Department of Biology, Science and Research Branch, Islamic Azad University, 1477893855, Tehran, Iran.
Department of Biology, Science and Research Branch, Islamic Azad University, 1477893855, Tehran, Iran.
Environ Pollut. 2020 Oct;265(Pt B):114727. doi: 10.1016/j.envpol.2020.114727. Epub 2020 May 5.
This study aimed to explore whether supplementation of the culture medium with selenium nanoparticles (nSe) can influence growth, biochemistry, expression of transcription factors, and epigenetic DNA methylation in Capsicum annuum. The seeds were grown in hormone-free MS culture medium supplemented with nSe (0, 0.5, 1, 10, and 30 mgL) or corresponding doses of bulk type selenate (BSe). Incorporation of nSe into the medium caused variations in morphology and growth in a manner dependent on the dose and Se type. The low doses of nSe displayed growth-promoting effects, whereas nSe at 10 and 30 mgL were associated with severe toxicity and abnormality in leaf and root development. MSAP analysis confirmed the substantial variation in cytosine DNA methylation in response to the toxic dose of nSe exhibiting epigenetic modification. The nSe toxicity was associated with DNA hyper-methylations. The nSe treatments transcriptionally upregulated the bZIP1 transcription factor by an average of 3.5 folds. With a similar trend, the upregulation (mean = 9.8 folds) in the expression of the WRKY1 transcription factor resulted from the nSe application. The nSe0.5 or nSe1 treatments resulted in a significant induction (mean = 48%) in nitrate reductase activity. A high dose of nSe led to an increase in proline concentration. The nSe treatments were also associated with modifications in activities of peroxidase and catalase enzymes. Besides, the nSe utilization increased the activity of phenylalanine ammonia-lyase enzyme (mean = 76%) and concentrations of soluble phenols (mean = 51%). The toxic dose of nSe also caused abnormalities in the structure of the stem apical meristem. The nSe toxicity was also associated with inhibition in the differentiation of xylem tissues. These findings provide novel insights into the nSe-associated molecular variations in conferring the modified growth, anatomy, and metabolism.
本研究旨在探索在培养基中添加硒纳米颗粒（nSe）是否会影响辣椒的生长、生物化学、转录因子表达和表观遗传 DNA 甲基化。种子在无激素 MS 培养基中生长，培养基中添加 nSe（0、0.5、1、10 和 30 mgL）或相应剂量的 bulk 型硒酸盐（BSe）。nSe 被纳入培养基中会导致形态和生长的变化，这种变化方式取决于剂量和 Se 类型。低剂量的 nSe 表现出促进生长的作用，而 nSe 剂量为 10 和 30 mgL 时则与叶片和根系发育的严重毒性和异常有关。MSAP 分析证实，nSe 的毒性剂量导致胞嘧啶 DNA 甲基化发生实质性变化，表现出表观遗传修饰。nSe 的毒性与 DNA 超甲基化有关。nSe 处理平均转录上调 bZIP1 转录因子 3.5 倍。具有相似趋势的是，WRKY1 转录因子的表达上调（平均值为 9.8 倍）是由于 nSe 的应用。nSe0.5 或 nSe1 处理导致硝酸还原酶活性显著诱导（平均值为 48%）。高剂量的 nSe 导致脯氨酸浓度增加。nSe 处理还与过氧化物酶和过氧化氢酶活性的变化有关。此外，nSe 的利用增加了苯丙氨酸解氨酶酶的活性（平均值为 76%）和可溶性酚的浓度（平均值为 51%）。nSe 的毒性还导致茎尖分生组织结构异常。nSe 的毒性还与木质部组织分化的抑制有关。这些发现为 nSe 引起的分子变化与修饰的生长、解剖和代谢提供了新的见解。
