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Laurentius A C J Voesenek - One of the best experts on this subject based on the ideXlab platform.
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is elongation induced leaf emergence beneficial for submerged rumex species
Annals of Botany, 2009Co-Authors: Ronald Pierik, Jan Aken, Laurentius A C J VoesenekAbstract:†Background and Aims Plant species from various taxa ‘escape’ from low oxygen conditions associated with submergence by a suite of traits collectively called the low oxygen escape syndrome (LOES). The expression of these traits is associated with costs and benefits. Thus far, remarkably few studies have dealt with the expected benefits of the LOES. †Methods Young plants were fully submerged at initial depths of 450 mm (deep) or 150– 240 mm (shallow). Rumex palustris leaf tips emerged from the shallow flooding within a few days, whereas a slight lowering of shallow flooding was required to expose R. acetosa leaf tips to the atmosphere. Shoot biomass and Petiole porosity were measured for all species, and treatments and data from the deep and shallow submergence treatments were compared with non-flooded controls. †Key Results R. palustris is characterized by submergence-induced enhanced Petiole elongation. R. acetosa lacked this growth response. Upon leaf tip emergence, R. palustris increased its biomass, whereas R. acetosa did not. Furthermore, Petiole porosity in R. palustris was twice as high as in R. acetosa. †Conclusions Leaf emergence restores gas exchange between roots and the atmosphere in R. palustris. This occurs to a much lesser extent in R. acetosa and is attributable to its lower Petiole porosity and therefore limited internal gas transport. Leaf emergence resulting from fast Petiole elongation appears to benefit biomass accumulation if these plants contain sufficient aerenchyma in Petioles and roots to facilitate internal gas exchange.
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contrasting interactions between ethylene and abscisic acid in rumex species differing in submergence tolerance
Plant Journal, 2005Co-Authors: Joris J Benschop, Robert A M Vreeburg, Anton J M Peeters, Stephen J Croker, Michael B Jackson, Kerstin Guhl, Laurentius A C J VoesenekAbstract:*† ‡ § Summary Complete submergence of flooding-tolerant Rumex palustris plants strongly stimulates Petiole elongation. This escape response is initiated by the accumulation of ethylene inside the submerged tissue. In contrast, Petioles of flooding-intolerant Rumex acetosa do not increase their elongation rate under water even though ethylene also accumulates when they are submerged. Abscisic acid (ABA) was found to be a negative regulator of enhanced Petiole growth in both species. In R. palustris, accumulated ethylene stimulated elongation by inhibiting biosynthesis of ABA via a reduction of RpNCED expression and enhancing degradation of ABA to phaseic acid. Externally applied ABA inhibited Petiole elongation and prevented the upregulation of gibberellin A 1 normally found in submerged R. palustris .I nR. acetosa submergence did not stimulate Petiole elongation nor did it depress levels of ABA. However, if ABA concentrations in R. acetosa were first artificially reduced, submergence (but not ethylene) was then able to enhance Petiole elongation strongly. This result suggests that in Rumex a decrease in ABA is a prerequisite for ethylene and other stimuli to promote elongation.
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the roles of ethylene auxin abscisic acid and gibberellin in the hyponastic growth of submerged rumex palustris Petioles
Plant Physiology, 2004Co-Authors: Marjolein C H Cox, Joris J Benschop, Robert A M Vreeburg, Anton J M Peeters, Thomas Moritz, Cornelis Wagemaker, Laurentius A C J VoesenekAbstract:Rumex palustris responds to complete submergence with upward movement of the younger Petioles. This so-called hyponastic response, in combination with stimulated Petiole elongation, brings the leaf blade above the water surface and restores contact with the atmosphere. We made a detailed study of this differential growth process, encompassing the complete range of the known signal transduction pathway: from the cellular localization of differential growth, to the hormonal regulation, and the possible involvement of a cell wall loosening protein (expansin) as a downstream target. We show that hyponastic growth is caused by differential cell elongation across the Petiole base, with cells on the abaxial (lower) surface elongating faster than cells on the adaxial (upper) surface. Pharmacological studies and endogenous hormone measurements revealed that ethylene, auxin, abscisic acid (ABA), and gibberellin regulate different and sometimes overlapping stages of hyponastic growth. Initiation of hyponastic growth and (maintenance of) the maximum Petiole angle are regulated by ethylene, ABA, and auxin, whereas the speed of the response is influenced by ethylene, ABA, and gibberellin. We found that a submergence-induced differential redistribution of endogenous indole-3-acetic acid in the Petiole base could play a role in maintenance of the response, but not in the onset of hyponastic growth. Since submergence does not induce a differential expression of expansins across the Petiole base, it is unlikely that this cell wall loosening protein is the downstream target for the hormones that regulate the differential cell elongation leading to submergence-induced hyponastic growth in R. palustris.
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submergence induced Petiole elongation in rumex palustris is controlled by developmental stage and storage compounds
Plant and Soil, 2003Co-Authors: Henri W Groeneveld, Laurentius A C J VoesenekAbstract:Submergence stimulates elongation of the leaves of Rumex palustris and under laboratory conditions the maximum final leaf length (of plants up to 7 weeks old) was obtained within a 9 day period. This elongation response, mainly determined by Petiole elongation, depends on the availability of storage compounds and developmental stage of a leaf. A starch accumulating tap root and mature leaves and Petioles were found to supply elongating leaves with substrates for polysaccharide synthesis in expanding cell walls. Changes in the composition of cell wall polysaccharides of elongated Petioles suggest a substantial cell wall metabolism during cell extension. Reduced starch levels or removal of mature leaves caused a substantial limitation of submerged leaf growth. From the 5th leaf onward enough reserves were available to perform submerged leaf growth from early developmental stages. Very young Petioles had a limited capacity to elongate. In slightly older Petioles submergence resulted in the longest final leaf lengths and these values gradually decreased when submergence was started at more mature developmental stages. Submerged leaf growth is mainly a matter of Petiole elongation in which cell elongation has a concurrent synthesis of xylem elements in the vascular tissue. Mature Petioles still elongated (when submerged) by cell and tissue elongation only: the annular tracheary elements stretched enabling up to 70% Petiole elongation.
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interactions between plant hormones regulate submergence induced shoot elongation in the flooding tolerant dicot rumex palustris
Annals of Botany, 2003Co-Authors: Laurentius A C J Voesenek, Joris J Benschop, H W Groeneveld, Frank F Millenaar, Robert A M Vreeburg, Anton J M PeetersAbstract:: Rumex palustris has the capacity to respond to complete submergence with hyponastic (upward) growth and stimulated elongation of Petioles. These adaptive responses allow survival of this plant in habitats with sustained high water levels by re-establishing contact with the aerial environment. Accumulated ethylene in submerged Petioles interacts with ethylene receptor proteins and operates as a reliable sensor for the under-water environment. Further downstream in the transduction pathway, a fast and substantial decrease of the endogenous abscisic acid concentration and a certain threshold level of endogenous auxin and gibberellin are required for hyponastic growth and Petiole elongation. Interactions of these plant hormones results in a significant increase of the in vitro cell wall extensibility in submerged Petioles. Furthermore, the pattern of transcript accumulation of a R. palustris alpha-expansin gene correlated with the pattern of Petiole elongation upon submergence.
Philipp W. Simon - One of the best experts on this subject based on the ideXlab platform.
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a cluster of myb transcription factors regulates anthocyanin biosynthesis in carrot daucus carota l root and Petiole
Frontiers in Plant Science, 2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 kb and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
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Table_1_A Cluster of MYB Transcription Factors Regulates Anthocyanin Biosynthesis in Carrot (Daucus carota L.) Root and Petiole.XLSX
2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
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Data_Sheet_1_A Cluster of MYB Transcription Factors Regulates Anthocyanin Biosynthesis in Carrot (Daucus carota L.) Root and Petiole.PDF
2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
Pablo F. Cavagnaro - One of the best experts on this subject based on the ideXlab platform.
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a cluster of myb transcription factors regulates anthocyanin biosynthesis in carrot daucus carota l root and Petiole
Frontiers in Plant Science, 2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 kb and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
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Table_1_A Cluster of MYB Transcription Factors Regulates Anthocyanin Biosynthesis in Carrot (Daucus carota L.) Root and Petiole.XLSX
2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
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Data_Sheet_1_A Cluster of MYB Transcription Factors Regulates Anthocyanin Biosynthesis in Carrot (Daucus carota L.) Root and Petiole.PDF
2019Co-Authors: Massimo Iorizzo, Pablo F. Cavagnaro, Hamed Bostan, Yunyang Zhao, Jianhui Zhang, Philipp W. SimonAbstract:Purple carrots can accumulate large quantities of anthocyanins in their roots and –in some genetic backgrounds- Petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and Petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas Petiole pigmentation segregated as a single dominant gene and mapped to one of these “root pigmentation” regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and Petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and Petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and Petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in Petioles. In the Petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for Petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple Petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the Petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.
Anton J M Peeters - One of the best experts on this subject based on the ideXlab platform.
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contrasting interactions between ethylene and abscisic acid in rumex species differing in submergence tolerance
Plant Journal, 2005Co-Authors: Joris J Benschop, Robert A M Vreeburg, Anton J M Peeters, Stephen J Croker, Michael B Jackson, Kerstin Guhl, Laurentius A C J VoesenekAbstract:*† ‡ § Summary Complete submergence of flooding-tolerant Rumex palustris plants strongly stimulates Petiole elongation. This escape response is initiated by the accumulation of ethylene inside the submerged tissue. In contrast, Petioles of flooding-intolerant Rumex acetosa do not increase their elongation rate under water even though ethylene also accumulates when they are submerged. Abscisic acid (ABA) was found to be a negative regulator of enhanced Petiole growth in both species. In R. palustris, accumulated ethylene stimulated elongation by inhibiting biosynthesis of ABA via a reduction of RpNCED expression and enhancing degradation of ABA to phaseic acid. Externally applied ABA inhibited Petiole elongation and prevented the upregulation of gibberellin A 1 normally found in submerged R. palustris .I nR. acetosa submergence did not stimulate Petiole elongation nor did it depress levels of ABA. However, if ABA concentrations in R. acetosa were first artificially reduced, submergence (but not ethylene) was then able to enhance Petiole elongation strongly. This result suggests that in Rumex a decrease in ABA is a prerequisite for ethylene and other stimuli to promote elongation.
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the roles of ethylene auxin abscisic acid and gibberellin in the hyponastic growth of submerged rumex palustris Petioles
Plant Physiology, 2004Co-Authors: Marjolein C H Cox, Joris J Benschop, Robert A M Vreeburg, Anton J M Peeters, Thomas Moritz, Cornelis Wagemaker, Laurentius A C J VoesenekAbstract:Rumex palustris responds to complete submergence with upward movement of the younger Petioles. This so-called hyponastic response, in combination with stimulated Petiole elongation, brings the leaf blade above the water surface and restores contact with the atmosphere. We made a detailed study of this differential growth process, encompassing the complete range of the known signal transduction pathway: from the cellular localization of differential growth, to the hormonal regulation, and the possible involvement of a cell wall loosening protein (expansin) as a downstream target. We show that hyponastic growth is caused by differential cell elongation across the Petiole base, with cells on the abaxial (lower) surface elongating faster than cells on the adaxial (upper) surface. Pharmacological studies and endogenous hormone measurements revealed that ethylene, auxin, abscisic acid (ABA), and gibberellin regulate different and sometimes overlapping stages of hyponastic growth. Initiation of hyponastic growth and (maintenance of) the maximum Petiole angle are regulated by ethylene, ABA, and auxin, whereas the speed of the response is influenced by ethylene, ABA, and gibberellin. We found that a submergence-induced differential redistribution of endogenous indole-3-acetic acid in the Petiole base could play a role in maintenance of the response, but not in the onset of hyponastic growth. Since submergence does not induce a differential expression of expansins across the Petiole base, it is unlikely that this cell wall loosening protein is the downstream target for the hormones that regulate the differential cell elongation leading to submergence-induced hyponastic growth in R. palustris.
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interactions between plant hormones regulate submergence induced shoot elongation in the flooding tolerant dicot rumex palustris
Annals of Botany, 2003Co-Authors: Laurentius A C J Voesenek, Joris J Benschop, H W Groeneveld, Frank F Millenaar, Robert A M Vreeburg, Anton J M PeetersAbstract:: Rumex palustris has the capacity to respond to complete submergence with hyponastic (upward) growth and stimulated elongation of Petioles. These adaptive responses allow survival of this plant in habitats with sustained high water levels by re-establishing contact with the aerial environment. Accumulated ethylene in submerged Petioles interacts with ethylene receptor proteins and operates as a reliable sensor for the under-water environment. Further downstream in the transduction pathway, a fast and substantial decrease of the endogenous abscisic acid concentration and a certain threshold level of endogenous auxin and gibberellin are required for hyponastic growth and Petiole elongation. Interactions of these plant hormones results in a significant increase of the in vitro cell wall extensibility in submerged Petioles. Furthermore, the pattern of transcript accumulation of a R. palustris alpha-expansin gene correlated with the pattern of Petiole elongation upon submergence.
Regine Delourme - One of the best experts on this subject based on the ideXlab platform.
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oilseed rape brassica napus resistance to growth of leptosphaeria maculans in leaves of young plants contributes to quantitative resistance in stems of adult plants
PLOS ONE, 2019Co-Authors: Yongju Huang, Sophie Paillard, Vinod Kumar, Graham J W King, Bruce D L Fitt, Regine DelourmeAbstract:Key message: One QTL for resistance against Leptosphaeria maculans growth in leaves of young plants in controlled environments overlapped with one QTL detected in adult plants in field experiments. The fungal pathogen Leptosphaeria maculans initially infects leaves of oilseed rape (Brassica napus) in autumn in Europe and then grows systemically from leaf lesions along the leaf Petiole to the stem, where it causes damaging phoma stem canker (blackleg) in summer before harvest. Due to the difficulties of investigating resistance to L. maculans growth in leaves and Petioles under field conditions, identification of quantitative resistance typically relies on end of season stem canker assessment on adult plants. To investigate whether quantitative resistance can be detected in young plants, we first selected nine representative DH (doubled haploid) lines from an oilseed rape DY (‘Darmor-bzh’ × ‘Yudal’) mapping population segregating for quantitative resistance against L. maculans for controlled environment experiment (CE). We observed a significant correlation between distance grown by L. maculans along the leaf Petiole towards the stem (r = 0.91) in CE experiments and the severity of phoma stem canker in field experiments. To further investigate quantitative trait loci (QTL) related to resistance against growth of L. maculans in leaves of young plants in CE experiments, we selected 190 DH lines and compared the QTL detected in CE experiments with QTL related to stem canker severity in stems of adult plants in field experiments. Five QTL for resistance to L. maculans growth along the leaf Petiole were detected; collectively they explained 35% of the variance. Two of these were also detected in leaf lesion area assessments and each explained 10–12% of the variance. One QTL on A02 co-localized with a QTL detected in stems of adult plants in field experiments. This suggests that resistance to the growth of L. maculans from leaves along the Petioles towards the stems contributes to the quantitative resistance assessed in stems of adult plants in field experiments at the end of the growing season.
