ZmSk2, a mitochondrial RNA processing protein, regulates maize kernel development via group II intron splicing.

ZmSk2 is essential for maize kernel development, as its disruption causes severe arrest and impairs mitochondrial complex assembly and activity.

• Why it matters: Understanding mitochondrial RNA splicing mechanisms is crucial because they underpin energy production and development in plants, yet the specific roles of auxiliary proteins like ZmSk2 remain unclear.
• What they did: Researchers characterized the zmsk2 mutant, revealing ZmSk2 as a mitochondria-targeted CRM-domain protein involved in splicing nad2 and nad5 introns, and identified its interactions with other mitochondrial proteins through protein-protein interaction experiments.
• The result: Loss of ZmSk2 led to absent mature nad2 and nad5 transcripts, defective mitochondrial complexes, decreased NADH dehydrogenase activity, and ultimately disrupted kernel growth, highlighting ZmSk2’s vital role in mitochondrial function and maize development.