The extract of crofton weed(Eupatorium adenophorum) inhibits seed germination and weed growth;however,the physiological mechanisms underlying the effect of crofton weed extract on the modulation of seedling growth and...The extract of crofton weed(Eupatorium adenophorum) inhibits seed germination and weed growth;however,the physiological mechanisms underlying the effect of crofton weed extract on the modulation of seedling growth and root system development remain largely unclear.In this study,we investigated the effects of the leaf extract of crofton weed(LECW) on primary root(PR) growth in maize seedlings.Treatment with LECW markedly inhibited seed germination and seedling growth in a dose-dependent manner.Physiological analysis indicated that the LECW induced reactive oxygen species(ROS) accumulation in root tips,thereby leading to cell swelling and deformation both in the root cap and elongation zone of root tips,finally leading to cell death in root border cells(RBCs) and PR growth inhibition.The LECW also inhibited pectin methyl esterase(PME) activity,thereby decreasing the RBC number.Taken together,our results indicated that the LECW inhibited PR growth by inducing ROS accumulation and subsequent cell death in RBCs.The present study provides a better understanding of how the LECW modifies root system development and provides insight for evaluating the toxicity of crofton weed extracts in plants.展开更多
Collective migration of loosely or closely associated cell groups is prevalent in animal development, physiological events, and cancer metastasis. However, our understanding of the mechanisms of collective cell migrat...Collective migration of loosely or closely associated cell groups is prevalent in animal development, physiological events, and cancer metastasis. However, our understanding of the mechanisms of collective cell migration is incomplete. Drosophila border cells provide a powerful in vivo genetic model to study collective migration and identify essential genes for this process. Using border cell-specific RNAi-silencing in Drosophila, we knocked down 360 conserved signaling transduction genes in adult flies to identify essential pathways and genes for border cell migration. We uncovered a plethora of signaling genes, a large proportion of which had not been reported for border cells, including Rack1 （Receptor of activated C kinase） and brk （brinker）, mad （mother against dpp）, and sax （saxophone）, which encode three components of TGF-β signaling. The RNAi knock down phenotype was validated by clonal analysis of Rack1 mutants. Our data suggest that inhibition of Src activity by Rackl may be important for border cell migration and cluster cohesion maintenance. Lastly, results from our screen not only would shed light on signaling pathways involved in collective migration during embryogenesis and organogenesis in general, but also could help our understanding for the functions of conserved human genes involved in cancer metastasis.展开更多
基金the Key Project of Science and Technology of Shanxi Province(20150311016-5)the Science and Technology innovation Foundation of Shanxi Agricultural University(2017ZZ09)。
文摘The extract of crofton weed(Eupatorium adenophorum) inhibits seed germination and weed growth;however,the physiological mechanisms underlying the effect of crofton weed extract on the modulation of seedling growth and root system development remain largely unclear.In this study,we investigated the effects of the leaf extract of crofton weed(LECW) on primary root(PR) growth in maize seedlings.Treatment with LECW markedly inhibited seed germination and seedling growth in a dose-dependent manner.Physiological analysis indicated that the LECW induced reactive oxygen species(ROS) accumulation in root tips,thereby leading to cell swelling and deformation both in the root cap and elongation zone of root tips,finally leading to cell death in root border cells(RBCs) and PR growth inhibition.The LECW also inhibited pectin methyl esterase(PME) activity,thereby decreasing the RBC number.Taken together,our results indicated that the LECW inhibited PR growth by inducing ROS accumulation and subsequent cell death in RBCs.The present study provides a better understanding of how the LECW modifies root system development and provides insight for evaluating the toxicity of crofton weed extracts in plants.
基金supported by grants from the National Natural Science Foundation of China(31271488,31171335,31071219)to Chen Jiong
文摘Collective migration of loosely or closely associated cell groups is prevalent in animal development, physiological events, and cancer metastasis. However, our understanding of the mechanisms of collective cell migration is incomplete. Drosophila border cells provide a powerful in vivo genetic model to study collective migration and identify essential genes for this process. Using border cell-specific RNAi-silencing in Drosophila, we knocked down 360 conserved signaling transduction genes in adult flies to identify essential pathways and genes for border cell migration. We uncovered a plethora of signaling genes, a large proportion of which had not been reported for border cells, including Rack1 （Receptor of activated C kinase） and brk （brinker）, mad （mother against dpp）, and sax （saxophone）, which encode three components of TGF-β signaling. The RNAi knock down phenotype was validated by clonal analysis of Rack1 mutants. Our data suggest that inhibition of Src activity by Rackl may be important for border cell migration and cluster cohesion maintenance. Lastly, results from our screen not only would shed light on signaling pathways involved in collective migration during embryogenesis and organogenesis in general, but also could help our understanding for the functions of conserved human genes involved in cancer metastasis.
