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Drought poses a significant constraint on rice production, and, in this study, we have discovered a novel drought-sensitive mutant, designated as <i>dsm3</i>, arising from the progenies of indica rice variety Zhonghui8015 treated with ethyl methane sulphonate (EMS). Under drought stress conditions, <i>dsm3</i> exhibited characteristic withered leaf tips, accompanied by increased levels of malondialdehyde (MDA) and H₂O₂, a reduced net photosynthetic rate (Pn), and decreased activity of peroxidase (POD) and superoxide dismutase (SOD). Genetic analysis revealed that the withered leaf tip phenotype was governed by a single recessive gene, designated as <i>Osdsm3</i>. To begin with, <i>Osdsm3</i> was initially mapped to the short arm of chromosome 1 through a cross involving <i>dsm3</i> and 02428. Subsequently, utilizing a population of 2591 F₂ individuals, we narrowed down the location of <i>Osdsm3</i> to a 78 Kb interval, encompassing 13 open reading frames (ORFs). Sequencing analysis unveiled a mutation (1275G → A) in the exon of the candidate gene (LOC_Os01g10680), leading to premature translation termination. Moreover, a quantitative RT-PCR assay demonstrated a high expression of <i>OsDSM3</i> in the panicle and sheath, with a significant upregulation of drought-stress-related genes under drought conditions. Phylogenetic analyses indicated that <i>Osdsm3</i> shares evolutionary homology with UNE1, an intracellular transport protein found in <i>Arabidopsis thaliana</i>. Subcellular studies further confirmed that <i>OsDSM3</i> resides in the cytoplasm. In conclusion, the forthcoming cloning of <i>Osdsm3</i> holds promise for delving deeper into the molecular mechanisms governing rice drought resistance.