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Verônica De Castro Leal; Naiara Ferreira Oliveira; Ricardo Argenton Ramos; Igor Juliano Da Silva Souza; Mário Carvalho; Paulo Ivan Fernandes Júnior; Clarisse Brígido; Lindete Miria Vieira Martins. A INFLUÊNCIA DA SALINIDADE NA SIMBIOSE DE MICRORGANISMOS BENÉFICOS: O CASO DO FEIJÃO CAUPI. Agroecologia: Métodos e Técnicas para uma Agricultura Sustentável - Volume 3 2021, 181 -192.
AMA StyleVerônica De Castro Leal, Naiara Ferreira Oliveira, Ricardo Argenton Ramos, Igor Juliano Da Silva Souza, Mário Carvalho, Paulo Ivan Fernandes Júnior, Clarisse Brígido, Lindete Miria Vieira Martins. A INFLUÊNCIA DA SALINIDADE NA SIMBIOSE DE MICRORGANISMOS BENÉFICOS: O CASO DO FEIJÃO CAUPI. Agroecologia: Métodos e Técnicas para uma Agricultura Sustentável - Volume 3. 2021; ():181-192.
Chicago/Turabian StyleVerônica De Castro Leal; Naiara Ferreira Oliveira; Ricardo Argenton Ramos; Igor Juliano Da Silva Souza; Mário Carvalho; Paulo Ivan Fernandes Júnior; Clarisse Brígido; Lindete Miria Vieira Martins. 2021. "A INFLUÊNCIA DA SALINIDADE NA SIMBIOSE DE MICRORGANISMOS BENÉFICOS: O CASO DO FEIJÃO CAUPI." Agroecologia: Métodos e Técnicas para uma Agricultura Sustentável - Volume 3 , no. : 181-192.
Manganese (Mn) toxicity is a very common soil stress around the world, which is responsible for low soil fertility. This manuscript evaluates the effect of the endophytic bacterium Pseudomonas sp. Q1 on different rhizobial-legume symbioses in the absence and presence of Mn toxicity. Three legume species, Cicer arietinum (chickpea), Trifolium subterraneum (subterranean clover), and Medicago polymorpha (burr medic) were used. To evaluate the role of 1-aminocyclopropane-1-carboxylate (ACC) deaminase produced by strain Q1 in these interactions, an ACC deaminase knockout mutant of this strain was constructed and used in those trials. The Q1 strain only promoted the symbiotic performance of Rhizobium leguminosarum bv. trifolii ATCC 14480T and Ensifer meliloti ATCC 9930T, leading to an increase of the growth of their hosts in both conditions. Notably, the acdS gene disruption of strain Q1 abolished the beneficial effect of this bacterium as well as causing this mutant strain to act deleteriously in those specific symbioses. This study suggests that the addition of non-rhizobia with functional ACC deaminase may be a strategy to improve the pasture legume–rhizobial symbioses, particularly when the use of rhizobial strains alone does not yield the expected results due to their difficulty in competing with native strains or in adapting to inhibitory soil conditions.
Ana Paço; José Rodrigo Da-Silva; Denise Pereira Torres; Bernard R. Glick; Clarisse Brígido. Exogenous ACC Deaminase Is Key to Improving the Performance of Pasture Legume-Rhizobial Symbioses in the Presence of a High Manganese Concentration. Plants 2020, 9, 1630 .
AMA StyleAna Paço, José Rodrigo Da-Silva, Denise Pereira Torres, Bernard R. Glick, Clarisse Brígido. Exogenous ACC Deaminase Is Key to Improving the Performance of Pasture Legume-Rhizobial Symbioses in the Presence of a High Manganese Concentration. Plants. 2020; 9 (12):1630.
Chicago/Turabian StyleAna Paço; José Rodrigo Da-Silva; Denise Pereira Torres; Bernard R. Glick; Clarisse Brígido. 2020. "Exogenous ACC Deaminase Is Key to Improving the Performance of Pasture Legume-Rhizobial Symbioses in the Presence of a High Manganese Concentration." Plants 9, no. 12: 1630.
Bacterial endophytes, a subset of a plant’s microbiota, can facilitate plant growth by a number of different mechanisms. The aims of this study were to assess the diversity and functionality of endophytic bacterial strains from internal root tissues of native legume species grown in two distinct sites in South of Portugal and to evaluate their ability to promote plant growth. Here, 122 endophytic bacterial isolates were obtained from 12 different native legume species. Most of these bacteria possess at least one of the plant growth-promoting features tested in vitro, with indole acetic acid production being the most common feature among the isolates followed by the production of siderophores and inorganic phosphate solubilization. The results of in planta experiments revealed that co-inoculation of chickpea plants with specific endophytic bacteria along with N2-fixing symbionts significantly improved the total biomass of chickpea plants, in particular when these plants were grown under saline conditions. Altogether, this study revealed that Mediterranean native legume species are a reservoir of plant growth-promoting bacteria, that are also tolerant to salinity and to toxic levels of Mn. Thus, these bacterial endophytes are well adapted to common constraints present in soils of this region which constitutes important factors to consider in the development of bacterial inoculants for stressful conditions in the Mediterranean region.
Clarisse Brígido; Esther Menéndez; Ana Paço; Bernard R. Glick; Anabela Belo; Maria R. Félix; Solange Oliveira; Mário Carvalho. Mediterranean Native Leguminous Plants: A Reservoir of Endophytic Bacteria with Potential to Enhance Chickpea Growth under Stress Conditions. Microorganisms 2019, 7, 392 .
AMA StyleClarisse Brígido, Esther Menéndez, Ana Paço, Bernard R. Glick, Anabela Belo, Maria R. Félix, Solange Oliveira, Mário Carvalho. Mediterranean Native Leguminous Plants: A Reservoir of Endophytic Bacteria with Potential to Enhance Chickpea Growth under Stress Conditions. Microorganisms. 2019; 7 (10):392.
Chicago/Turabian StyleClarisse Brígido; Esther Menéndez; Ana Paço; Bernard R. Glick; Anabela Belo; Maria R. Félix; Solange Oliveira; Mário Carvalho. 2019. "Mediterranean Native Leguminous Plants: A Reservoir of Endophytic Bacteria with Potential to Enhance Chickpea Growth under Stress Conditions." Microorganisms 7, no. 10: 392.
The aims of this study were to isolate, identify and characterize culturable endophytic bacteria from chickpea (Cicer arietinum L.) roots grown in different soils. In addition, the effects of rhizobial inoculation, soil and stress on the functionality of those culturable endophytic bacterial communities were also investigated. Phylogenetic analysis based on partial 16S rRNA gene sequences revealed that the endophytic bacteria isolated in this work belong to the phyla Proteobacteria, Firmicutes and Actinobacteria, with Enterobacter and Pseudomonas being the most frequently observed genera. Production of indoleacetic acid and ammonia were the most widespread plant growth-promoting features, while antifungal activity was relatively rare among the isolates. Despite the fact that the majority of bacterial endophytes were salt- and Mn-tolerant, the isolates obtained from soil with Mn toxicity were generally more Mn-tolerant than those obtained from the same soil amended with dolomitic limestone. Several associations between an isolate’s genus and specific plant growth-promoting mechanisms were observed. The data suggest that soil strongly impacts the Mn tolerance of endophytic bacterial communities present in chickpea roots while rhizobial inoculation induces significant changes in terms of isolates’ plant growth-promoting abilities. In addition, this study also revealed chickpea-associated endophytic bacteria that could be exploited as sources with potential application in agriculture.
Clarisse Brígido; Sakshi Singh; Esther Menéndez; Maria J. Tavares; Bernard R. Glick; Maria Do Rosário Félix; Solange Oliveira; Mário Carvalho. Diversity and Functionality of Culturable Endophytic Bacterial Communities in Chickpea Plants. Plants 2019, 8, 42 .
AMA StyleClarisse Brígido, Sakshi Singh, Esther Menéndez, Maria J. Tavares, Bernard R. Glick, Maria Do Rosário Félix, Solange Oliveira, Mário Carvalho. Diversity and Functionality of Culturable Endophytic Bacterial Communities in Chickpea Plants. Plants. 2019; 8 (2):42.
Chicago/Turabian StyleClarisse Brígido; Sakshi Singh; Esther Menéndez; Maria J. Tavares; Bernard R. Glick; Maria Do Rosário Félix; Solange Oliveira; Mário Carvalho. 2019. "Diversity and Functionality of Culturable Endophytic Bacterial Communities in Chickpea Plants." Plants 8, no. 2: 42.
Evidences for an involvement of the bacterial type IV secretion system (T4SS) in the symbiotic relationship between rhizobia and legumes have been pointed out by several recent studies. However, information regarding this secretion system in Mesorhizobium is still very scarce. The aim of the present study was to investigate the phylogeny and expression of the traG gene, which encodes a substrate receptor of the T4SS. In addition, the occurrence and genomic context of this and other T4SS genes, namely, genes from tra/trb and virB/virD4 complexes, were also analyzed in order to unveil the structural and functional organization of T4SS in mesorhizobia. The location of the T4SS genes in the symbiotic region of the analyzed rhizobial genomes, along with the traG phylogeny, suggests that T4SS genes could be horizontally transferred together with the symbiosis genes. Regarding the T4SS structural organization in Mesorhizobium, the virB/virD4 genes were absent in all chickpea (Cicer arietinum L.) microsymbionts and in the Lotus symbiont Mesorhizobium japonicum MAFF303099T. Interestingly, the presence of genes belonging to another secretion system (T3SS) was restricted to these strains lacking the virB/virD4 genes. The traG gene expression was detected in M. mediterraneum Ca36T and M. ciceri LMS-1 strains when exposed to chickpea root exudates and also in the early nodules formed by M. mediterraneum Ca36T, but not in older nodules. This study contributes to a better understanding of the importance of T4SS in mutualistic symbiotic bacteria.
A. Paço; J. R. Da-Silva; F. Eliziário; C. Brígido; S. Oliveira; A. Alexandre. traG Gene Is Conserved across Mesorhizobium spp. Able to Nodulate the Same Host Plant and Expressed in Response to Root Exudates. BioMed Research International 2019, 2019, 1 -13.
AMA StyleA. Paço, J. R. Da-Silva, F. Eliziário, C. Brígido, S. Oliveira, A. Alexandre. traG Gene Is Conserved across Mesorhizobium spp. Able to Nodulate the Same Host Plant and Expressed in Response to Root Exudates. BioMed Research International. 2019; 2019 ():1-13.
Chicago/Turabian StyleA. Paço; J. R. Da-Silva; F. Eliziário; C. Brígido; S. Oliveira; A. Alexandre. 2019. "traG Gene Is Conserved across Mesorhizobium spp. Able to Nodulate the Same Host Plant and Expressed in Response to Root Exudates." BioMed Research International 2019, no. : 1-13.
The symbiosis established between arbuscular mycorrhizal fungi (AMF) and roots of most land plants plays a key role in plant nutrient acquisition and alleviation of environmental stresses. Despite the ubiquity of the symbiosis, AMF and host species display significant specificity in their interactions. To clarify preferential associations between wheat (Triticum aestivum) and AMF, we characterized root AMF communities in the transition from two first host species, ryegrass (Lolium rigidum) and yellow-serradella (Ornithopus compressus), grown separately or together, to a second host (wheat), by sequencing the large subunit ribosomal DNA (LSU rDNA) gene. The response of AMF communities in wheat to prior soil disturbance – and consequently of the mycelial network [intact extraradical mycelium (ERM) vs. disrupted mycelium] established with either of the first hosts – was also investigated. Since the outcome of a specific host–symbiont interaction depends on the molecular responses of the host plant upon microbial colonization, we studied the expression of six key symbiosis-related genes in wheat roots. AMF communities on L. rigidum and O. compressus roots were clearly distinct. Within an undisturbed ERM, wheat AMF communities were similar to that of previous host, and O. compressus-wheat-AMF interactions supported a greater growth of wheat than L. rigidum-wheat-AMF interactions. This effect declined when ERM was disrupted, but generated a greater activation of symbiotic genes in wheat, indicating that plant symbiotic program depends on some extent on the colonizing symbiont propagule type. When a mixture of L. rigidum and O. compressus was planted, the wheat colonization pattern resembled that of O. compressus, although this was not reflected in a greater growth. These results show a lasting effect of previous hosts in shaping wheat AMF communities through an efficient use of the established ERM, although not completely obliterating host–symbiont specificity.
Catarina Campos; Mário Carvalho; Clarisse Brígido; Michael J. Goss; Tania Nobre. Symbiosis Specificity of the Preceding Host Plant Can Dominate but Not Obliterate the Association Between Wheat and Its Arbuscular Mycorrhizal Fungal Partners. Frontiers in Microbiology 2018, 9, 2920 .
AMA StyleCatarina Campos, Mário Carvalho, Clarisse Brígido, Michael J. Goss, Tania Nobre. Symbiosis Specificity of the Preceding Host Plant Can Dominate but Not Obliterate the Association Between Wheat and Its Arbuscular Mycorrhizal Fungal Partners. Frontiers in Microbiology. 2018; 9 ():2920.
Chicago/Turabian StyleCatarina Campos; Mário Carvalho; Clarisse Brígido; Michael J. Goss; Tania Nobre. 2018. "Symbiosis Specificity of the Preceding Host Plant Can Dominate but Not Obliterate the Association Between Wheat and Its Arbuscular Mycorrhizal Fungal Partners." Frontiers in Microbiology 9, no. : 2920.
Intentional use of arbuscular mycorrhizal fungi (AMF) in cropping systems has been marginal, owing to the high cost and limited biodiversity of commercial inocula, together with the timeliness of colonization to achieve benefits. Additionally, mycorrhiza are considered incompatible with high input cropping systems. Combining results from 4 different experiments resulted in a strategy for the earlier and faster colonization by AMF, through an extensive extraradical mycelium (ERM) acting as a preferential source of inoculum if kept intact by the adoption of appropriate tillage techniques. Selection of host plants on which the ERM develops, provides the tool to manage AMF functional diversity. This strategy resulted in protection of sensitive crop species against biotic and abiotic stresses and can be implemented in low- and high-input cropping systems. Under Mn toxicity arbuscular colonization increased 2.6-fold and shoot dry weight 2.3-fold. In presence of Fusarium, arbuscular colonization increased 2.1-fold and shoot dry weight 1.5-fold.
Isabel Brito; M.J. Goss; L. Alho; Clarisse Brigido; D. van Tuinen; Maria Felix; M. Carvalho. Agronomic management of AMF functional diversity to overcome biotic and abiotic stresses - The role of plant sequence and intact extraradical mycelium. Fungal Ecology 2018, 40, 72 -81.
AMA StyleIsabel Brito, M.J. Goss, L. Alho, Clarisse Brigido, D. van Tuinen, Maria Felix, M. Carvalho. Agronomic management of AMF functional diversity to overcome biotic and abiotic stresses - The role of plant sequence and intact extraradical mycelium. Fungal Ecology. 2018; 40 ():72-81.
Chicago/Turabian StyleIsabel Brito; M.J. Goss; L. Alho; Clarisse Brigido; D. van Tuinen; Maria Felix; M. Carvalho. 2018. "Agronomic management of AMF functional diversity to overcome biotic and abiotic stresses - The role of plant sequence and intact extraradical mycelium." Fungal Ecology 40, no. : 72-81.
As functional diversity influences the benefits conferred on host plants by arbuscular mycorrhizal fungi (AMF) and large scale commercial inoculation is currently impracticable, strategies are required to manage communities of indigenous AMF associated with different hosts within agricultural cropping systems. In a non-sterilized soil, using 454 pyrosequencing of the LSU-D2 rDNA gene, host plant AMF diversity was assessed following successions of different plant species, grown with or without prior soil disturbance. Diversity present in the roots of two species of the Fabaceae (Ornithopus compressus and Trifolium subterraneum) was compared with those of two species of Poaceae (Lolium rigidum and Triticum aestivum). When spores and colonised root fragments formed were the main propagules source (disturbed soil), the communities of AMF present in the two legumes were clearly different from those of the two members of the Poaceae but were similar for plants within each family, consistent with there being preferential symbioses existing within an AMF population for host classes. Significantly, wheat grown in undisturbed soil immediately after the legume O. compressus acquired a mycorrhizal fungal community closely related to that of the previous host plant, and different to that found when the soil was disturbed or not cropped prior to the growth of the wheat. Parallel effects were seen in the succession from L rigidum to T subterraneum, indicating that these effects are not unique to the legume wheat sequence. These results also suggest that, under no-till cropping, selected cover crops or crops in rotation could help build mycorrhizal communities that function throughout a sequence of several main crops.
Clarisse Brígido; Diederik van Tuinen; Isabel Brito; Luís Alho; Michael J. Goss; Mário Carvalho. Management of the biological diversity of AM fungi by combination of host plant succession and integrity of extraradical mycelium. Soil Biology and Biochemistry 2017, 112, 237 -247.
AMA StyleClarisse Brígido, Diederik van Tuinen, Isabel Brito, Luís Alho, Michael J. Goss, Mário Carvalho. Management of the biological diversity of AM fungi by combination of host plant succession and integrity of extraradical mycelium. Soil Biology and Biochemistry. 2017; 112 ():237-247.
Chicago/Turabian StyleClarisse Brígido; Diederik van Tuinen; Isabel Brito; Luís Alho; Michael J. Goss; Mário Carvalho. 2017. "Management of the biological diversity of AM fungi by combination of host plant succession and integrity of extraradical mycelium." Soil Biology and Biochemistry 112, no. : 237-247.
Michael J. Goss; Mário Carvalho; Isabel Brito; Clarisse Brígido. Diversity in Arbuscular Mycorrhizal Fungi * *With Clarisse Brígido. Functional Diversity of Mycorrhiza and Sustainable Agriculture 2017, 59 -79.
AMA StyleMichael J. Goss, Mário Carvalho, Isabel Brito, Clarisse Brígido. Diversity in Arbuscular Mycorrhizal Fungi * *With Clarisse Brígido. Functional Diversity of Mycorrhiza and Sustainable Agriculture. 2017; ():59-79.
Chicago/Turabian StyleMichael J. Goss; Mário Carvalho; Isabel Brito; Clarisse Brígido. 2017. "Diversity in Arbuscular Mycorrhizal Fungi * *With Clarisse Brígido." Functional Diversity of Mycorrhiza and Sustainable Agriculture , no. : 59-79.
Rhizobia are soil bacteria able to form symbioses with legumes and fix atmospheric nitrogen, converting it into a form that can be assimilated by the plant. The biological nitrogen fixation is a possible strategy to reduce the environmental pollution caused by the use of chemical N-fertilizers in agricultural fields. Successful colonization of the host root by free-living rhizobia requires that these bacteria are able to deal with adverse conditions in the soil, in addition to stresses that may occur in their endosymbiotic life inside the root nodules. Stress response genes, such as otsAB, groEL, clpB, rpoH play an important role in tolerance of free-living rhizobia to different environmental conditions and some of these genes have been shown to be involved in the symbiosis. This review will focus on stress response genes that have been reported to improve the symbiotic performance of rhizobia with their host plants. For example, chickpea plants inoculated with a Mesorhizobium strain modified with extra copies of the groEL gene showed a symbiotic effectiveness approximately 1.5 fold higher than plants inoculated with the wild-type strain. Despite these promising results, more studies are required to obtain highly efficient and tolerant rhizobia strains, suitable for different edaphoclimatic conditions, to be used as field inoculants.
José Rodrigo Da-Silva; Ana Alexandre; Clarisse Brígido; Solange Oliveira. Can stress response genes be used to improve the symbiotic performance of rhizobia? AIMS Microbiology 2017, 3, 365 -382.
AMA StyleJosé Rodrigo Da-Silva, Ana Alexandre, Clarisse Brígido, Solange Oliveira. Can stress response genes be used to improve the symbiotic performance of rhizobia? AIMS Microbiology. 2017; 3 (3):365-382.
Chicago/Turabian StyleJosé Rodrigo Da-Silva; Ana Alexandre; Clarisse Brígido; Solange Oliveira. 2017. "Can stress response genes be used to improve the symbiotic performance of rhizobia?" AIMS Microbiology 3, no. 3: 365-382.
Rhizobia may possess other plant growth-promoting mechanisms besides nitrogen fixation. These mechanisms and the tolerance to different environmental factors, such as metals, may contribute to the use of rhizobia inocula to establish a successful legume-rhizobia symbiosis. Our goal was to characterize a collection of native Portuguese chickpea Mesorhizobium isolates in terms of plant growth-promoting (PGP) traits and tolerance to different metals as well as to investigate whether these characteristics are related to the biogeography of the isolates. The occurrence of six PGP mechanisms and tolerance to five metals were evaluated in 61 chickpea Mesorhizobium isolates previously obtained from distinct provinces in Portugal and assigned to different species clusters. Chickpea microsymbionts show high diversity in terms of PGP traits as well as in their ability to tolerate different metals. All isolates synthesized indoleacetic acid, 50 isolates produced siderophores, 19 isolates solubilized phosphate, 12 isolates displayed acid phosphatase activity, and 22 exhibited cytokinin activity. Most isolates tolerated Zn or Pb but not Ni, Co, or Cu. Several associations between specific PGP mechanisms and the province of origin and species clusters of the isolates were found. Our data suggests that the isolate’s tolerance to metals and ability to solubilize inorganic phosphate and to produce IAA may be responsible for the persistence and distribution of the native Portuguese chickpea Mesorhizobium species. Furthermore, this study revealed several chickpea microsymbionts with potential as PGP rhizobacteria as well as for utilization in phytoremediation strategies.
Clarisse Brigido; Bernard R. Glick; Solange Oliveira. Survey of Plant Growth-Promoting Mechanisms in Native Portuguese Chickpea Mesorhizobium Isolates. Microbial Ecology 2016, 73, 900 -915.
AMA StyleClarisse Brigido, Bernard R. Glick, Solange Oliveira. Survey of Plant Growth-Promoting Mechanisms in Native Portuguese Chickpea Mesorhizobium Isolates. Microbial Ecology. 2016; 73 (4):900-915.
Chicago/Turabian StyleClarisse Brigido; Bernard R. Glick; Solange Oliveira. 2016. "Survey of Plant Growth-Promoting Mechanisms in Native Portuguese Chickpea Mesorhizobium Isolates." Microbial Ecology 73, no. 4: 900-915.
Symbiotic rhizobia-legumes associations are extremely important in terms of sustainable agricultural practices. This symbiosis involves a complex interaction between both partners, plant and bacterium, for bacterial infection and the formation of symbiotic N-fixing nodules. In this regard, the phytohormone ethylene plays a significant role in nodule formation, acting as an inhibitor of the nodulation process. Ethylene not only regulates nodule development but also regulates many other plant developmental cues, including various stress responses that inhibit overall plant growth. Some rhizobia produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, thus, being able to decrease ACC and, consequently, decrease deleterious ethylene levels that affect the nodulation process. This occurs because ACC is the immediate precursor of ethylene in all higher plants. Hence, rhizobia that express this enzyme have an increased symbiotic potential. In addition to the direct role that ACC deaminase plays in the nodulation processper se, in a limited number of instances, ACC deaminase can also modulate nodule persistence. This review focuses on the important role of rhizobial ACC deaminase during the nodulation process, emphasizing its significance to legume growth promotion.
Francisco X. Nascimento; Clarisse Brígido; Bernard R. Glick; Márcio J. Rossi. The Role of Rhizobial ACC Deaminase in the Nodulation Process of Leguminous Plants. International Journal of Agronomy 2016, 2016, 1 -9.
AMA StyleFrancisco X. Nascimento, Clarisse Brígido, Bernard R. Glick, Márcio J. Rossi. The Role of Rhizobial ACC Deaminase in the Nodulation Process of Leguminous Plants. International Journal of Agronomy. 2016; 2016 ():1-9.
Chicago/Turabian StyleFrancisco X. Nascimento; Clarisse Brígido; Bernard R. Glick; Márcio J. Rossi. 2016. "The Role of Rhizobial ACC Deaminase in the Nodulation Process of Leguminous Plants." International Journal of Agronomy 2016, no. : 1-9.
The ClpB chaperone is known to be involved in bacterial stress response. Moreover, recent studies suggest that this protein has also a role in the chickpea-rhizobia symbiosis. In order to improve both stress tolerance and symbiotic performance of a chickpea microsymbiont, the Mesorhizobium mediterraneum UPM-Ca36T strain was genetically transformed with pPHU231 containing an extra-copy of the clpB gene. To investigate if the clpB-transformed strain displays an improved stress tolerance, bacterial growth was evaluated under heat and acid stress conditions. In addition, the effect of the extra-copies of the clpB gene in the symbiotic performance was evaluated using plant growth assays (hydroponic and pot trials). The clpB-transformed strain is more tolerant to heat shock than the strain transformed with pPHU231, supporting the involvement of ClpB in rhizobia heat shock tolerance. Both plant growth assays showed that ClpB has an important role in chickpea-rhizobia symbiosis. The nodulation kinetics analysis showed a higher rate of nodule appearance with the clpB-transformed strain. This strain also induced a greater number of nodules and, more notably, its symbiotic effectiveness increased ~60% at pH5 and 83% at pH7, compared to the wild-type strain. Furthermore, a higher frequency of root hair curling was also observed in plants inoculated with the clpB-transformed strain, compared to the wild-type strain. The superior root hair curling induction, nodulation ability and symbiotic effectiveness of the clpB-transformed strain may be explained by an increased expression of symbiosis genes. Indeed, higher transcript levels of the nodulation genes nodA and nodC (~3 folds) were detected in the clpB-transformed strain. The improvement of rhizobia by addition of extra-copies of the clpB gene may be a promising strategy to obtain strains with enhanced stress tolerance and symbiotic effectiveness, thus contributing to their success as crop inoculants, particularly under environmental stresses. This is the first report on the successful improvement of a rhizobium with a chaperone gene.
Ana Paço; Clarisse Brígido; Ana Alexandre; Pedro Mateos; Solange Oliveira. The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene. PLOS ONE 2016, 11, e0148221 .
AMA StyleAna Paço, Clarisse Brígido, Ana Alexandre, Pedro Mateos, Solange Oliveira. The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene. PLOS ONE. 2016; 11 (2):e0148221.
Chicago/Turabian StyleAna Paço; Clarisse Brígido; Ana Alexandre; Pedro Mateos; Solange Oliveira. 2016. "The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene." PLOS ONE 11, no. 2: e0148221.
The use of plants to clean up polluted sites, named phytoremediation, is an attractive methodology for the cleanup of metals and other soil contaminants. While some plants can hyperaccumulate metals from the environment or break down diverse organic contaminants, they typically do not produce a large amount of biomass, and many other plants are unable to grow under such conditions. Legumes are well known for their importance as both animal and human foods and for their role in maintaining soil fertility; they are also of great interest in sustainable agricultural systems. In this context, the use of rhizobia that form a symbiotic relationship with legumes to increase the productivity and yield of legume plants in metal-contaminated soils is a promising approach to metal phytoremediation. Thus, selection of particular rhizobial strains with some degree of tolerance to metals and possessing various plant growth-promoting activities is imperative. Recent studies have indicated that metal-resistant rhizobia possessing plant growth-promoting traits, including nitrogen fixation, phosphorus solubilization, phytohormone synthesis, siderophore production and release, and synthesis of ACC deaminase may facilitate legume growth while lessening metal toxicity. This chapter discusses the possible application of rhizobia, as symbiotic nitrogen fixers and plant growth-promoting bacteria, which may improve the productivity and yield of legumes in metal-contaminated soils.
Clarisse Brígido; Bernard R. Glick. Phytoremediation Using Rhizobia. Phytoremediation 2015, 95 -114.
AMA StyleClarisse Brígido, Bernard R. Glick. Phytoremediation Using Rhizobia. Phytoremediation. 2015; ():95-114.
Chicago/Turabian StyleClarisse Brígido; Bernard R. Glick. 2015. "Phytoremediation Using Rhizobia." Phytoremediation , no. : 95-114.
The lowering of plant ethylene levels by the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase is one of the key mechanisms employed by plant growth-promoting bacteria (PGPB) to facilitate plant growth. Since its discovery, it has been detected in both fungi and bacteria. It has been shown by a large number of workers in a wide range of bacteria that the activity of this enzyme in PGPB is important during normal plant development and also protects plants from the deleterious effects of a wide range of environmental stresses. ACC deaminase-containing PGPB bound to a plant act as a sink for ACC, thereby lowering ethylene levels in plant tissues. The result of the functioning of this enzyme is an increase in the growth of plant roots and shoots and a reduction of the inhibitory effects of ethylene synthesis especially during stressful conditions. This chapter briefly summarizes the current knowledge of various ACC deaminases emphasizing the use of ACC deaminase-containing bacteria in promoting plant growth under diverse biotic and abiotic stresses, and describes methods for the isolation and study of ACC deaminase-containing bacteria.
Clarisse Brígido; Jin Duan; Bernard R. Glick. Methods to Study 1-Aminocyclopropane-1-carboxylate (ACC) Deaminase in Plant Growth-Promoting Bacteria. Handbook for Azospirillum 2015, 287 -305.
AMA StyleClarisse Brígido, Jin Duan, Bernard R. Glick. Methods to Study 1-Aminocyclopropane-1-carboxylate (ACC) Deaminase in Plant Growth-Promoting Bacteria. Handbook for Azospirillum. 2015; ():287-305.
Chicago/Turabian StyleClarisse Brígido; Jin Duan; Bernard R. Glick. 2015. "Methods to Study 1-Aminocyclopropane-1-carboxylate (ACC) Deaminase in Plant Growth-Promoting Bacteria." Handbook for Azospirillum , no. : 287-305.
Our goal was to study the symbiotic performance of two Mesorhizobium ciceri strains, transformed with an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene (acdS), in chickpea plants under salinity stress. The EE-7 (salt-sensitive) and G-55 (salt-tolerant) M. ciceri strains were transformed with an acdS gene present on plasmid pRKACC. Salinity significantly reduced the overall growth of plants inoculated with either wild-type strains. Although the growth of plants inoculated with either salt-sensitive or salt-tolerant strain was reduced under salinity, the salt-tolerant strain showed a higher ability to nodulate chickpea under salt stress compared with the salt-sensitive strain. The shoot dry weight was significantly higher in plants inoculated with the acdS-transformed salt-sensitive strain compared with the plants inoculated with the native strain in the presence of salt. The negative effects of salt stress were also reduced in nodulation when using acdS-transformed strains in comparison with the wild-type strains. Interestingly, by expressing the exogenous acdS gene, the salt-sensitive strain was able to induce nodules in the same extent as the salt-tolerant strain. Although preliminary, these results suggest that genetic modification of a Mesorhizobium strain can improve its symbiotic performance under salt stress and indicate that ACC deaminase can play an important role in facilitating plant–rhizobium interaction under salinity conditions.
Clarisse Brigido; Francisco X. Nascimento; Jin Duan; Bernard R. Glick; Solange Oliveira. Expression of an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene inMesorhizobiumspp. reduces the negative effects of salt stress in chickpea. FEMS Microbiology Letters 2013, 349, 46 -53.
AMA StyleClarisse Brigido, Francisco X. Nascimento, Jin Duan, Bernard R. Glick, Solange Oliveira. Expression of an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene inMesorhizobiumspp. reduces the negative effects of salt stress in chickpea. FEMS Microbiology Letters. 2013; 349 (1):46-53.
Chicago/Turabian StyleClarisse Brigido; Francisco X. Nascimento; Jin Duan; Bernard R. Glick; Solange Oliveira. 2013. "Expression of an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene inMesorhizobiumspp. reduces the negative effects of salt stress in chickpea." FEMS Microbiology Letters 349, no. 1: 46-53.
Salinity is an important abiotic stress that limits rhizobia-legume symbiosis, affecting plant growth, thus reducing crop productivity. Our aims were to evaluate the tolerance to salinity of native chickpea rhizobia as well as to investigate the expression of chaperone genes groEL, dnaKJ and clpB in both tolerant and sensitive isolates. One hundred and six native chickpea mesorhizobia were screened for salinity tolerance by measuring their growth with 1.5% and 3% NaCl. Most isolates were salt-sensitive, showing a growth below 20% compared to control. An association between salt tolerance and province of origin of the isolates was found. The transcriptional analysis by northern hybridization of chaperone genes was performed using tolerant and sensitive isolates belonging to different Mesorhizobium species. Upon salt shock, most isolates revealed a slight increase in the expression of the dnaK gene, whereas the groESL and clpB expression was unchanged or slightly repressed. No clear relationship was found between the chaperone genes induction and the level of salt tolerance of the isolates. This is the first report on transcriptional analysis of the major chaperones genes in chickpea mesorhizobia under salinity, which may contribute to a better understanding of the mechanisms that influence rhizobia salt tolerance. Copyright 2012 Elsevier GmbH. All rights reserved
Clarisse Brígido; Ana Alexandre; Solange Oliveira. Transcriptional analysis of major chaperone genes in salt-tolerant and salt-sensitive mesorhizobia. Microbiological Research 2012, 167, 623 -629.
AMA StyleClarisse Brígido, Ana Alexandre, Solange Oliveira. Transcriptional analysis of major chaperone genes in salt-tolerant and salt-sensitive mesorhizobia. Microbiological Research. 2012; 167 (10):623-629.
Chicago/Turabian StyleClarisse Brígido; Ana Alexandre; Solange Oliveira. 2012. "Transcriptional analysis of major chaperone genes in salt-tolerant and salt-sensitive mesorhizobia." Microbiological Research 167, no. 10: 623-629.
Several molecular chaperones are known to be involved in bacteria stress response. To investigate the role of chaperone ClpB in rhizobia stress tolerance as well as in the rhizobia-plant symbiosis process, the clpB gene from a chickpea microsymbiont, strain Mesorhizobium ciceri LMS-1, was identified and a knockout mutant was obtained. The ClpB knockout mutant was tested to several abiotic stresses, showing that it was unable to grow after a heat shock and it was more sensitive to acid shock than the wild-type strain. A plant-growth assay performed to evaluate the symbiotic performance of the clpB mutant showed a higher proportion of ineffective root nodules obtained with the mutant than with the wild-type strain. Nodulation kinetics analysis showed a 6- to 8-day delay in nodule appearance in plants inoculated with the ΔclpB mutant. Analysis of nodC gene expression showed lower levels of transcript in the ΔclpB mutant strain. Analysis of histological sections of nodules formed by the clpB mutant showed that most of the nodules presented a low number of bacteroids. No differences in the root infection abilities of green fluorescent protein–tagged clpB mutant and wild-type strains were detected. To our knowledge, this is the first study that presents evidence of the involvement of the chaperone ClpB from rhizobia in the symbiotic nodulation process.
Clarisse Brígido; Marta Robledo; Esther Menendez; Pedro Mateos; Solange Oliveira. A ClpB Chaperone Knockout Mutant of Mesorhizobium ciceri Shows a Delay in the Root Nodulation of Chickpea Plants. Molecular Plant-Microbe Interactions® 2012, 25, 1594 -1604.
AMA StyleClarisse Brígido, Marta Robledo, Esther Menendez, Pedro Mateos, Solange Oliveira. A ClpB Chaperone Knockout Mutant of Mesorhizobium ciceri Shows a Delay in the Root Nodulation of Chickpea Plants. Molecular Plant-Microbe Interactions®. 2012; 25 (12):1594-1604.
Chicago/Turabian StyleClarisse Brígido; Marta Robledo; Esther Menendez; Pedro Mateos; Solange Oliveira. 2012. "A ClpB Chaperone Knockout Mutant of Mesorhizobium ciceri Shows a Delay in the Root Nodulation of Chickpea Plants." Molecular Plant-Microbe Interactions® 25, no. 12: 1594-1604.
Rhizobia strains expressing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase have been reported to display an augmented symbiotic performance as a consequence of lowering the plant ethylene levels that inhibit the nodulation process. Genes encoding ACC deaminase (acdS) have been studied in Rhizobium spp.; however, not much is known about the presence of acdS genes in Mesorhizobium spp. The aim of this study was to assess the prevalence and phylogeny of acdS genes in Mesorhizobium strains including a collection of chickpea-nodulating mesorhizobia from Portugal. ACC deaminase genes were detected in 10 of 12 mesorhizobia type strains as well as in 18 of 18 chickpea Mesorhizobium isolates studied in this work. No ACC deaminase activity was detected in any Mesorhizobium strain tested under free-living conditions. Despite the lack of ACC deaminase activity, it was possible to demonstrate that in Mesorhizobium ciceri UPM-Ca7T, the acdS gene is transcribed under symbiotic conditions. Phylogenetic analysis indicates that strains belonging to different species of Mesorhizobium, but nodulating the same host plant, have similar acdS genes, suggesting that acdS genes are horizontally acquired by transfer of the symbiosis island. This data, together with analysis of the symbiosis islands from completely sequenced Mesorhizobium genomes, suggest the presence of the acdS gene in a Mesorhizobium common ancestor that possessed this gene in a unique symbiosis island.
Francisco X. Nascimento; Clarisse Brigido; Bernard R. Glick; Solange Oliveira. ACC deaminase genes are conserved amongMesorhizobiumspecies able to nodulate the same host plant. FEMS Microbiology Letters 2012, 336, 26 -37.
AMA StyleFrancisco X. Nascimento, Clarisse Brigido, Bernard R. Glick, Solange Oliveira. ACC deaminase genes are conserved amongMesorhizobiumspecies able to nodulate the same host plant. FEMS Microbiology Letters. 2012; 336 (1):26-37.
Chicago/Turabian StyleFrancisco X. Nascimento; Clarisse Brigido; Bernard R. Glick; Solange Oliveira. 2012. "ACC deaminase genes are conserved amongMesorhizobiumspecies able to nodulate the same host plant." FEMS Microbiology Letters 336, no. 1: 26-37.
Our goals were to evaluate the tolerance of mesorhizobia to acid and alkaline conditions as well as to investigate whether acid tolerance is related to the species or the origin site of the isolates. In addition, to investigate the molecular basis of acid tolerance, the expression of chaperone genes groEL and dnaKJ was analyzed using acid-tolerant and sensitive mesorhizobia. Tolerance to pH 5 and 9 was evaluated in liquid medium for 98 Portuguese chickpea mesorhizobia belonging to four species clusters. All isolates showed high sensitivity to pH 9. In contrast, mesorhizobia revealed high diversity in terms of tolerance to acid stress: 35 % of the isolates were acid sensitive and 45 % were highly tolerant to pH 5 or moderately acidophilic. An association between mesorhizobia tolerance to acid conditions and the origin soil pH was found. Furthermore, significant differences between species clusters regarding tolerance to acidity were obtained. Ten isolates were used to investigate the expression levels of the chaperone genes by northern hybridization. Interestingly, most acid-tolerant isolates displayed induction of the dnaK and groESL genes upon acid shock while the sensitive ones showed repression. This study suggests that acid tolerance in mesorhizobia is related to the pH of the origin soil and to the species cluster of the isolates. Additionally, the transcriptional analysis suggests a relationship between induction of major chaperone genes and higher tolerance to acid pH in mesorhizobia. This is the first report on transcriptional analysis of the major chaperones genes in mesorhizobia under acidity, contributing to a better understanding of the molecular mechanisms of rhizobia acidity tolerance.
Clarisse Brígido; Solange Oliveira. Most Acid-Tolerant Chickpea Mesorhizobia Show Induction of Major Chaperone Genes upon Acid Shock. Microbial Ecology 2012, 65, 145 -153.
AMA StyleClarisse Brígido, Solange Oliveira. Most Acid-Tolerant Chickpea Mesorhizobia Show Induction of Major Chaperone Genes upon Acid Shock. Microbial Ecology. 2012; 65 (1):145-153.
Chicago/Turabian StyleClarisse Brígido; Solange Oliveira. 2012. "Most Acid-Tolerant Chickpea Mesorhizobia Show Induction of Major Chaperone Genes upon Acid Shock." Microbial Ecology 65, no. 1: 145-153.