Institute of Environment and Ecology, Shandong Normal University, Jinan 250014, China.
Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Int J Mol Sci. 2024 Sep 27;25(19):10430. doi: 10.3390/ijms251910430.
Wheat is the most widely grown crop in the world; its production is severely disrupted by increasing water deficit. Plant roots play a crucial role in the uptake of water and perception and transduction of water deficit signals. In the past decade, the mechanisms of drought tolerance have been frequently reported; however, the transcriptome and metabolome regulatory network of root responses to water stress has not been fully understood in wheat. In this study, the global transcriptomic and metabolomics profiles were employed to investigate the mechanisms of roots responding to water stresses using the drought-tolerant (DT) and drought-susceptible (DS) wheat genotypes. The results showed that compared with the control group, wheat roots exposed to polyethylene glycol (PEG) had 25941 differentially expressed genes (DEGs) and more upregulated genes were found in DT (8610) than DS (7141). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs of the drought-tolerant genotype were preferably enriched in the flavonoid biosynthetic process, anthocyanin biosynthesis and suberin biosynthesis. The integrated analysis of the transcriptome and metabolome showed that in DT, the KEGG pathways, including flavonoid biosynthesis and arginine and proline metabolism, were shared by differentially accumulated metabolites (DAMs) and DEGs at 6 h after treatment (HAT) and pathways including alanine, aspartate, glutamate metabolism and carbon metabolism were shared at 48 HAT, while in DS, the KEGG pathways shared by DAMs and DEGs only included arginine and proline metabolism at 6 HAT and the biosynthesis of amino acids at 48 HAT. Our results suggest that the drought-tolerant genotype may relieve the drought stress by producing more ROS scavengers, osmoprotectants, energy and larger roots. Interestingly, hormone signaling plays an important role in promoting the development of larger roots and a higher capability to absorb and transport water in drought-tolerant genotypes.
小麦是世界上种植最广泛的作物；其产量因日益严重的水分亏缺而受到严重影响。植物根系在吸收水分以及感知和转导水分亏缺信号方面起着至关重要的作用。在过去的十年中，经常有报道称植物具有耐旱性；然而，小麦根系对水分胁迫响应的转录组和代谢组调控网络尚未完全被理解。在这项研究中，使用耐旱（DT）和干旱敏感（DS）小麦基因型，通过全转录组和代谢组分析来研究根系对水分胁迫响应的机制。结果表明，与对照组相比，PEG 处理的小麦根系有 25941 个差异表达基因（DEGs），其中 DT（8610 个）的上调基因多于 DS（7141 个）。GO 和 KEGG 分析表明，耐旱基因型的 DEGs 主要富集在类黄酮生物合成、花青素生物合成和亚表皮生物合成过程中。转录组和代谢组的综合分析表明，在 DT 中，KEGG 途径包括类黄酮生物合成和精氨酸和脯氨酸代谢，在处理后 6 小时（HAT），差异积累代谢物（DAMs）和 DEGs 之间共享，在 48 HAT 时，途径包括丙氨酸、天冬氨酸、谷氨酸代谢和碳代谢之间也共享，而在 DS 中，在 6 HAT 时，DAMs 和 DEGs 之间仅共享精氨酸和脯氨酸代谢途径，在 48 HAT 时，仅共享氨基酸生物合成途径。我们的结果表明，耐旱基因型可能通过产生更多的 ROS 清除剂、渗透保护剂、能量和更大的根来缓解干旱胁迫。有趣的是，激素信号在促进耐旱基因型较大根系的发育和更高的吸水和输水能力方面起着重要作用。
