Genome-Wide Characterization of the MADS-Box Gene Family and Expression Pattern in Different Tissues and Stresses in Zanthoxylum armatum

The construction and development of plant floral organs, sexual differentiation, and resistance to abiotic stressors are all crucial functions of the MADS-box family genes. Zanthoxylum armatum is a significant spice and medicinal plant, but there is little known about its MADS-box transcription factors, especially those involved in abiotic stress. In the present study, 111 MADS-box genes spread across 27 chromosomes were shown to have entire structural domains. Analysis of gene duplication events revealed 24 pairs of tandem repeats that create gene clusters, suggesting that gene duplication may be one of the drivers driving ZaMADS development. Moreover, the majority of genes had cis-acting regions linked to phytohormones and abiotic challenges, indicating a critical involvement in the response to abiotic stimuli. Based on an analysis of ZaMADS expression patterns in 22 distinct tissues, pepper flowers develop according to the ABCDE model of floral development. Besides, the majority of the ZaMADS genes were highly susceptible to abiotic challenges, with ZaMADS22, ZaMADS25, ZaMADS47, and ZaMADS56 exhibiting notable changes in expression patterns in response to cold temperature and waterlogging conditions. Tobacco cis-conversion experiments demonstrated that ZaMADS47 could enhance the antioxidant enzyme activity, reduce the MDA and H2O2 content, and thus enhance the tolerance of leaves to cold stress. The results of the present study provide a scientific basis for elucidating the functional characteristics of the MADS-box genes in Z. armatum in response to environmental stress.