摘要
Silicon(Si)has been shown to alleviate Cd stress in rice.Here,we investigated the beneficial effects of foliar Si in an indica rice Huanghuazhan(HHZ).Our results showed that foliar Si in-creases the dry weight and decreases Cd translocation in Cd-exposed rice at the grain-filling stage only,implying that the filling stage is critical for foliar Si to reduce Cd accumulation.We also investigated the transcriptomics in flag leaves(FLs),spikelets(SPs),and node Is(NIs)of Cd-exposed HHZ after foliar Si application at the filling stage.Importantly,the gene expression profiles associated with the Si-mediated alleviation of Cd stress were tissue spe-cific,while shared pathways were mediated by Si in Cd-exposed rice tissues.Furthermore,after the Si treatment of Cd-exposed rice,the ATP-binding cassette(ABC)-transporters were mostly upregulated in FL and SP,while the bivalent cation transporters were mostly down-regulated in FL and NI,possibly helping to reduce Cd accumulation.The genes associated with essential nutrient transporters,carbohydrate and secondary metabolite biosynthesis,and cytochrome oxidase activity were mostly upregulated in Cd-exposed FL and SP,which may help to alleviate oxidative stress and improve plant growth under Cd exposure.Inter-estingly,genes responsible for signal transduction were negatively regulated in FL,but pos-itively regulated in SP,by foliar Si.Our results provide transcriptomic evidence that foliar Si plays an active role in alleviating the effects of Cd exposure in rice.In particular,foliar Si may alter the expression pattern of genes associated with transport,biosynthesis and metabolism,and oxidation reduction.
基金
This work was financially supported by the National Key Research and Development Project of China(No.2016YFD0800700)
the National Natural Science Foundation of China(No.41877143)
the Science and Technology Planning Project of Guangdong Province,China(No.2015B020237008)
the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010906)
the Special Rural Revitalization Funds of Guangdong Province(No.2021KJ382).
