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Sofie Goormachtig - One of the best experts on this subject based on the ideXlab platform.
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Sesbania rostrata a case study of natural variation in legume nodulation
New Phytologist, 2010Co-Authors: Ward Capoen, Sofie Goormachtig, Marcelle Holsters, Giles E D OldroydAbstract:Summary Legumes acquired the ability to engage in a symbiotic interaction with soil-borne bacteria and establish a nitrogen-fixing symbiosis in a novel root organ, the nodule. Most legume crops and the model legumes Medicago truncatula and Lotus japonicus are infected intracellularly in root hairs via infection threads that lead the bacteria towards a nodule primordium in the root cortex. This infection process, however, does not reflect the great diversity of infection strategies that are used by leguminous plants. An alternative, intercellular invasion occurs in the semiaquatic legume Sesbania rostrata. Bacteria colonize epidermal fissures at lateral root bases and trigger cortical cell death for infection pocket formation and subsequent intercellular and intracellular infection thread progression towards the primordium. This infection mode evolved as an adaptation to waterlogged conditions that inhibit intracellular invasion. In this review, we discuss the molecular basis for this adaptation and how insights into this process contribute to general knowledge of the rhizobial infection process.
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comparative transcriptome analysis reveals common and specific tags for root hair and crack entry invasion in Sesbania rostrata
Plant Physiology, 2007Co-Authors: Ward Capoen, Marcelle Holsters, Jeroen Den Herder, Stephane Rombauts, Jeroen De Gussem, Annick De Keyser, Sofie GoormachtigAbstract:The tropical legume Sesbania rostrata provides its microsymbiont Azorhizobium caulinodans with versatile invasion strategies to allow nodule formation in temporarily flooded habitats. In aerated soils, the bacteria enter via the root hair curling mechanism. Submergence prevents this epidermal invasion by accumulation of inhibiting concentrations of ethylene and, under these conditions, the bacterial colonization occurs via intercellular cortical infection at lateral root bases. The transcriptome of both invasion ways was compared by cDNA-amplified fragment length polymorphism analysis. Clusters of gene tags were identified that were specific for either epidermal or cortical invasion or were shared by both. The data provide insight into mechanisms that control infection and illustrate that entry via the epidermis adds a layer of complexity to rhizobial invasion.
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a symbiotic plant peroxidase involved in bacterial invasion of the tropical legume Sesbania rostrata
Plant Physiology, 2007Co-Authors: Jeroen Den Herder, Marcelle Holsters, Sam Lievens, Stephane Rombauts, Sofie GoormachtigAbstract:Aquatic nodulation on the tropical legume Sesbania rostrata occurs at lateral root bases via intercellular crack-entry invasion. A gene was identified (Srprx1) that is transiently up-regulated during the nodulation process and codes for a functional class III plant peroxidase. The expression strictly depended on bacterial nodulation factors (NFs) and could be modulated by hydrogen peroxide, a downstream signal for crack-entry invasion. Expression was not induced after wounding or pathogen attack, indicating that the peroxidase is a symbiosis-specific isoform. In situ hybridization showed Srprx1 transcripts around bacterial infection pockets and infection threads until they reached the central tissue of the nodule. A root nodule extensin (SrRNE1) colocalized with Srprx1 both in time and space and had the same NF requirement, suggesting a function in a similar process. Finally, in mixed inoculation nodules that were invaded by NF-deficient bacteria and differed in infection thread progression, infection-associated peroxidase transcripts were not observed. Lack of Srprx1 gene expression could be one of the causes for the aberrant structure of the infection threads.
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gibberellins are involved in nodulation of Sesbania rostrata
Plant Physiology, 2005Co-Authors: Sam Lievens, Sofie Goormachtig, Jeroen Den Herder, Ward Capoen, Rene Mathis, Peter Hedden, Marcelle HolstersAbstract:Upon submergence, Azorhizobium caulinodans infects the semiaquatic legume Sesbania rostrata via the intercellular crack entry process, resulting in lateral root-based nodules. A gene encoding a gibberellin (GA) 20-oxidase, SrGA20ox1, involved in GA biosynthesis, was transiently up-regulated during lateral root base nodulation. Two SrGA20ox1 expression patterns were identified, one related to intercellular infection and a second observed in nodule meristem descendants. The infection-related expression pattern depended on bacterially produced nodulation (Nod) factors. Pharmacological studies demonstrated that GAs were involved in infection pocket and infection thread formation, two Nod factor-dependent events that initiate lateral root base nodulation, and that they were also needed for nodule primordium development. Moreover, GAs inhibited the root hair curling process. These results show that GAs are Nod factor downstream signals for nodulation in hydroponic growth.
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nodulation enhanced sequences from the water stress tolerant tropical legume Sesbania rostrata
Plant Science, 2004Co-Authors: Katrien Schroeyers, Sofie Goormachtig, Cristian Chaparro, Marcelle HolstersAbstract:The interaction of the tropical legume Sesbania rostrata with the Azorhizobium caulinodans bacterium results in the formation of nodules not only on roots but also on stems at adventitious root bases. Transcripts that are expressed during stem nodule initiation were identified with the suppression subtractive hybridization technique. Out of an original collection of 102, 26 genes were confirmed to be differentially expressed in macroarray hybridizations. Most of the genes belong to the medium-abundant expression group, but more information on some low-abundant differentially expressed genes was obtained by in situ hybridization. Two genes, SrSAMS and SrERF1 that are clearly enhanced during nodulation could be involved in the production and perception of ethylene, which is necessary for nodulation of S. rostrata under aquatic conditions.
Marcelle Holsters - One of the best experts on this subject based on the ideXlab platform.
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Sesbania rostrata a case study of natural variation in legume nodulation
New Phytologist, 2010Co-Authors: Ward Capoen, Sofie Goormachtig, Marcelle Holsters, Giles E D OldroydAbstract:Summary Legumes acquired the ability to engage in a symbiotic interaction with soil-borne bacteria and establish a nitrogen-fixing symbiosis in a novel root organ, the nodule. Most legume crops and the model legumes Medicago truncatula and Lotus japonicus are infected intracellularly in root hairs via infection threads that lead the bacteria towards a nodule primordium in the root cortex. This infection process, however, does not reflect the great diversity of infection strategies that are used by leguminous plants. An alternative, intercellular invasion occurs in the semiaquatic legume Sesbania rostrata. Bacteria colonize epidermal fissures at lateral root bases and trigger cortical cell death for infection pocket formation and subsequent intercellular and intracellular infection thread progression towards the primordium. This infection mode evolved as an adaptation to waterlogged conditions that inhibit intracellular invasion. In this review, we discuss the molecular basis for this adaptation and how insights into this process contribute to general knowledge of the rhizobial infection process.
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comparative transcriptome analysis reveals common and specific tags for root hair and crack entry invasion in Sesbania rostrata
Plant Physiology, 2007Co-Authors: Ward Capoen, Marcelle Holsters, Jeroen Den Herder, Stephane Rombauts, Jeroen De Gussem, Annick De Keyser, Sofie GoormachtigAbstract:The tropical legume Sesbania rostrata provides its microsymbiont Azorhizobium caulinodans with versatile invasion strategies to allow nodule formation in temporarily flooded habitats. In aerated soils, the bacteria enter via the root hair curling mechanism. Submergence prevents this epidermal invasion by accumulation of inhibiting concentrations of ethylene and, under these conditions, the bacterial colonization occurs via intercellular cortical infection at lateral root bases. The transcriptome of both invasion ways was compared by cDNA-amplified fragment length polymorphism analysis. Clusters of gene tags were identified that were specific for either epidermal or cortical invasion or were shared by both. The data provide insight into mechanisms that control infection and illustrate that entry via the epidermis adds a layer of complexity to rhizobial invasion.
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a symbiotic plant peroxidase involved in bacterial invasion of the tropical legume Sesbania rostrata
Plant Physiology, 2007Co-Authors: Jeroen Den Herder, Marcelle Holsters, Sam Lievens, Stephane Rombauts, Sofie GoormachtigAbstract:Aquatic nodulation on the tropical legume Sesbania rostrata occurs at lateral root bases via intercellular crack-entry invasion. A gene was identified (Srprx1) that is transiently up-regulated during the nodulation process and codes for a functional class III plant peroxidase. The expression strictly depended on bacterial nodulation factors (NFs) and could be modulated by hydrogen peroxide, a downstream signal for crack-entry invasion. Expression was not induced after wounding or pathogen attack, indicating that the peroxidase is a symbiosis-specific isoform. In situ hybridization showed Srprx1 transcripts around bacterial infection pockets and infection threads until they reached the central tissue of the nodule. A root nodule extensin (SrRNE1) colocalized with Srprx1 both in time and space and had the same NF requirement, suggesting a function in a similar process. Finally, in mixed inoculation nodules that were invaded by NF-deficient bacteria and differed in infection thread progression, infection-associated peroxidase transcripts were not observed. Lack of Srprx1 gene expression could be one of the causes for the aberrant structure of the infection threads.
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gibberellins are involved in nodulation of Sesbania rostrata
Plant Physiology, 2005Co-Authors: Sam Lievens, Sofie Goormachtig, Jeroen Den Herder, Ward Capoen, Rene Mathis, Peter Hedden, Marcelle HolstersAbstract:Upon submergence, Azorhizobium caulinodans infects the semiaquatic legume Sesbania rostrata via the intercellular crack entry process, resulting in lateral root-based nodules. A gene encoding a gibberellin (GA) 20-oxidase, SrGA20ox1, involved in GA biosynthesis, was transiently up-regulated during lateral root base nodulation. Two SrGA20ox1 expression patterns were identified, one related to intercellular infection and a second observed in nodule meristem descendants. The infection-related expression pattern depended on bacterially produced nodulation (Nod) factors. Pharmacological studies demonstrated that GAs were involved in infection pocket and infection thread formation, two Nod factor-dependent events that initiate lateral root base nodulation, and that they were also needed for nodule primordium development. Moreover, GAs inhibited the root hair curling process. These results show that GAs are Nod factor downstream signals for nodulation in hydroponic growth.
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nodulation enhanced sequences from the water stress tolerant tropical legume Sesbania rostrata
Plant Science, 2004Co-Authors: Katrien Schroeyers, Sofie Goormachtig, Cristian Chaparro, Marcelle HolstersAbstract:The interaction of the tropical legume Sesbania rostrata with the Azorhizobium caulinodans bacterium results in the formation of nodules not only on roots but also on stems at adventitious root bases. Transcripts that are expressed during stem nodule initiation were identified with the suppression subtractive hybridization technique. Out of an original collection of 102, 26 genes were confirmed to be differentially expressed in macroarray hybridizations. Most of the genes belong to the medium-abundant expression group, but more information on some low-abundant differentially expressed genes was obtained by in situ hybridization. Two genes, SrSAMS and SrERF1 that are clearly enhanced during nodulation could be involved in the production and perception of ethylene, which is necessary for nodulation of S. rostrata under aquatic conditions.
Sam Lievens - One of the best experts on this subject based on the ideXlab platform.
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a symbiotic plant peroxidase involved in bacterial invasion of the tropical legume Sesbania rostrata
Plant Physiology, 2007Co-Authors: Jeroen Den Herder, Marcelle Holsters, Sam Lievens, Stephane Rombauts, Sofie GoormachtigAbstract:Aquatic nodulation on the tropical legume Sesbania rostrata occurs at lateral root bases via intercellular crack-entry invasion. A gene was identified (Srprx1) that is transiently up-regulated during the nodulation process and codes for a functional class III plant peroxidase. The expression strictly depended on bacterial nodulation factors (NFs) and could be modulated by hydrogen peroxide, a downstream signal for crack-entry invasion. Expression was not induced after wounding or pathogen attack, indicating that the peroxidase is a symbiosis-specific isoform. In situ hybridization showed Srprx1 transcripts around bacterial infection pockets and infection threads until they reached the central tissue of the nodule. A root nodule extensin (SrRNE1) colocalized with Srprx1 both in time and space and had the same NF requirement, suggesting a function in a similar process. Finally, in mixed inoculation nodules that were invaded by NF-deficient bacteria and differed in infection thread progression, infection-associated peroxidase transcripts were not observed. Lack of Srprx1 gene expression could be one of the causes for the aberrant structure of the infection threads.
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gibberellins are involved in nodulation of Sesbania rostrata
Plant Physiology, 2005Co-Authors: Sam Lievens, Sofie Goormachtig, Jeroen Den Herder, Ward Capoen, Rene Mathis, Peter Hedden, Marcelle HolstersAbstract:Upon submergence, Azorhizobium caulinodans infects the semiaquatic legume Sesbania rostrata via the intercellular crack entry process, resulting in lateral root-based nodules. A gene encoding a gibberellin (GA) 20-oxidase, SrGA20ox1, involved in GA biosynthesis, was transiently up-regulated during lateral root base nodulation. Two SrGA20ox1 expression patterns were identified, one related to intercellular infection and a second observed in nodule meristem descendants. The infection-related expression pattern depended on bacterially produced nodulation (Nod) factors. Pharmacological studies demonstrated that GAs were involved in infection pocket and infection thread formation, two Nod factor-dependent events that initiate lateral root base nodulation, and that they were also needed for nodule primordium development. Moreover, GAs inhibited the root hair curling process. These results show that GAs are Nod factor downstream signals for nodulation in hydroponic growth.
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nodule enhanced protease inhibitor gene emerging patterns of gene expression in nodule development on Sesbania rostrata
Journal of Experimental Botany, 2003Co-Authors: Sam Lievens, Sofie Goormachtig, Marcelle HolstersAbstract:A novel marker for the early stages of nodulation of Sesbania rostrata was found to encode a putative member of the Kunitz family of protease inhibitors (SrPI1). Its expression was enhanced during nodulation, and was not up-regulated by wounding or upon infection with wide host-range pathogens. In situ expression patterns resembled those previously described for functions that may be implicated in delimiting infected nodule tissues from the rest of the plant. Thus, SrPI1 may be a component of a multilayered barrier that restrains the invading rhizobia.
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patterns of pectin methylesterase transcripts in developing stem nodules of Sesbania rostrata
Molecular Plant-microbe Interactions, 2002Co-Authors: Sam Lievens, Sofie Goormachtig, Sylvia Herman, Marcelle HolstersAbstract:Differential display was applied to the early stages of the interaction between the tropical legume Sesbania rostrata and its microsymbiont Azorhizobium caulinodans ORS571. An upregulated clone that is similar to pectin methylesterase-encoding genes was isolated (Srpmel). The full-length sequence of Srpmel was used to localize PME transcripts in situ during S. rostrata stem-nodule development. Several expression patterns were distinguished, hinting at general roles in vascular tissue development and cell division or expansion and at symbiosis-specific functions, such as uninfected cell differentiation.
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srchi24 a chitinase homolog lacking an essential glutamic acid residue for hydrolytic activity is induced during nodule development on Sesbania rostrata
Plant Physiology, 2001Co-Authors: Sofie Goormachtig, Sam Lievens, Willem Van De Velde, Sylvia Herman, Annick De Keyser, Christa Verplancke, Marcelle HolstersAbstract:The interaction between the tropical legume Sesbania rostrata and the bacterium Azorhizobium caulinodans results in the formation of nodules on both stem and roots. Stem nodulation was used as a model system to isolate early markers by differential display. One of them, Srchi24 is a novel early nodulin whose transcript level increased already 4 h after inoculation. This enhancement depended on Nod factor-producing bacteria. Srchi24 transcript levels were induced also by exogenous cytokinins. In situ hybridization and immunolocalization experiments showed that Srchi24 transcripts and proteins were present in the outermost cortical cell layers of the developing nodules. Sequence analyses revealed that Srchi24 is similar to class III chitinases, but lacks an important catalytic glutamate residue. A fusion between a maltose-binding protein and Srchi24 had no detectable hydrolytic activity. A function in nodulation is proposed for the Srchi24 protein.
M Van Montagu - One of the best experts on this subject based on the ideXlab platform.
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chalcone reductase homologous transcripts accumulate during development of stem borne nodules on the tropical legume Sesbania rostrata
Planta, 1999Co-Authors: Sofie Goormachtig, Sam Lievens, M Van Montagu, Sylvia Herman, Marcelle HolstersAbstract:During a search for genes with induced or enhanced expression in the early stages of development of stem-borne nodules on Sesbania rostrata, a cDNA with homology to chalcone reductase (CHR) genes was isolated. Here, we describe the characterization of a full-length CHR cDNA (Srchr1) and the pattern of CHR transcript accumulation in stem-borne nodules. Expression was correlated with both nodule development and bacterial invasion. In young nodules, CHR transcripts were observed in cells of the parenchyma, in cells around the nodule vascular bundles, and in the uninfected cells of the central tissue.
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ethylene mediated phenotypic plasticity in root nodule development on Sesbania rostrata
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Manuel Fernandezlopez, Sofie Goormachtig, M Van Montagu, Wim Dhaeze, Marcelle HolstersAbstract:Leguminous plants in symbiosis with rhizobia form either indeterminate nodules with a persistent meristem or determinate nodules with a transient meristematic region. Sesbania rostrata was thought to possess determinate stem and root nodules. However, the nature of nodule development is hybrid, and the early stages resemble those of indeterminate nodules. Here we show that, depending on the environmental conditions, mature root nodules can be of the indeterminate type. In situ hybridizations with molecular markers for plant cell division, as well as the patterns of bacterial nod and nif gene expression, confirmed the indeterminate nature of 30-day-old functional root nodules. Experimental data provide evidence that the switch in nodule type is mediated by the plant hormone ethylene.
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srchi13 a novel early nodulin from Sesbania rostrata is related to acidic class iii chitinases
The Plant Cell, 1998Co-Authors: Sofie Goormachtig, Sam Lievens, M Van Montagu, Willem Van De Velde, Marcelle HolstersAbstract:On the tropical legume Sesbania rostrata, stem-borne nodules develop after inoculation of adventitious root primordia with the microsymbiont Azorhizobium caulinodans. A cDNA clone, Srchi13, with homology to acidic class III chitinase genes, corresponds to an early nodulin gene with transiently induced expression during nodule ontogeny. Srchi13 transcripts accumulated strongly 2 days after inoculation, decreased from day 7 onward, and disappeared in mature nodules. Induction was dependent on Nod factor-producing bacteria. Srchi13 was expressed around infection pockets, in infection centra, around the developing nodule and its vascular bundles, and in uninfected cells of the central tissue. The specific and transient transcript accumulation together with the lipochitooligosaccharide degradation activity of the recombinant protein hint at a role of Srchi13 in normal nodule ontogeny by limiting the action of Nod factors.
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patterns of enod40 gene expression in stem borne nodules of Sesbania rostrata
Plant Molecular Biology, 1998Co-Authors: Viviana Corich, Sofie Goormachtig, Sam Lievens, M Van Montagu, Marcelle HolstersAbstract:At the base of adventitious root primordia, located on the stem of the tropical legume Sesbania rostrata, nitrogen-fixing nodules are formed upon inoculation with the microsymbiont Azorhizobium caulinodans. This pattern of nodule development presents features of indeterminate and determinate nodules in early and later stages, respectively. A S. rostrata cDNA clone homologous to early nodulin ENOD40 genes was isolated from a cDNA library of developing stem nodules. SrENOD40-1 contained the conserved regions I and II of other ENOD40 genes. By reverse transcriptase PCR, enhanced SrENOD40-1 expression was observed in the adventitious root primordia between 4 and 8 h after inoculation with A. caulinodans. In situ hybridization showed that SrENOD40-1 transcripts, present around the central vascular bundle of the uninfected root primordia, were strongly enhanced upon induction of nodule development. De novo SrENOD40-1 expression was observed in the initiating and growing nodule primordia and around vascular bundles. When cell type specification sets in, the expression became pronounced in cells derived from the meristematic regions. In other parts of the plant, weak SrENOD40-1 expression was associated with vascular bundles and was observed in leaf and stipule primordia.
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the early nodulin gene enod2 shows different expression patterns during Sesbania rostrata stem nodule development
Molecular Plant-microbe Interactions, 1998Co-Authors: Sofie Goormachtig, M Van Montagu, Marcelle HolstersAbstract:During nodule development on stems of Sesbania rostrata, the ENOD2 gene was expressed in the nodule parenchyma and in outer cortical cells. The latter; novel expression pattern was low in uninfected nodulation sites, strongly enhanced 1 day after infection, and correlated with young peridermal cells at later stages. The induction of both ENOD2 transcript accumulation patterns was dependent on Nod factor-producing bacteria.
Zhongyi Yang - One of the best experts on this subject based on the ideXlab platform.
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characterization of the Sesbania rostrata phytochelatin synthase gene alternative splicing and function of four isoforms
International Journal of Molecular Sciences, 2009Co-Authors: Anming Li, Fuhua Chen, Zhongyi Yang, Jiangang Yuan, Bingyun Yu, Junchao Huang, Zengfu XuAbstract:Phytochelatins (PCs) play an important role in detoxification of heavy metals in plants. PCs are synthesized from glutathione by phytochelatin synthase (PCS), a dipeptidyltransferase. Sesbania rostrata is a tropical legume plant that can tolerate high concentrations of Cd and Zn. In this study, the S. rostrata PCS gene (SrPCS) and cDNAs were isolated and characterized. Southern blot and sequence analysis revealed that a single copy of the SrPCS gene occurs in the S. rostrata genome, and produces four different SrPCS mRNAs and proteins, SrPCS1-SrPCS4, by alternative splicing of the SrPCS pre-mRNA. The SrPCS1 and SrPCS3 proteins conferred Cd tolerance when expressed in yeast cells, whereas the SrPCS2 and SrPCS4 proteins, which lack the catalytic triad and the N-terminal domains, did not. These results suggested that SrPCS1 and SrPCS3 have potential applications in genetic engineering of plants for enhancing heavy metal tolerance and phytoremediation of contaminated soils.
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cadmium and copper uptake and accumulation by Sesbania rostrata seedling a n fixing annual plant implications for the mechanism of heavy metal tolerance
Frontiers of Biology in China, 2009Co-Authors: Fuhua Chen, Wei Fang, Zhongyi Yang, Jiangang YuanAbstract:Sesbania rostrata, an annual tropical legume, has been found to be tolerant to heavy metals, with an unknown mechanism. It is a promising candidate species for revegetation at mine tailings. In this study, sequential extractions with five buffers and strong acids were used to extract various chemical forms of cadmium and copper in S. rostrata, with or without Cd or Cu treatments, so that the mechanisms of tolerance and detoxification could be inferred. Both metals had low transition rates from roots to the aboveground of S. rostrata. The transition ratio of Cd (4.00%) was higher than that of Cu (1.46%). The proportion of NaCl extracted Cd (mostly in protein-binding forms) increased drastically in Cd treated plants from being undetectable in untreated plants. This suggests that Cd induced biochemical processes producing protein-like phytochelatins that served as a major mechanism for the high Cd tolerance of S. rostrata. The case for Cu was quite different, indicating that the mechanism for metal tolerance in S. rostrata is metal-specific. The proportion of water-insoluble Cu (e.g. oxalate and phosphate) in roots increased significantly with Cu treatment, which partially explains the tolerance of S. rostrata to Cu. However, how S. rostrata copes with the high biotic activity of inorganic salts of Cu, which increased in all parts of the plant under Cu stress, is a question for future studies. Sesbania rostrata is among the very few N-fixing plants tolerant to heavy metals. This study provides evidence for the detoxification mechanism of metals in Sesbania rostrata.
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enhanced adaptability of Sesbania rostrata to pb zn tailings via stem nodulation
Journal of Environmental Sciences-china, 2009Co-Authors: Shuguang Jian, Weijun Shen, Zhongyi YangAbstract:Sesbania rostrata is wellknown for its stem nodulation, but the roles of stem nodulation in root nodulation and adaptation of S. rostrata to Pb/Zn-enriched tailings environment has been poorly understood. We investigated the effects of inoculating (with stem nodule treatment) and non-inoculating (without stem nodule treatment) Azorhizobium caulinodans on the growth, root nodulation, and N fixation of S. rostrata grown on three different types of soil substrata: Pb/Zn tailings, garden soil amended tailings, and garden soil. The results showed that plant height, stem basal diameter, biomass, chlorophyll content, nitrogen content and N-accumulation per plant were 2.3%–4.9%, 2.2%–7.7%, 27.8%–72.2%, 17.1%–23.5%, 12.3%–34.2%, and 43.1%–131.2%, respectively, higher in treatments with stem nodule than those without stem nodule for the same soil substrate. With respect to soil substrata, all measurements had consistently higher values in tailings than in amended tailings and garden soil, indicating that the poorer the soil condition, the greater the contribution of stem nodule. In contrast, the number and fresh weight of root nodules on plants without stem nodule were 6.9–11.6 times and 5.8–29.0 times higher than those with stem nodule, respectively, especially with respect to the plants grew on Pb/Zn tailings. In general, stem nodulation favored plant growth and nitrogen fixation of S. rostrata, but suppressed root nodulation. With the ability of stem and root nodulation, S. rostrata can be used as a pioneer plant species for remediation of Pb/Zn tailings.
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responses of Sesbania rostrata and s cannabina to pb zn cu and cd toxi cities
Journal of Environmental Sciences-china, 2004Co-Authors: Zhongyi Yang, Fuhua Chen, Jiangang Yuan, Zhengwei Zheng, Minghung WongAbstract:Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities were assessed by a seed-suspending seedbed(SSS) approach. The results showed that the SSS approach was suitable for testing the tolerance of a plant to the stress of toxic metals. The endpoints include seed germination success, straightened radicle and hypocotyl of the seedlings from the seeds. The measurements could be done easily and accurately. It was found that the elongation of radicle was the most sensitive indicator to the stress of heavy metals among the endpoints. When exposure to lower or medium concentrations of Pb, Zn, and Cd, the development of the lateral roots were favorable. Species of S. rostrata was more tolerant than S. cannabina to the heavy metals, especially to Zn and Cd. The ED 50 of Pb, Zn, Cu and Cd were 32.90, 5.32, 4.40 and 12.00 μg/ml for S. rostrata, respectively, and they were 30.11, 2.87, 4.05 and 4.94 μg/ml respectively for S. cannabina.
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an investigation for heavy metal tolerances of root stem and leaf of Sesbania rostrata by using callus suspension culture method
Acta Scientiarum Naturalium Universitatis Sunyatseni, 2001Co-Authors: Haojuan Xu, Jiabin Xi, Zhongyi YangAbstract:Heavy metal tolerances of root, stem and leaf of Sesbania rostrata were investigated by using callus suspension culture method The results showed that the method was effective for testing the heavy metal tolerance of respective root, stem and leaf of S rostrata. The highest tolerances to Pb, Zn, Cu and Cd were observed in the root callus The tolerances in leaf callus were only 1/8～1/4 of that in root callus. ED\-\{50\}s of Pb for growth of root, stem and leaf callus were 80, 40 and 15 mg/L, respectively Those of Zn, Cu and Cd were 80, 30 and 10 mg/L, 20, 8 and 4 mg/L, and 15, 8 and 6 mg/L, respectively.