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1.
Microbes Environ ; 34(4): 393-401, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31597890

RESUMO

The nifV gene encodes homocitrate synthase, the enzyme that catalyzes the formation of homocitrate, which is essential for arranging the FeMo-cofactor in the catalytic center of nitrogenase. Some host plants, such as Lotus japonicus, supply homocitrate to their symbionts, in this case, Mesorhizobium loti, which lacks nifV. In contrast, Bradyrhizobium ORS285, a symbiont of Aeschynomene cross-inoculation (CI) groups 2 and 3, requires nifV for symbiosis with Aeschynomene species that belong to CI group 3, and some species belonging to CI group 2. However, it currently remains unclear whether rhizobial nifV is required for symbiosis with Aeschynomene species belonging to CI group 1 or with other legumes. We generated nifV-disruption (ΔnifV) mutants of two wide-host-range rhizobia, Bradyrhizobium SUTN9-2 and DOA9, to investigate whether they require nifV for symbiosis. Both ΔnifV mutant strains showed significantly less nitrogenase activity in a free-living state than the respective wild-type strains. The symbiotic phenotypes of SUTN9-2, DOA9, and their ΔnifV mutants were examined with four legumes, Aeschynomene americana, Stylosanthes hamata, Indigofera tinctoria, and Desmodium tortuosum. nifV was required for the efficient symbiosis of SUTN9-2 with A. americana (CI group 1), but not for that of DOA9. SUTN9-2 established symbiosis with all three other legumes; nifV was required for symbiosis with I. tinctoria and D. tortuosum. These results suggest that, in addition to Aeschynomene CI groups 2 and 3, CI group 1 and several other legumes require the rhizobial nifV for symbiosis.


Assuntos
Proteínas de Bactérias/metabolismo , Bradyrhizobium/fisiologia , Fabaceae/microbiologia , Oxo-Ácido-Liases/metabolismo , Simbiose , Proteínas de Bactérias/genética , Bradyrhizobium/classificação , Bradyrhizobium/enzimologia , Bradyrhizobium/genética , Fabaceae/classificação , Fabaceae/crescimento & desenvolvimento , Especificidade de Hospedeiro , Mutação , Fixação de Nitrogênio , Nitrogenase/metabolismo , Oxo-Ácido-Liases/genética , Filogenia , Nódulos Radiculares de Plantas/classificação , Nódulos Radiculares de Plantas/crescimento & desenvolvimento , Nódulos Radiculares de Plantas/microbiologia
2.
Braz J Microbiol ; 50(4): 1011-1020, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31396863

RESUMO

Positive feedback between arbuscular mycorrhizal fungal (AMF) and vascular plants can contribute to plant species establishment, but how this feedback affects plant invasion by Prosopis juliflora SW. (DC.), or resistance to invasion by Mimosa tenuiflora (Willd.) Poir in Brazilian semi-arid region is not well known. In this work, we tested how modified and native AMF communities affect the establishment of P. juliflora and M. tenuiflora plants. We examined the effects of inoculation with modified and native AMF communities on number of AMF spores, root colonization, number of N-fixing nodules, plant dry biomass, plant phosphorous concentration, and plant responsiveness to mycorrhizas of P. juliflora and M. tenuiflora. We found that the modified AMF community enhanced the root colonization, plant dry biomass, and plant phosphorous concentration of invasive P. juliflora, whereas native AMF enhanced M. tenuiflora. Our results demonstrate that the invasive P. juliflora alters soil AMF community composition, and this change generates positive feedback to the invasive P. juliflora itself and decreases AMF associations with native M. tenuiflora.


Assuntos
Fabaceae/microbiologia , Fungos/isolamento & purificação , Mimosa/microbiologia , Micorrizas/isolamento & purificação , Biodiversidade , Brasil , Fabaceae/crescimento & desenvolvimento , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Espécies Introduzidas , Mimosa/crescimento & desenvolvimento , Micorrizas/classificação , Micorrizas/genética , Micorrizas/metabolismo , Fósforo/metabolismo , Raízes de Plantas/microbiologia , Solo/química , Microbiologia do Solo , Esporos Fúngicos/classificação , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação , Esporos Fúngicos/metabolismo
3.
Genes (Basel) ; 10(6)2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234426

RESUMO

Chitinase is a kind of hydrolase with chitin as a substrate and is proposed to play an essential role in plant defense system by functioning against fungal pathogens through degrading chitin. Recent studies indicated chitinase is also involved in abiotic stress response in plants, helping plants to survive in stressful environments. A. nanus, a rare evergreen broad-leaved shrub distrusted in deserts in Central Asia, exhibits a high level of tolerance to drought and low temperature stresses. To identify the chitinase gene involved in drought and low temperature responses in A. nanus, we performed genome-wide identification, classification, sequence alignment, and spatio-temporal gene expression analysis of the chitinases in A. nanus under osmotic and low temperature stress. A total of 32 chitinase genes belonging to glycosyl hydrolase 18 (GH18) and GH19 families were identified from A. nanus. Class III chitinases appear to be amplified quantitatively in A. nanus, and their genes carry less introns, indicating their involvement in stress response in A. nanus. The expression level of the majority of chitinases varied in leaves, stems, and roots, and regulated under environmental stress. Some chitinases, such as EVM0022783, EVM0020238, and EVM0003645, are strongly induced by low temperature and osmotic stress, and the MYC/ICE1 (inducer of CBF expression 1) binding sites in promoter regions may mediate the induction of these chitinases under stress. These chitinases might play key roles in the tolerance to these abiotic stress in A. nanus and have potential for biotechnological applications. This study provided important data for understanding the biological functions of chitinases in A. nanus.


Assuntos
Quitinases/genética , Resposta ao Choque Frio/genética , Fabaceae/genética , Filogenia , Quitinases/classificação , Secas , Fabaceae/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Pressão Osmótica/fisiologia , Folhas de Planta/genética , Alinhamento de Sequência , Estresse Fisiológico/genética
4.
PLoS One ; 14(6): e0219100, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31242263

RESUMO

Dugout canoes are boats made from a single tree trunk. Even with the modernization of fishing, they are still made and used for artisanal fishing on the coast of southern and southeastern Brazil and in other regions of the world. Various tree species are used to construct these canoes and choosing a species is related to characteristics of the location, available raw materials and purpose of the boat. Our objective was to better understand the variation in dugout canoes in relation to tree species, tree size and fishing use, over time, along a coastal strip of southern and southeastern Brazil within the Atlantic Forest domain. We interviewed 53 artisans and analyzed 358 canoes that ranged from 1 to around 200 years old. Schizolobium parahyba is currently used the most. In the past, species of the family Lauraceae (Nectandra sp. / Ocotea sp.) were frequently used, as well as Cedrela fissilis and Ficus sp. The size of the canoes varied based on time, coastal region, environment where the boat is used (exposed or sheltered) and type of fishing. The average size of recent canoes was smaller than older canoes for more common species (S. parahyba and C. fissilis), reflecting changes in the vegetation of the biome over time, both in the species and size of individuals available. Latitudinal variation can also influence the availability of tree species along the studied regions. An increase in environmental monitoring has contributed to a decline in constructing dugout canoes, resulting in the use of fiberglass canoes and other motorized boats. Although canoe size varied based on region, location and use, today some of the older canoes represent large trees of the past and pieces of Atlantic Forest history.


Assuntos
Navios/métodos , Árvores/crescimento & desenvolvimento , Brasil , Cedrela/crescimento & desenvolvimento , Ecossistema , Fabaceae/crescimento & desenvolvimento , Florestas , Humanos , Lauraceae/crescimento & desenvolvimento , Clima Tropical
5.
Planta ; 250(3): 891-909, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31115659

RESUMO

MAIN CONCLUSION: Tailoring crops to withstand rising temperature and declining precipitation may be unrewarding, therefore the potential of alternative undervalued crops such as horse gram can be explored for safeguarding food and nutritional security with health benefits in the era of climate change. Horse gram [Macrotyloma uniflorum (Lam.) Verdc] under the family Fabaceae, has been cultivated for food, folklore medicine and fodder mainly by rural and tribal communities since prehistoric times in Asian and African countries. This valuable ancient legume not only offers diversification and resilience to agro-ecosystems but it also possesses high adaptation in risk-prone traditional farming systems in marginal environments of semi-arid and arid regions. Being a nutrient dense legume with remedial health-promoting effects due to the presence of various bioactive compounds, it is suitable for the development of functional food as well as for addressing micronutrient deficiencies among poor rural communities. Despite its enormous potential and a growing awareness about the utility of this underutilized crop for future climate adaptation and human well-being, this legume continues to be seriously neglected and labelled as "food of the poors". India is the major producer of horse gram and presently, cultivation of horse gram remains confined to small-scale farming systems as an inter- or mixed crop. This crop is alienated from mainstream agriculture and relegated to a status of "underutilized" due to its limited competitiveness as compared to other commercial crops. Besides a scanty basic research on this crop, no attention has been paid to the factors like improvement of plant type, yield improvement, processing, value addition to suit consumer needs and reduction of anti-nutritional factors, which restricted the diffusion of this crop outside its niche area. The present review therefore is an attempt to compile the meagre information available on crop history, evolution, genetic enhancement, nutritional and health benefits to make the crop competitive and revitalize horse gram cultivation.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Fabaceae/crescimento & desenvolvimento , Ração Animal , Produção Agrícola , Produtos Agrícolas/história , Fabaceae/genética , Previsões , Genoma de Planta/genética , História Antiga , Valor Nutritivo , Melhoramento Vegetal
6.
Pest Manag Sci ; 75(9): 2446-2454, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31074055

RESUMO

Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest-caused economic losses. However, over-reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi-based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry.


Assuntos
Agentes de Controle Biológico/administração & dosagem , Brassica , Fabaceae , Controle Biológico de Vetores/métodos , África , Ásia , Brassica/crescimento & desenvolvimento , Fabaceae/crescimento & desenvolvimento , Verduras/crescimento & desenvolvimento
7.
Antonie Van Leeuwenhoek ; 112(9): 1369-1385, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31053961

RESUMO

Twelve nodulating Paraburkholderia strains isolated from indigenous South African fynbos legume Hypocalyptus sophoroides were investigated to determine their taxonomic status. Genealogical concordance analysis, based on six loci (16S rRNA, atpD, recA, rpoB, lepA and gltB), revealed that they separate into two consistent and exclusive groups. Average nucleotide identity and DNA-DNA hybridisation comparisons indicated that they were sufficiently divergent from their closest known phylogenetic relatives (Paraburkholderia caledonica and Paraburkholderia terrae, respectively) to be regarded as novel species. This was also supported by the results of fatty acid analysis and metabolic characterisation. For these two isolate groups, we accordingly propose the new species Paraburkholderia strydomiana sp. nov. with WK1.1fT (= LMG 28731T = SARCC1213T) as its type strain and Paraburkholderia steynii sp. nov. with HC1.1baT (= LMG 28730T = SARCC696T) as its type strain. Our data thus showed that H. sophoroides may be considered a promiscuous symbiotic partner due to its ability to associate with multiple species of Paraburkholderia.


Assuntos
Burkholderiaceae/classificação , Burkholderiaceae/isolamento & purificação , Fabaceae/microbiologia , Raízes de Plantas/microbiologia , Microbiologia do Solo , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Burkholderiaceae/genética , Burkholderiaceae/fisiologia , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fabaceae/crescimento & desenvolvimento , Ácidos Graxos/análise , Hibridização de Ácido Nucleico , Filogenia , Nodulação , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA
8.
Science ; 363(6432): 1213-1216, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30872524

RESUMO

Ecological theory predicts that the high local diversity observed in tropical forests is maintained by negative density-dependent interactions within and between closely related plant species. By using long-term data on tree growth and survival for coexisting Inga (Fabaceae, Mimosoideae) congeners, we tested two mechanisms thought to underlie negative density dependence (NDD): competition for resources and attack by herbivores. We quantified the similarity of neighbors in terms of key ecological traits that mediate these interactions, as well as the similarity of herbivore communities. We show that phytochemical similarity and shared herbivore communities are associated with decreased growth and survival at the sapling stage, a key bottleneck in the life cycle of tropical trees. None of the traits associated with resource acquisition affect plant performance, indicating that competition between neighbors may not shape local tree diversity. These results suggest that herbivore pressure is the primary mechanism driving NDD at the sapling stage.


Assuntos
Biodiversidade , Fabaceae/crescimento & desenvolvimento , Florestas , Herbivoria , Árvores/crescimento & desenvolvimento , Animais
9.
Sci Total Environ ; 667: 77-85, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30826683

RESUMO

In the context of global precipitation anomalies and climate warming, the evolution of fragile desert ecosystems, which account for one-third of the world's land area, will become more complex. Studies of regional climate change and ecosystem response are important components of global climate change research, especially in arid desert regions. Zygophyllum xanthoxylum and Ammopiptanthus mongolicus are two dominant but endangered shrub species in the Alxa Desert in the arid region of central Asia. Using dendrochronological methods, we studied the response of radial growth of those two species to climate factors, and the adaptability of the two shrub populations under a regional warming trend. We found that radial growth of both shrubs was mainly affected by precipitation during the growing season. In additionally, along with the decrease of precipitation and the increase of temperature from east to west of Alxa desert Plateau, the limiting effect of drought during the growing season on radial growth increased. The climate response characteristics and changes between dry and wet periods exhibited spatial and temporal heterogeneity due to micro-level geomorphological factors. Under a regional climate warming trend, individual growth and population development of the two endangered shrubs will be adversely affected. In areas where these species are naturally distributed, populations will gradually become concentrated in micro-geomorphic regions with better soil moisture conditions, such as low-lying areas in the gullies that develop in alluvial fans. This finding has important scientific significance for understanding the development of the region's dominant shrub populations and protection of these and other endangered plants in arid desert areas.


Assuntos
Mudança Climática , Fabaceae/crescimento & desenvolvimento , Zygophyllum/crescimento & desenvolvimento , China , Clima Desértico , Especificidade da Espécie
10.
Food Chem ; 288: 325-332, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902300

RESUMO

Nutrient content and digestibility as well as factors with a potentially negative effect on these parameters were studied in legume sprouts enriched with L. plantarum 299v. The nutrient digestibility and contents were not strongly affected by the co-culture of the probiotic and sprouts. The highest digestibility of starch was observed for adzuki bean preparations (from 91.6% to 95.5%), while the lowest value was noted for soybean preparations (from 49.6% to 60.8%). A slight decrease in starch digestibility was observed in adzuki and soybean sprouts enriched with the probiotic (by about 5% and 7% respectively). An increase in starch digestibility was noted in lentil and mung bean sprouts. A key influence on protein digestibility was exerted by the activity of trypsin and chymotrypsin inhibitors. Generally, there was no negative effect of the studied factors on starch digestibility. Most importantly, the control and probiotic-rich sprouts retained high quality after cold storage.


Assuntos
Fabaceae/crescimento & desenvolvimento , Lactobacillus plantarum/metabolismo , Valor Nutritivo , Fabaceae/microbiologia , Armazenamento de Alimentos , Lens (Planta)/crescimento & desenvolvimento , Lens (Planta)/microbiologia , Probióticos , Plântula/microbiologia , Soja/crescimento & desenvolvimento , Soja/microbiologia , Amido/análise , Amido/metabolismo
11.
Planta ; 250(3): 911-931, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30911885

RESUMO

MAIN CONCLUSION: Winged bean is popularly known as "One Species Supermarket" for its nutrient-dense green pods, immature seeds, tubers, leaves, and mature seeds. This underutilised crop has potential beneficial traits related to its biological nitrogen-fixation to support low-input farming. Drawing from past knowledge, and based on current technologies, we propose a roadmap for research and development of winged bean for sustainable food systems. Reliance on a handful of "major" crops has led to decreased diversity in crop species, agricultural systems and human diets. To reverse this trend, we need to encourage the greater use of minor, "orphan", underutilised species. These could contribute to an increase in crop diversity within agricultural systems, to improve human diets, and to support more sustainable and resilient food production systems. Among these underutilised species, winged bean (Psophocarpus tetragonolobus) has long been proposed as a crop for expanded use particularly in the humid tropics. It is an herbaceous perennial legume of equatorial environments and has been identified as a rich source of protein, with most parts of the plant being edible when appropriately prepared. However, to date, limited progress in structured improvement programmes has restricted the expansion of winged bean beyond its traditional confines. In this paper, we discuss the reasons for this and recommend approaches for better use of its genetic resources and related Psophocarpus species in developing improved varieties. We review studies on the growth, phenology, nodulation and nitrogen-fixation activity, breeding programmes, and molecular analyses. We then discuss prospects for the crop based on the greater understanding that these studies have provided and considering modern plant-breeding technologies and approaches. We propose a more targeted and structured research approach to fulfil the potential of winged bean to contribute to food security.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Fabaceae/crescimento & desenvolvimento , Produção Agrícola/tendências , Abastecimento de Alimentos/métodos , Previsões , Valor Nutritivo , Melhoramento Vegetal
12.
Sci Total Environ ; 666: 652-661, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30807955

RESUMO

The urban environment features poor air quality and harsher climate conditions that affect the life in the cities. Citizens are especially vulnerable to climate change, because heat island and impervious exacerbates extreme climate events. Urban trees are important tools for mitigation and adaptation of cities to climate change because they provide ecosystem services that increase while trees grow. Nonetheless, the growth of trees may be affected by the harsher conditions found in the urban environment. We assessed the impact of air pollution and climate on the spatial/temporal variability of tree growth in São Paulo, Brazil, one of the largest urban conglomerates in the world. For this purpose, we sampled 41 trees of the Tipuana tipu species in a region that includes industrial areas. We built a tree-ring chronology using standard dendrochronological methods. Spatial analyses show that trees grow faster in the warmer parts of the city and under higher concentrations of airborne P, whereas growth is reduced under higher concentrations of Al, Ba, Zn. Particulate matter (PM10) from the industrial cluster also reduce average growth rate of trees, up to 37% in all diameter classes. Similar results were obtained via temporal analyses, suggesting that the annual growth rate is positively associated with temperature, which explain 16% of interannual growth variability. Precipitation, on the other hand, has no association with tree growth. The average concentration of PM10 explains 41% of interannual growth variability, and higher concentrations during the driest months reduce growth rate. Despite heat island effect and water limitation in the soil of the city, this species takes advantage of warmer conditions and it is not limited by water availability as measured by precipitation. On the other hand, air pollution directly impacts the growth of these trees being a major limiting growth factor.


Assuntos
Poluição do Ar/efeitos adversos , Mudança Climática , Fabaceae/crescimento & desenvolvimento , Árvores/genética , Brasil , Cidades , Clima , Fabaceae/efeitos dos fármacos , Árvores/efeitos dos fármacos
13.
Environ Sci Pollut Res Int ; 26(8): 8125-8135, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30693447

RESUMO

Researches involving the use of association between legumes and PGPBs (plant growth-promoting bacteria) in heavy metal phytoremediation process were mainly performed for soils highly contaminated. However, even in agriculture soils, with moderate or low contamination levels, plants can accumulate high rates of heavy metals. So, food chain contamination by these metals presents a real threat to animal and human health. This work aimed to evaluate the use of two legumes/PGPB symbioses; Vicia faba var. minor and Sulla coronaria have been inoculated with specific heavy metal-resistant inocula in a crop rotation system with Lactuca sativa as a following crop, in order to assess their effects on soil fertility, lettuce yield, and heavy metal content. Our results showed that legume inoculation significantly enhanced their biomass production, nitrogen and phosphorus content. The use of our symbioses as green manure before lettuce cultivation, as a rotation cropping system, affected positively soil fertility. In fact, we recorded a higher organic matter content, with rapid decomposition in the soil of inoculated plots. Besides, results demonstrated a greater nitrogen and phosphorus content in this soil, especially in the plot cultivated with inoculated V. faba var. minor. The improvement of soil fertility enhanced lettuce yield and its nitrogen and phosphorus content. Moreover, inoculated legumes extracted and accumulated more heavy metals than non-inoculated legumes. Our symbioses play the role of organic trap for heavy metals, making them unavailable for following crops. These facts were supported by lettuce heavy metal content, showing a significant decrease in metal accumulation, mainly zinc and cadmium, in edible parts. Results showed the usefulness of the studied symbioses, as a main part of a rotation system with lettuce. Our symbioses can be suggested for agriculture soil phytoremediation, aiming to enhance non-legume crop yield and limit heavy metal translocation to food chain.


Assuntos
Inoculantes Agrícolas/crescimento & desenvolvimento , Alface/crescimento & desenvolvimento , Metais Pesados/análise , Rhizobium/crescimento & desenvolvimento , Poluentes do Solo/análise , Vicia faba/crescimento & desenvolvimento , Inoculantes Agrícolas/metabolismo , Biodegradação Ambiental , Produção Agrícola/métodos , Fabaceae/crescimento & desenvolvimento , Fabaceae/metabolismo , Fabaceae/microbiologia , Alface/metabolismo , Metais Pesados/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Rhizobium/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Simbiose , Vicia faba/metabolismo , Vicia faba/microbiologia
14.
Tree Physiol ; 39(4): 641-649, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30597081

RESUMO

Despite the long history of research on xylem structure and function, there are no reports in the literature explaining how xylem vessel elements began conducting water just after their maturation. This study was conducted to demonstrate the anatomical arrangement of newly matured vessels, looking specifically for the first pathways connecting newly matured vessels to the transpiration stream. Using the developing stems of Paraserianthes lophantha (Willd.) I.C.Nielsen as the experimental system, the course of vessel differentiation and maturation along the developing bundles was followed by using the dye-pressure method. Water pathways from newly matured vessels to other functioning vessels were directly visualized by the technique of single-vessel dye injection. Some isolated newly matured vessels from the transpiration stream were detected using two apoplastic tracers. The results of this study converge to support the hypothesis that the movement of water in the newly matured vessels depends completely on lateral contacts with other functioning vessels via vessel-to-vessel paths or vessel relays. In cases where the lateral pathways were absent, the flow within the newly matured vessels was substantially blocked resulting in a significant hydraulic isolation of the newly matured vessels. These results might contribute to a better understanding of the pattern of water movement within the developing xylem systems, and underscore that xylem vessels start conducting water through lateral transport, although their primary function is the axial transport.


Assuntos
Fabaceae/fisiologia , Transpiração Vegetal/fisiologia , Água/metabolismo , Xilema/fisiologia , Transporte Biológico , Fabaceae/citologia , Fabaceae/crescimento & desenvolvimento , Caules de Planta/citologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/fisiologia , Xilema/citologia , Xilema/crescimento & desenvolvimento
15.
Appl Environ Microbiol ; 85(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658982

RESUMO

A lack of knowledge of the microbial responses to environmental change at the species and functional levels hinders our ability to understand the intrinsic mechanisms underlying the maintenance of microbial ecosystems. Here, we present results from temporal microcosms that introduced inorganic and organic contaminants into agro-soils for 90 days, with three common legume plants. Temporal dynamics and assemblage of soil microbial communities and functions in response to contamination under the influence of growth of different plants were explored via sequencing of the 16S rRNA amplicon and by shotgun metagenomics. Soil microbial alpha diversity and structure at the taxonomic and functional levels exhibited resilience patterns. Functional profiles showed greater resilience than did taxonomic ones. Different legume plants imposed stronger selection on taxonomic profiles than on functional ones. Network and random forest analyses revealed that the functional potential of soil microbial communities was fostered by various taxonomic groups. Betaproteobacteria were important predictors of key functional traits such as amino acid metabolism, nucleic acid metabolism, and hydrocarbon degradation. Our study reveals the strong resilience of the soil microbiome to chemical contamination and sensitive responses of taxonomic rather than functional profiles to selection processes induced by different legume plants. This is pivotal to develop approaches and policies for the protection of soil microbial diversity and functions in agro-ecosystems with different response strategies from global environmental drivers, such as soil contamination and plant invasion.IMPORTANCE Exploring the microbial responses to environmental disturbances is a central issue in microbial ecology. Understanding the dynamic responses of soil microbial communities to chemical contamination and the microbe-soil-plant interactions is essential for forecasting the long-term changes in soil ecosystems. Nevertheless, few studies have applied multi-omics approaches to assess the microbial responses to soil contamination and the microbe-soil-plant interactions at the taxonomic and functional levels simultaneously. Our study reveals clear succession and resilience patterns of soil microbial diversity and structure in response to chemical contamination. Different legume plants exerted stronger selection processes on taxonomic than on functional profiles in contaminated soils, which could benefit plant growth and fitness as well as foster the potential abilities of hydrocarbon degradation and metal tolerance. These results provide new insight into the resilience and assemblage of soil microbiome in response to environmental disturbances in agro-ecosystems at the species and functional levels.


Assuntos
Bactérias/isolamento & purificação , Fabaceae/crescimento & desenvolvimento , Fabaceae/microbiologia , Microbiota , Poluentes do Solo/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Biodiversidade , Metagenômica , Metais/análise , Metais/metabolismo , Filogenia , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
16.
J Sci Food Agric ; 99(1): 191-198, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29855053

RESUMO

BACKGROUND: In Mediterranean grazed woodlands, microclimate changes induced by trees influence the growth and development of the understory, although very little is known about its polyphenolic composition in relation to light intensity. We investigated the bioactive compounds and antioxidant capacity of different legume-based swards and variations as a result of full sunlight and partial shade. The research was carried out in a cork oak agrosilvopastoral system in Sardinia. RESULTS: The highest values of (1,1-diphenyl-2-picrylhydrazyl) (DPPH) reached 7 mmol Trolox equivalent antioxidant capacity 100 g-1 dry weight (DW), total phenolics 67.1 g gallic acid equivalent kg-1 DW and total flavonoids 7.5 g catechin equivalent kg-1 DW. Compared to full sunlight, partial shade reduced DPPH values by 29% and 42%, and the total phenolic content by 23% and 53% in 100% legume mixture and semi-natural pasture, respectively. Twelve phenolic compounds were detected: chlorogenic acid in 80% legume mixture (partial shade) and verbascoside in pure sward of bladder clover (full sunlight) were the most abundant. CONCLUSION: Light intensity significantly affected antioxidant capacity, composition and levels of phenolic compounds. The results of the present study provide new insights into the effects of light intensity on plant secondary metabolites from legume-based swards, highlighting the important functions provided by agroforestry systems. © 2018 Society of Chemical Industry.


Assuntos
Antioxidantes/química , Fabaceae/química , Fabaceae/efeitos da radiação , Polifenóis/química , Fabaceae/crescimento & desenvolvimento , Agricultura Florestal , Itália , Luz
17.
Braz J Biol ; 79(3): 369-376, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30231136

RESUMO

This study aimed to inventory the herbivore insects associated with Enterolobium contortisiliquum (Vell.) Morong (Fabaceae) fruits and seeds and their primary and secondary parasitoids. Six samples collected between May and October 2013 yielded 210 fruits, from which 326 insects of six orders emerged: Coleoptera, Hymenoptera, Lepidoptera, Diptera, Thysanoptera and Psocoptera. Coleoptera (five families) was represented by the seed consumers Merobruchus bicoloripes Pic, Stator sp. Bridwell (Chrysomelidae, Bruchinae), two species of Silvanidae, one species of Scolytinae (Curculionidae), one species of Nitidulidae and one species of Cerambycidae. The cerambycid was also observed forming galleries on fruit mesocarp. Immature individuals of Lepidoptera were observed consuming the fruits and seeds. From the seven Hymenoptera families, only two species were associated with Coleoptera, being Horismenus Walker sp. (Eulophidae) as parasitoid of M. bicoloripes, and Neoheterospilus falcatus (Marsh) (Braconidae) as parasitoid of Scolytinae. The Lepidoptera parasitoids represented four genera: Pseudophanerotoma Zetel, Chelonus Panzer (Braconidae), Orgilus Nees (Braconidae) and Goniozus Forster (Bethylidae). The host associations for the reared parasitoids Bracon Fabricius (Braconidae), Pimplinae sp. (Ichneumonidae) and Perilampus Forster (Perilampidae) were not confirmed. We obtained a single representative of Diptera (Tachinidae) associated with Lepidoptera hosts in this food web.


Assuntos
Fabaceae , Cadeia Alimentar , Herbivoria , Interações Hospedeiro-Parasita , Insetos/fisiologia , Insetos/parasitologia , Animais , Brasil , Besouros/crescimento & desenvolvimento , Besouros/parasitologia , Besouros/fisiologia , Dípteros/fisiologia , Fabaceae/crescimento & desenvolvimento , Frutas/fisiologia , Insetos/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/parasitologia , Larva/fisiologia , Lepidópteros/crescimento & desenvolvimento , Lepidópteros/parasitologia , Lepidópteros/fisiologia , Vespas/fisiologia
18.
Plant Cell Environ ; 42(1): 373-385, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30329164

RESUMO

The superior agronomic and human nutritional properties of grain legumes (pulses) make them an ideal foundation for future sustainable agriculture. Legume-based farming is particularly important in Africa, where small-scale agricultural systems dominate the food production landscape. Legumes provide an inexpensive source of protein and nutrients to African households as well as natural fertilization for the soil. Although the consumption of traditionally grown legumes has started to decline, the production of soybeans (Glycine max Merr.) is spreading fast, especially across southern Africa. Predictions of future land-use allocation and production show that the soybean is poised to dominate future production across Africa. Land use models project an expansion of harvest area, whereas crop models project possible yield increases. Moreover, a seed change in farming strategy is underway. This is being driven largely by the combined cash crop value of products such as oils and the high nutritional benefits of soybean as an animal feed. Intensification of soybean production has the potential to reduce the dependence of Africa on soybean imports. However, a successful "soybean bonanza" across Africa necessitates an intensive research, development, extension, and policy agenda to ensure that soybean genetic improvements and production technology meet future demands for sustainable production.


Assuntos
Produção Agrícola , Grão Comestível , Soja , África , Mudança Climática/estatística & dados numéricos , Produção Agrícola/estatística & dados numéricos , Produção Agrícola/tendências , Grão Comestível/crescimento & desenvolvimento , Fabaceae/crescimento & desenvolvimento , Previsões , Modelos Estatísticos , Soja/crescimento & desenvolvimento
19.
J Appl Microbiol ; 126(2): 523-533, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30276936

RESUMO

AIMS: The objective of this work was to isolate and characterize indigenous rhizobia from coal-mining areas able to efficiently nodulate and fix nitrogen in association with Calopogonium mucunoides (calopo). METHODS AND RESULTS: Isolation, authentication and morphological, biochemical and molecular characterization of the autochthonous rhizobia were performed and their symbiotic efficiency (SE) evaluated. Efficient rhizobial isolates suitable for the inoculation of calopo in coal-mining regions were obtained. A total of 30 isolates were obtained after nodulation authentication, of which five presented high SE with plant-growth promoting traits such as indole-3-acetic acid production, phosphate solubilization and biofilm formation. These isolates were identified as belonging to Bradyrhizobium, Pseudomonas and Rhizobium. CONCLUSIONS: Bradyrhizobium sp. A2-10 and Pseudomonas sp. A6-05 were able to promote calopo plant growth using soil obtained from coal-mining degraded areas, thus indicating their potential as inoculants aiming at land reclamation. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of Pseudomonas nodule formation in calopo. Furthermore, the results demonstrated that autochthonous rhizobia obtained from degraded soils presented high SE in calopo and possess a wide range of plant-growth promoting traits. Ultimately, they may all contribute to an increased leguminous plant growth under stress conditions. The selected rhizobia strains may be used as inoculants and present a valuable role in the development of strategies aiming to recover coal-mining degraded areas. Bacterial inoculants would greatly reduce the use of often harmful nitrogen fertilizers vastly employed in revegetation programmes of degraded areas.


Assuntos
Bradyrhizobium/fisiologia , Minas de Carvão , Recuperação e Remediação Ambiental , Fabaceae/crescimento & desenvolvimento , Pseudomonas/fisiologia , Bradyrhizobium/isolamento & purificação , Bradyrhizobium/metabolismo , Fabaceae/metabolismo , Fabaceae/microbiologia , Fabaceae/fisiologia , Nodulação , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Rhizobium/isolamento & purificação , Rhizobium/metabolismo , Rhizobium/fisiologia , Solo , Simbiose
20.
Sci Total Environ ; 657: 270-278, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30543976

RESUMO

Ammopiptanthus mongolicus, the only drought-resistant, leguminous, evergreen shrub in the desert region of China, is endangered due to climate change and its growth stages urgently need to be non-destructively detected. Although many spectral indexes have been proposed for characterizing vegetation, the relationships are often inconsistent, making it challenging to characterize the status of vegetation across all growth stages. This study investigated the Spectral Features of the endangered desert plant A. mongolicus at different growth stages, and extracted the identified Spectral Features for the establishment of detection and discrimination models using Partial Least Square Regression (PLSR) and Fisher Linear Discriminate Analysis (FLDA), respectively. The results showed spectral reflectance of A. mongolicus differed across different growth stages and it generally increased with the degree of senescence. Poor performance was found in the single factor model, with RMSE ranging from 20.34 to 27.39 or Overall Accuracy of 60% in the validation datasets. The multivariate PLSR model, based on Normalized Difference Vegetation Index (NDVI), Normalized Difference Red Edge Index (NDRE), Physiological Reflectance Index (PhRI) and Plant Senescence Reflectance Index (PSRI), turned out to be accurate in detecting the growth stages, with R2 of 0.89 and RMSE of 12.46, and the performance of the multivariate FLDA model based on 14 Spectral Features was acceptable, with an Overall Accuracy of 89% in the validation datasets. This research provides useful insights for timely and non-destructively discriminating different growth stages by using multivariate PLSR and FLDA analysis.


Assuntos
Espécies em Perigo de Extinção , Fabaceae/fisiologia , Tecnologia de Sensoriamento Remoto , Análise Espectral , China , Fabaceae/crescimento & desenvolvimento , Análise dos Mínimos Quadrados , Modelos Lineares
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