Genome-wide identification and expression analysis of C3H gene family in melon

Zinc finger protein (ZFP) represent a significant class of transcription factors in plants, involved in various functions, including tissue development, signal transduction, and responses to both biotic and abiotic stresses. ZFPs are categorized into 10 distinct subfamilies, among which the C3H gene family is recognized as a functionally significant group of transcription factors.To date, no studies have been reported regarding the <i>C3H</i> gene family in melon (<i>Cucumis melo</i>). In this study, 38 <i>CmC3H</i> genes were identified in the melon genome, and these genes are unevenly distributed across the 12 chromosomes. Phylogenetic analysis classified the <i>C3H</i> family members into four groups, with significant differences observed in sequence, protein motifs, and gene structure among <i>CmC3H</i> genes within the same group. The <i>CmC3H</i> family contains one pair of segmentally duplicated genes and shares 20, 7, 39, and 38 pairs of homologous <i>C3H</i> genes with <i>Arabidopsis thaliana</i>, rice (<i>Oryza sativa</i>), cucumber (<i>Cucumis sativus</i>), and watermelon (<i>Citrullus lanatus</i>), respectively. Promoter region analysis revealed a high abundance of <i>cis</i>-elements associated with growth and development, hormone regulation, and stress responses. Expression profiling revealed that <i>CmC3H</i> family members exhibit significant tissue-specific expression patterns. Quantitative PCR analysis indicated that six genes (<i>CmC3H4</i>, <i>CmC3H7</i>, <i>CmC3H13</i>, <i>CmC3H24</i>, <i>CmC3H33</i>, and <i>CmC3H38</i>) may play roles in melon's drought stress resistance. Heavy metal lead stress appears to suppress the expression of <i>CmC3H</i> genes. The genes <i>CmC3H24</i> and <i>CmC3H33</i> may be involved in regulating melon's resistance to <i>Fusarium wilt</i> infection. <i>CmC3H11</i> and <i>CmC3H21</i> can be considered as the key candidate genes for improving the melon's ability to resist both biotic and abiotic stresses.This study provides preliminary insights into the expression profiles of <i>CmC3H</i> genes under drought stress, heavy metal lead stress, and <i>Fusarium wilt</i> infection, offering a theoretical foundation for the molecular mechanisms underlying melon improvement and stress resistance.