Genome-Wide Identification and Expression Analysis of the GRX Gene Family Reveals Its Potential Role in Floral Organ Development and Sex Differentiation in Litsea cubeba

As a class of glutathione-dependent oxidoreductases, glutaredoxins (GRXs) play a central role in maintaining cellular redox homeostasis, thereby influencing diverse biological processes including growth, development, and stress adaptation in plants. This study identified 36 GRX genes in Litsea cubeba through whole-genome analysis. Phylogenetic classification placed them into four subfamilies (CC-, CGFS-, CPYC-type, and a species-specific SS branch), consistent with patterns in model plants like Arabidopsis thaliana and Oryza sativa, indicating evolutionary conservation of GRX core motifs. Genomic analyses including chromosomal location, collinearity, and gene structure revealed family evolution features. Expression profiling showed 11 LcGRX genes were flower-specific, with marked differential expression during stamen (M2) and pistil (F2) degeneration, supporting their roles in sexual dimorphism. Functional assays confirmed that floral highly expressed LcGRX12 directly interacts with TGA transcription factor LcTGA10, similar to its Arabidopsis homolog ROXY1. This study reveals the GRX-TGA module’s role in floral organ development in L. cubeba, offering insights into redox-mediated sex differentiation in Lauraceae and providing candidate genes for molecular breeding.