As a traditional Chinese medicine,the root of Astragalus membranaceus var.mongholicus(AMM)or A.membranaceus(AM)has been widely used in China and other Asian countries for thousands of years.Till now,the flavonoids,phe...As a traditional Chinese medicine,the root of Astragalus membranaceus var.mongholicus(AMM)or A.membranaceus(AM)has been widely used in China and other Asian countries for thousands of years.Till now,the flavonoids,phenolic acids and saponins are considered as the main active components contributing to their therapeutic effect in these plants.In order to clarify the distribution and contents of these compounds in different organs of these plants,a rapid and sensitive analytical method for simultaneous determination of 25 active compounds including seven types(i.e.dihydroflavones,isoflavane,isoflavones,flavones,pterocarpans,phenolic acid and saponins)within 10 min was established using ultra-pressure liquid chromatography coupled with tandem mass spectrometry(UPLCeMS/MS).Then,the established method was fully validated and successfully applied to the determination of the contents of these analytes in different parts(root,rhizome,stem,leaf and flower)of AMM and AM.The results indicated that the contents of the same type of compounds in two different species plants were significantly different.Moreover,the obvious differences were also found for the distribution and contents of different type of compounds in five organs of the same species.The present study could provide necessary information for the rational development and utilization of AMM and AM resource.展开更多
Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-e...Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-essential and toxic even at relatively low concentrations(e.g.,As,Cd,Cr,Pb,and Hg).Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities.Trace metal contamination can cause toxicity and growth inhibition in plants,as well as accumulation in the edible parts to levels that threatens food safety and human health.Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils.The accumulation of excess trace metals in plants can cause oxidative stress,genotoxicity,programmed cell death,and disturbance in multiple physiological processes.Plants have evolved various strategies to detoxify trace metals through cell-wall binding,complexation,vacuolar sequestration,efflux,and translocation.Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses.In this review,we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity,detoxification,and regulation,as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.展开更多
Root developmental plasticity is crucial for plants to adapt to a changing soil environment,where nutrients and abiotic stress factors are distributed heterogeneously.How plant roots sense and avoid heterogeneous abio...Root developmental plasticity is crucial for plants to adapt to a changing soil environment,where nutrients and abiotic stress factors are distributed heterogeneously.How plant roots sense and avoid heterogeneous abiotic stress in soil remains unclear.Here,we show that,in response to asymmetric stress of heavy metals(cadmium,copper,or lead)and salt,rice roots rapidly proliferate lateral roots(LRs)in the stress-free area,thereby remodeling root architecture to avoid localized stress.Imaging and quantitative analyses of reactive oxygen species(ROS)showed that asymmetric stress induces a ROS burst in the tips of the exposed roots and simultaneously triggers rapid systemic ROS signaling to the unexposed roots.Addition of a ROS scavenger to either the stressed or stress-free area abolished systemic ROS signaling and LR proliferation induced by asymmetric stress.Asymmetric stress also enhanced cytosolic calcium(Ca^(2+))signaling;blocking Ca^(2+)signaling inhibited systemic ROS propagation and LR branching in the stress-free area.We identified two plasma-membrane-localized respiratory burst oxidase homologs,OsRBOHA and OsRBOHI,as key players in systemic ROS signaling under asymmetric stress.Expression of OsRBOHA and OsRBOHI in roots was upregulated by Cd stress,and knockout of either gene reduced systemic ROS signaling and LR proliferation under asymmetric stress.Furthermore,we demonstrated that auxin signaling and cell wall remodeling act downstream of the systemic ROS signaling to promote LR development.Collectively,our study reveals an RBOH-ROS-auxin signaling cascade that enables rice roots to avoid localized stress of heavy metals and salt and provides new insight into root system plasticity in heterogenous soil.展开更多
基金supported by the National Natural Science Foundation of China(No.81473538,81873189)the Key R&D Program of Ningxia Hui Autonomous Region,China(2017BY079,2018ZWYQ0077)China Agricultural Research System(CARS-21)
文摘As a traditional Chinese medicine,the root of Astragalus membranaceus var.mongholicus(AMM)or A.membranaceus(AM)has been widely used in China and other Asian countries for thousands of years.Till now,the flavonoids,phenolic acids and saponins are considered as the main active components contributing to their therapeutic effect in these plants.In order to clarify the distribution and contents of these compounds in different organs of these plants,a rapid and sensitive analytical method for simultaneous determination of 25 active compounds including seven types(i.e.dihydroflavones,isoflavane,isoflavones,flavones,pterocarpans,phenolic acid and saponins)within 10 min was established using ultra-pressure liquid chromatography coupled with tandem mass spectrometry(UPLCeMS/MS).Then,the established method was fully validated and successfully applied to the determination of the contents of these analytes in different parts(root,rhizome,stem,leaf and flower)of AMM and AM.The results indicated that the contents of the same type of compounds in two different species plants were significantly different.Moreover,the obvious differences were also found for the distribution and contents of different type of compounds in five organs of the same species.The present study could provide necessary information for the rational development and utilization of AMM and AM resource.
基金supported by the National Natural Science Foundation of China(31972500 and 41930758)the Key Research&Development Program of Jiangsu Province(BE2021717)。
文摘Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-essential and toxic even at relatively low concentrations(e.g.,As,Cd,Cr,Pb,and Hg).Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities.Trace metal contamination can cause toxicity and growth inhibition in plants,as well as accumulation in the edible parts to levels that threatens food safety and human health.Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils.The accumulation of excess trace metals in plants can cause oxidative stress,genotoxicity,programmed cell death,and disturbance in multiple physiological processes.Plants have evolved various strategies to detoxify trace metals through cell-wall binding,complexation,vacuolar sequestration,efflux,and translocation.Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses.In this review,we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity,detoxification,and regulation,as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.
基金supported by the Key R&D Program of the Ministry of Science&Technology of China(2022YFD1700102)the Key Research and Development Program of Jiangsu Province(BE2021717)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX220756)the Fundamental Research Funds for the Central Universities(QTPY2023003 and XUEKEN2023042).
文摘Root developmental plasticity is crucial for plants to adapt to a changing soil environment,where nutrients and abiotic stress factors are distributed heterogeneously.How plant roots sense and avoid heterogeneous abiotic stress in soil remains unclear.Here,we show that,in response to asymmetric stress of heavy metals(cadmium,copper,or lead)and salt,rice roots rapidly proliferate lateral roots(LRs)in the stress-free area,thereby remodeling root architecture to avoid localized stress.Imaging and quantitative analyses of reactive oxygen species(ROS)showed that asymmetric stress induces a ROS burst in the tips of the exposed roots and simultaneously triggers rapid systemic ROS signaling to the unexposed roots.Addition of a ROS scavenger to either the stressed or stress-free area abolished systemic ROS signaling and LR proliferation induced by asymmetric stress.Asymmetric stress also enhanced cytosolic calcium(Ca^(2+))signaling;blocking Ca^(2+)signaling inhibited systemic ROS propagation and LR branching in the stress-free area.We identified two plasma-membrane-localized respiratory burst oxidase homologs,OsRBOHA and OsRBOHI,as key players in systemic ROS signaling under asymmetric stress.Expression of OsRBOHA and OsRBOHI in roots was upregulated by Cd stress,and knockout of either gene reduced systemic ROS signaling and LR proliferation under asymmetric stress.Furthermore,we demonstrated that auxin signaling and cell wall remodeling act downstream of the systemic ROS signaling to promote LR development.Collectively,our study reveals an RBOH-ROS-auxin signaling cascade that enables rice roots to avoid localized stress of heavy metals and salt and provides new insight into root system plasticity in heterogenous soil.
