Abstract
Cadmium (Cd) is a toxic heavy metal that endangers human health through contaminated rice consumption. Reducing Cd uptake in rice is essential for minimizing grain Cd accumulation. However, the transcriptional regulation of Cd uptake in rice remains largely elusive. This study reveals that the transcription factor OsNAC5 in Oryza sativa positively regulates the Cd transporter gene OsNRAMP1, influencing Cd uptake. OsNAC5 is primarily expressed in roots, localized to the nucleus, and upregulated by Cd-induced H2O2. Knocking out OsNAC5 reduces Cd levels in both shoots and roots and increases Cd sensitivity. OsNRAMP1 expression, enhanced by Cd stress, depends on OsNAC5, which binds to “CATGTG” motifs in the OsNRAMP1 promoter activating its expression. Loss of OsNAC5 function decreases Cd accumulation in rice grains. Our findings elucidate the transcriptional regulation of Cd stress response in rice and suggest biotechnological approaches to reduce Cd uptake in crops.
Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Figure 3 revised. This study addresses the critical issue of cadmium (Cd) contamination in rice, which poses a significant threat to human health, and elucidates the transcriptional regulatory mechanisms that govern Cd uptake in rice plants. Cadmium is a highly toxic heavy metal, and its accumulation in rice grains is a major concern for food safety. The reduction of Cd uptake in rice is vital for ensuring the safety of this staple food. Our research provides novel insights into the role of the transcription factor OsNAC5 in the positive regulation of the Cd transporter gene OsNRAMP1 and its subsequent impact on Cd uptake and accumulation in rice.
