부산대학교 도서관

Maize (Zea maysL.) is a monoecious grass species with separate male and female inflorescences which form the tassel and ear, respectively. The mature ear inflorescences usually bear hundreds of grains, thus directly influence maize grain production and yield. Here, we isolated a recessive maize mutant, tasselseed2016(ts2016), which exhibits pleiotropic inflorescence defects and a reduction in grain yield. These defects include loss of determinacy and identity in meristems and floral organs, as well as a lack of the lower floret abortion in maize ear, and the smaller grain size. Using map-based cloning and allelic test, we identified and confirmed a microRNA gene MIR172eas the target gene controlling these related traits. Furthermore, our evidence uncovered a new potential miR172e/ETHYLENE RESPONSIVE ELEMENT BINDING197 (EREB197) regulatory module which controls the abortion of lower floret in maize ear. Transcriptome analysis revealed that the mutation of MIR172erepresses multiple biological processes, particularly the flower development and hormone-related pathways in maize ear. Additionally, we found the mutation in the DNA sequence of MIR172eaffects in RNA transcription, resulting in elongation blockage at the mutant site. Our results reveal the function and molecular mechanism of MIR172ein maize inflorescences and grain yield, and this study deepens our knowledge of maize inflorescence development.