镉(Cd)是植物的非必须元素,对植物的生长发育有不良影响。然而,镉植物毒性的分子机制,高蓄积剂龙葵的耐受性和积累还没有得到很好的理解。这里,生理学,转录组,进行代谢组分析,以研究在0、25、50、75和100µMCd浓度下7天对黑曲霉的影响。盆栽实验表明,与对照相比,Cd处理显著抑制了生物量,促进了Cd的积累和转运,并扰乱了黑草中矿物质营养代谢的平衡,特别是在100µMCd水平。此外,光合色素含量严重下降,而总蛋白质的含量,脯氨酸,丙二醛(MDA),H2O2和抗氧化酶活性一般随着Cd浓度的增加先增加后略有下降,在叶子和根部。此外,结合以前的转录组数据,与矿质养分和Cd离子运输相关的许多关键编码基因,并鉴定了抗氧化酶的生物合成,在不同的Cd胁迫下,它们的表达模式受到调控。同时,代谢组学分析表明,Cd处理显著改变了许多与氨基酸相关的代谢物的表达水平,脂质,碳水化合物,和核苷酸代谢。代谢途径分析还表明,黑草根激活了一些参与能量代谢的差异表达代谢产物(DEM),这可能会增强解毒的能量供应。重要的是,DEG和DEM的主要常见代谢途径,包括“TCA循环”,使用联合转录组学和代谢组学分析筛选“谷胱甘肽代谢途径”和“乙醛酸盐和二羧酸盐代谢”。我们的研究结果提供了一些新的证据,在高积累的植物镉耐受的生理和分子机制。
Cadmium (Cd) is a nonessential element in plants and has adverse effects on the growth and development of plants. However, the molecular mechanisms of Cd phytotoxicity, tolerance and accumulation in hyperaccumulators Solanum nigrum L. has not been well understood. Here, physiology, transcriptome, and metabolome analyses were conducted to investigate the influence on the S. nigrum under 0, 25, 50, 75 and 100 µM Cd concentrations for 7 days. Pot experiments demonstrated that compared with the control, Cd treatment significantly inhibited the biomass, promoted the Cd accumulation and translocation, and disturbed the balance of mineral nutrient metabolism in S. nigrum, particularly at 100 µM Cd level. Moreover, the photosynthetic pigments contents were severely decreased, while the content of total protein, proline, malondialdehyde (MDA), H2O2, and antioxidant enzyme activities generally increased first and then slightly declined with increasing Cd concentrations, in both leaves and roots. Furthermore, combined with the previous transcriptomic data, numerous crucial coding-genes related to mineral nutrients and Cd ion transport, and the antioxidant enzymes biosynthesis were identified, and their expression pattern was regulated under different Cd stress. Simultaneously, metabolomic analyses revealed that Cd treatment significantly changed the expression level of many metabolites related to amino acid, lipid, carbohydrate, and nucleotide metabolism. Metabolic pathway analysis also showed that S. nigrum roots activated some differentially expressed metabolites (DEMs) involved in energy metabolism, which may enhance the energy supply for detoxification. Importantly, central common metabolism pathways of DEGs and DEMs, including the \"TCA cycle\", \"glutathione metabolic pathway\" and \"glyoxylate and dicarboxylate metabolism\" were screened using conjoint transcriptomics and metabolomics analysis. Our results provide some novel evidences on the physiological and molecular mechanisms of Cd tolerance in hyperaccumulator S. nigrum plants.