Abstract:

The multi-level interactive networks and genetic regulatory mechanisms of cadmium absorption, translocation, and distribution in rice were discussed in order to provide a theoretical basis for cultivating low-cadmium-accumulating rice. The processes of root uptake, xylem loading, phloem redistribution, and grain accumulation of cadmium in rice were summarized, as well as the genetic regulatory networks for low accumulation and molecular breeding technologies. And the roles of transport proteins, transcription factors, and non-coding RNAs in the absorption, translocation, distribution, and grain accumulation of heavy metals were analyzed as key points. Additionally, the application potential of gene overexpression and gene editing technologies in reducing cadmium accumulation in rice grains were discussed. Current research on the multi-level interaction networks and genetic regulation of cadmium absorption, transport, and distribution in rice still faces challenges, such as the complexity of interaction networks, unclear regulatory hierarchies, difficulties in gene-environment interactions and field applications, and insufficient understanding of the molecular mechanisms underlying co-stress from multiple heavy metals in complex field environments. It is recommended to precisely edit or design of regulatory elements targeting key transcription factors or non-coding RNAs, and integrate spatiotemporal-specific gene editing, synthetic biology, and multi-omics analyses to deeply elucidate and precisely regulate the cadmium uptake-transport-detoxification network. This will provide a basis for the targeted development of new germplasms with both low cadmium accumulation and high, stable yields.

Key words: rice, cadmium, low accumulation, response mechanisms, genetic regulation