College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin 150030, PR China.
Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Engineering Research Center for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Science and Oceanography, Shenzhen University, Shenzhen 518060, PR China.
J Hazard Mater. 2024 Sep 5;476:135106. doi: 10.1016/j.jhazmat.2024.135106. Epub 2024 Jul 4.
Excessive heavy metal contaminants in soils have serious ecological and environmental impacts, and affect plant growth and crop yields. Phytoremediation is an environmentally friendly means of lowering heavy metal concentrations in soils. In this study, we analyzed phenotypic and physiological traits, and the transcriptome and metabolome, of sheepgrass (Leymus chinensis) exposed to cadmium (Cd), lead (Pb), or zinc (Zn). Phenotypic and physiological analysis indicated that sheepgrass had strong tolerance to Cd/Pb/Zn. Transcriptomic analysis revealed that phenylpropanoid biosynthesis and organic acid metabolism were enriched among differentially expressed genes, and metabolomic analysis indicated that the citrate cycle was enriched in response to Cd/Pb/Zn exposure. Genes encoding enzymes involved in the phenylpropanoid and citrate cycle pathways were up-regulated under the Cd/Pb/Zn treatments. Organic acids significantly reduced heavy metal accumulation and improved sheepgrass tolerance of heavy metals. The results suggest that synergistic interaction of the phenylpropanoid and citrate cycle pathways in sheepgrass roots induced organic acid secretion to alleviate heavy metal toxicity. A cascade of enzymes involved in the interacting pathways could be targeted in molecular design breeding to enhance phytoremediation.
土壤中过量的重金属污染物会对生态和环境造成严重影响，同时还会影响植物的生长和作物产量。植物修复是降低土壤中重金属浓度的一种环保手段。在这项研究中，我们分析了羊草（Leymus chinensis）暴露在镉（Cd）、铅（Pb）或锌（Zn）下的表型和生理特征，以及转录组和代谢组。表型和生理分析表明，羊草对 Cd/Pb/Zn 具有很强的耐受性。转录组分析显示，苯丙烷生物合成和有机酸代谢在差异表达基因中富集，代谢组分析表明，柠檬酸循环对 Cd/Pb/Zn 的暴露有富集作用。在 Cd/Pb/Zn 处理下，参与苯丙烷和柠檬酸循环途径的酶编码基因被上调。有机酸显著降低了重金属的积累，提高了羊草对重金属的耐受性。这些结果表明，羊草根中苯丙烷和柠檬酸循环途径的协同相互作用诱导了有机酸的分泌，从而减轻了重金属的毒性。参与相互作用途径的一系列酶可以作为分子设计育种的目标，以增强植物修复。
