EMB-7L is required for embryogenesis and plant development in maize involved in RNA splicing of multiple chloroplast genes.

• Emb-7L encodes the chloroplast-targeted P-type PPR protein. • The emb-7L exhibits embryo lethality and albinism. • Full transcriptome analysis indicates the expression of protein-encoding genes is dramatically variable in albino leaves. • The intron splicing efficiency of chloroplast protein-encoding genes is generally reduced. Embryo and endosperm originate from the double fertilization, but they have different developmental fates and biological functions. We identified a previously undescribed maize seed mutant, wherein the embryo appears to be more severely affected than the endosperm (embryo-specific , emb). In the W22 background, the emb embryo arrests at the transition stage whereas its endosperm appears nearly normal in size. At maturity, the embryo in W22- emb is apparently small or even invisible. In contrast, the emb endosperm develops into a relative normal size. We cloned the mutant gene on the Chromosome 7L and designated it emb - 7L. This gene is generally expressed, but it has a relatively higher expression level in leaves. Emb - 7L encodes a chloroplast-localized P-type pentatricopeptide repeat (PPR) protein, consistent with the severe chloroplast deficiency in emb - 7L albino seedling leaves. Full transcriptome analysis of the leaves of WT and emb - 7L seedlings reveals that transcription of chloroplast protein-encoding genes are dramatically variable with pre-mRNA intron splicing apparently affected in a tissue-dependent pattern and the chloroplast structure and activity were dramatically affected including chloroplast membrane and photosynthesis machinery component and synthesis of metabolic products (e.g., fatty acids, amino acids, starch). [ABSTRACT FROM AUTHOR]