OsV14 interacts with OsPetC to affect photosynthetic efficiency.

mTERFs in plants have been implicated in regulating many physiological processes. However, the molecular mechanisms underpinning these critical physiological functions are yet to be fully elucidated. In this study, we isolated the albino leaf mutant al11 from an EMS-mutagenized library generated from the seeds of the indica cultivar RH2B. The al11 mutant displayed a significant reduction in chlorophyll content, photosynthetic indicators, and starch content compared with wild type RH2B. Using MutMap + analysis, we identified the gene OsV14 as the causative locus and successfully cloned it. Our results show that an SNP at the junction of the third exon and intron of OsV14 prevents splicing factor recognition, causing a misidentified splice site. This leads to a 13 bp extension of the third exon and premature translation termination in al11 mutant. OsV14 encodes an mTERF protein that interacts with OsPetC, the Rieske FeS protein, an essential component of the Cytbf complex involved in photosynthesis. In the Osv14 mutant, the expression levels of several photosynthesis-related genes, including OsPetC, have significantly decreased compared with wild-type. Similar to the al11 mutant, Ospetc mutants exhibit albino leaves. The chlorophyll content, photosynthetic indicators, and starch content were significantly decreased compared with wild type plants. Collectively, our study suggests that OsV14 interacts with OsPetC, and their mutants alter the leaf color and affect photosynthetic efficiency.