Wax accumulation on the sorghum surface plays an important role in drought tolerance by preventing non-stomatal water loss. Thereby, the effects of post-flowering drought stress (PFDS) on the chemical compositions of epicuticular wax (EW), relative water content (RWC), chlorophyll, and grain yield in sorghum drought contrasting genotypes were investigated. The experiment was conducted as a split-plot based on randomized complete block design (RCBD) with two water treatments (normal watering and water holding after 50% flowering stage), and three genotypes (Kimia and KGS23 as drought-tolerant and Sepideh as drought-susceptible). Scanning electron microscopy and GC-MS analyses were used to determine the wax crystals density and its compositions, respectively. Finally, based on literature reviews and publicly available datasets, six wax biosynthesis drought stress-responsive genes were chosen for expression analysis. The results showed that the EW and wax crystals density were increased in Kimia and Sepideh genotypes and no changed in KGS23 genotype under drought stress. Chemical compositions of wax were classified into six major groups including alkanes, fatty acids, aldehydes, esters, alcohols, and cyclic compounds. Alkanes increment in drought-tolerant genotypes led to make an effective barrier against the drought stress to control water losses. In addition, the drought-tolerant genotypes had higher levels of RWC compared to the drought- susceptible ones, resulted in higher yield produced under drought condition. According to the results, SbWINL1, FATB, and CER1 genes play important roles in drought-induced wax biosynthesis. The results of the present study revealed a comprehensive view of the wax and its compositions and some involved genes in sorghum under drought stress.

高粱表面的蜡积累通过防止非气孔失水而在耐旱性中发挥重要作用。因此，研究了开花后干旱胁迫（PFDS）对高粱干旱对比基因型的表皮蜡（EW）的化学组成，相对含水量（RWC），叶绿素和籽粒产量的影响。该实验以基于随机完全区组设计（RCBD）的分割图进行，其中两种水处理（开花后50％时正常浇水和持水）和三种基因型（耐旱的Kimia和KGS23和干旱的Sepideh） -敏感）。扫描电子显微镜和GC-MS分析分别用于确定蜡晶体密度及其组成。最后，根据文献评论和公开可用的数据集，选择了六个蜡生物合成干旱胁迫响应基因进行表达分析。结果表明，在干旱胁迫下，Kimia和Sepideh基因型的EW和蜡晶体密度增加，而KGS23基因型的EW和蜡晶体密度增加。蜡的化学成分分为六大类，包括烷烃，脂肪酸，醛，酯，醇和环状化合物。耐旱基因型中烷烃的增加导致了有效抵抗干旱以控制水分流失的障碍。另外，与干旱敏感基因型相比，耐旱基因型的RWC水平更高，导致干旱条件下产量更高。根据结果​​，结果表明，在干旱胁迫下，Kimia和Sepideh基因型的EW和蜡晶体密度增加，而KGS23基因型的EW和蜡晶体密度增加。蜡的化学成分分为六大类，包括烷烃，脂肪酸，醛，酯，醇和环状化合物。耐旱基因型中烷烃的增加导致了有效抵抗干旱以控制水分流失的障碍。此外，耐旱基因型的RWC水平高于干旱敏感基因型，导致干旱条件下产量更高。根据结果​​，结果表明，在干旱胁迫下，Kimia和Sepideh基因型的EW和蜡晶体密度增加，而KGS23基因型的EW和蜡晶体密度增加。蜡的化学成分分为六大类，包括烷烃，脂肪酸，醛，酯，醇和环状化合物。耐旱基因型中烷烃的增加导致了有效抵抗干旱以控制水分流失的障碍。另外，与干旱敏感基因型相比，耐旱基因型的RWC水平更高，导致干旱条件下产量更高。根据结果​​，和环状化合物。耐旱基因型中烷烃的增加导致了对抗干旱胁迫以控制水分流失的有效屏障。另外，与干旱敏感的基因型相比，耐旱的基因型具有更高的RWC水平，导致在干旱条件下产生更高的产量。根据结果​​，和环状化合物。耐旱基因型中烷烃的增加导致了有效抵抗干旱以控制水分流失的障碍。另外，与干旱敏感的基因型相比，耐旱的基因型具有更高的RWC水平，导致在干旱条件下产生更高的产量。根据结果​​，SbWINL1，FATB和CER1基因在干旱诱导的蜡生物合成中起重要作用。本研究的结果揭示了干旱胁迫下高粱中蜡及其组成和一些相关基因的全面概况。