Transcriptome analysis of the responses involved in the regulation of cadmium stress by exogenous hydrogen in rice (Oryza sativa)

摘要

Cadmium is a major threat to agricultural production and human health. Exogenous hydrogen plays an important role in plant stress resistance through a mechanism that remains unknown. To elucidate this mechanism, this study investigated the effect of exogenous hydrogen on rice ( Oryza sativa ) gene expression under cadmium stress. Four libraries of the super hybrid rice LYP9 were sequenced through high-throughput sequencing technology. Approximately 13 GB of unique sequences were obtained. Comparative analysis identified 1329 differentially expressed genes in rice with normal growth exposed to exogenous hydrogen and 1217 differentially expressed genes in rice subjected to cadmium stress. The analyses of the functional enrichment and metabolic pathways of the differentially expressed genes revealed that exogenous hydrogen down-regulates the expression levels of stress-related genes under non-stress conditions and up-regulates the expression levels of stress-related genes under cadmium stress. Under non-stress conditions, exogenous hydrogen promotes the expression of genes related to photosynthesis and energy metabolism. Under cadmium stress, exogenous hydrogen down-regulates the expression of energy-metabolism-related genes while inhibiting rice growth by down-regulating the expression of cadmium-transporter-related genes. The latter effect prevents the absorption of cadmium by roots and increases the resistance of rice to cadmium toxicity. This study provides an experimental basis for the in-depth study of the mechanism underlying cadmium tolerance in rice.