Sorghum accumulates epi-cuticular wax (EW) in leaves, sheaths, and culms. EW reduces the transpirational and nontranspirational (nonstomatal) water loss and protects the plant from severe drought stress in addition to imparting resistance against insect pests. Results presented here are from the analysis of EW content of 387 diverse sorghum accessions and its genome-wide association study (GWAS). EW content in sorghum leaves ranged from 0.1 to 29.7 mg cm⁻² with a mean value of 5.1 mg cm⁻². GWAS using 265,487 single nucleotide polymorphisms identified thirty-seven putative genes associated (P < 9.89E−06) with EW biosynthesis and transport in sorghum. Major EW biosynthetic genes identified included 3-Oxoacyl-[acyl-carrier-protein (ACP)] synthase III, an Ankyrin repeat protein, a bHLH-MYC, and an R2R3-MYB transcription factor. Genes involved in EW regulation or transport included an ABC transporter, a Lipid exporter ABCA1, a Multidrug resistance protein, Inositol 1, 3, 4-trisphosphate 5/6-kinase, and a Cytochrome P450. This GWA study thus demonstrates the potential for genetic manipulation of EW content in sorghum for better adaptation to biotic and abiotic stress.

中文翻译：

---

双色高粱表皮蜡质基因的全基因组关联作图。

高粱在叶子、鞘和秆中积累表皮蜡 (EW)。EW 可减少蒸腾和非蒸腾（非气孔）水分流失，并保护植物免受严重干旱胁迫，同时赋予对害虫的抗性。这里呈现的结果来自对 387 个不同高粱种质的 EW 含量的分析及其全基因组关联研究 (GWAS)。高粱叶中的 EW 含量范围为 0.1 至 29.7 mg cm ^-2  ，平均值为 5.1 mg cm ^-2。GWAS 使用 265,487 个单核苷酸多态性鉴定了 37 个推定的相关基因（P < 9.89E-06) 与高粱中的电子战生物合成和运输。确定的主要 EW 生物合成基因包括 3-氧代酰基-[酰基载体蛋白 (ACP)] 合酶 III、锚蛋白重复蛋白、bHLH-MYC 和 R2R3-MYB 转录因子。参与电子战调节或运输的基因包括 ABC 转运蛋白、脂质输出蛋白 ABCA1、多药抗性蛋白、肌醇 1, 3, 4-三磷酸 5/6-激酶和细胞色素 P450。因此，这项 GWA 研究证明了对高粱中 EW 含量进行基因操作以更好地适应生物和非生物胁迫的潜力。