Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Red...Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Reducing the application of P fertilizer and enhancing the P utilization efficiency of crops are significant for the sustainable development of agriculture.Cadmium(Cd)contamination in rice is another serious agricultural issue.However,whether reducing the application of P fertilizer and enhancing the P utilization efficiency of crops will increase the risk of Cd accumulation in crops remains obscure.In this study,we are aiming to elucidate the relationship between Cd and P in rice from physiological and genetic perspectives.For this purpose,the wild type(WT)rice plants and phosphate(Pi)-starvation signaling repressed mutant phr2 were used to analyze the relationship between Cd and P.Here,we found that Cd stress could promote P accumulation and induce Pi-starvation signaling in WT and phr2 shoots under Pi-sufficient condition in a PHOSPHATE STARVATION RESPONSE 2(PHR2)independent manner.Besides,the expression level of Cd transporter of OsNramp5 and the uptake speed of Cd2+were not obviously changed under Pi-sufficient and Pi-deficient conditions.Furthermore,our Cd determination results showed that the Cd concentrations in WT and phr2 were not obviously changed under Pi-sufficient and Pi-deficient conditions.These results indicate that the external P availability and internal Pi-starvation signaling cannot obviously affect the accumulation of Cd in rice seedling.展开更多
The association between the rhizospheric microbial community and Cd accumulation in rice is poorly understood.A field trial was conducted to investigate the different rhizobacterial communities of two rice cultivars w...The association between the rhizospheric microbial community and Cd accumulation in rice is poorly understood.A field trial was conducted to investigate the different rhizobacterial communities of two rice cultivars with high Cd accumulation(HA)and low Cd accumulation(LA)at four growth stages.Results showed that the Cd content in the roots of the HA cultivar was 1.23-27.53 higher than that of the LA cultivar(0.08-10.5μg/plant)at four stages.The LA cultivar had a significantly lower Cd availability in rhizosphere and a higher quantity of iron plaque(IP)on the root surface than the HA cultivar at four stages.This resulted in the reduction of Cd concentration in IPs and Cd translocation from IP-to-root.Microbial analysis indicated that the LA cultivar formed a distinct rhizobacterial community from the HA cultivar and had lessα-diversity.The rhizosphere of the LA cultivar was enriched in specific bacterial taxa(e.g.,Massilia and Bacillus)involved in Cd immobilization by phosphate precipitation and IP formation by iron oxidization.However,the rhizosphere in the HA cultivar assembled abundant sulfur-oxidizing bacteria(e.g.,Sulfuricurvum)and iron reduction bacteria(Geobacter).They promoted Cd mobilization and reduced IP formation via the metal redox process.This study reveals a potential approach in which specific rhizobacteria decrease or increase Cd accumulation in rice on contaminated soil and provides a new perspective for secure rice production.展开更多
基金supported by the National Key Research and Development of China (2017YFD0200204)the National Natural Science Foundation of China (31601807)
文摘Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Reducing the application of P fertilizer and enhancing the P utilization efficiency of crops are significant for the sustainable development of agriculture.Cadmium(Cd)contamination in rice is another serious agricultural issue.However,whether reducing the application of P fertilizer and enhancing the P utilization efficiency of crops will increase the risk of Cd accumulation in crops remains obscure.In this study,we are aiming to elucidate the relationship between Cd and P in rice from physiological and genetic perspectives.For this purpose,the wild type(WT)rice plants and phosphate(Pi)-starvation signaling repressed mutant phr2 were used to analyze the relationship between Cd and P.Here,we found that Cd stress could promote P accumulation and induce Pi-starvation signaling in WT and phr2 shoots under Pi-sufficient condition in a PHOSPHATE STARVATION RESPONSE 2(PHR2)independent manner.Besides,the expression level of Cd transporter of OsNramp5 and the uptake speed of Cd2+were not obviously changed under Pi-sufficient and Pi-deficient conditions.Furthermore,our Cd determination results showed that the Cd concentrations in WT and phr2 were not obviously changed under Pi-sufficient and Pi-deficient conditions.These results indicate that the external P availability and internal Pi-starvation signaling cannot obviously affect the accumulation of Cd in rice seedling.
基金supported by the National Natural Science Foundation of China(No.41907032)the Major Science,and Technology Programs of Changsha(No.kq2006026)the High Technology Industry S&T Innovation Leading Project of Hunan Province(No.2020NK2001)。
文摘The association between the rhizospheric microbial community and Cd accumulation in rice is poorly understood.A field trial was conducted to investigate the different rhizobacterial communities of two rice cultivars with high Cd accumulation(HA)and low Cd accumulation(LA)at four growth stages.Results showed that the Cd content in the roots of the HA cultivar was 1.23-27.53 higher than that of the LA cultivar(0.08-10.5μg/plant)at four stages.The LA cultivar had a significantly lower Cd availability in rhizosphere and a higher quantity of iron plaque(IP)on the root surface than the HA cultivar at four stages.This resulted in the reduction of Cd concentration in IPs and Cd translocation from IP-to-root.Microbial analysis indicated that the LA cultivar formed a distinct rhizobacterial community from the HA cultivar and had lessα-diversity.The rhizosphere of the LA cultivar was enriched in specific bacterial taxa(e.g.,Massilia and Bacillus)involved in Cd immobilization by phosphate precipitation and IP formation by iron oxidization.However,the rhizosphere in the HA cultivar assembled abundant sulfur-oxidizing bacteria(e.g.,Sulfuricurvum)and iron reduction bacteria(Geobacter).They promoted Cd mobilization and reduced IP formation via the metal redox process.This study reveals a potential approach in which specific rhizobacteria decrease or increase Cd accumulation in rice on contaminated soil and provides a new perspective for secure rice production.
