OsPPR19, a rice pentatricopeptide repeat protein, is essential for mitochondrial biogenesis and seed development

• Published in: Biologia plantarum 2024-10, Vol.68 (1), p.152-160
• Main Authors: LEE, Kwanuk, Jung PARK, Su, Yeon-Ok, KIM, JEON, Jong-Seong, KANG, Hunseung
• Format: Article
• Language: English
• Subjects: intron splicing; mitochondria; pentatricopeptide repeat; rice; seed development
• ISSN: 1573-8264; 1573-8264
• DOI: 10.32615/bp.2024.014

Despite the accumulating evidence showing the essential role of pentatricopeptide repeat (PPR) proteins in organellar biogenesis and plant development in Arabidopsis thaliana and maize (Zea mays), the functions of most PPR proteins in rice (Oryza sativa) are still unknown. A former study demonstrated that the mitochondria-localized Arabidopsis PPR19 is crucial for mitochondrial function and normal plant growth and development. In this study, we characterized the functional role of a rice ortholog (LOC_Os12g04110) of Arabidopsis PPR19 protein. The loss-of-function osppr19 mutant displayed delayed seed germination and stunted root and seedling growth compared with wild-type. The height of the osppr19 mutant was significantly shorter, and the grain mass of the mutant was lower than that of the wild-type. The osppr19 mutant carried few filled grains and a higher number of aborted seeds than the wild-type. The structures of mitochondria in the osppr19 mutant were abnormal, and more reactive oxygen species were accumulated in the mutant, suggesting defective mitochondrial biogenesis and function in the osppr19 mutant. Importantly, the amount of mature mitochondrial transcripts was significantly decreased in the mutant. Taken together, these results suggest that the mitochondrial OsPPR19 is essential for mitochondrial biogenesis and function, which is crucial for plant growth and development of rice grain.