Genome-Wide Analysis and Expression Profiles of Auxin Response Factors in Ginger (Zingiber officinale Roscoe)

Ginger, an economically important crop, fulfills multifunctional roles as a spice, vegetable, and raw material for medicinal and chemical products. The family of Auxin Response Factors (ARFs) plays an essential role in facilitating auxin signal transduction and regulating plant growth and development. However, the role of ARF genes in ginger, a crop of considerable economic importance, remains elucidated. In this study, a total of 26 ZoARF genes were identified in the ginger genome, which were further categorized into four subfamilies (I-IV) and displayed a non-uniform distribution across 11 chromosomes. The proteins are predominantly localized to the nucleus. Promoter regions contained numerous cis-elements linked to light signaling, phytohormones, growth, development, and stress responses. Collinearity analysis revealed 9 pairs of fragment duplication events in ZoARFs, all uniformly distributed across their related chromosomes. In addition, the expression profiles of ZoARFs in ginger were analyzed during development and under several stress conditions like ABA, cold, drought, heat, and salt, employing RNA-seq data and qRT-PCR analysis. Notably, expression profiling revealed tissue-specific functions, with ZoARF#04/05/12/22 associated with flower development and ZoARF#06/13/14/23 implicated in root growth. This work provides an in-depth insight into the ARF family and establishes a foundation for future investigations of ZoARF gene functions in ginger growth, development, and abiotic stress tolerance.