College of Agriculture, Anhui Science and Technology University, Fengyang, Anhui, China.
Anhui Sungu Agritech CO., LTD, Hefei, China.
PLoS One. 2024 Aug 19;19(8):e0308541. doi: 10.1371/journal.pone.0308541. eCollection 2024.
Plants have developed precise defense mechanisms against cadmium (Cd) stress, with vacuolar compartmentalization of Cd2+ being a crucial process in Cd detoxification. The transport of Cd into vacuoles by these cation / H+ antiporters is powered by the pH gradient created by proton pumps. In this study, the full-length cDNA of a vacuolar H+-pyrophosphatase (V-PPase) gene from Boehmeria nivea (ramie), BnVP1, was isolated using the rapid amplification of cDNA ends (RACE) method. The open reading frame (ORF) of BnVP1 is 2292 bp, encoding a 763 amino acid V-PPase protein with 15 predicted transmembrane domains. Sequence alignment and phylogenetic analysis revealed that BnVP1 belongs to the Type I V-PPase family. Quantitative RT-PCR assays demonstrated that BnVP1 expression was significantly higher in ramie roots than in shoots. Cd treatments markedly induced BnVP1 expression in both roots and leaves of ramie seedlings, with a more pronounced effect in roots. Additionally, BnVP1 expression was significantly upregulated by the plant hormone methyl jasmonate (MeJA). Heterologous expression of BnVP1 in transgenic Arabidopsis significantly enhanced V-PPase activity in the roots. The growth performance, root elongation, and total chlorophyll content of transgenic plants with high tonoplast H+-PPase (V-PPase) activity were superior to those of wild-type plants. Overexpression of BnVP1 reduced membrane lipid peroxidation and ion leakage, and significantly increased Cd accumulation in the roots of transgenic Arabidopsis seedlings. This study provides new genetic resources for the phytoremediation of Cd-contaminated farmland.
植物已经发展出了精确的防御机制来应对镉（Cd）胁迫，其中将 Cd2+区室化到液泡中是 Cd 解毒的关键过程。这些阳离子/H+反向转运蛋白将 Cd 转运到液泡中，其动力来自质子泵产生的 pH 梯度。在这项研究中，我们使用快速扩增 cDNA 末端（RACE）方法从苎麻（Boehmeria nivea）中分离出液泡 H+-焦磷酸酶（V-PPase）基因的全长 cDNA，BnVP1。BnVP1 的开放阅读框（ORF）为 2292 bp，编码一个 763 个氨基酸的 V-PPase 蛋白，具有 15 个预测的跨膜结构域。序列比对和系统发育分析表明，BnVP1 属于 I 型 V-PPase 家族。定量 RT-PCR 分析表明，BnVP1 在苎麻根中的表达明显高于茎。Cd 处理显著诱导苎麻幼苗根和叶中 BnVP1 的表达，在根中更为明显。此外，植物激素茉莉酸甲酯（MeJA）显著上调 BnVP1 的表达。BnVP1 在转基因拟南芥中的异源表达显著提高了根中的 V-PPase 活性。具有高液泡 H+-PPase（V-PPase）活性的转基因植物的生长表现、根伸长和总叶绿素含量均优于野生型植物。BnVP1 的过表达减少了膜脂过氧化和离子渗漏，并显著增加了 Cd 在转基因拟南芥幼苗根中的积累。这项研究为农田 Cd 污染的植物修复提供了新的遗传资源。
