Os microrganismos tem papel importante no crescimento vegetal por atuarem na transformacao da mat... more Os microrganismos tem papel importante no crescimento vegetal por atuarem na transformacao da materia orgânica e ciclagem de nutrientes, podendo ser determinante para o crescimento de especies vegetais. O objetivo deste trabalho foi avaliar a contribuicao dos microrganismos do solo no crescimento inicial de milho crioulo em um Latossolo Vermelho distroferrico de Cerrado. O delineamento experimental foi inteiramente casualizado em esquema fatorial (2x5) em que, os tratamentos constituiram-se da combinacao entre duas condicoes de solo (nao esterilizado e esterilizado) e cinco niveis de adubacao de NPK. O maior crescimento de plantas, tanto em altura quanto em diâmetro e maior producao de materia seca e de raizes no solo com microrganismos (nao esterilizado), em relacao a ausencia destes no solo esterilizado, indicam que a atividade microbiana no solo e determinante para o crescimento de milho crioulo no Latossolo Vermelho Distroferrico de Cerrado. O solo nao esterilizado apresentou maiores teores de carbono da biomassa microbiana e atividade da fosfatase acida superior quando comparado ao solo esterilizado. Isso evidencia a importância da atividade microbiana do solo no aumento dos estoques de carbono microbiano alem de promover maior disponibilidade de nutrientes essenciais, como o P, via aumento da atividade enzimatica
RESUMO: A incorporação de áreas nativas aos sistemas produtivos tem provocado alterações em ecoss... more RESUMO: A incorporação de áreas nativas aos sistemas produtivos tem provocado alterações em ecossistemas, especialmente em regiões tropicais e, devido ao uso inadequado do solo, tem resultado na rápida perda do carbono orgânico. O objetivo deste estudo foi avaliar o impacto de sistemas de manejo e uso do solo sobre a biomassa e a atividade microbiana, assim como o estoque de carbono orgânico total e suas frações em um Latossolo Vermelho distrófico e um Neossolo Quartzarênico de Cerrado. Os sistemas de manejo e uso no Neossolo Quartzarênico foram: Cerrado nativo, integração lavoura-pecuária, pastagem, plantio direto 1 (soja/braquiária) e plantio direto 2 (milho/braquiária). No Latossolo Vermelho os sistemas foram: Cerrado nativo, integração lavoura-pecuária, plantio convencional, plantio direto 3 (soja/nabo/milho/nabo) e plantio direto 4 (soja/milho/sorgo/soja). Para ambos os solos avaliados, o sistema de integração lavoura-pecuária promoveu melhorias nos teores de carbono da biomass...
Microorganisms play an important role in plant growth, because they act in the process of extreme... more Microorganisms play an important role in plant growth, because they act in the process of extreme importance to plant nutrition and transformation of organic matter and nutrient cycling, and may be crucial for growth of plant species. The objective of this study was to evaluate the contribution of soil microorganisms in the early growth of maize landraces in Cerrado Oxisol. The experimental design was completely randomized in factorial scheme (2x5), the treatments were the combination of two soil conditions (non-sterile and sterile), and five levels of NPK fertilization. The parameters assessed were: dry shoots and roots, plant height, stem diameter, microbial biomass carbon and acid phosphatase activity. The greater growth of plants, both in height and in diameter and greater dry matter production of roots and soil with microorganisms (not sterilized), regarding the absence of the sterilized soil, indicating that the microbial activity in soil is crucial to the growth in maize land...
ABSTRACT Symbioses of plants with rhizobia and mycorrhizal fungi have been poorly studied in heav... more ABSTRACT Symbioses of plants with rhizobia and mycorrhizal fungi have been poorly studied in heavy metal-contaminated tropical soils. Studies found were mainly in areas subject to Zn processing, coal and gold mining activities and sewage sludge application. Although no data were found about the occurrence of rhizobia in these soils, tolerance of rhizobia from diverse origins (plant species and ecosystems) revealed strains with high tolerance to Zn, Cd and Cu. Cupriavidus necator, recently described as a nitrogenfixing legume symbiont, is among the high-tolerant species. The AMF genera most commonly reported in HM-contaminated areas were Glomus and Acaulospora. Some tropical legume trees have been identified as promising for programmes to recover soils degraded by excess HMs, such as Enterolobium contortisiliquum and Acacia mangium, which are able to form an efficient symbiosis with Bradyrhizobium, Mimosa caesalpiniaefolia and Leucaena leucocephala, which form symbioses with Cupriavidus necator. AMF were shown to improve the tolerance of hosting plants to As in contaminated soils. Leguminous species had a low As translocation index from the roots to shoots when inoculated with AMF species.
Soil structure has major influence on ecosystem sustainability and plant growth. Arbuscular mycor... more Soil structure has major influence on ecosystem sustainability and plant growth. Arbuscular mycorrhizal fungi (AMF) are an important functional group of soil microbiota, acting in the process of aggregation, especially in agroecosystems and related to the production and plant diversity. AMF are widely distributed in tropical agroecosystems and are extremely important for development of many agricultural crops. The present study evaluated the effect of inoculation with Glomus macrocarpum in different crop sequences on plant growth, microbial activity and aggregation of a Cerrado Oxisol. The study was conducted in a completely randomized design in a4 x 4 factorial scheme. Treatments consisted of four conditions of elimination and/or introduction of AMF (NS-NI: non-sterilized and non-inoculated; NS-I: non-sterilized and inoculated; S-NI: sterilized and non-inoculated; andS-I: sterilized and inoculated) and four crop sequences (Panicum maximum/Panicum maximum, Brachiaria ruziziensis/ so...
Symbiotic microorganisms increase plants resistance to metal(oid)s toxicity by various mechanisms... more Symbiotic microorganisms increase plants resistance to metal(oid)s toxicity by various mechanisms, including changes in antioxidant defense system. Apparently, arbuscular mycorrhizal fungi (AMF) and diazotrophic bacteria modify the antioxidant system response to metal(oid)s contamination. There are positive results in enzymatic and non-enzymatic defense systems. AMF can accumulate ROS in your structures (arbuscules, apoplastic spaces of hyphae, fungal cytosol, intracellular hyphae, cell wall of hyphae and spores). These microorganisms up-regulate various antioxidant defense system enzymes such as SOD, CAT, POD, APX, and GR and regulate genes encoding proteins involved in ROS homeostasis. Higher concentrations of non-enzymatic antioxidants (glutathione, flavonoids, ascorbic acid, phenolic compounds, alkaloids, tocopherol, carotenoids) occur more frequently in colonized plants. Future research should prioritize physiological and molecular genetic approaches under metal(loid)s phytotoxicity in plants associated with these microorganisms. Moreover, advanced ultrastructural analysis techniques can support identification of ROS and antioxidant molecules and enzymes distribution in the structures of these microorganisms.
Os microrganismos tem papel importante no crescimento vegetal por atuarem na transformacao da mat... more Os microrganismos tem papel importante no crescimento vegetal por atuarem na transformacao da materia orgânica e ciclagem de nutrientes, podendo ser determinante para o crescimento de especies vegetais. O objetivo deste trabalho foi avaliar a contribuicao dos microrganismos do solo no crescimento inicial de milho crioulo em um Latossolo Vermelho distroferrico de Cerrado. O delineamento experimental foi inteiramente casualizado em esquema fatorial (2x5) em que, os tratamentos constituiram-se da combinacao entre duas condicoes de solo (nao esterilizado e esterilizado) e cinco niveis de adubacao de NPK. O maior crescimento de plantas, tanto em altura quanto em diâmetro e maior producao de materia seca e de raizes no solo com microrganismos (nao esterilizado), em relacao a ausencia destes no solo esterilizado, indicam que a atividade microbiana no solo e determinante para o crescimento de milho crioulo no Latossolo Vermelho Distroferrico de Cerrado. O solo nao esterilizado apresentou maiores teores de carbono da biomassa microbiana e atividade da fosfatase acida superior quando comparado ao solo esterilizado. Isso evidencia a importância da atividade microbiana do solo no aumento dos estoques de carbono microbiano alem de promover maior disponibilidade de nutrientes essenciais, como o P, via aumento da atividade enzimatica
RESUMO: A incorporação de áreas nativas aos sistemas produtivos tem provocado alterações em ecoss... more RESUMO: A incorporação de áreas nativas aos sistemas produtivos tem provocado alterações em ecossistemas, especialmente em regiões tropicais e, devido ao uso inadequado do solo, tem resultado na rápida perda do carbono orgânico. O objetivo deste estudo foi avaliar o impacto de sistemas de manejo e uso do solo sobre a biomassa e a atividade microbiana, assim como o estoque de carbono orgânico total e suas frações em um Latossolo Vermelho distrófico e um Neossolo Quartzarênico de Cerrado. Os sistemas de manejo e uso no Neossolo Quartzarênico foram: Cerrado nativo, integração lavoura-pecuária, pastagem, plantio direto 1 (soja/braquiária) e plantio direto 2 (milho/braquiária). No Latossolo Vermelho os sistemas foram: Cerrado nativo, integração lavoura-pecuária, plantio convencional, plantio direto 3 (soja/nabo/milho/nabo) e plantio direto 4 (soja/milho/sorgo/soja). Para ambos os solos avaliados, o sistema de integração lavoura-pecuária promoveu melhorias nos teores de carbono da biomass...
Microorganisms play an important role in plant growth, because they act in the process of extreme... more Microorganisms play an important role in plant growth, because they act in the process of extreme importance to plant nutrition and transformation of organic matter and nutrient cycling, and may be crucial for growth of plant species. The objective of this study was to evaluate the contribution of soil microorganisms in the early growth of maize landraces in Cerrado Oxisol. The experimental design was completely randomized in factorial scheme (2x5), the treatments were the combination of two soil conditions (non-sterile and sterile), and five levels of NPK fertilization. The parameters assessed were: dry shoots and roots, plant height, stem diameter, microbial biomass carbon and acid phosphatase activity. The greater growth of plants, both in height and in diameter and greater dry matter production of roots and soil with microorganisms (not sterilized), regarding the absence of the sterilized soil, indicating that the microbial activity in soil is crucial to the growth in maize land...
ABSTRACT Symbioses of plants with rhizobia and mycorrhizal fungi have been poorly studied in heav... more ABSTRACT Symbioses of plants with rhizobia and mycorrhizal fungi have been poorly studied in heavy metal-contaminated tropical soils. Studies found were mainly in areas subject to Zn processing, coal and gold mining activities and sewage sludge application. Although no data were found about the occurrence of rhizobia in these soils, tolerance of rhizobia from diverse origins (plant species and ecosystems) revealed strains with high tolerance to Zn, Cd and Cu. Cupriavidus necator, recently described as a nitrogenfixing legume symbiont, is among the high-tolerant species. The AMF genera most commonly reported in HM-contaminated areas were Glomus and Acaulospora. Some tropical legume trees have been identified as promising for programmes to recover soils degraded by excess HMs, such as Enterolobium contortisiliquum and Acacia mangium, which are able to form an efficient symbiosis with Bradyrhizobium, Mimosa caesalpiniaefolia and Leucaena leucocephala, which form symbioses with Cupriavidus necator. AMF were shown to improve the tolerance of hosting plants to As in contaminated soils. Leguminous species had a low As translocation index from the roots to shoots when inoculated with AMF species.
Soil structure has major influence on ecosystem sustainability and plant growth. Arbuscular mycor... more Soil structure has major influence on ecosystem sustainability and plant growth. Arbuscular mycorrhizal fungi (AMF) are an important functional group of soil microbiota, acting in the process of aggregation, especially in agroecosystems and related to the production and plant diversity. AMF are widely distributed in tropical agroecosystems and are extremely important for development of many agricultural crops. The present study evaluated the effect of inoculation with Glomus macrocarpum in different crop sequences on plant growth, microbial activity and aggregation of a Cerrado Oxisol. The study was conducted in a completely randomized design in a4 x 4 factorial scheme. Treatments consisted of four conditions of elimination and/or introduction of AMF (NS-NI: non-sterilized and non-inoculated; NS-I: non-sterilized and inoculated; S-NI: sterilized and non-inoculated; andS-I: sterilized and inoculated) and four crop sequences (Panicum maximum/Panicum maximum, Brachiaria ruziziensis/ so...
Symbiotic microorganisms increase plants resistance to metal(oid)s toxicity by various mechanisms... more Symbiotic microorganisms increase plants resistance to metal(oid)s toxicity by various mechanisms, including changes in antioxidant defense system. Apparently, arbuscular mycorrhizal fungi (AMF) and diazotrophic bacteria modify the antioxidant system response to metal(oid)s contamination. There are positive results in enzymatic and non-enzymatic defense systems. AMF can accumulate ROS in your structures (arbuscules, apoplastic spaces of hyphae, fungal cytosol, intracellular hyphae, cell wall of hyphae and spores). These microorganisms up-regulate various antioxidant defense system enzymes such as SOD, CAT, POD, APX, and GR and regulate genes encoding proteins involved in ROS homeostasis. Higher concentrations of non-enzymatic antioxidants (glutathione, flavonoids, ascorbic acid, phenolic compounds, alkaloids, tocopherol, carotenoids) occur more frequently in colonized plants. Future research should prioritize physiological and molecular genetic approaches under metal(loid)s phytotoxicity in plants associated with these microorganisms. Moreover, advanced ultrastructural analysis techniques can support identification of ROS and antioxidant molecules and enzymes distribution in the structures of these microorganisms.
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