<italic>ZmEDD1</italic> is involved in maize seed development by affecting RNA splicing of multiple mitochondrial genes

<p indent="0mm">Post transcriptional processing is an important process for regulating mitochondrial gene expression. Abnormal post transcriptional processing will seriously affect the development of maize seeds. Multiple protein families such as pentatricopeptide repeat (PPR) protein family are involved in post-transcriptional processing such as mitochondrial gene RNA splicing. The members of these protein families have not been fully identified in maize. This study identified an endosperm development defect related gene <italic>ZmEDD1</italic> through positional cloning and evaluated its function during maize seed development. <italic>ZmEDD1</italic> encodes a P-type PPR protein, named maize endosperm developmental defect protein 1 (ZmEDD1). The <italic>edd1</italic> mutant has smaller seeds than B73, and the seeds are wrinkled with a decreased thousand-grain weight. Observation of the seeds at 15 days after pollination (DAP) and 21 DAP revealed that the <italic>edd1</italic> mutant had empty fruit shells at the top of the kernels and delayed embryo development. Genetic analysis indicates that <italic>edd1</italic> is a single gene recessive mutant. Mapping analysis revealed that the mutated gene <italic>ZmEDD1</italic> was located at Bin 1.08 on chromosome 1, and the ZmEDD1 protein was located in mitochondria and had the highest expression level in the ear. The mutation of <italic>ZmEDD1</italic> affected the RNA splicing of 8 mitochondrial genes, including <italic>nad1</italic>. At the same time, the cristae structure of mitochondria was abnormal in the <italic>edd1</italic> mutant. This study indicates that <italic>ZmEDD1</italic> may participate in maize seed development by affecting RNA splicing of multiple mitochondrial genes.