Chen Congcong, Yan Yujie, Li Dongxiao, Dong Weixin, Zhang Yuechen, Tao Peijun
College of Agriculture, Hebei Agricultural University, Baoding 071001, China.
Teaching Support Department, Hebei Open University, Shijiazhuang 050080, China.
Genes (Basel). 2025 Mar 31;16(4):415. doi: 10.3390/genes16040415.
Isopentyltransferase () is a key rate-limiting enzyme in cytokinin synthesis, playing a crucial role in plant growth, development, and response to adverse conditions. Although the IPT gene family has been studied in various plants, comprehensive identification and functional characterization of genes in maize () remain underexplored. In this study, ten gene family members (-) were identified in the maize genome, and their gene structure, physicochemical properties, evolutionary relationships, expression patterns, and stress response characteristics were systematically analyzed. The genes were found to be unevenly distributed across six chromosomes, with most proteins predicted to be basic and localized primarily in chloroplasts. Phylogenetic analysis grouped the family into four subfamilies, showing close evolutionary relationships with rice IPT genes. Conserved motif and gene structure analyses indicated that the family members were structurally conserved, with five collinear gene pairs being identified. Ka/Ks analysis revealed that these gene pairs underwent strong purifying selection during evolution.Cis-element analysis of promoter regions suggested that genes are widely involved in hormone signaling and abiotic stress responses. Tissue-specific expression profiling showed that , , and were highly expressed in roots, with exhibiting consistently high expression under multiple abiotic stresses. qRT-PCR validation confirmed that expression peaked at 24 h after stress treatment, indicating its key role in long-term stress adaptation. Protein interaction analysis further revealed potential interactions between and cytokinin oxidases (, ), as well as FPP/GGPP synthase family proteins, suggesting a regulatory role in cytokinin homeostasis and stress adaptation. Overall, this study provides comprehensive insights into the structure and function of the gene family and identifies as a promising candidate for improving stress tolerance in maize through molecular breeding.
异戊烯基转移酶（IPT）是细胞分裂素合成中的关键限速酶，在植物生长、发育及对逆境的响应中发挥着至关重要的作用。尽管IPT基因家族已在多种植物中得到研究，但玉米（Zea mays）中IPT基因的全面鉴定和功能表征仍有待深入探索。在本研究中，在玉米基因组中鉴定出10个IPT基因家族成员（ZmIPT1 - ZmIPT10），并对其基因结构、理化性质、进化关系、表达模式及胁迫响应特征进行了系统分析。发现ZmIPT基因在六条染色体上分布不均，大多数蛋白质预测为碱性，主要定位于叶绿体中。系统发育分析将ZmIPT家族分为四个亚家族，显示出与水稻IPT基因密切的进化关系。保守基序和基因结构分析表明家族成员在结构上保守，鉴定出五对共线基因对。Ka/Ks分析表明这些基因对在进化过程中经历了强烈的纯化选择。启动子区域的顺式作用元件分析表明ZmIPT基因广泛参与激素信号传导和非生物胁迫响应。组织特异性表达谱显示，ZmIPT2、ZmIPT5和ZmIPT9在根中高表达，ZmIPT3在多种非生物胁迫下均表现出持续高表达。qRT-PCR验证证实ZmIPT3在胁迫处理后24小时表达达到峰值，表明其在长期胁迫适应中的关键作用。蛋白质相互作用分析进一步揭示了ZmIPT3与细胞分裂素氧化酶（CKX1、CKX2）以及FPP/GGPP合酶家族蛋白之间的潜在相互作用，表明其在细胞分裂素稳态和胁迫适应中的调节作用。总体而言，本研究为ZmIPT基因家族的结构和功能提供了全面的见解，并鉴定出ZmIPT3是通过分子育种提高玉米胁迫耐受性的有前景的候选基因。
