College of Tobacco Science, Henan Agricultural University, National Tobacco Cultivation and Physiology and Biochemistry Research center, Key Laboratory for Tobacco Cultivation of Tobacco Industry, Zhengzhou, Henan, China.
College of Resources and Environment, Henan Agricultural University, Zhengzhou, Henan, China.
J Hazard Mater. 2024 Jan 5;461:132641. doi: 10.1016/j.jhazmat.2023.132641. Epub 2023 Sep 27.
Chromium (Cr) is a hazardous heavy metal that negatively affects animals and plants. The micronutrients selenium (Se) and molybdenum (Mo) have been widely shown to alleviate heavy metal toxicity in plants. However, the molecular mechanism of Cr chelation on the cell wall by combined treatment with Se and Mo has not been reported. Therefore, this study aimed to explore the effects of Se-Mo interactions on the subcellular distribution of Cr (50 µM) and on cell wall composition, structure, functional groups and Cr content, in addition to performing a comprehensive analysis of the transcriptome. Our results showed that the cell walls of shoots and roots accumulated 51.0% and 65.0% of the Cr, respectively. Furthermore, pectin in the cell wall bound 69.5%/90.2% of the Cr in the shoots/roots. Se-Mo interactions upregulated the expression levels of related genes encoding galacturonosyltransferase (GAUT), UTP-glucose-1-phosphate uridylyltransferase (UGP), and UDP-glucose-4-epimerase (GALE), involved in polysaccharide biosynthesis, thereby increasing pectin and cellulose levels. Moreover, combined treatment with Se and Mo increased the lignin content and cell wall thickness by upregulating the expression levels of genes encoding cinnamyl alcohol dehydrogenase (CAD), peroxidase (POX) and phenylalanine amino-lyase (PAL), involved in lignin biosynthesis. Fourier-transform infrared (FTIR) spectroscopy results showed that Se + Mo treatment (in combination) increased the number of carboxylic acid groups (-COOH) groups, thereby enhancing the Cr chelation ability. The results not only elucidate the molecular mechanism of action of Se-Mo interactions in mitigating Cr toxicity but also provide new insights for phytoremediation and food safety.
铬（Cr）是一种有害的重金属，对动植物都有负面影响。微量元素硒（Se）和钼（Mo）已被广泛证明可减轻植物的重金属毒性。然而，关于 Se 和 Mo 联合处理通过细胞壁螯合 Cr 的分子机制尚未报道。因此，本研究旨在探讨 Se-Mo 相互作用对 Cr（50µM）亚细胞分布以及细胞壁组成、结构、官能团和 Cr 含量的影响，同时进行转录组的综合分析。我们的结果表明，Cr 分别在地上部和根部的细胞壁中积累了 51.0%和 65.0%。此外，细胞壁中的果胶结合了地上部/根部 Cr 的 69.5%/90.2%。Se-Mo 相互作用上调了编码半乳糖醛酸转移酶（GAUT）、尿苷二磷酸葡萄糖-1-磷酸尿苷转移酶（UGP）和 UDP-葡萄糖-4-差向异构酶（GALE）的相关基因的表达水平，这些基因参与多糖的生物合成，从而增加了果胶和纤维素的含量。此外，通过上调木质素生物合成相关基因编码肉桂醇脱氢酶（CAD）、过氧化物酶（POX）和苯丙氨酸解氨酶（PAL）的表达水平，Se 和 Mo 的联合处理增加了木质素的含量和细胞壁的厚度。傅里叶变换红外（FTIR）光谱结果表明，Se + Mo 处理（联合处理）增加了羧基（-COOH）基团的数量，从而增强了 Cr 的螯合能力。这些结果不仅阐明了 Se-Mo 相互作用缓解 Cr 毒性的作用机制，还为植物修复和食品安全提供了新的见解。
