Different cadmium(Cd)-accumulated rice genotypes(Erjiunan 1 and Fupin 36)were used to explore the effect of rice rhizosphere aeration on Cd uptake and accumulation.Aeration in the nutrient soluti on influe need the ag...Different cadmium(Cd)-accumulated rice genotypes(Erjiunan 1 and Fupin 36)were used to explore the effect of rice rhizosphere aeration on Cd uptake and accumulation.Aeration in the nutrient soluti on influe need the agronomic characteristics in duced by Cd-stress,such as the in creases of rice root length and root vigor,but the reductions of plant height and shoot dry weight.Aeration also alleviated the decreasing effects of Cd stress on antioxidant enzyme activities and soluble protein,malonaldehyde and nicotianamine contents in rice.Moreover,with aeration treatment,the accumulation and bioavailability of metal elements changed significantly,with a Cd increase and an Fe reduction in both rice genotypes.In addition,at the molecular level,aeration upregulated the expression of Fe-inducible genes(such as OsIRTI,OsNRAMPI,OsYSL15 and OsNAS3).Furthermore,as a Cd^(2+)/Fe^(2+) transporter,the high transcription level of OsNRAMPI can elevate the Cd uptake and translocation in rice due to the Fe reduction caused by aeration and Cd-exposure,which indicated that OsNRAMPI might play a crucial role in the effect of aeration on Cd uptake and accumulation.展开更多
Soil cadmium (Cd) causes toxicity and oxidative stress, alters biochemical processes and rootknot formation in rice. Irrigation of exogenous peroxidase (POX) together with its co-substrate H2O2(POXRice + H2O2), is lik...Soil cadmium (Cd) causes toxicity and oxidative stress, alters biochemical processes and rootknot formation in rice. Irrigation of exogenous peroxidase (POX) together with its co-substrate H2O2(POXRice + H2O2), is likely to have protective effect upon the biochemical and nodular changes in ricegrown in Cd-rich soil. Exposure to Cd concentration of 1.00 mg/L increased oxidative stress, loss of cellviability, electrolyte leakage and root knot formation, whereas it significantly lowered the chlorophyll leveland rhizobium growth in rice. Irrigation of exogenous POXRice + H2O2 to Cd-stressed rice seedlingsreversed the Cd-induced alterations in rice to levels similar in control (non-stressed) seedlings. Resultsprovided strong evidence of exogenous POXRice + H2O2-mediated reversal and restoration of physiologicaland biochemical processes as well as increased resistance of rice seedlings to root knot formation.Irrigation with POXRice + H2O2 appeared to contribute towards bringing normoxic conditions in the otherwisehypoxic soil environment by enhancing the O2 in pot-experiments due to reduced Cd uptake, enhancedmineral homeostasis of essential elements viz. P, Fe, Mo, Mg and Mn for maintenance of root architecturedamaged by lipid peroxidation and reduction in oxidative stress by reducing Cd-induced reactive oxygenspecies generation. Therefore, the mitigation of Cd-toxicity in rice through this novel approach appeared tobe a promising mode to limit Cd-uptake, modulate protective and tolerance mechanisms for sustainablerice yield in Cd-contaminated rice-croplands and prevent nematode attack in rice, however, more detailedstudies are needed prior to large scale applications.展开更多
Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors,including drought,ultraviolet radiation,and extreme temperatures.In this study,we identified the drought tolerance gene Nfcr...Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors,including drought,ultraviolet radiation,and extreme temperatures.In this study,we identified the drought tolerance gene NfcrtO,which encodes aβ-carotene ketolase,through screening the transcriptome of N.flagelliforme under water loss stress.Prokaryotic expression of NfcrtO under 0.6 mol/L sorbitol or under 0.3 mol/L NaCl stress significantly increased the growth rate of Escherichia coli.When NfcrtO was heterologously expressed in rice,the seedling height and root length of NfcrtO-overexpressing rice plants were significantly higher than those of the wild type(WT)plants grown on½Murashige and Skoog solid medium with 120 mmol/L mannitol at the seedling stage.Transcriptome analysis revealed that NfcrtO was involved in osmotic stress,antioxidant,and other stress-related pathways.Additionally,the survival rate of the NfcrtO-overexpression lines was significantly higher than that of the WT line under both hydroponic stress(24%PEG and 100 mmol/L H_(2)O_(2))and soil drought treatment at the seedling stage.Physiological traits,including the activity levels of superoxide dismutase,peroxidase,catalase,total antioxidant capacity,and the contents of proline,trehalose,and soluble sugar,were significantly improved in the NfcrtO-overexpression lines relative to those in the WT line under 20%PEG treatment.Furthermore,when water was withheld at the booting stage,the grain yield per plant of NfcrtO-overexpression lines was significantly higher than that of the WT line.Yeast two-hybrid analysis identified interactions between NfcrtO and Dna J protein,E3 ubiquitin-protein ligase,and pyrophosphate-energized vacuolar membrane proton pump.Thus,heterologous expression of NfcrtO in rice could significantly improve the tolerance of rice to osmotic stress,potentially facilitating the development of new rice varieties.展开更多
Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of...Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of two soil amendments, sodium sulfide-biofuel ash (SSBA) and lime (0.1%), and three foliar applications, silicon (Si, 2.5 mmol L-1), selenium (Se, 40 mg L-1), and their combination (SS), on Cd reduction in rice (Oryza sativa L.) in a pot experiment, which were then verified in a field experiment. Compared with the control without amendment but with spraying of deionized water, both SSBA and lime significantly reduced concentrations of CaCl2-extractable Cd in soil by 30%–39% and 31%–40% and Cd in brown rice by 44%–63% and 53%–72% in the pot and field experiments, respectively. Foliar Si, Se, and SS applications significantly reduced Cd accumulation in brown rice by 62%–64%, 72%–83%, and 39%–73%, respectively, increased rice grain yield, and improved antioxidant enzyme activities in rice leaves but with different trends in the pot and field experiments. Combinations of SSBA and lime with Si, Se, and SS had a non-significant synergistic effect on Cd reduction in brown rice compared to only foliar spraying or soil amendment in both pot and field experiments, although SSBA + Se and SSBA + Si reduced Cd concentration in brown rice by 16%–34% and 14%–24% compared to only foliar Si and Se and soil SSBA applications, respectively. Soil lime application and foliar Si spraying were the most cost-effective strategies to reduce Cd accumulation in brown rice in the field and pot experiments, respectively. Although soil amendments and foliar treatments were individually effective, their combinations failed to generate a significant synergistic reduction of Cd concentration in brown rice.展开更多
Drought is the major abiotic stress factor that limits rice production worldwide.To evaluate the osmotic stress responses in rice varieties under drought condition,a total of 42 high-yielding rice varieties were colle...Drought is the major abiotic stress factor that limits rice production worldwide.To evaluate the osmotic stress responses in rice varieties under drought condition,a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India.The experimental setup comprises of initial hydroponic treatments at different osmotic potentials,artificially induced by desired strengths of polyethylene glycol(PEG6000),and followed by the pot planted experiments in the rain-out-zone.The activities of antioxidant enzymes,relative water content,cell membrane stability,photosynthetic pigments,proline content,along with plant growth parameters of the varieties under drought condition were evaluated.Moreover,the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice.Among the 42 rice varieties,we identified 2 rice varieties,Swarnaprabha and Kattamodan,with less leaf rolling,better drought recovery ability as well as relative water content,increased membrane stability index,osmolyte accumulation,and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress.The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.展开更多
采用土壤盆栽试验研究水溶性有机肥料对水稻抗氧化酶活性及镉吸收的影响。结果表明:施用水溶性有机肥料可提高稻谷产量,显著降低水稻孕穗期叶片超氧化物歧化酶(SOD)、灌浆期超氧化物歧化酶(SOD)和过氧化物酶(POD)活性;降低稻米镉含量,...采用土壤盆栽试验研究水溶性有机肥料对水稻抗氧化酶活性及镉吸收的影响。结果表明:施用水溶性有机肥料可提高稻谷产量,显著降低水稻孕穗期叶片超氧化物歧化酶(SOD)、灌浆期超氧化物歧化酶(SOD)和过氧化物酶(POD)活性;降低稻米镉含量,降低率为2.9%~21.5%,提高稻草镉含量,提高率为26.8%~99.1%。以750倍稀释液喷施增产幅度最大,达43.1%,基施(0.16 m L·kg^(-1))配合喷施(750倍稀释液)处理稻米降镉率最高。展开更多
基金supported by the National Key Research and Development Plan of China(Grant No.2017YFD0801102)the Central Public-Interest Scientific Institution Basal Research Fund,China(Grant No.2017RG006-5)+1 种基金the National Science Foundation of China(Grant No.31701407)the Chinese Academy of Agricultural Sciences to the Scientific and Technical Innovation Team.
文摘Different cadmium(Cd)-accumulated rice genotypes(Erjiunan 1 and Fupin 36)were used to explore the effect of rice rhizosphere aeration on Cd uptake and accumulation.Aeration in the nutrient soluti on influe need the agronomic characteristics in duced by Cd-stress,such as the in creases of rice root length and root vigor,but the reductions of plant height and shoot dry weight.Aeration also alleviated the decreasing effects of Cd stress on antioxidant enzyme activities and soluble protein,malonaldehyde and nicotianamine contents in rice.Moreover,with aeration treatment,the accumulation and bioavailability of metal elements changed significantly,with a Cd increase and an Fe reduction in both rice genotypes.In addition,at the molecular level,aeration upregulated the expression of Fe-inducible genes(such as OsIRTI,OsNRAMPI,OsYSL15 and OsNAS3).Furthermore,as a Cd^(2+)/Fe^(2+) transporter,the high transcription level of OsNRAMPI can elevate the Cd uptake and translocation in rice due to the Fe reduction caused by aeration and Cd-exposure,which indicated that OsNRAMPI might play a crucial role in the effect of aeration on Cd uptake and accumulation.
文摘Soil cadmium (Cd) causes toxicity and oxidative stress, alters biochemical processes and rootknot formation in rice. Irrigation of exogenous peroxidase (POX) together with its co-substrate H2O2(POXRice + H2O2), is likely to have protective effect upon the biochemical and nodular changes in ricegrown in Cd-rich soil. Exposure to Cd concentration of 1.00 mg/L increased oxidative stress, loss of cellviability, electrolyte leakage and root knot formation, whereas it significantly lowered the chlorophyll leveland rhizobium growth in rice. Irrigation of exogenous POXRice + H2O2 to Cd-stressed rice seedlingsreversed the Cd-induced alterations in rice to levels similar in control (non-stressed) seedlings. Resultsprovided strong evidence of exogenous POXRice + H2O2-mediated reversal and restoration of physiologicaland biochemical processes as well as increased resistance of rice seedlings to root knot formation.Irrigation with POXRice + H2O2 appeared to contribute towards bringing normoxic conditions in the otherwisehypoxic soil environment by enhancing the O2 in pot-experiments due to reduced Cd uptake, enhancedmineral homeostasis of essential elements viz. P, Fe, Mo, Mg and Mn for maintenance of root architecturedamaged by lipid peroxidation and reduction in oxidative stress by reducing Cd-induced reactive oxygenspecies generation. Therefore, the mitigation of Cd-toxicity in rice through this novel approach appeared tobe a promising mode to limit Cd-uptake, modulate protective and tolerance mechanisms for sustainablerice yield in Cd-contaminated rice-croplands and prevent nematode attack in rice, however, more detailedstudies are needed prior to large scale applications.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFE0106200)the Science and Technology Research Project of Jiangxi Provincial Department of Education,China(Grant No.K4100131)the Science and Technology Research Project of Shangrao,Jiangxi Province,China(Grant No.K4000019).
文摘Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors,including drought,ultraviolet radiation,and extreme temperatures.In this study,we identified the drought tolerance gene NfcrtO,which encodes aβ-carotene ketolase,through screening the transcriptome of N.flagelliforme under water loss stress.Prokaryotic expression of NfcrtO under 0.6 mol/L sorbitol or under 0.3 mol/L NaCl stress significantly increased the growth rate of Escherichia coli.When NfcrtO was heterologously expressed in rice,the seedling height and root length of NfcrtO-overexpressing rice plants were significantly higher than those of the wild type(WT)plants grown on½Murashige and Skoog solid medium with 120 mmol/L mannitol at the seedling stage.Transcriptome analysis revealed that NfcrtO was involved in osmotic stress,antioxidant,and other stress-related pathways.Additionally,the survival rate of the NfcrtO-overexpression lines was significantly higher than that of the WT line under both hydroponic stress(24%PEG and 100 mmol/L H_(2)O_(2))and soil drought treatment at the seedling stage.Physiological traits,including the activity levels of superoxide dismutase,peroxidase,catalase,total antioxidant capacity,and the contents of proline,trehalose,and soluble sugar,were significantly improved in the NfcrtO-overexpression lines relative to those in the WT line under 20%PEG treatment.Furthermore,when water was withheld at the booting stage,the grain yield per plant of NfcrtO-overexpression lines was significantly higher than that of the WT line.Yeast two-hybrid analysis identified interactions between NfcrtO and Dna J protein,E3 ubiquitin-protein ligase,and pyrophosphate-energized vacuolar membrane proton pump.Thus,heterologous expression of NfcrtO in rice could significantly improve the tolerance of rice to osmotic stress,potentially facilitating the development of new rice varieties.
基金supported by the Key Scientific Research and Development Projects of Jiangxi Provence,China(No.20194ABC28010)the National Key Technology R&D Program,China(No.2015BAD05B01).
文摘Agricultural soil contamination by cadmium (Cd) is becoming one of the most serious environmental issues and public concerns. In this study, factorial arrangements of treatments were designed to explore the effects of two soil amendments, sodium sulfide-biofuel ash (SSBA) and lime (0.1%), and three foliar applications, silicon (Si, 2.5 mmol L-1), selenium (Se, 40 mg L-1), and their combination (SS), on Cd reduction in rice (Oryza sativa L.) in a pot experiment, which were then verified in a field experiment. Compared with the control without amendment but with spraying of deionized water, both SSBA and lime significantly reduced concentrations of CaCl2-extractable Cd in soil by 30%–39% and 31%–40% and Cd in brown rice by 44%–63% and 53%–72% in the pot and field experiments, respectively. Foliar Si, Se, and SS applications significantly reduced Cd accumulation in brown rice by 62%–64%, 72%–83%, and 39%–73%, respectively, increased rice grain yield, and improved antioxidant enzyme activities in rice leaves but with different trends in the pot and field experiments. Combinations of SSBA and lime with Si, Se, and SS had a non-significant synergistic effect on Cd reduction in brown rice compared to only foliar spraying or soil amendment in both pot and field experiments, although SSBA + Se and SSBA + Si reduced Cd concentration in brown rice by 16%–34% and 14%–24% compared to only foliar Si and Se and soil SSBA applications, respectively. Soil lime application and foliar Si spraying were the most cost-effective strategies to reduce Cd accumulation in brown rice in the field and pot experiments, respectively. Although soil amendments and foliar treatments were individually effective, their combinations failed to generate a significant synergistic reduction of Cd concentration in brown rice.
基金the financial support provided by the University Grant Commission(UGC),Government of India,in the frame of the UGC Postdoctoral fellowship programmer ‘Molecular characterization of drought tolerance in rice(Oryza sativa L.)’
文摘Drought is the major abiotic stress factor that limits rice production worldwide.To evaluate the osmotic stress responses in rice varieties under drought condition,a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India.The experimental setup comprises of initial hydroponic treatments at different osmotic potentials,artificially induced by desired strengths of polyethylene glycol(PEG6000),and followed by the pot planted experiments in the rain-out-zone.The activities of antioxidant enzymes,relative water content,cell membrane stability,photosynthetic pigments,proline content,along with plant growth parameters of the varieties under drought condition were evaluated.Moreover,the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice.Among the 42 rice varieties,we identified 2 rice varieties,Swarnaprabha and Kattamodan,with less leaf rolling,better drought recovery ability as well as relative water content,increased membrane stability index,osmolyte accumulation,and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress.The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.
文摘采用土壤盆栽试验研究水溶性有机肥料对水稻抗氧化酶活性及镉吸收的影响。结果表明:施用水溶性有机肥料可提高稻谷产量,显著降低水稻孕穗期叶片超氧化物歧化酶(SOD)、灌浆期超氧化物歧化酶(SOD)和过氧化物酶(POD)活性;降低稻米镉含量,降低率为2.9%~21.5%,提高稻草镉含量,提高率为26.8%~99.1%。以750倍稀释液喷施增产幅度最大,达43.1%,基施(0.16 m L·kg^(-1))配合喷施(750倍稀释液)处理稻米降镉率最高。
