In nature,plants acquire nutrients from soils to sustain growth,and at the same time,they need to avoid the uptake of toxic compounds and/or possess tolerance systems to cope with them.This is particularly challenging...In nature,plants acquire nutrients from soils to sustain growth,and at the same time,they need to avoid the uptake of toxic compounds and/or possess tolerance systems to cope with them.This is particularly challenging when the toxic compound and the nutrient are chemically similar,as in the case of phosphate and arsenate.In this study,we demonstrated that regulatory elements of the phosphate starvation response(PSR)coordinate the arsenate detoxification machinery in the cell.We showed that arsenate repression of the phosphate transporter PHT1;1 is associated with the degradation of the PSR master regulator PHR1.Once arsenic is sequestered into the vacuole,PHR1 stability is restored and PHT1;1 expression is recovered.Furthermore,we identified an arsenite responsive SKP1-like protein and a PHR1 interactor F-box(PHIF1)as constituents of the SCF complex responsible for PHR1 degradation.We found that arsenite,the form to which arsenate is reduced for compartmentalization in vacuoles,represses PHT1;1 expression,providing a highly selective signal versus phosphate to control PHT1;1 expression in response to arsenate.Collectively,our results provide molecular insights into a sensing mechanism that regulates arsenate/phosphate uptake depending on the plant’s detoxification capacity.展开更多
Arsenic（As）is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers（e.g.,skin,bladder,and lung）and increases the risk of developing diabetes,hypertension,a...Arsenic（As）is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers（e.g.,skin,bladder,and lung）and increases the risk of developing diabetes,hypertension,and cardiovascular and neurological diseases.The prevalence of arsenic species and the severity of their health effects continue to drive and demand for extensive research（Carlin et al.,2016）.展开更多
A mesophilic,Gram-negative,arsenite[As（Ⅲ）]-oxidizing and arsenate[As（V）]-reducing bacterial strain,Pseudomonas sp.HN-2,was isolated from an As-contaminated soil.Phylogenetic analysis based on 16 S r RNA gene sequ...A mesophilic,Gram-negative,arsenite[As（Ⅲ）]-oxidizing and arsenate[As（V）]-reducing bacterial strain,Pseudomonas sp.HN-2,was isolated from an As-contaminated soil.Phylogenetic analysis based on 16 S r RNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri.Under aerobic conditions,this strain oxidized 92.0%（61.4 μmol/L） of arsenite to arsenate within 3 hr of incubation.Reduction of As（V） to As（Ⅲ） occurred in anoxic conditions.Pseudomonas sp.HN-2 is among the first soil bacteria shown to be capable of both aerobic As（Ⅲ） oxidation and anoxic As（V） reduction.The strain,as an efficient As（Ⅲ） oxidizer and As（V） reducer in Pseudomonas,has the potential to impact arsenic mobility in both anoxic and aerobic environments,and has potential application in As remediation processes.展开更多
基金This work was supported by fellowships from the Spanish Ministry of Science and Innovation(MICINN)to C.N.,C.M.-E.,E.S.-B.and G.C.and by afellowship from Severo Ochoa Centres of Excellence Grant Programme to C.N.and from La Caixa/CNB International PhD fellowship to T.C.M.Thiswork was funded by Spanish Ministry of Science and lnnovation GrantsBIO2014-55741-R,BIO2017-87524-R and BIO2017-89530by the Com-mission of Science and Technology Grant CTQ2017-83569-C2-1-Randby the Comunidad of Madrid and European funding from FSE and FEDERprograms Grants S2018/BAA-4393 and AVANSECAL-Il-CM.
文摘In nature,plants acquire nutrients from soils to sustain growth,and at the same time,they need to avoid the uptake of toxic compounds and/or possess tolerance systems to cope with them.This is particularly challenging when the toxic compound and the nutrient are chemically similar,as in the case of phosphate and arsenate.In this study,we demonstrated that regulatory elements of the phosphate starvation response(PSR)coordinate the arsenate detoxification machinery in the cell.We showed that arsenate repression of the phosphate transporter PHT1;1 is associated with the degradation of the PSR master regulator PHR1.Once arsenic is sequestered into the vacuole,PHR1 stability is restored and PHT1;1 expression is recovered.Furthermore,we identified an arsenite responsive SKP1-like protein and a PHR1 interactor F-box(PHIF1)as constituents of the SCF complex responsible for PHR1 degradation.We found that arsenite,the form to which arsenate is reduced for compartmentalization in vacuoles,represses PHT1;1 expression,providing a highly selective signal versus phosphate to control PHT1;1 expression in response to arsenate.Collectively,our results provide molecular insights into a sensing mechanism that regulates arsenate/phosphate uptake depending on the plant’s detoxification capacity.
基金the Natural Sciences and Engineering Research Council of CanadaCanadian Institutes of Health Research, Alberta InnovatesAlberta Health for their support
文摘Arsenic（As）is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers（e.g.,skin,bladder,and lung）and increases the risk of developing diabetes,hypertension,and cardiovascular and neurological diseases.The prevalence of arsenic species and the severity of their health effects continue to drive and demand for extensive research（Carlin et al.,2016）.
基金supported by the National Natural Science Foundation of China (No.41571451)the Special Funds for Science and Education Fusion of University of Chinese Academy of Sciences
文摘A mesophilic,Gram-negative,arsenite[As（Ⅲ）]-oxidizing and arsenate[As（V）]-reducing bacterial strain,Pseudomonas sp.HN-2,was isolated from an As-contaminated soil.Phylogenetic analysis based on 16 S r RNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri.Under aerobic conditions,this strain oxidized 92.0%（61.4 μmol/L） of arsenite to arsenate within 3 hr of incubation.Reduction of As（V） to As（Ⅲ） occurred in anoxic conditions.Pseudomonas sp.HN-2 is among the first soil bacteria shown to be capable of both aerobic As（Ⅲ） oxidation and anoxic As（V） reduction.The strain,as an efficient As（Ⅲ） oxidizer and As（V） reducer in Pseudomonas,has the potential to impact arsenic mobility in both anoxic and aerobic environments,and has potential application in As remediation processes.
