<p>Seedless grapes occur naturally or through the treatment of flower clusters with streptomycin (Stm) and/or gibberellic acid (GA). Stm inhibits protein synthesis in plastids and is an antibiotic used as a pesticide. The molecular mechanisms underlying their effects remain unclear. Therefore, we analyzed protein abundance using Stm-treated flower clusters of the ‘Shine Muscat’ grape 6&#xa0;h after the treatment; similarly, the effect of GA treatment was also investigated. The isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analyses detected 3,386 non-redundant protein groups in Stm- or GA-treated flower clusters and revealed that these treatments altered the protein profiles in grape flower clusters. The common differentially expressed proteins (DEPs) significantly upregulated by Stm- or GA-treatment were annotated as a sucrose transporter domain-containing protein and a Phi-class glutathione S-transferase (GST), whereas the common significantly downregulated DEPs were annotated as a dehydroascorbate reductase-class GST and a fatty acyl-CoA reductase. These DEPs are potentially involved in the seedless effect of Stm or GA through the inhibition of pollen and ovule development. A few DEPs are encoded by the chloroplast/mitochondrial genome; the nuclear genome encodes most of the DEPs. Stm also demonstrated its inhibitory effect on seed development in rice and <i>Arabidopsis</i>. Overall, these findings reveal that Stm induced seedlessness in crops other than grapes and citrus, indicating that the Stm-mediated seedlessness is conserved in other plants.</p>