National Beet Medium-Term Gene Bank, Heilongjiang University, Harbin 150080, China; Key Laboratory of Beet Genetics and Breeding/College of Modern Agriculture and Ecological Environment, Heilongjiang University, Harbin 150080, China.
National Beet Medium-Term Gene Bank, Heilongjiang University, Harbin 150080, China; Engineering Research Center of Agricultural Microbiology Technology, Ministry of Education & Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region & Key Laboratory of Molecular Biology, College of Heilongjiang Province & School of Life Sciences, Heilongjiang University, Harbin 150080, China.
J Hazard Mater. 2024 Dec 5;480:135968. doi: 10.1016/j.jhazmat.2024.135968. Epub 2024 Sep 26.
Sugar beet (Beta vulgaris L.) shows potential as an energy crop for cadmium (Cd) phytoremediation. To elucidate its in vivo response strategy to Cd exposure, seedlings were treated with 1, 3, and 5 mmol/L CdCl (Cd-1, Cd-3, and Cd-5) for 6 h, using 0 mmol/L CdCl (Cd-0) as the control. The results showed that Cd-3 promoted a unique "hormesis" effect, leading to superior growth performance, increased levels of chlorophyll, soluble protein, and SOD activity, and reduced MDA content in sugar beet, compared to Cd-1, Cd-5, and even Cd-0. GO and KEGG enrichments and PPI networks of transcriptomic analysis revealed that the differentially expressed genes (DEGs) were primarily involved in lipid metabolism, cellular protein catabolism, and photosynthesis. Notably, the MAPK signaling pathway was significantly enriched only under Cd-3, with the up-regulation of ABA-related core gene BvPYL9 and an increase in ABA content after 6 h of Cd exposure. Furthermore, overexpression of BvPYL9 in Arabidopsis thaliana (OE-1 and OE-2) resulted in enhanced growth (fresh weight, dry weight, and root length), as well as higher ABA and soluble protein contents under different Cd treatments. Cd-induced transcriptional responses of BvPYL9 were also evident in OE-1 and OE-2, especially at 10 µmol/L, indicated by qRT-PCR. These findings suggest that ABA-mediated MAPK signaling pathway is activated in response to Cd toxicity, with BvPYL9 being a key factor in the cascade effects for the Cd-induced hormesis in sugar beet.
甜菜（Beta vulgaris L.）作为一种用于镉（Cd）植物修复的能源作物具有很大的潜力。为了阐明其对 Cd 暴露的体内响应策略，将幼苗用 1、3 和 5 mmol/L 的 CdCl（Cd-1、Cd-3 和 Cd-5）处理 6 h，以 0 mmol/L 的 CdCl（Cd-0）作为对照。结果表明，与 Cd-1、Cd-5 甚至 Cd-0 相比，Cd-3 促进了独特的“毒物兴奋效应”，导致甜菜的生长性能提高、叶绿素、可溶性蛋白和 SOD 活性增加，MDA 含量降低。GO 和 KEGG 富集以及转录组分析的 PPI 网络显示，差异表达基因（DEGs）主要参与脂类代谢、细胞蛋白分解代谢和光合作用。值得注意的是，MAPK 信号通路仅在 Cd-3 下显著富集，ABA 相关核心基因 BvPYL9 的上调以及 Cd 暴露 6 h 后 ABA 含量增加。此外，在拟南芥中过表达 BvPYL9（OE-1 和 OE-2）导致在不同 Cd 处理下生长（鲜重、干重和根长）增强，以及 ABA 和可溶性蛋白含量升高。BvPYL9 在 OE-1 和 OE-2 中对 Cd 诱导的转录反应也很明显，特别是在 10 μmol/L 时，通过 qRT-PCR 可以看出。这些发现表明，ABA 介导的 MAPK 信号通路在 Cd 毒性下被激活，BvPYL9 是甜菜中 Cd 诱导毒物兴奋效应级联反应的关键因素。
