Upland rice is a distinct ecotype that grows in aerobic environments and tolerates drought stress. However, the genetic basis of its drought resistance is unclear. Here, using an integrative approach combining a genome-wide association study with analyses of introgression lines and transcriptomic profiles, we identify a gene, DROUGHT1 (DROT1), encoding a COBRA-like protein that confers drought resistance in rice. DROT1 is specifically expressed in vascular bundles and is directly repressed by ERF3 and activated by ERF71, both drought-responsive transcription factors. DROT1 improves drought resistance by adjusting cell wall structure by increasing cellulose content and maintaining cellulose crystallinity. A C-to-T single-nucleotide variation in the promoter increases DROT1 expression and drought resistance in upland rice. The potential elite haplotype of DROT1 in upland rice could originate in wild rice (O. rufipogon) and may be beneficial for breeding upland rice varieties.

旱稻是一种独特的生态型，可在有氧环境中生长并耐受干旱胁迫。然而，其抗旱性的遗传基础尚不清楚。在这里，使用一种综合方法，将全基因组关联研究与基因渗入系和转录组谱分析相结合，我们鉴定了一个基因DROUGHT1 ( DROT1 )，该基因编码一种 COBRA 样蛋白，该蛋白赋予水稻抗旱性。DROT1在维管束中特异性表达并被ERF3直接抑制并被ERF71激活，这两种转录因子都是干旱反应性转录因子。DROT1 通过增加纤维素含量和维持纤维素结晶度来调整细胞壁结构，从而提高抗旱性。启动子中的 C 到 T 单核苷酸变异增加了旱稻的DROT1表达和抗旱性。旱稻DROT1的潜在优良单倍型可能起源于野生稻（ O. rufipogon），可能有利于培育旱稻品种。