近日，安徽农业大学杨俊及其研究小组发现，玉米mTERF18调控线粒体nad6基因的转录终止并对籽粒发育至关重要。相关论文于2025年1月9日在线发表在《遗传学报》。

研究人员表示，线粒体是存在于真核细胞中的半自主性细胞器，拥有自己的基因组和转录机制。然而，它们的功能与核基因组编码的蛋白质密切相关。线粒体转录终止因子（mTERF）是结合核酸的蛋白质，参与植物线粒体和叶绿体中的RNA剪接和转录终止。尽管mTERF蛋白的重要性已经得到认可，但其在玉米中的具体作用仍未得到充分探索。

研究人员克隆并功能性表征了玉米mTERF18基因。研究发现，mTERF18突变导致胚胎严重未分化，导致失败表型。早期籽粒表现出异常的基底胚乳转运层，并且在mterf18中淀粉和蛋白质积累显著减少。研究人员通过基于定位的克隆方法鉴定了mTERF18基因，并通过等位基因检测验证了该基因。mTERF18在玉米的各种组织中广泛表达，编码一个高度保守的线粒体蛋白。转录组数据表明，mTERF18突变破坏了nad6基因的转录终止，导致Nad6蛋白无法检测到，并且复合体I的组装和活性减少。此外，通过透射电子显微镜观察mterf18胚乳揭示了严重的线粒体缺陷。

综上所述，这些发现突出了mTERF18在线粒体基因转录终止中的关键作用，并强调其对玉米籽粒发育的重要影响。

附：英文原文

Title: The maize mTERF18 regulates transcriptional termination of the mitochondrial nad6 gene and is essential for kernel development

Author: Jun Yang a

Issue&Volume: 2025/01/09

Abstract: Mitochondria are semi-autonomous organelle present in eukaryotic cells, containing their own genome and transcriptional machinery. However, their functions are intricately linked to proteins encoded by the nuclear genome. Mitochondrial transcription termination factors (mTERFs) are nucleic acid-binding proteins involved in RNA splicing and transcription termination within plant mitochondria and chloroplasts. Despite their recognized importance, the specific roles of mTERF proteins in maize remain largely unexplored. Here, we clone and functionally characterize maize mTERF18 gene. Our findings reveal that mTERF18 mutations lead to severely undifferentiated embryos, resulting in abortive phenotypes. Early kernel exhibits abnormal basal endosperm transfer layer and a significant reduction in both starch and protein accumulation in mterf18. We identify the mTERF18 gene through mapping-based cloning and validate this gene through allelic tests. mTERF18 is widely expressed across various maize tissues and encodes a highly conserved mitochondrial protein. Transcriptome data reveal that mTERF18 mutations disrupt transcriptional termination of the nad6 gene, leading to undetectable levels of Nad6 protein and reduced complex I assembly and activity. Furthermore, transmission electron microscopy observation of mterf18 endosperm uncover severe mitochondrial defects. Collectively, these findings highlight the critical role of mTERF18 in mitochondrial gene transcription termination and its pivotal impact on maize kernel development.

DOI: 10.1016/j.jgg.2025.01.001

Source: https://www.sciencedirect.com/science/article/abs/pii/S1673852725000037