Mitochondrial Ribosomal Protein S9M is Involved in Male Gametogenesis and Seed Development in Arabidopsis

Mitochondrial function is critical for cellular vitality in all eukaryotes including plants. Although plant mitochondria house a large number of proteins, only a small portion of proteins have been studied in the context of plant development and physiology. We used knock-down mutant of RPS9M to study its important role in male gametogenesis and seed development in Arabidopsis thaliana. Knock-down of RPS9M in rps9m-3 mutant led to abnormal pollen development and impaired pollen tube growth. In addition, both the embryo and endosperm development were affected. Phenotype analysis revealed that the rps9m-3 mutant contained lesser endosperm nuclear, and the embryo cell divisions and embryo pattern were affected, resulting in abnormal and defective embryo. Lowering the level of RPS9M in rps9m-3 plants affect mitochondrial ribosome biogenesis, energy metabolism and production of reactive oxygen species. Our data revealed that RPS9M plays important roles in normal gametophyte development and seed formation, possibly by sustaining mitochondria function.