Identification and Analysis of the ZmGDS1 Gene Family in Maize

Background/Objectives: The Arabidopsis thaliana GDS1 (Growth, Development and Splicing 1) gene has recently been identified as a key regulator linking nitrate signaling to leaf senescence. However, a systematic analysis of the GDS1 gene family in maize (Zea mays L.) is lacking. This study aims to identify and characterize the ZmGDS1 gene family in maize, providing a foundation for functional studies on their roles in growth, development, and low-nitrogen-induced leaf senescence. Methods: Putative ZmGDS1 family members were identified by searching the maize B73 reference genome using BLASTP (version 2.11.0+) and HMMER (version 3.4), with the Arabidopsis GDS1 protein sequence as the query. Candidate sequences were verified for the presence of the conserved zf-CCCH domain using NCBI CD-Search and SMART. Phylogenetic relationships, gene structures, conserved motifs, chromosomal distribution, collinearity, and promoter cis elements were comprehensively analyzed using MEGA 11, TBtools (version 1.098), MEME (version 5.5.9), and PlantCARE. Phylogenetic trees were constructed using the maximum likelihood (ML) method with the LG+G+I model and 1000 bootstrap replicates. Results: Thirteen ZmGDS1 genes were identified, distributed unevenly across eight maize chromosomes. Phylogenetic analysis classified the ZmGDS1 proteins into four distinct groups (A-D), revealing a lineage-specific expansion in group D. While all members contained the conserved zf-CCCH domain, their motif compositions varied considerably; ZmGDS1.1 exhibited the most complex structure, whereas ZmGDS1.12 had the most simplified. Subcellular localization predictions indicated that most ZmGDS1 proteins are targeted to the nucleus, consistent with a potential role as transcription factors. Promoter analysis revealed an abundance of cis elements associated with light response, hormone signaling (methyl jasmonate, abscisic acid, auxin), and stress responses. Notably, phylogenetically related genes tended to share similar cis-element profiles. Conclusions: This genome-wide analysis provides the first characterization of the ZmGDS1 gene family in maize. The observed structural conservation and diversity, together with regulatory elements linked to senescence-associated signals, support the hypothesis that ZmGDS1 genes may contribute to leaf senescence, particularly under low-nitrogen conditions. These findings provide a basis for future functional validation studies.