Giant Juncao is often used as feed for livestock because of its huge biomass. However, drought stress reduces forage production by affecting the normal growth and development of plants. Therefore, investigating the molecular mechanisms of drought tolerance will provide important information for the improvement of drought tolerance in this grass. A total of 144.96 Gb of clean data was generated and assembled into 144,806 transcripts and 93,907 unigenes. After 7 and 14 days of drought stress, a total of 16,726 and 46,492 differentially expressed genes (DEGs) were observed, respectively. Compared with normal irrigation, 16,247, 23,503, and 11,598 DEGs were observed in 1, 5, and 9 days following rehydration, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed abiotic stress-responsive genes and pathways related to catalytic activity, methyltransferase activity, transferase activity, and superoxide metabolic process. We also identified transcription factors belonging to several families, including basic helix-loop-helix (bHLH), WRKY, NAM (no apical meristem), ATAF1/2 and CUC2 (cup-shaped cotyledon) (NAC), fatty acyl-CoA reductase (FAR1), B3, myeloblastosis (MYB)-related, and basic leucine zipper (bZIP) families, which are important drought-rehydration-responsive proteins. Weighted gene co-expression network analysis was also used to analyze the RNA-seq data to predict the interrelationship between genes. Twenty modules were obtained, and four of these modules may be involved in photosynthesis and plant hormone signal transduction that respond to drought and rehydration conditions. Our research is the first to provide a more comprehensive understanding of DEGs involved in drought stress at the transcriptome level in Giant Juncao with different drought and recovery conditions. These results may reveal insights into the molecular mechanisms of drought tolerance in Giant Juncao and provide diverse genetic resources involved in drought tolerance research.

中文翻译：

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转录组分析揭示了巨型菌草耐旱性的影响


巨型菌草因其巨大的生物量而常被用作牲畜饲料。然而，干旱胁迫会影响植物的正常生长和发育，从而降低牧草产量。因此，研究该草耐旱性的分子机制将为提高该草的耐旱性提供重要信息。总共生成了 144.96 GB 的干净数据，并将其组装成 144,806 个转录本和 93,907 个 unigene。干旱胁迫7天和14天后，分别观察到16,726个和46,492个差异表达基因（DEG）。与正常灌溉相比，补水后1、5和9天分别观察到16,247、23,503和11,598 DEG。基因本体论和京都基因和基因组百科全书途径分析揭示了与催化活性、甲基转移酶活性、转移酶活性和超氧化物代谢过程相关的非生物胁迫响应基因和途径。我们还鉴定了属于几个家族的转录因子，包括基本螺旋-环-螺旋 (bHLH)、WRKY、NAM（无顶端分生组织）、ATAF1/2 和 CUC2（杯形子叶）(NAC)、脂肪酰辅酶 A 还原酶(FAR1)、B3、成髓细胞增多症 (MYB) 相关蛋白和碱性亮氨酸拉链 (bZIP) 家族是重要的干旱补液响应蛋白。加权基因共表达网络分析也用于分析RNA-seq数据以预测基因之间的相互关系。获得了二十个模块，其中四个模块可能涉及响应干旱和补水条件的光合作用和植物激素信号转导。 我们的研究首次在转录组水平上更全面地了解了不同干旱和恢复条件下巨菌草参与干旱胁迫的DEG。这些结果可能揭示巨菌草耐旱的分子机制，并为耐旱研究提供多样化的遗传资源。