The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Krzysztof Szczyglowski - One of the best experts on this subject based on the ideXlab platform.
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inside out Root Cortex localized lhk1 cytokinin receptor limits epidermal infection of lotus japonicus Roots by mesorhizobium loti
New Phytologist, 2019Co-Authors: Mandana Miri, Preetam Janakirama, Terry Huebert, Loretta Ross, Tim Mcdowell, Kathleen Orosz, Katharina Markmann, Krzysztof SzczyglowskiAbstract:During Lotus japonicus–Mesorhizobium loti symbiosis, the LOTUS HISTIDINE KINASE1 (LHK1) cytokinin receptor regulates both the initiation of nodule formation and the scope of Root infection. However, the exact spatiotemporal mechanism by which this receptor exerts its symbiotic functions has remained elusive. In this study, we performed cell type‐specific complementation experiments in the hyperinfected lhk1‐1 mutant background, targeting LHK1 to either the Root epidermis or the Root Cortex. We also utilized various genetic backgrounds to characterize expression of several genes regulating symbiotic infection. We show here that expression of LHK1 in the Root Cortex is required and sufficient to regulate both nodule formation and epidermal infections. The LHK1‐dependent signalling that restricts subsequent infection events is triggered before initial cell divisions for nodule primordium formation. We also demonstrate that AHK4, the Arabidopsis orthologue of LHK1, is able to regulate M. loti infection in L. japonicus, suggesting that an endogenous cytokinin receptor could be sufficient for engineering nitrogen‐fixing Root nodule symbiosis in nonlegumes. Our data provide experimental evidence for the existence of an LHK1‐dependent Root Cortex‐to‐epidermis feedback mechanism regulating rhizobial infection. This Root‐localized regulatory module functionally links with the systemic autoregulation of nodulation (AON) to maintain the homeostasis of symbiotic infection.
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Inside out: Root Cortex‐localized LHK1 cytokinin receptor limits epidermal infection of Lotus japonicus Roots by Mesorhizobium loti
New Phytologist, 2019Co-Authors: Mandana Miri, Preetam Janakirama, Terry Huebert, Loretta Ross, Tim Mcdowell, Kathleen Orosz, Katharina Markmann, Krzysztof SzczyglowskiAbstract:During Lotus japonicus–Mesorhizobium loti symbiosis, the LOTUS HISTIDINE KINASE1 (LHK1) cytokinin receptor regulates both the initiation of nodule formation and the scope of Root infection. However, the exact spatiotemporal mechanism by which this receptor exerts its symbiotic functions has remained elusive. In this study, we performed cell type‐specific complementation experiments in the hyperinfected lhk1‐1 mutant background, targeting LHK1 to either the Root epidermis or the Root Cortex. We also utilized various genetic backgrounds to characterize expression of several genes regulating symbiotic infection. We show here that expression of LHK1 in the Root Cortex is required and sufficient to regulate both nodule formation and epidermal infections. The LHK1‐dependent signalling that restricts subsequent infection events is triggered before initial cell divisions for nodule primordium formation. We also demonstrate that AHK4, the Arabidopsis orthologue of LHK1, is able to regulate M. loti infection in L. japonicus, suggesting that an endogenous cytokinin receptor could be sufficient for engineering nitrogen‐fixing Root nodule symbiosis in nonlegumes. Our data provide experimental evidence for the existence of an LHK1‐dependent Root Cortex‐to‐epidermis feedback mechanism regulating rhizobial infection. This Root‐localized regulatory module functionally links with the systemic autoregulation of nodulation (AON) to maintain the homeostasis of symbiotic infection.
Mandana Miri - One of the best experts on this subject based on the ideXlab platform.
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inside out Root Cortex localized lhk1 cytokinin receptor limits epidermal infection of lotus japonicus Roots by mesorhizobium loti
New Phytologist, 2019Co-Authors: Mandana Miri, Preetam Janakirama, Terry Huebert, Loretta Ross, Tim Mcdowell, Kathleen Orosz, Katharina Markmann, Krzysztof SzczyglowskiAbstract:During Lotus japonicus–Mesorhizobium loti symbiosis, the LOTUS HISTIDINE KINASE1 (LHK1) cytokinin receptor regulates both the initiation of nodule formation and the scope of Root infection. However, the exact spatiotemporal mechanism by which this receptor exerts its symbiotic functions has remained elusive. In this study, we performed cell type‐specific complementation experiments in the hyperinfected lhk1‐1 mutant background, targeting LHK1 to either the Root epidermis or the Root Cortex. We also utilized various genetic backgrounds to characterize expression of several genes regulating symbiotic infection. We show here that expression of LHK1 in the Root Cortex is required and sufficient to regulate both nodule formation and epidermal infections. The LHK1‐dependent signalling that restricts subsequent infection events is triggered before initial cell divisions for nodule primordium formation. We also demonstrate that AHK4, the Arabidopsis orthologue of LHK1, is able to regulate M. loti infection in L. japonicus, suggesting that an endogenous cytokinin receptor could be sufficient for engineering nitrogen‐fixing Root nodule symbiosis in nonlegumes. Our data provide experimental evidence for the existence of an LHK1‐dependent Root Cortex‐to‐epidermis feedback mechanism regulating rhizobial infection. This Root‐localized regulatory module functionally links with the systemic autoregulation of nodulation (AON) to maintain the homeostasis of symbiotic infection.
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Inside out: Root Cortex‐localized LHK1 cytokinin receptor limits epidermal infection of Lotus japonicus Roots by Mesorhizobium loti
New Phytologist, 2019Co-Authors: Mandana Miri, Preetam Janakirama, Terry Huebert, Loretta Ross, Tim Mcdowell, Kathleen Orosz, Katharina Markmann, Krzysztof SzczyglowskiAbstract:During Lotus japonicus–Mesorhizobium loti symbiosis, the LOTUS HISTIDINE KINASE1 (LHK1) cytokinin receptor regulates both the initiation of nodule formation and the scope of Root infection. However, the exact spatiotemporal mechanism by which this receptor exerts its symbiotic functions has remained elusive. In this study, we performed cell type‐specific complementation experiments in the hyperinfected lhk1‐1 mutant background, targeting LHK1 to either the Root epidermis or the Root Cortex. We also utilized various genetic backgrounds to characterize expression of several genes regulating symbiotic infection. We show here that expression of LHK1 in the Root Cortex is required and sufficient to regulate both nodule formation and epidermal infections. The LHK1‐dependent signalling that restricts subsequent infection events is triggered before initial cell divisions for nodule primordium formation. We also demonstrate that AHK4, the Arabidopsis orthologue of LHK1, is able to regulate M. loti infection in L. japonicus, suggesting that an endogenous cytokinin receptor could be sufficient for engineering nitrogen‐fixing Root nodule symbiosis in nonlegumes. Our data provide experimental evidence for the existence of an LHK1‐dependent Root Cortex‐to‐epidermis feedback mechanism regulating rhizobial infection. This Root‐localized regulatory module functionally links with the systemic autoregulation of nodulation (AON) to maintain the homeostasis of symbiotic infection.
Andrzej Kaźmierczak - One of the best experts on this subject based on the ideXlab platform.
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membrane related hallmarks of kinetin induced pcd of Root Cortex cells
Plant Cell Reports, 2017Co-Authors: Andrzej Kaźmierczak, Magdalena Doniak, Przemyslaw BernatAbstract:Key message Changes in cellular membrane potential and their fluidisation are the hallmarks of cell death induction with kinetin in Root Cortex.
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reactive oxygen species and sugars may be the messengers in kinetin induced death of field bean Root Cortex cells
Biologia Plantarum, 2017Co-Authors: Magdalena Doniak, Andrzej Kaźmierczak, Anna Byczkowska, S GlinskaAbstract:Kinetin-induced programmed cell death of field bean (Vicia faba spp. minor) Root Cortex cells led to aerenchyma formation. The process was accompanied by appearance of a greater amount of reactive oxygen species (ROS), greater superoxide dismutase (SOD) and catalase (CAT) activities, as well as by thickening cell walls and changes in sugar amounts, particularly in cell wall-bound sugars. The obtained results justify the supposition that ROS scavengers together with an increased amount of sugars (soluble, storage, and cell wall-bound) and thick cell walls protected the cells against death. Thus, kinetin played a dual role because it induced programmed death of chosen cells and simultaneously stimulated protective mechanisms against death in other cells. These results confirm an earlier suggestion that cell death induced by kinetin is a specific process during which its progression is hallmarked by metabolic and morphological features.
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the crucial elements of the last step of programmed cell death induced by kinetin in Root Cortex of v faba ssp minor seedlings
Plant Cell Reports, 2014Co-Authors: Magdalena Doniak, Miroslawa Z Barciszewska, Joanna M Kaźmierczak, Andrzej KaźmierczakAbstract:Key message Kinetin-induced programmed cell death, manifested by condensation, degradation and methylation of DNA and fluctuation of kinase activities and ATP levels, is an autolytic and Root Cortex cell-specific process.
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kinetin induces cell death in Root Cortex cells of vicia faba ssp minor seedlings
Protoplasma, 2013Co-Authors: Anita Kunikowska, Anna Byczkowska, Andrzej KaźmierczakAbstract:The double fluorescence staining with acridine orange and ethidium bromide (AO/EB) revealed that treatment of Vicia faba ssp. minor seedlings with kinetin-induced programmed cell death (PCD) in Root Cortex cells. Kinetin-induced cell death reflected by the morphological changes of nuclei including their invagination, volume increase, chromatin condensation and degradation as well as formation of micronuclei showed by AO/EB and 4,6-diamidino-2-phenylindol staining was accompanied by changes including increase in conductivity of cell electrolytes secreted to culture media, decrease in the number of the G1- and G2-phase cells and appearance of fraction of hypoploid cells as the effect of DNA degradation without ladder formation. Decrease in the number of mitochondria and in the activity of cellular dehydrogenases, production of reactive oxygen species (ROS), appearance of small and then large lytic vacuoles and increase in the amount of cytosolic calcium ions were also observed. The PCD was also manifested by increased width and weight of apical fragments of Roots as well as decreased length of Cortex cells which led to shortening of the whole Roots. The kinetin-induced PCD process was almost completely inhibited by adenine, an inhibitor of phosphoribosyl transferase, and mannitol, an inhibitor of ROS production. These cell-death hallmarks and pathway of this process suggested that the induction of kinetin-specific vacuolar type of death, expressed itself with similar intensity on both morphological and metabolic levels, was a transient protecting whole Roots and whole seedlings against elimination.
Mikio Nakazono - One of the best experts on this subject based on the ideXlab platform.
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Root Cortex provides a venue for gas space formation and is essential for plant adaptation to waterlogging
Frontiers in Plant Science, 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro TsutsumiAbstract:Lysigenous aerenchyma, which develops by death and subsequent lysis of the cortical cells in Roots, is essential for internal long-distance oxygen transport from shoot base to Root tips of plants in waterlogged soil. Although many studies focus on the amounts of aerenchyma in Roots, significance of the size of the Root Cortex in which aerenchyma forms has received less research attention. In the present study, we evaluated the cross-sectional area of each Root tissue in adventitious Roots of upland crops, wheat (Triticum aestivum) and maize (Zea mays ssp. mays), and the wetland crop, rice (Oryza sativa) under aerated or stagnant deoxygenated conditions; the latter can mimic the changes in gas composition in waterlogged soils. Our analyses revealed that the areas of whole Root and Cortex of the three species increased under stagnant conditions. In rice Roots, Cortex to stele ratio and aerenchyma to Cortex ratio, which is associated with the areas of gas spaces, were much higher than those in wheat and maize Roots, suggesting that these anatomical features are essential for a high capacity for oxygen transport along Roots. To test this hypothesis, rates of radial oxygen loss, which is the diffusive flux of oxygen from within a Root to the external medium, from thick and thin adventitious Roots of rice were measured using a cylindrical (Root-sleeving) oxygen electrode, for plants with shoots in air and Roots in an oxygen-free medium. As expected, the rate of radial oxygen loss from thick Roots, which have larger Cortex and aerenchyma areas, was higher than that of thin Roots. The rate of radial oxygen loss was highest at the apical part of rice Roots, where aerenchyma was hardly detected, but at which cuboidal cell arrangement in the Cortex provides tissue porosity. We conclude that high Cortex to stele ratio in combination with large Root diameter is a feature which promotes oxygen transport from shoot base to Root tips of plants. Moreover, we propose that Cortex to stele ratio should be a useful quantitative index for the evaluation and improvement of Root traits contributing to tolerance of crops to soil waterlogging.
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metallothionein genes encoding ros scavenging enzymes are down regulated in the Root Cortex during inducible aerenchyma formation in rice
Plant Signaling & Behavior, 2017Co-Authors: Takaki Yamauchi, Aya Fukazawa, Mikio NakazonoAbstract:Under waterlogged conditions, Roots of gramineous plants form lysigenous aerenchyma (internal gas spaces) by inducing the death of cortical cells. Rice (Oryza sativa) Roots induce aerenchyma formation through ethylene- and reactive oxygen species (ROS)-mediated signaling. Metallothionein (MT) is a small, cysteine-rich protein that acts as a ROS scavenger. In rice Roots, the expression of MT1a, MT1b, MT1c and MT1Ld were higher than those of the other MT genes. In the Root Cortex, where aerenchyma forms exclusively, the expression of MT1a, MT1b and MT1Ld was reduced prior to aerenchyma formation. These findings suggest that ROS accumulation in the Cortex, which is aided by downregulation of MT1 genes, is needed for aerenchyma formation in rice Roots.
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Lysigenous aerenchyma formation in maize Root is confined to cortical cells by regulation of genes related to generation and scavenging of reactive oxygen species.
Plant Signaling & Behavior, 2011Co-Authors: Takaki Yamauchi, Imene Rajhi, Mikio NakazonoAbstract:To adapt to waterlogging, maize (Zea mays) forms lysigenous aerenchyma in Root Cortex as a result of ethylene-promoted programmed cell death (PCD). Respiratory burst oxidase homolog (RBOH) gene encodes a homolog of gp91phox in NADPH oxidase, and has a role in the generation of reactive oxygen species (ROS). Recently, we found that, during aerenchyma formation, RBOH was up-regulated in all maize Root tissues examined, whereas an ROS scavenging-related metallothionein (MT) gene was down-regulated specifically in cortical cells. Together, these changes should lead to high accumulations of ROS in Root Cortex, thereby inducing PCD for aerenchyma formation. As further evidence of the involvement of ROS in Root aerenchyma formation, the PCD was inhibited by diphenyleneiodonium (DPI), an NADPH oxidase inhibitor. Based on these results, we propose a model of cortical cell-specific PCD for Root aerenchyma formation.
Takaki Yamauchi - One of the best experts on this subject based on the ideXlab platform.
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Root Cortex provides a venue for gas space formation and is essential for plant adaptation to waterlogging
Frontiers in Plant Science, 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro TsutsumiAbstract:Lysigenous aerenchyma, which develops by death and subsequent lysis of the cortical cells in Roots, is essential for internal long-distance oxygen transport from shoot base to Root tips of plants in waterlogged soil. Although many studies focus on the amounts of aerenchyma in Roots, significance of the size of the Root Cortex in which aerenchyma forms has received less research attention. In the present study, we evaluated the cross-sectional area of each Root tissue in adventitious Roots of upland crops, wheat (Triticum aestivum) and maize (Zea mays ssp. mays), and the wetland crop, rice (Oryza sativa) under aerated or stagnant deoxygenated conditions; the latter can mimic the changes in gas composition in waterlogged soils. Our analyses revealed that the areas of whole Root and Cortex of the three species increased under stagnant conditions. In rice Roots, Cortex to stele ratio and aerenchyma to Cortex ratio, which is associated with the areas of gas spaces, were much higher than those in wheat and maize Roots, suggesting that these anatomical features are essential for a high capacity for oxygen transport along Roots. To test this hypothesis, rates of radial oxygen loss, which is the diffusive flux of oxygen from within a Root to the external medium, from thick and thin adventitious Roots of rice were measured using a cylindrical (Root-sleeving) oxygen electrode, for plants with shoots in air and Roots in an oxygen-free medium. As expected, the rate of radial oxygen loss from thick Roots, which have larger Cortex and aerenchyma areas, was higher than that of thin Roots. The rate of radial oxygen loss was highest at the apical part of rice Roots, where aerenchyma was hardly detected, but at which cuboidal cell arrangement in the Cortex provides tissue porosity. We conclude that high Cortex to stele ratio in combination with large Root diameter is a feature which promotes oxygen transport from shoot base to Root tips of plants. Moreover, we propose that Cortex to stele ratio should be a useful quantitative index for the evaluation and improvement of Root traits contributing to tolerance of crops to soil waterlogging.
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metallothionein genes encoding ros scavenging enzymes are down regulated in the Root Cortex during inducible aerenchyma formation in rice
Plant Signaling & Behavior, 2017Co-Authors: Takaki Yamauchi, Aya Fukazawa, Mikio NakazonoAbstract:Under waterlogged conditions, Roots of gramineous plants form lysigenous aerenchyma (internal gas spaces) by inducing the death of cortical cells. Rice (Oryza sativa) Roots induce aerenchyma formation through ethylene- and reactive oxygen species (ROS)-mediated signaling. Metallothionein (MT) is a small, cysteine-rich protein that acts as a ROS scavenger. In rice Roots, the expression of MT1a, MT1b, MT1c and MT1Ld were higher than those of the other MT genes. In the Root Cortex, where aerenchyma forms exclusively, the expression of MT1a, MT1b and MT1Ld was reduced prior to aerenchyma formation. These findings suggest that ROS accumulation in the Cortex, which is aided by downregulation of MT1 genes, is needed for aerenchyma formation in rice Roots.
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Lysigenous aerenchyma formation in maize Root is confined to cortical cells by regulation of genes related to generation and scavenging of reactive oxygen species.
Plant Signaling & Behavior, 2011Co-Authors: Takaki Yamauchi, Imene Rajhi, Mikio NakazonoAbstract:To adapt to waterlogging, maize (Zea mays) forms lysigenous aerenchyma in Root Cortex as a result of ethylene-promoted programmed cell death (PCD). Respiratory burst oxidase homolog (RBOH) gene encodes a homolog of gp91phox in NADPH oxidase, and has a role in the generation of reactive oxygen species (ROS). Recently, we found that, during aerenchyma formation, RBOH was up-regulated in all maize Root tissues examined, whereas an ROS scavenging-related metallothionein (MT) gene was down-regulated specifically in cortical cells. Together, these changes should lead to high accumulations of ROS in Root Cortex, thereby inducing PCD for aerenchyma formation. As further evidence of the involvement of ROS in Root aerenchyma formation, the PCD was inhibited by diphenyleneiodonium (DPI), an NADPH oxidase inhibitor. Based on these results, we propose a model of cortical cell-specific PCD for Root aerenchyma formation.
