Transcriptomic Sequencing Analysis on Key Genes and Pathways Regulating Cadmium (Cd) in Ryegrass (Lolium perenne L.) under Different Cadmium Concentrations

Bingjian Cui; Chuncheng Liu; Chao Hu; Shengxian Liang

doi:10.3390/toxics10120734

Transcriptomic Sequencing Analysis on Key Genes and Pathways Regulating Cadmium (Cd) in Ryegrass (Lolium perenne L.) under Different Cadmium Concentrations

Toxics. 2022 Nov 28;10(12):734. doi: 10.3390/toxics10120734.

Authors

Bingjian Cui^{1

2}, Chuncheng Liu^{1

2}, Chao Hu^{1

2}, Shengxian Liang³

Affiliations

¹ Institute of Farmland Irrigation, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
² Key Laboratory of High-Efficient and Safe Utilization of Agriculture Water Resources, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
³ Institute of Life Sciences and Green Development, College of Life Sciences, Hebei University, Baoding 071000, China.

Abstract

Perennial ryegrass (Lolium perenne L.) is an important forage grass and has the potential to be used in phytoremediation, while little information is available regarding the transcriptome profiling of ryegrass leaves in response to high levels of Cd. To investigate and uncover the physiological responses and gene expression characteristics of perennial ryegrass under Cd stress, a pot experiment was performed to study the transcriptomic profiles of ryegrass with Cd-spiked soils. Transcriptome sequencing and comparative analysis were performed on the Illumina RNA-Seq platform at different concentrations of Cd-treated (0, 50 and 500 mg·kg−1 soil) ryegrass leaves and differentially expressed genes (DEGs) were verified by RT-qPCR. The results show that high concentrations of Cd significantly inhibited the growth of ryegrass, while the lower concentrations (5 and 25 mg·kg−1) showed minor effects. The activity levels of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and malondialdehyde (MDA) increased in Cd-treated ryegrass leaves. We identified 1103 differentially expressed genes (DEGs) and profiled the molecular regulatory pathways of ryegrass leaves with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis in response to Cd stress. Cd stress significantly increased the membrane part, the metabolic process, the cellular process and catalytic activity. The numbers of unigenes related to signal transduction mechanisms, post-translational modification, replication, recombination and repair significantly increased. KEGG function annotation and enrichment analysis were performed based on DEGs with different treatments, indicating that the MAPK signaling pathway, the mRNA surveillance pathway and RNA transport were regulated significantly. Taken together, this study explores the effect of Cd stress on the growth physiology and gene level of ryegrass, thus highlighting significance of preventing and controlling heavy metal pollution in the future.

Keywords: RNA-Seq; RT-qPCR; cadmium; perennial ryegrass.

Grants and funding

This research was funded by the Agricultural Science and Technology Innovation Program (ASTIP) of Chinese Academy of Agricultural Sciences and the Natural Science Foundation of Henan Province of China (202300410552).