Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.
Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
Plant Physiol Biochem. 2021 Feb;159:383-391. doi: 10.1016/j.plaphy.2021.01.001. Epub 2021 Jan 5.
Wax accumulation on the sorghum surface plays an important role in drought tolerance by preventing non-stomatal water loss. Thereby, the effect of post-flowering drought stress (PFDS) on the epicuticular wax (EW) amount, 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. In addition, 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 amounts of 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.
高粱表面的蜡质积累在防止非气孔水分损失方面对耐旱性起着重要作用。因此，本研究调查了开花后干旱胁迫（PFDS）对高粱耐旱对照基因型的表皮蜡（EW）量、相对水含量（RWC）、叶绿素和籽粒产量的影响。该试验采用基于随机完全区组设计（RCBD）的裂区设计进行，设两个水分处理（正常浇水和 50%开花期后持水）和三个基因型（Kimia、KGS23 为耐旱型和 Sepideh 为耐旱型）。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。此外，根据文献综述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 量和蜡晶体密度增加，而 KGS23 基因型没有变化。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形成了有效的屏障，以控制水分流失，从而抵御干旱胁迫。此外，耐旱基因型的 RWC 水平高于耐旱型，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。本研究结果全面揭示了高粱在干旱胁迫下蜡及其组成和一些相关基因的情况。
