The rice stunted lemma/palea 1 (slp1) mutant displays a dwarf, shortened panicle length, degenerated lemma and palea, and sterility. A previous study suggested that a missense mutation at the sixth amino acid of the OsSPL16 protein was likely to be responsible for the slp1 mutant phenotype. The current study shows that the overexpression of the wild-type OsSPL16 allele in slp1/slp1 and Slp1/slp1 mutants was unable to convert the slp1 mutant phenotype to normal. However, the introduction of the mutant OsSPL16 allele into a normal rice cultivar led to the slp1 mutant phenotype in transgenic plants. These results indicated that the missense mutation in OsSPL16 creates a neomorphic allele, which affects plant height and the development of the inflorescence and spikelet.