with 7 involved in tandem duplication events and 10 involved in segmental duplicate events, indicating that both types of duplications contributed to the expansion of the AP2/ERF gene family. The Ka / Ks ratio analysis suggested that the CcAP2/ERF gene family underwent strong purifying selection. Two phytohormones, methyl jasmonate and abscisic acid, were identified as potential key inducers of BIAs biosynthesis due to the cis -acting element prediction. Analysis of the spatial transcriptomic data revealed that 28 differentially expressed AP2/ERF genes had the highest or relatively higher expression levels in the rhizome, 17 of which positively correlated with the tissue-specific accumulation of BIAs. Further real-time PCR verification and protein-protein interaction analysis indicated that DREB1B might be one of the central regulators in a highly complex BIAs biosynthesis network. Conclusion These findings provide significant insight into the function of AP2/ERF genes in C. chinensis , particularly in the regulatory network of BIAs biosynthesis in C. chinensis . This study also identifies candidate genes for metabolic engineering to increase BIAs content in C. chinensis . Supplementary Information The online version contains supplementary material available at 10.1186/s12864-024-10883-1.