| Summary: | Vegetative to reproductive phase transition in phototropic plants is an important developmental process and is sequentially mediated by the expression of micro-RNA <i>MIR172</i>. To obtain insight into the evolution, adaptation, and function of <i>MIR172</i> in photophilic rice and its wild relatives, we analyzed the genescape of a 100 kb segment harboring <i>MIR172</i> homologs from 11 genomes. The expression analysis of <i>MIR172</i> revealed its incremental accumulation from the 2-leaf to 10-leaf stage, with maximum expression coinciding with the flag-leaf stage in rice. Nonetheless, the microsynteny analysis of <i>MIR172</i>s revealed collinearity within the genus <i>Oryza,</i> but a loss of synteny was observed in (i) <i>MIR172</i>A in <i>O. barthii</i> (AA) and <i>O. glaberima</i> (AA); (ii) <i>MIR172</i>B in <i>O. brachyantha</i> (FF); and (iii) <i>MIR172</i>C in O. <i>punctata</i> (BB). Phylogenetic analysis of precursor sequences/region of <i>MIR172</i> revealed a distinct tri-modal clade of evolution. The genomic information generated in this investigation through comparative analysis of <i>MIRNA,</i> suggests mature <i>MIR172</i>s to have evolved in a disruptive and conservative mode amongst all <i>Oryza</i> species with a common origin of descent. Further, the phylogenomic delineation provided an insight into the adaptation and molecular evolution of <i>MIR172</i> to changing environmental conditions (biotic and abiotic) of phototropic rice through natural selection and the opportunity to harness untapped genomic regions from rice wild relatives (RWR).
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