Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Agronomy College, Jiangxi Agricultural University, Nanchang 330045, China.
Graduate School of Jiangxi Normal University, Jiangxi Normal University, Nanchang 330045, China.
Int J Mol Sci. 2023 Jun 15;24(12):10163. doi: 10.3390/ijms241210163.
Rapeseed has the ability to absorb cadmium in the roots and transfer it to aboveground organs, making it a potential species for remediating soil cadmium (Cd) pollution. However, the genetic and molecular mechanisms underlying this phenomenon in rapeseed are still unclear. In this study, a 'cadmium-enriched' parent, 'P1', with high cadmium transport and accumulation in the shoot (cadmium root: shoot transfer ratio of 153.75%), and a low-cadmium-accumulation parent, 'P2', (with a cadmium transfer ratio of 48.72%) were assessed for Cd concentration using inductively coupled plasma mass spectrometry (ICP-MS). An F genetic population was constructed by crossing 'P1' with 'P2' to map QTL intervals and underlying genes associated with cadmium enrichment. Fifty extremely cadmium-enriched F individuals and fifty extremely low-accumulation F individuals were selected based on cadmium content and cadmium transfer ratio and used for bulk segregant analysis (BSA) in combination with whole genome resequencing. This generated a total of 3,660,999 SNPs and 787,034 InDels between these two segregated phenotypic groups. Based on the delta SNP index (the difference in SNP frequency between the two bulked pools), nine candidate Quantitative trait loci (QTLs) from five chromosomes were identified, and four intervals were validated. RNA sequencing of 'P1' and 'P2' in response to cadmium was also performed and identified 3502 differentially expressed genes (DEGs) between 'P1' and 'P2' under Cd treatment. Finally, 32 candidate DEGs were identified within 9 significant mapping intervals, including genes encoding a glutathione S-transferase (GST), a molecular chaperone (DnaJ), and a phosphoglycerate kinase (PGK), among others. These genes are strong candidates for playing an active role in helping rapeseed cope with cadmium stress. Therefore, this study not only sheds new light on the molecular mechanisms of Cd accumulation in rapeseed but could also be useful for rapeseed breeding programs targeting this trait.
油菜具有在根部吸收镉并将其转移到地上器官的能力，使其成为修复土壤镉（Cd）污染的潜在物种。然而，油菜中这种现象的遗传和分子机制仍不清楚。在这项研究中，使用电感耦合等离子体质谱法（ICP-MS）评估了一种具有高镉转运和积累能力的“富镉”亲本“P1”（地上部镉根：比为 153.75%）和一种低镉积累亲本“P2”（转运比为 48.72%）的 Cd 浓度。通过“P1”与“P2”杂交构建了一个 F 遗传群体，以定位与镉富集相关的 QTL 区间和潜在基因。根据镉含量和镉转运比，从 F 群体中选择了 50 个极度富镉的 F 个体和 50 个极度低积累的 F 个体，用于结合全基因组重测序的批量分离分析（BSA）。这总共产生了这两个分离表型群体之间的 3660999 个 SNPs 和 787034 个 InDels。基于德尔塔 SNP 指数（两个批量池之间 SNP 频率的差异），从五个染色体上鉴定了 9 个候选数量性状基因座（QTL），并验证了四个区间。还对“P1”和“P2”在镉胁迫下的响应进行了 RNA 测序，在 Cd 处理下，“P1”和“P2”之间鉴定出 3502 个差异表达基因（DEGs）。最后，在 9 个显著映射区间内鉴定出 32 个候选 DEG，包括编码谷胱甘肽 S-转移酶（GST）、分子伴侣（DnaJ）和磷酸甘油酸激酶（PGK）等基因。这些基因是在油菜应对镉胁迫中发挥积极作用的有力候选基因。因此，本研究不仅为油菜中 Cd 积累的分子机制提供了新的见解，而且可能对针对该特性的油菜育种计划也具有一定的参考价值。
