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Mikio Nakazono - One of the best experts on this subject based on the ideXlab platform.
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a role for auxin in ethylene dependent inducible Aerenchyma formation in rice roots
Plants (Basel Switzerland), 2020Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Akihiro Tanaka, Yoshiaki InukaiAbstract:Internal oxygen diffusion from shoot to root tips is enhanced by the formation of Aerenchyma (gas space) in waterlogged soils. Lysigenous Aerenchyma is created by programmed cell death and subsequent lysis of the root cortical cells. Rice (Oryza sativa) forms Aerenchyma constitutively under aerobic conditions and increases its formation under oxygen-deficient conditions. Recently, we have demonstrated that constitutive Aerenchyma formation is regulated by auxin signaling mediated by Auxin/indole-3-acetic acid protein (AUX/IAA; IAA). While ethylene is involved in inducible Aerenchyma formation, the relationship of auxin and ethylene during Aerenchyma formation remains unclear. Here, we examined the effects of oxygen deficiency and ethylene on Aerenchyma formation in the roots of a rice mutant (iaa13) in which auxin signaling is suppressed by a mutation in the degradation domain of IAA13 protein. The results showed that AUX/IAA-mediated auxin signaling contributes to ethylene-dependent inducible Aerenchyma formation in rice roots. An auxin transport inhibitor abolished Aerenchyma formation under oxygen-deficient conditions and reduced the expression of genes encoding ethylene biosynthesis enzymes, further supporting the idea that auxin is involved in ethylene-dependent inducible Aerenchyma formation. Based on these studies, we propose a mechanism that underlies the relationship between auxin and ethylene during inducible Aerenchyma formation in rice roots.
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fine control of Aerenchyma and lateral root development through aux iaa and arf dependent auxin signaling
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Naoko K Nishizawa, Akihiro Tanaka, Yoshiaki Inukai, Hiroki InahashiAbstract:Lateral roots (LRs) are derived from a parental root and contribute to water and nutrient uptake from the soil. Auxin/indole-3-acetic acid protein (AUX/IAA; IAA) and auxin response factor (ARF)-mediated signaling are essential for LR formation. Lysigenous Aerenchyma, a gas space created by cortical cell death, aids internal oxygen transport within plants. Rice (Oryza sativa) forms lysigenous Aerenchyma constitutively under aerobic conditions and increases its formation under oxygen-deficient conditions; however, the molecular mechanisms regulating constitutive Aerenchyma (CA) formation remain unclear. LR number is reduced by the dominant-negative effect of a mutated AUX/IAA protein in the iaa13 mutant. We found that CA formation is also reduced in iaa13. We have identified ARF19 as an interactor of IAA13 and identified a lateral organ boundary domain (LBD)-containing protein (LBD1-8) as a target of ARF19. IAA13, ARF19, and LBD1-8 were highly expressed in the cortex and LR primordia, suggesting that these genes function in the initiation of CA and LR formation. Restoration of LBD1-8 expression recovered Aerenchyma formation and partly recovered LR formation in the iaa13 background, in which LBD1-8 expression was reduced. An auxin transport inhibitor suppressed CA and LR formation, and a natural auxin stimulated CA formation in the presence of the auxin transport inhibitor. Our findings suggest that CA and LR formation are both regulated through AUX/IAA- and ARF-dependent auxin signaling. The initiation of CA formation lagged that of LR formation, which indicates that the formation of CA and LR are regulated differently by auxin signaling during root development in rice.
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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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Root Cortex Provides a Venue for Gas-Space Formation and Is Essential for Plant Adaptation to Waterlogging
Frontiers Media S.A., 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Fumitaka AbeAbstract: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 (CSR) and Aerenchyma to cortex ratio (ACR), 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 (ROL), 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 ROL from thick roots, which have larger cortex and Aerenchyma areas, was higher than that of thin roots. The rate of ROL 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 CSR 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 CSR 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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Data_Sheet_1_Root Cortex Provides a Venue for Gas-Space Formation and Is Essential for Plant Adaptation to Waterlogging.PDF
2019Co-Authors: Takaki Yamauchi, Nobuhiro Tsutsumi, Fumitaka Abe, Mikio NakazonoAbstract: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 (CSR) and Aerenchyma to cortex ratio (ACR), 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 (ROL), 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 ROL from thick roots, which have larger cortex and Aerenchyma areas, was higher than that of thin roots. The rate of ROL 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 CSR 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 CSR should be a useful quantitative index for the evaluation and improvement of root traits contributing to tolerance of crops to soil waterlogging.
Takaki Yamauchi - One of the best experts on this subject based on the ideXlab platform.
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a role for auxin in ethylene dependent inducible Aerenchyma formation in rice roots
Plants (Basel Switzerland), 2020Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Akihiro Tanaka, Yoshiaki InukaiAbstract:Internal oxygen diffusion from shoot to root tips is enhanced by the formation of Aerenchyma (gas space) in waterlogged soils. Lysigenous Aerenchyma is created by programmed cell death and subsequent lysis of the root cortical cells. Rice (Oryza sativa) forms Aerenchyma constitutively under aerobic conditions and increases its formation under oxygen-deficient conditions. Recently, we have demonstrated that constitutive Aerenchyma formation is regulated by auxin signaling mediated by Auxin/indole-3-acetic acid protein (AUX/IAA; IAA). While ethylene is involved in inducible Aerenchyma formation, the relationship of auxin and ethylene during Aerenchyma formation remains unclear. Here, we examined the effects of oxygen deficiency and ethylene on Aerenchyma formation in the roots of a rice mutant (iaa13) in which auxin signaling is suppressed by a mutation in the degradation domain of IAA13 protein. The results showed that AUX/IAA-mediated auxin signaling contributes to ethylene-dependent inducible Aerenchyma formation in rice roots. An auxin transport inhibitor abolished Aerenchyma formation under oxygen-deficient conditions and reduced the expression of genes encoding ethylene biosynthesis enzymes, further supporting the idea that auxin is involved in ethylene-dependent inducible Aerenchyma formation. Based on these studies, we propose a mechanism that underlies the relationship between auxin and ethylene during inducible Aerenchyma formation in rice roots.
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fine control of Aerenchyma and lateral root development through aux iaa and arf dependent auxin signaling
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Naoko K Nishizawa, Akihiro Tanaka, Yoshiaki Inukai, Hiroki InahashiAbstract:Lateral roots (LRs) are derived from a parental root and contribute to water and nutrient uptake from the soil. Auxin/indole-3-acetic acid protein (AUX/IAA; IAA) and auxin response factor (ARF)-mediated signaling are essential for LR formation. Lysigenous Aerenchyma, a gas space created by cortical cell death, aids internal oxygen transport within plants. Rice (Oryza sativa) forms lysigenous Aerenchyma constitutively under aerobic conditions and increases its formation under oxygen-deficient conditions; however, the molecular mechanisms regulating constitutive Aerenchyma (CA) formation remain unclear. LR number is reduced by the dominant-negative effect of a mutated AUX/IAA protein in the iaa13 mutant. We found that CA formation is also reduced in iaa13. We have identified ARF19 as an interactor of IAA13 and identified a lateral organ boundary domain (LBD)-containing protein (LBD1-8) as a target of ARF19. IAA13, ARF19, and LBD1-8 were highly expressed in the cortex and LR primordia, suggesting that these genes function in the initiation of CA and LR formation. Restoration of LBD1-8 expression recovered Aerenchyma formation and partly recovered LR formation in the iaa13 background, in which LBD1-8 expression was reduced. An auxin transport inhibitor suppressed CA and LR formation, and a natural auxin stimulated CA formation in the presence of the auxin transport inhibitor. Our findings suggest that CA and LR formation are both regulated through AUX/IAA- and ARF-dependent auxin signaling. The initiation of CA formation lagged that of LR formation, which indicates that the formation of CA and LR are regulated differently by auxin signaling during root development in rice.
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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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Root Cortex Provides a Venue for Gas-Space Formation and Is Essential for Plant Adaptation to Waterlogging
Frontiers Media S.A., 2019Co-Authors: Takaki Yamauchi, Mikio Nakazono, Nobuhiro Tsutsumi, Fumitaka AbeAbstract: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 (CSR) and Aerenchyma to cortex ratio (ACR), 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 (ROL), 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 ROL from thick roots, which have larger cortex and Aerenchyma areas, was higher than that of thin roots. The rate of ROL 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 CSR 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 CSR 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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Data_Sheet_1_Root Cortex Provides a Venue for Gas-Space Formation and Is Essential for Plant Adaptation to Waterlogging.PDF
2019Co-Authors: Takaki Yamauchi, Nobuhiro Tsutsumi, Fumitaka Abe, Mikio NakazonoAbstract: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 (CSR) and Aerenchyma to cortex ratio (ACR), 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 (ROL), 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 ROL from thick roots, which have larger cortex and Aerenchyma areas, was higher than that of thin roots. The rate of ROL 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 CSR 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 CSR should be a useful quantitative index for the evaluation and improvement of root traits contributing to tolerance of crops to soil waterlogging.
Fumie Omori - One of the best experts on this subject based on the ideXlab platform.
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relationship between constitutive root Aerenchyma formation and flooding tolerance in zea nicaraguensis
Plant and Soil, 2013Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:The teosinte Zea nicaraguensis, which is adapted to frequently flooded lowlands, is considered a valuable germplasm resource for the development of flooding-tolerant maize. This species can form constitutive root Aerenchyma under well-drained conditions. The objectives of this study were to screen Z. nicaraguensis accessions for the capacity to form constitutive Aerenchyma, to obtain progeny with differing degrees of Aerenchyma formation, and to compare the flooding tolerance of these progeny. We evaluated constitutive Aerenchyma formation in the root cortex of seedlings of eight accessions and several segregating populations of Z. nicaraguensis. We also evaluated flooding tolerance in lines selected for high or low degrees of constitutive Aerenchyma formation. Seedlings of the eight accessions showed an extremely wide and continuous range of variation in Aerenchyma formation. By phenotypic selection within two accessions, we obtained lines with either high or low degrees of constitutive Aerenchyma formation. The lines selected for a higher degree of formation showed relatively high flooding tolerance evaluated by shoot dry weight ratio (flooded:control) than those with a lower degree of formation. A greater capacity to form constitutive Aerenchyma can enhance flooding tolerance.
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relationship between constitutive root Aerenchyma formation and flooding tolerance in zea nicaraguensis
Plant and Soil, 2013Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:Background and aims The teosinte Zea nicaraguensis, which is adapted to frequently flooded lowlands, is considered a valuable germplasm resource for the development of flooding-tolerant maize. This species can form constitutive root Aerenchyma under well-drained conditions. The objectives of this study were to screen Z. nicaraguensis accessions for the capacity to form constitutive Aerenchyma, to obtain progeny with differing degrees of Aerenchyma formation, and to compare the flooding tolerance of these progeny.
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construction of intraspecific linkage maps detection of a chromosome inversion and mapping of qtl for constitutive root Aerenchyma formation in the teosinte zea nicaraguensis
Molecular Breeding, 2012Co-Authors: Yoshiro Mano, Fumie Omori, Kazuyoshi TakedaAbstract:The teosinte Zea nicaraguensis, a wild relative of maize, possesses a flooding tolerance-related trait: the formation of constitutive root Aerenchyma under drained (non-flooded) soil conditions. A previous study suggested that the degree of constitutive Aerenchyma formation varies within Z. nicaraguensis. The objectives of this study were to construct linkage maps, to determine the marker order in a region of chromosome 4 in which recombination between maize and Z. nicaraguensis is suppressed, and to identify quantitative trait loci (QTL) controlling constitutive root Aerenchyma formation in two segregating populations of Z. nicaraguensis. A total of 236 simple sequence repeat (SSR) markers were screened for polymorphism in an S1 population of Z. nicaraguensis. Seventy-one polymorphic SSR markers were assigned to 10 chromosomes, and a linkage map was constructed covering 793.5 cM. In the S1 map, a paracentric inversion was detected on the long arm of chromosome 4; this rearrangement was confirmed in an S1 linkage map of a different Z. nicaraguensis accession. Composite interval mapping analysis in 96 S1 plants revealed QTL for Aerenchyma formation on chromosomes 1 (bins 1.06–1.07) and 7 (bin 7.01), explaining 17 and 12% of the total phenotypic variance, respectively. The QTL on chromosome 1 was verified by using 156 S2 plants. Near-isogenic lines exhibiting the presence or absence of the Aerenchyma QTL have been developed that should be useful for genetic and physiological analyses of root Aerenchyma formation.
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high density linkage map around the root Aerenchyma locus qaer1 06 in the backcross populations of maize mi29 teosinte zea nicaraguensis
Breeding Science, 2009Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:The teosinte Zea nicaraguensis forms constitutive Aerenchyma in the root cortex as observed in flooding tolerant wetland plants. We have previously identified a quantitative trait locus (QTL) controlling Aerenchyma formation under non-flooding conditions on chromosome 1 (Qaer1.06) using 214 individuals of a maize Mi29 × Z. nicaraguensis BC2F1 population. The present studies objective was to increase the marker density around the Qaer1.06 locus, which is essential for the development of near-isogenic lines possessing the Aerenchyma-forming gene with only a small region of the Z. nicaraguensis chromosome segment. A survey of 62 SSR and 38 insertion/deletion (INDEL) markers identified a total of 36 useful markers in the region of interest. These were selected for the construction of a linkage map in a 214 individual BC2F1 and a 123 individual BC4F1 population from a cross between Mi29 × Z. nicaraguensis. Using the BC4F1 population, we performed QTL mapping and the results indicated that a QTL for Aerenchyma formation under non-flooding condition was located on chromosome 1 (bin 1.05) at a position that is near to Qaer1.06. The markers obtained here should be useful for the development of high quality near-isogenic lines possessing the Qaer1.05-6.
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verification of qtl controlling root Aerenchyma formation in a maize teosinte zea nicaraguensis advanced backcross population
Breeding Science, 2008Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:Root Aerenchyma formation is considered to be one of the most important characteristics for adapting to flooding. Using an F2 population of maize B64 × teosinte Zea nicaraguensis, we earlier found that, in Z. nicaraguensis, quantitative trait loci (QTLs) in two regions of chromosome 1 (Qaer1.02-3 and Qaer1.07) are associated with Aerenchyma formation under non-flooding conditions. The objective of this study was to determine the utility of these (and any other) Aerenchyma QTLs in marker-assisted maize breeding. For this study, an elite maize Mi29 × teosinte Z. nicaraguensis 214 BC2F1 individual population was used for advanced backcross-QTL mapping (AB-QTL). An SSR-based map was constructed using 94 markers, covering 852.7 cM for the ten chromosomes. Mapping revealed that a QTL for Aerenchyma formation under non-flooding conditions exhibiting a larger effect was located on chromosome 1 (bin 1.06), the position of which was close to the previously identified Qaer1.07. Also, two QTLs with minor effects were mapped to a different position on chromosomes 1 (bin 1.11) and 5 (bin 5.09). With a few additional backcrosses, it will be possible to obtain near-isogenic lines possessing Aerenchyma-forming genes. These materials may be useful in breeding flooding-tolerant maize hybrids.
Yoshiro Mano - One of the best experts on this subject based on the ideXlab platform.
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relationship between constitutive root Aerenchyma formation and flooding tolerance in zea nicaraguensis
Plant and Soil, 2013Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:The teosinte Zea nicaraguensis, which is adapted to frequently flooded lowlands, is considered a valuable germplasm resource for the development of flooding-tolerant maize. This species can form constitutive root Aerenchyma under well-drained conditions. The objectives of this study were to screen Z. nicaraguensis accessions for the capacity to form constitutive Aerenchyma, to obtain progeny with differing degrees of Aerenchyma formation, and to compare the flooding tolerance of these progeny. We evaluated constitutive Aerenchyma formation in the root cortex of seedlings of eight accessions and several segregating populations of Z. nicaraguensis. We also evaluated flooding tolerance in lines selected for high or low degrees of constitutive Aerenchyma formation. Seedlings of the eight accessions showed an extremely wide and continuous range of variation in Aerenchyma formation. By phenotypic selection within two accessions, we obtained lines with either high or low degrees of constitutive Aerenchyma formation. The lines selected for a higher degree of formation showed relatively high flooding tolerance evaluated by shoot dry weight ratio (flooded:control) than those with a lower degree of formation. A greater capacity to form constitutive Aerenchyma can enhance flooding tolerance.
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relationship between constitutive root Aerenchyma formation and flooding tolerance in zea nicaraguensis
Plant and Soil, 2013Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:Background and aims The teosinte Zea nicaraguensis, which is adapted to frequently flooded lowlands, is considered a valuable germplasm resource for the development of flooding-tolerant maize. This species can form constitutive root Aerenchyma under well-drained conditions. The objectives of this study were to screen Z. nicaraguensis accessions for the capacity to form constitutive Aerenchyma, to obtain progeny with differing degrees of Aerenchyma formation, and to compare the flooding tolerance of these progeny.
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construction of intraspecific linkage maps detection of a chromosome inversion and mapping of qtl for constitutive root Aerenchyma formation in the teosinte zea nicaraguensis
Molecular Breeding, 2012Co-Authors: Yoshiro Mano, Fumie Omori, Kazuyoshi TakedaAbstract:The teosinte Zea nicaraguensis, a wild relative of maize, possesses a flooding tolerance-related trait: the formation of constitutive root Aerenchyma under drained (non-flooded) soil conditions. A previous study suggested that the degree of constitutive Aerenchyma formation varies within Z. nicaraguensis. The objectives of this study were to construct linkage maps, to determine the marker order in a region of chromosome 4 in which recombination between maize and Z. nicaraguensis is suppressed, and to identify quantitative trait loci (QTL) controlling constitutive root Aerenchyma formation in two segregating populations of Z. nicaraguensis. A total of 236 simple sequence repeat (SSR) markers were screened for polymorphism in an S1 population of Z. nicaraguensis. Seventy-one polymorphic SSR markers were assigned to 10 chromosomes, and a linkage map was constructed covering 793.5 cM. In the S1 map, a paracentric inversion was detected on the long arm of chromosome 4; this rearrangement was confirmed in an S1 linkage map of a different Z. nicaraguensis accession. Composite interval mapping analysis in 96 S1 plants revealed QTL for Aerenchyma formation on chromosomes 1 (bins 1.06–1.07) and 7 (bin 7.01), explaining 17 and 12% of the total phenotypic variance, respectively. The QTL on chromosome 1 was verified by using 156 S2 plants. Near-isogenic lines exhibiting the presence or absence of the Aerenchyma QTL have been developed that should be useful for genetic and physiological analyses of root Aerenchyma formation.
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high density linkage map around the root Aerenchyma locus qaer1 06 in the backcross populations of maize mi29 teosinte zea nicaraguensis
Breeding Science, 2009Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:The teosinte Zea nicaraguensis forms constitutive Aerenchyma in the root cortex as observed in flooding tolerant wetland plants. We have previously identified a quantitative trait locus (QTL) controlling Aerenchyma formation under non-flooding conditions on chromosome 1 (Qaer1.06) using 214 individuals of a maize Mi29 × Z. nicaraguensis BC2F1 population. The present studies objective was to increase the marker density around the Qaer1.06 locus, which is essential for the development of near-isogenic lines possessing the Aerenchyma-forming gene with only a small region of the Z. nicaraguensis chromosome segment. A survey of 62 SSR and 38 insertion/deletion (INDEL) markers identified a total of 36 useful markers in the region of interest. These were selected for the construction of a linkage map in a 214 individual BC2F1 and a 123 individual BC4F1 population from a cross between Mi29 × Z. nicaraguensis. Using the BC4F1 population, we performed QTL mapping and the results indicated that a QTL for Aerenchyma formation under non-flooding condition was located on chromosome 1 (bin 1.05) at a position that is near to Qaer1.06. The markers obtained here should be useful for the development of high quality near-isogenic lines possessing the Qaer1.05-6.
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verification of qtl controlling root Aerenchyma formation in a maize teosinte zea nicaraguensis advanced backcross population
Breeding Science, 2008Co-Authors: Yoshiro Mano, Fumie OmoriAbstract:Root Aerenchyma formation is considered to be one of the most important characteristics for adapting to flooding. Using an F2 population of maize B64 × teosinte Zea nicaraguensis, we earlier found that, in Z. nicaraguensis, quantitative trait loci (QTLs) in two regions of chromosome 1 (Qaer1.02-3 and Qaer1.07) are associated with Aerenchyma formation under non-flooding conditions. The objective of this study was to determine the utility of these (and any other) Aerenchyma QTLs in marker-assisted maize breeding. For this study, an elite maize Mi29 × teosinte Z. nicaraguensis 214 BC2F1 individual population was used for advanced backcross-QTL mapping (AB-QTL). An SSR-based map was constructed using 94 markers, covering 852.7 cM for the ten chromosomes. Mapping revealed that a QTL for Aerenchyma formation under non-flooding conditions exhibiting a larger effect was located on chromosome 1 (bin 1.06), the position of which was close to the previously identified Qaer1.07. Also, two QTLs with minor effects were mapped to a different position on chromosomes 1 (bin 1.11) and 5 (bin 5.09). With a few additional backcrosses, it will be possible to obtain near-isogenic lines possessing Aerenchyma-forming genes. These materials may be useful in breeding flooding-tolerant maize hybrids.
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role of abscisic acid in flood induced secondary Aerenchyma formation in soybean glycine max hypocotyls
Plant Production Science, 2014Co-Authors: Satoshi Shimamura, Ryo Yamamoto, Takuji Nakamura, Shinji Shimada, Toshihito Yoshioka, Susumu Hiraga, Setsuko KomatsuAbstract:AbstractPhellogen (cork cambium) usually produces cork tissue, but when flooded it produces secondary Aerenchyma, comprising living cells with non-suberized walls in the stems, roots, and root nodules of some Fabaceae. In the cell walls of cork tissues, the plant hormone abscisic acid (ABA), promotes suberin deposition. Thus, ABA may decrease in flooded tissues, where secondary Aerenchyma cells are developing. Here, we investigated whether ABA is involved in the formation of Aerenchyma in soybean (Glycine max) hypocotyls when flooded. Hypocotyls flooded with water produced a large amount of secondary Aerenchyma, and were highly porous. On the other hand, application of 1.0 μM ABA suppressed the enlargement of phellogen-derived cells, thereby suppressing subsequent gas space formation, and then almost completely inhibited Aerenchyma development. Berberine-aniline blue staining indicated that not only elongated cells in the secondary Aerenchyma but also packed cells, which were formed under flooding with AB...
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Role of Abscisic Acid in Flood-Induced Secondary Aerenchyma Formation in Soybean (Glycine max) Hypocotyls
Taylor & Francis Group, 2014Co-Authors: Satoshi Shimamura, Ryo Yamamoto, Takuji Nakamura, Shinji Shimada, Toshihito Yoshioka, Susumu Hiraga, Setsuko KomatsuAbstract:Phellogen (cork cambium) usually produces cork tissue, but when flooded it produces secondary Aerenchyma, comprising living cells with non-suberized walls in the stems, roots, and root nodules of some Fabaceae. In the cell walls of cork tissues, the plant hormone abscisic acid (ABA), promotes suberin deposition. Thus, ABA may decrease in flooded tissues, where secondary Aerenchyma cells are developing. Here, we investigated whether ABA is involved in the formation of Aerenchyma in soybean (Glycine max) hypocotyls when flooded. Hypocotyls flooded with water produced a large amount of secondary Aerenchyma, and were highly porous. On the other hand, application of 1.0 μM ABA suppressed the enlargement of phellogen-derived cells, thereby suppressing subsequent gas space formation, and then almost completely inhibited Aerenchyma development. Berberine-aniline blue staining indicated that not only elongated cells in the secondary Aerenchyma but also packed cells, which were formed under flooding with ABA, contained no suberized cell walls. Compared to non-flooded plants, the endogenous ABA concentration in the flooded hypocotyls was decreased to 50% within 24 hr, and the low level was maintained for at least 72 hr. In addition, phellogen developed at 48 hr after flooding and secondary Aerenchyma was observed at 72 hr. These results indicate that secondary Aerenchyma formation requires a decrease in negative regulator ABA in soybean plants, that is, ABA inhibits elongation of cells derived from phellogen in secondary Aerenchyma formation such as internodal cell elongation of floating rice stems
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Aerenchyma formation in crop species a review
Field Crops Research, 2013Co-Authors: Takaki Yamauchi, Mikio Nakazono, Satoshi Shimamura, Toshihiro MochizukiAbstract:Flooding is a major problem in many crop areas around the world. However, many wetland plant species can expand their roots into flooded soils because of the presence of longitudinal Aerenchyma channels that facilitate oxygen diffusion from the shoots to the root tips. Aerenchyma also forms in rice roots, allowing rice plants to grow well in flooded paddy fields. Aerenchyma formation therefore helps plants to survive flooding. “Primary Aerenchyma” forms in the roots of some cereal crops such as rice, maize, barley and wheat. “Secondary Aerenchyma” forms in the stem, hypocotyl, tap root, adventitious roots, and root nodules of some legume crops such as soybean. This paper reviews the recent progress in the study of Aerenchyma formation, and highlights the role that primary Aerenchyma in cereal crops and secondary Aerenchyma in soybean can play in improving their tolerance to flooding.
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Stem hypertrophic lenticels and secondary Aerenchyma enable oxygen transport to roots of soybean in flooded soil
Annals of botany, 2010Co-Authors: Satoshi Shimamura, Ryo Yamamoto, Takuji Nakamura, Shinji Shimada, Setsuko KomatsuAbstract:†Background and Aims Aerenchyma provides a low-resistance O2 transport pathway that enhances plant survival during soil flooding. When in flooded soil, soybean produces Aerenchyma and hypertrophic stem lenticels. The aims of this study were to investigate O2 dynamics in stem Aerenchyma and evaluate O2 supply via stem lenticels to the roots of soybean during soil flooding. †Methods Oxygen dynamics in Aerenchymatous stems were investigated using Clark-type O2 microelectrodes, and O2 transport to roots was evaluated using stable-isotope 18 O2 as a tracer, for plants with shoots in air and roots in flooded sand or soil. Short-term experiments also assessed venting of CO2 via the stem lenticels. †Key Results The radial distribution of the O2 partial pressure (pO2) was stable at 17 kPa in the stem Aerenchyma 15 mm below the water level, but rapidly declined to 8 kPa at 200‐300 mm inside the stele. Complete submergence of the hypertrophic lenticels at the stem base, with the remainder of the shoot still in air, resulted in gradual declines in pO2 in stem Aerenchyma from 17. 5t o 7.6 kPa at 13 mm below the water level, and from 14. 7t o 6.1 kPa at 51 mm below the water level. Subsequently, re-exposure of the lenticels to air caused pO2 to increase again to 14 ‐17 kPa at both positions within 10 min. After introducing 18 O2 gas via the stem lenticels, significant 18 O2 enrichment in water extracted from roots after 3 h was confirmed, suggesting that transported O2 sustained root respiration. In contrast, slight 18 O2 enrichment was detected 3 h after treatment of stems that lacked Aerenchyma and lenticels. Moreover, Aerenchyma accelerated venting of CO2 from submerged tissues to the atmosphere. †Conclusions Hypertrophic lenticels on the stem of soybean, just above the water surface, are entry points for O2, and these connect to Aerenchyma and enable O2 transport into roots in flooded soil. Stems that develop Aerenchyma thus serve as a ‘snorkel’ that enables O2 movement from air to the submerged roots.
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Cortical Aerenchyma Formation in Hypocotyl and Adventitious Roots of Luffa cylindrica Subjected to Soil Flooding
Annals of botany, 2007Co-Authors: Satoshi Shimamura, Satoshi Yoshida, Toshihiro MochizukiAbstract:Background and aims Aerenchyma formation is thought to be one of the important morphological adaptations to hypoxic stress. Although sponge gourd is an annual vegetable upland crop, in response to flooding the hypocotyl and newly formed adventitious roots create Aerenchyma that is neither schizogenous nor lysigenous, but is produced by radial elongation of cortical cells. The aim of this study is to characterize the morphological changes in flooded tissues and the pattern of cortical Aerenchyma formation, and to analyse the relative amount of Aerenchyma formed. Methods Plants were harvested at 16 d after the flooding treatment was initiated. The root system was observed, and sections of fresh materials (hypocotyl, tap root and adventitious root) were viewed with a light or fluorescence microscope. Distributions of porosity along adventitious roots were estimated by a pycnometer method. Key results Under flooded conditions, a considerable part of the root system consisted of new adventitious roots which soon emerged and grew quickly over the soil surface. The outer cortical cells of these roots and those of the hypocotyl elongated radially and contributed to the development of large intercellular spaces. The elongated cortical cells of adventitious roots were clearly T-shaped, and occurred regularly in mesh-like lacunate structures. In these positions, slits were formed in the epidermis. In the roots, the enlargement of the gas space system began close to the apex in the cortical cell layers immediately beneath the epidermis. The porosity along these roots was 11-45 %. In non-flooded plants, adventitious roots were not formed and no Aerenchyma developed in the hypocotyl or tap root. Conclusions Sponge gourd Aerenchyma is produced by the unique radial elongation of cells that make the expansigeny. These morphological changes seem to enhance flooding tolerance by promoting tissue gas exchange, and sponge gourd might thereby adapt to flooding stress.