DataSheet_1_Combined analysis of transcriptome and metabolome reveals the molecular mechanism and candidate genes of Haloxylon drought tolerance.pdf

Haloxylon ammodendron and Haloxylon persicum, as typical desert plants, show strong drought tolerance and environmental adaptability. They are ideal model plants for studying the molecular mechanisms of drought tolerance. Transcriptomic and metabolomic analyses were performed to reveal the response mechanisms of H. ammodendron
and H. persicum
to a drought environment at the levels of transcription and physiological metabolism. The results showed that the morphological structures of H. ammodendron
and H. persicum
showed adaptability to drought stress. Under drought conditions, the peroxidase activity, abscisic acid content, auxin content, and gibberellin content of H. ammodendron increased, while the contents of proline and malondialdehyde decreased. The amino acid content of H. persicum was increased, while the contents of proline, malondialdehyde, auxin, and gibberellin were decreased. Under drought conditions, 12,233 and 17,953 differentially expressed genes (DEGs) were identified in H. ammodendron
and H. persicum
, respectively, including members of multiple transcription factor families such as FAR1, AP2/ERF, C2H2, bHLH, MYB, C2C2, and WRKY that were significantly up-regulated under drought stress. In the positive ion mode, 296 and 452 differential metabolites (DEMs) were identified in H. ammodendron
and H. persicum, respectively; in the negative ion mode, 252 and 354 DEMs were identified, primarily in carbohydrate and lipid metabolism. A combined transcriptome and metabolome analysis showed that drought stress promoted the glycolysis/gluconeogenesis pathways of H. ammodendron
and H. persicum
and increased the expression of amino acid synthesis pathways, consistent with the physiological results. In addition, transcriptome and metabolome were jointly used to analyze the expression changes of the genes/metabolites of H. ammodendron
and H. persicum
that were associated with drought tolerance but were regulated differently in the two plants. This study identified drought-tolerance genes and metabolites in H. ammodendron
and H. persicum
and has provided new ideas for studying the drought stress response of Haloxylon.

梭梭（Haloxylon ammodendron）与白梭梭（Haloxylon persicum）作为典型荒漠植物，具备极强的耐旱性与环境适应能力，是探究耐旱分子机制的理想模式植物。本研究开展转录组学与代谢组学分析，从转录与生理代谢层面揭示梭梭与白梭梭对干旱环境的响应机制。研究结果显示，二者的形态结构均表现出对干旱胁迫的适应性。干旱胁迫下，梭梭的过氧化物酶活性、脱落酸含量、生长素含量及赤霉素含量均显著升高，而脯氨酸与丙二醛含量则呈下降趋势；白梭梭的氨基酸总含量升高，但脯氨酸、丙二醛、生长素及赤霉素含量均降低。干旱胁迫条件下，梭梭与白梭梭中分别鉴定出12233个和17953个差异表达基因（differentially expressed genes, DEGs），其中包含FAR1、AP2/ERF、C2H2、bHLH、MYB、C2C2及WRKY等多个转录因子家族成员，这些基因在干旱胁迫下均显著上调表达。在正离子模式下，梭梭与白梭梭分别鉴定出296种和452种差异代谢物（differential metabolites, DEMs）；在负离子模式下则分别鉴定出252种和354种差异代谢物，此类差异代谢物主要参与碳水化合物与脂类代谢过程。转录组与代谢组联合分析表明，干旱胁迫可促进梭梭与白梭梭的糖酵解/糖异生通路，并上调氨基酸合成通路的基因表达，该结果与生理实验结论相一致。此外，本研究联合转录组与代谢组分析了两种植物中与耐旱性相关但调控模式存在差异的基因/代谢物的表达变化。本研究鉴定出梭梭与白梭梭中的耐旱相关基因与代谢物，为荒漠植物的干旱胁迫响应研究提供了全新的研究思路。