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1.
Chemosphere ; 262: 127749, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805655

RESUMO

Beans of cacao (Theobroma cacaoL.) are used to produce a variety of chocolate products. Bioaccumulation of metals at toxic levels through the consumption of contaminated products has been identified as a health concern in humans. Both metal diversity and concentration as well as their interactions in the soil influence essential and non-essential metal uptake in plants; but the effects of these on bioaccumulation of metals in cacao is not understood across diverse soil types. In this study eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were investigated in 12 soil subgroups belonging to four soil orders across 15 locations in Trinidad, with the aim to investigate the effect of soil metal diversity and concentration on metal bioaccumulation in cacao. Soil metals were extracted using five methods (aqua regia, DTPA, Mehlich 3, nitric acid, and water). Cacao leaf metal concentrations were determined using the USEPA 3052 method. Metal extraction efficiency ranged between methods with aqua regia ≥ nitric acid > Mehlich 3 ≥ DTPA ≥ water across all metals. The soil extraction method that best predicted cacao leaf metal concentrations varied with the metal - Mehlich 3 or DTPA for Cd, Ni, Zn; aqua regia, Mehlich 3, or nitric acid for Pb, and water for Mn. A stepwise regression analysis showed that plant metal concentration can be predicted using soil physicochemical characteristics as well as the concentration of metals in the soil. The importance of soil type on cacao leaf metal bioaccumulation is discussed.


Assuntos
Bioacumulação , Cacau/química , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Disponibilidade Biológica , Cacau/efeitos dos fármacos , Cacau/crescimento & desenvolvimento , Humanos , Metais Pesados/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Poluentes do Solo/metabolismo , Trinidad e Tobago
2.
Aquat Toxicol ; 228: 105646, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33011648

RESUMO

2,4-dinitrophenol (2,4-DNP) is a phenolic compound used as a wood preservative or pesticide. The chemical is hazardous to freshwater organisms. Although 2,4-DNP poses ecological risks, only a few of its aquatic environmental risks have been investigated and very limited guidelines for freshwater aquatic ecosystems have been established by governments. This study addresses the paucity of 2,4-DNP toxicity data for freshwater ecosystems and the current lack of highly reliable trigger values for this highly toxic compound. We conducted acute bioassays using 12 species from nine taxonomic groups and chronic assays using five species from four taxonomic groups to improve the quality of the dataset and enable the estimation of protective concentrations based on species sensitivity distributions. The acute and hazardous concentrations of 2,4-DNP in 5% of freshwater aquatic species (HC5) were determined to be 0.91 (0.32-2.65) mg/L and 0.22 (0.11-0.42) mg/L, respectively. To the best of our knowledge, this is the first report of a suggested chronic HC5 for 2,4-DNP and it provides the much-needed fundamental data for the risk assessment and management of freshwater ecosystems.


Assuntos
2,4-Dinitrofenol/análise , Ecossistema , Monitoramento Ambiental , Água Doce/química , Praguicidas/toxicidade , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Chlamydomonas/efeitos dos fármacos , Clorofíceas/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Euglena/efeitos dos fármacos , Oryzias , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Especificidade da Espécie , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Qualidade da Água
3.
PLoS One ; 15(9): e0238887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32913358

RESUMO

Leaf morphology is one of the most important agronomic traits in rice breeding because of its contribution to crop yield. The drooping leaf (dr) mutant was developed from the Ilpum rice cultivar by ethyl methanesulfonate (EMS) mutagenesis. Compared with the wild type, dr plants exhibited drooping leaves accompanied by a small midrib, short panicle, and reduced plant height. The phenotype of the dr plant was caused by a mutation within a single recessive gene on chromosome 2, dr (LOC_Os02g15230), which encodes a GDSL esterase. Analysis of wild-type and dr sequences revealed that the dr allele carried a single nucleotide substitution, glycine to aspartic acid. RNAi targeted to LOC_Os02g15230 produced same phenotypes to the dr mutation, confirming LOC_Os02g15230 as the dr gene. Microscopic observations and plant nutrient analysis of SiO2 revealed that silica was less abundant in dr leaves than in wild-type leaves. This study suggests that the dr gene is involved in the regulation of silica deposition and that disruption of silica processes lead to drooping leaf phenotypes.


Assuntos
Esterases/genética , Oryza/crescimento & desenvolvimento , Dióxido de Silício/metabolismo , Substituição de Aminoácidos , Clonagem Molecular , Esterases/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação , Oryza/genética , Oryza/metabolismo , Folhas de Planta/anatomia & histologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sequenciamento Completo do Genoma
4.
Ecotoxicol Environ Saf ; 205: 111298, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32950806

RESUMO

Mulberry (Morus atropurpurea) is an economically important woody tree and has great potential for the remediation of heavy metals. To investigate how cadmium accumulates and its detoxification in mulberry, we assessed the physiological and transcriptomic effects of cadmium contamination and as well as its chemical forms and subcellular distribution. Cadmium significantly inhibited mulberry plant growth and primarily accumulated in mulberry roots. Antioxidant enzymes were induced by cadmium in all tissues of mulberry. Subcellular fractionation analyses of cadmium indicated that the majority was compartmentalized in soluble fraction in roots while it mainly located in cell wall in leaves and stems. The greatest amount of the cadmium was integrated with proteins and pectates in all mulberry tissues. RNA-seq transcriptomic analyses of mulberry roots revealed that various metabolic pathways involved in cadmium stress response such as RNA regulation, hormone metabolism, and response to stress, secondary metabolism, as well as signaling, protein metabolism, transport, and cell-wall metabolism. These results will increase our understanding of the molecular mechanisms of cadmium detoxification in mulberry and provide new insights into engineering woody plants for phytoremediation.


Assuntos
Bioacumulação , Cádmio/toxicidade , Morus/efeitos dos fármacos , Poluentes do Solo/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Biodegradação Ambiental , Cádmio/metabolismo , Perfilação da Expressão Gênica , Morus/crescimento & desenvolvimento , Morus/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo , Estresse Fisiológico/genética
5.
Ecotoxicol Environ Saf ; 203: 111010, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888587

RESUMO

Manganese (Mn) toxicity is common in plants grown on very acid soils. However, some plants species that grow in this condition can take up high amounts of Mn and are referred to as hyperaccumulating species. In this study, we evaluated the capacity of Ilex paraguariensis to accumulate Mn and the effect of excessive concentrations on plant growth and nutrition. For this, a container experiment was conducted using soils from different parent materials (basalt and sandstone), with and without liming, and at six doses of applied Mn (0, 30, 90, 270, 540 and 1,080 mg kg-1). Clonal plants grown for 203 days were harvested to evaluate yield, and leaf tissue samples were evaluated for Mn and other elements. Without liming and with high Mn doses, leaf Mn concentrations reached 13,452 and 12,127 mg kg-1 in sandstone and basalt soils, respectively; concentrations in excess of 10,000 mg kg-1 are characteristic of hyperaccumulating plants. Liming reduced these values to 7203 and 8030 mg kg-1. More plant growth accompanied increased Mn leaf concentrations, with a growth reduction noted at the highest dose in unlimed soils. Elemental distribution showed Mn presence in the mesophyll, primarily in vascular bundles, without high Mn precipitates. Interveinal chlorosis of young leaves associated with high Mn concentration and lower Fe concentrations was observed, especially in sandstone soil without liming. However, the occurrence of this symptom was not associated with decreased plant growth.


Assuntos
Ácidos/farmacologia , Ilex paraguariensis/metabolismo , Manganês/metabolismo , Doenças das Plantas/induzido quimicamente , Poluentes do Solo/metabolismo , Ácidos/análise , Compostos de Cálcio/análise , Compostos de Cálcio/farmacologia , Ilex paraguariensis/efeitos dos fármacos , Ilex paraguariensis/crescimento & desenvolvimento , Ferro/metabolismo , Manganês/análise , Manganês/toxicidade , Óxidos/análise , Óxidos/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
6.
Virology ; 548: 192-199, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32758716

RESUMO

Plum pox virus (PPV) is a worldwide threat to stone fruit production. Its woody perennial hosts provide a dynamic environment for virus evolution over multiple growing seasons. To investigate the impact seasonal host development plays in PPV population structure, next generation sequencing of ribosome associated viral genomes, termed translatome, was used to assess PPV variants derived from phloem or whole leaf tissues over a range of plum leaf and bud developmental stages. Results show that translatome PPV variants occur at proportionately higher levels in bud and newly developing leaf tissues that have low infection levels while more mature tissues with high infection levels display proportionately lower numbers of viral variants. Additional variant analysis identified distinct groups based on population frequency as well as sets of phloem and whole tissue specific variants. Combined, these results indicate PPV population dynamics are impacted by the tissue type and developmental stage of their host.


Assuntos
Doenças das Plantas/virologia , Vírus Eruptivo da Ameixa/fisiologia , Prunus domestica/virologia , Frutas/virologia , Genoma Viral , Floema/virologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/virologia , Vírus Eruptivo da Ameixa/genética , Vírus Eruptivo da Ameixa/crescimento & desenvolvimento , Prunus domestica/crescimento & desenvolvimento
7.
Ecotoxicol Environ Saf ; 205: 111160, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32853864

RESUMO

The functional similarity between indigenous plant species (IPS) and invasive alien species (IAS) governs the invasion process of successful IAS because IPS and coexisting IAS suffer alike or even same ecological selection pressures. The aggravated condition created by heavy metal pollution (HMP) and drought stress may generate a noticeable impact on the invasive competitiveness and invasion process of IAS possibly via the variations in the functional similarity between IPS and IAS. Consequently, it is necessary to illumine the functional similarity between IPS and IAS under HMP and drought stress to clarify the mechanisms underlying the successful invasion of IAS. This study aims to estimate the functional similarity between IPS Amaranthus tricolor L. and IAS A. retroflexus L. under the condition with the alone and combined effects of HMP with different kinds (e.g., Cu and Pb) and drought stress [simulated by polyethylene glycol-6000 (PEG) solution]. HMP notably declines A. tricolor growth but has no remarkable effect on A. retroflexus growth. A. retroflexus displays a strong competitive intensity than A. tricolor under HMP. Further, HMP makes a greater stress intensity on A. tricolor growth than A. retroflexus growth. Therefore, HMP can accelerate A. retroflexus invasion. A. retroflexus displays a poor competitive intensity under drought stress. Thus, drought stress can hinder A. retroflexus invasion. However, drought stress causes a greater stress intensity on A. tricolor growth than A. retroflexus growth. Thus, the continued drought stress may converse the adverse effects of drought stress on A. retroflexus invasion potentially. The two Amaranthus species tend to diverge functionally under the combined HMP and drought stress. Further, A. retroflexus shows a strong competitive intensity than A. tricolor under the combined HMP and drought stress. Moreover, the combined HMP and drought stress induces a greater stress intensity on A. tricolor growth than A. retroflexus growth. Thus, the combined HMP and drought stress can facilitate A. retroflexus invasion. Meanwhile, the competitiveness for sunlight acquisition and leaf photosynthetic capacity may play a key role in the successful invasion of A. retroflexus under the combined HMP and drought stress.


Assuntos
Amaranthus/efeitos dos fármacos , Secas , Espécies Introduzidas , Metais Pesados/toxicidade , Poluentes do Solo/toxicidade , Amaranthus/crescimento & desenvolvimento , Modelos Teóricos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento
8.
Proc Natl Acad Sci U S A ; 117(35): 21766-21774, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817516

RESUMO

Leaf architecture directly determines canopy structure, and thus, grain yield in crops. Leaf droopiness is an agronomic trait primarily affecting the cereal leaf architecture but the genetic basis and underlying molecular mechanism of this trait remain unclear. Here, we report that DROOPY LEAF1 (DPY1), an LRR receptor-like kinase, plays a crucial role in determining leaf droopiness by controlling the brassinosteroid (BR) signaling output in Setaria, an emerging model for Panicoideae grasses. Loss-of-function mutation in DPY1 led to malformation of vascular sclerenchyma and low lignin content in leaves, and thus, an extremely droopy leaf phenotype, consistent with its preferential expression in leaf vascular tissues. DPY1 interacts with and competes for SiBAK1 and as a result, causes a sequential reduction in SiBRI1-SiBAK1 interaction, SiBRI1 phosphorylation, and downstream BR signaling. Conversely, DPY1 accumulation and affinity of the DPY1-SiBAK1 interaction are enhanced under BR treatment, thus preventing SiBRI1 from overactivation. As such, those findings reveal a negative feedback mechanism that represses leaf droopiness by preventing an overresponse of early BR signaling to excess BRs. Notably, plants overexpressing DPY1 have more upright leaves, thicker stems, and bigger panicles, suggesting potential utilization for yield improvement. The maize ortholog of DPY1 rescues the droopy leaves in dpy1, suggesting its conserved function in Panicoideae. Together, our study provides insights into how BR signaling is scrutinized by DPY1 to ensure the upward leaf architecture.


Assuntos
Brassinosteroides/metabolismo , Folhas de Planta/metabolismo , Setaria (Planta)/genética , Regulação da Expressão Gênica de Plantas/genética , Mutação , Fenótipo , Fosforilação , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Poaceae/genética , Poaceae/metabolismo , Setaria (Planta)/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo
9.
Chemosphere ; 261: 127721, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32745740

RESUMO

The uptake and distribution of Pb and the mechanisms involved in the metal tolerance have been investigated in a mine population of Biscutella auriculata. Seedlings were exposed to 125 µM Pb(NO3)2 for 15 days under semihydroponic conditions. The results showed an increase in the size of Pb-treated seedlings and symptoms of toxicity were not observed. ICP-OES analyses showed that Pb accumulation was restricted to root tissue. Imaging of Pb accumulation by dithizone histochemistry revealed the presence of the metal in vacuoles and cell wall in root cells. The accumulation of Pb in vacuoles could be stimulated by an increase in phytochelatin PC2 content. Pb did not promote oxidative damage and this is probably due the increase of antioxidative defenses. In the leaves, Pb produced a significant increase in superoxide dismutase activity, while in roots an increase in catalase and components of the Foyer- Halliwell-Asada cycle were observed. The results indicated that Biscutella auriculata has a high capacity to tolerate Pb and this is mainly due to a very efficient mechanism to sequester the metal in roots and a capacity to avoid oxidative stress. This species could therefore be very useful for phytostabilization and repopulation of areas contaminated with Pb.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/metabolismo , Bioacumulação/efeitos dos fármacos , Brassicaceae/metabolismo , Chumbo/metabolismo , Mineração , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Brassicaceae/efeitos dos fármacos , Brassicaceae/crescimento & desenvolvimento , Catalase/metabolismo , Chumbo/análise , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Fitoquelatinas/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Poluentes do Solo/análise
10.
PLoS One ; 15(7): e0235795, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645115

RESUMO

To investigate the growth, physiological changes and mechanism of drought resistance of Camellia oleifera GWu-2 under drought stress conditions, changes in the main growth and physiological indices of GWu-2 under different water gradients were studied. Factor analysis was used to study the differences between indicators under different water gradients, and correlation analysis was implemented to analyze the relationship between different factors. We observed that the growth state, enzyme secretion, stomatal morphology and leaf osmotic adjustment substances were significantly affected by drought stress. In particular, increases in leaf abscisic acid (ABA), indole acetic acid (IAA) and methyl jasmonate (MeJA) contents under drought stress were negatively correlated with the stomatal opening degree, and the ratio of ZR/GA3 was significantly correlated with the growth and physiological indicators of GWu-2, indicating that different hormones respond differently to drought stress and have different functions in the growth regulation and drought resistance of GWu-2. We concluded that the drought resistance mechanism of GWu-2 was controlled by maintaining root growth to obtain the necessary water, increasing the contents of osmotic substances of leaves to maintain water holding capacity, reducing the transpiration of water by increasing leaf ABA, IAA and MeJA content to close stomata and reducing the damage caused by drought by increasing the activity of superoxide dismutase (SOD).


Assuntos
Aclimatação , Camellia/fisiologia , Ácido Abscísico/metabolismo , Acetatos/metabolismo , Camellia/crescimento & desenvolvimento , Ciclopentanos/metabolismo , Secas , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Estômatos de Plantas/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Estresse Fisiológico , Água/metabolismo
11.
PLoS One ; 15(7): e0235928, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32697785

RESUMO

Several species of dryland cyanobacteria are known to occur as hypoliths under semi-translucent rocks. In the Mojave Desert, these organisms find refuge from intense solar radiation under milky quartz where moisture persists for a longer period of time than in adjacent soil surface habitat. Desert mosses, which are extremely desiccation-tolerant, can also occur in these hypolithic spaces, though little is known about this unique moss microhabitat and how species composition compares to that of adjacent soil surface communities. To address this question, we deployed microclimate dataloggers and collected moss samples from under and adjacent to 18 milky quartz rocks (quartz mean center thickness 26 ± 15 mm) in a western high elevation Mojave Desert site. Light transmission through Mojave quartz rocks may be as low as 1.2%, and data from microclimate loggers deployed for five months support the hypothesis that quartz provides thermal buffering and higher relative humidity compared to the soil surface. Of the 53 samples collected from hypolith and surface microhabitats, 68% were Syntrichia caninervis, the dominant bryophyte of the Mojave Desert biological soil crust. Tortula inermis accounted for 28% of the samples and 4% were Bryum argenteum. In a comparison of moss community composition, we found that S. caninervis was more likely to be on the soil surface, though it was abundant in both microhabitats, while T. inermis was more restricted to hypoliths, perhaps due to protection from temperature extremes. In our study site, the differences between hypolithic and surface microhabitats enable niche partitioning between T. inermis and S. caninervis, enhancing alpha diversity. This work points to the need to thoroughly consider microhabitats when assessing bryophyte species diversity and modelling species distributions. This focus is particularly important in extreme environments, where mosses may find refuge from the prevailing macroclimatic conditions in microhabitats such as hypoliths.


Assuntos
Briófitas/crescimento & desenvolvimento , Clima Desértico , Quartzo/química , Briófitas/fisiologia , Ecossistema , Umidade , Microclima , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Solo/química
12.
PLoS One ; 15(7): e0234648, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645027

RESUMO

Adaptation of weeds to water stress could result in the broader distribution, and make weed control task increasingly difficult. Therefore, a clear understanding of the biology of weeds under water stress could assist in the development of sustainable weed management strategies. Avena fatua (wild oat) and A. ludoviciana (sterile oat) are problematic weeds in Australian winter crops. The objectives of this study were to determine the growth and reproductive behaviour of A. fatua and A. ludoviciana at different soil moisture levels [20, 40, 60, 80, and 100% water holding capacity (WHC)]. Results revealed that A. fatua did not survive and failed to produce seeds at 20 and 40% WHC. However, A. ludoviciana survived at 40% WHC and produced 54 seeds plant-1. A. fatua produced a higher number of seeds per plant than A. ludoviciana at 80 (474 vs 406 seeds plant-1) and 100% WHC (480 vs 417 seeds plant-1). Seed production for both species remained similar at 80 and 100% WHC; however, higher than 60% WHC. Seed production of A. fatua and A. ludoviciana was 235 and 282 seeds plant-1, respectively, at 60% WHC. The 60% WHC reduced seed production of A. fatua and A. ludoviciana by 51 and 32% respectively, compared to 100% WHC. The plant height, leaf weight, stem weight, and root weight per plant of A. fatua at 60% WHC reduced by 45, 27, 32, and 59%, respectively, as compared with 100% WHC. Similarly, the plant height, leaf weight, stem weight, and root weight per plant of A. ludoviciana at 60% WHC reduced by 45, 35, 47 and 76%, respectively, as compared with 100% WHC. Results indicate that A. ludoviciana can survive and produce seeds at 40% of WHC, indicating the adaptation of the species to dryland conditions. The results also suggest that A. ludoviciana is likely to be robust under water stress conditions, potentially reducing crop yield. The ability of A. fatua and A. ludoviciana to produce seeds under water-stressed conditions (60% WHC) necessitates integrated weed management strategies that suppress these weeds whilst taking into account the efficient utilization of stored moisture for winter crops.


Assuntos
Avena/crescimento & desenvolvimento , Solo/química , Controle de Plantas Daninhas/métodos , Austrália , Fenômenos Biológicos , Produtos Agrícolas/crescimento & desenvolvimento , Desidratação/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Plantas Daninhas/crescimento & desenvolvimento , Água/metabolismo
13.
Ecotoxicol Environ Saf ; 203: 110943, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678750

RESUMO

High temperature damage impairs the growth of tall fescue by inhibiting secondary metabolites. Little is known about the regulation pattern of the fatty acids and carbohydrate metabolism at the whole-transcriptome level in tall fescue under high temperature stress. Here, two tall fescue genotypes, heat tolerant PI578718 and heat sensitive PI234881 were subjected to high temperature stress for 36 h. PI 578718 showed higher SPAD chloroplast value, lower EL and leaf injury than PI 234881 during the first 36 h high-temperature stress. Furthermore, by transcriptomic analysis, 121 genes were found to be induced during the second energy production phase in tall fescue exposed to high-temperature conditions, indicating that there may be one energy-sensing system in cool-season turfgrass to adapt high-temperature conditions. PI 578718 showed higher differentially expressed unigenes involved in fatty acids and carbohydrate metabolism compared with PI 234881 for 36 h heat stress. Interestingly, a metabolomic analysis using GC-MS uncovered that the sugars and sugar alcohol accounted for more than 65.06% of the total 41 metabolites content and high-temperature elevated the rate to 82.89-91.16% in PI 578718. High-temperature damage decreased the rate of fatty acid in the total 41 metabolites content and PI 578718 showed lower content than in PI 234881, which might be attributed to the down-regulated genes in fatty acid biosynthesis pathway in tall fescue. The integration of deep transcriptome and metabolome analyses provides systems-wide datasets to facilitate the identification of crucial regulation factors in cool-season turfgrass in response to high-temperature damage.


Assuntos
Metabolismo dos Carboidratos/efeitos dos fármacos , Ácidos Graxos/metabolismo , Festuca , Resposta ao Choque Térmico , Temperatura Alta , Metabolismo dos Carboidratos/genética , Ácidos Graxos/genética , Festuca/genética , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Perfilação da Expressão Gênica , Resposta ao Choque Térmico/genética , Metabolômica , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
14.
Aquat Toxicol ; 226: 105559, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32652412

RESUMO

High nitrate (NO3--N) concentration is a growing aquatic risk concern worldwide. However, adverse effects of high NO3--N concentration on submerged macrophytes-epiphytic biofilms are unclear. In this study, the alterations in physiological changes, biofilms formation and chemical compositions were investigated on leaves of Vallisneria asiatica exposed to different NO3--N concentrations. The findings showed that 10 mg L-1NO3--N resulted in low photosynthetic efficiency by inhibiting chlorophyll content 26.2 % and decreased intrinsic efficiency of photosystem II significantly at 14th day post treatment. Malondialdehyde, several antioxidant enzyme activities (i.e., superoxide dismutase, peroxidase and catalase), and secondary metabolites (i.e., phenolic compounds and anthocyanin) were all significantly up-regulated with 10 mg L-1NO3--N, implied oxidative stress were stimulated. However, no significant alterations in these indicators were observed with 5 mg L-1NO3--N. Compared to control, 10 mg L-1NO3--N concentration significantly stimulated microbes growth in biofilm and reduced the roughness of leaf-biofilms surface, but it had little effect on the biofilms distribution (from single clone to blocks) as revealed by scanning electron microscope and multifractal analysis. Results from X-ray photoelectron spectroscopy analysis showed that the percentage of P, Cl, K and the ratio of O1 (-O-) /O2 (C = O) were higher in leaves of control than treatments with 10 mg L-1NO3--N, indicating that 10 mg L-1NO3--N concentration exhibited significant inhibition of chemical activity and nutrient uptake of the leaf surfaces. Overall, these results demonstrated that high NO3--N does stimulate the biofilm growth and can cause negative impacts on submerged macrophytes growth.


Assuntos
Biofilmes/crescimento & desenvolvimento , Hydrocharitaceae/efeitos dos fármacos , Nitratos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Biofilmes/efeitos dos fármacos , Catalase/metabolismo , Clorofila/metabolismo , Hydrocharitaceae/crescimento & desenvolvimento , Hydrocharitaceae/metabolismo , Hydrocharitaceae/microbiologia , Malondialdeído/metabolismo , Peroxidases/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Superóxido Dismutase/metabolismo
15.
Ecotoxicol Environ Saf ; 203: 111017, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678748

RESUMO

In this study, the effect of two metal-immobilizing bacterial strains, Serratia liquefaciens CL-1 and Bacillus thuringiensis X30, on the availability of Cd and Pb and the metal accumulation in potato tubers, as well as the underlying mechanisms in metal-contaminated soils were characterized. Moreover, the impacts of the strains on metal immobilization, pH, and NH4+ concentration in metal-contaminated soil solutions were evaluated. Strains CL-1 and X30 increased tuber dry weight by 46% and 40%, reduced tuber Cd and Pb contents by 68-83% and 42-47%, and decreased the Cd and Pb translocation factors by 61-70% and 30-34%, respectively, compared to the controls. Strains CL-1 and X30 decreased the available Cd and Pb contents by 52-67% and 30-44% and increased the NH4+ content by 55% and 31%, pH, urease activity by 70% and 41%, and relative abundance of ureC gene copies by 37% and 20% in the rhizosphere soils, respectively, compared with the controls. Reduced Cd and Pb concentrations and increased pH and NH4+ concentration were found in the bacteria-inoculated soil solution compared to the controls. These results suggested that the strains reduced tuber metal uptake through decreasing the metal availability and increasing the pH, ureC gene relative abundance and urease activity as well as decreasing the metal translocation from the leaves to tubers. These results may provide an effective metal-immobilizing bacteria (especially strain CL-1)-enhanced approach to reduce metal uptake of potato tubers in metal-polluted soils.


Assuntos
Bacillus thuringiensis/metabolismo , Metais Pesados/metabolismo , Serratia liquefaciens/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Urease/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Chumbo/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Rizosfera , Solo/química , Poluentes do Solo/análise , Solanum tuberosum/metabolismo , Especificidade da Espécie
16.
Chemosphere ; 260: 127521, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32688310

RESUMO

The Punchuncaví Valley is one of the most polluted areas in central Chile affected by anthropogenic emissions from the Ventanas Industrial Complex (IC) where the most important industry is the copper smelter and refinery. In this context, this research aims were to assess the usefulness of the Cupressus macrocarpa as a biomonitor. The leaf samples were taken from five selected sites, located between 0.8 and 15 km away from the source. A total of 34 elements were analyzed in leaf samples by ICP-MS and examined by enrichment factor (EF), hierarchical cluster analysis (HCA), and principal component analysis (PCA). Leaf concentration of As, Ca, Cd, Cu, Dy, Er, Gd, K, Li, Mg, Mn, Mo, Na, Nd, P, Pb, Pr, S, Sb, Sr, Ti, Yb and Zn showed statistically significant differences between sampling sites (p-value < 0.05). A clear trend to increase the concentration of Cu, Sb, S, As, Cd and Pb with the proximity to the IC. Besides, high values of Cu (93.4-369 mg kg-1) and As (7.6-12.7 mg kg-1) were observed near to industrial area exceed the phytotoxic levels reported in plants with EF > 3000% for Cu and >1300% for As. The application of PCA and HCA identified 6 factors related to the industrial complex, traffic and geogenic sources, providing the greatest variance the component related to industrial activity mainly with copper smelter and refinery. According to the results, the C. macrocarpa leaves are a good biomonitor to evaluate the high pollution load for anthropogenic elements in industrial areas.


Assuntos
Poluentes Atmosféricos , Monitoramento Biológico/métodos , Cupressus/química , Metalurgia , Folhas de Planta/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Chile , Cupressus/crescimento & desenvolvimento , Metais/análise , Metais/toxicidade , Folhas de Planta/crescimento & desenvolvimento , Análise de Componente Principal , Oligoelementos/análise , Oligoelementos/toxicidade
17.
Mol Genet Genomics ; 295(6): 1393-1400, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32651630

RESUMO

Anthocyanins are a group of important secondary metabolites, functioning as colorant in plant organs as well as protective agents against several stresses. Sub-red plant (Rs) cottons, accumulating moderate level of anthocyanins in shoots, had increased photosynthesis efficiency compared to green- (GL) and red-plant (R1) cottons. The present work aimed to clarify the molecular base of anthocyanin regulation in Rs cotton. It was found that GhPAP1A was significantly up-regulated in Rs plants compared to GL cottons, but its expression level is lower than that of GhPAP1D in R1 plants. Virus induced gene silencing of GhPAP1s inhibited the red pigmentation in Rs plants. Comparative cloning revealed a 50-bp tandem repeat in the promoter of GhPAP1A in Rs cotton, which showed stronger activity to drive the expression of downstream genes in petals. Considered that the coding sequence of GhPAP1As from Rs and GL cottons had similar functions to promote anthocyanin biosynthesis in transgenic tobaccos, we attributed moderate anthocyanin accumulation in Rs cotton to increased transcription of GhPAP1A, resulted from varied promoter structure. Our works suggested GhPAP1s as useful tool to manipulate anthocyanin level and several breeding targets, including herbivore- and pathogen- resistance, high photosynthesis efficiency and colored fibers.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Gossypium/metabolismo , Pigmentação/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Gossypium/genética , Gossypium/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética
18.
PLoS One ; 15(6): e0232633, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555651

RESUMO

Maize, a main crop worldwide, establishes a mutualistic symbiosis with arbuscular mycorrhizal (AM) fungi providing nutrients to the roots from soil volumes which are normally not in reach of the non-colonized root. The mycorrhizal phosphate uptake pathway (MPU) spans from extraradical hyphae to root cortex cells housing fungal arbuscules and promotes the supply of phosphate to the mycorrhizal host in exchange for photosynthetic carbon. This symbiotic association with the mycobiont has been shown to affect plant host nutritional status and growth performance. However, whether and how the MPU affects the root microbial community associated with mycorrhizal hosts in association with neighboring plants, remains to be demonstrated. Here the maize germinal Mu transposon insertion mutant pht1;6, defective in mycorrhiza-specific Pi transporter PHT1;6 gene, and wild type B73 (wt) plants were grown in mono- and mixed culture and examined under greenhouse and field conditions. Disruption of the MPU in pht1;6 resulted in strongly diminished growth performance, in reduced P allocation to photosynthetic source leaves, and in imbalances in leaf elemental composition beyond P. At the microbial community level a loss of MPU activity had a minor effect on the root-associated fungal microbiome which was almost fully restricted to AM fungi of the Glomeromycotina. Moreover, while wt grew better in presence of pht1;6, pht1;6 accumulated little biomass irrespective of whether it was grown in mono- or mixed culture and despite of an enhanced fungal colonization of its roots in co-culture with wt. This suggested that a functional MPU is prerequisite to maintain maize growth and that neighboring plants competed for AM fungal Pi in low P soil. Thus future strategies towards improving yield in maize populations on soils with low inputs of P fertilizer could be realized by enhancing MPU at the individual plant level while leaving the root-associated fungal community largely unaffected.


Assuntos
Micorrizas/metabolismo , Fosfatos/metabolismo , Zea mays/microbiologia , Zea mays/fisiologia , Biomassa , Mutação com Perda de Função , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas , Solo/química , Simbiose/fisiologia , Zea mays/genética , Zea mays/crescimento & desenvolvimento
19.
PLoS One ; 15(6): e0234512, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32511280

RESUMO

Nutritional deficiencies limit the growth of snap bean plants, therefore knowing the biological mechanisms involved in it is fundamental. This study is aimed to evaluate the damage caused by a deficiency of macronutrients in physiological variables that cause decreased growth and the appearance of visual symptoms in snap bean. Thus, we design a hydroponic system of snap bean cultivation in order to test the effect of macronutrient deficiencies in a controlled environment. The treatments consisted in evaluate the effects of lack of one macronutrient in time. To perform this, we used Hoagland and Arnon solution in its complete formulation (control) or without N, P; K; Mg, Ca or S in each treatment. Physiological, nutritional, and growth analyses were performed when visual deficiency symptoms of each omitted nutrient appeared. Thus, the omissions of N and P in the nutrient solution led to lower accumulations of all macronutrients in the shoot. And the K, Ca, Mg, and S omissions decreased the amounts of K, Ca, Mg, P, and S in the shoot of the snap bean plants when compared with the plants grown in the complete nutrient solution. With the lowest accumulation of macronutrients, the content of photosynthetic pigments and the photosynthetic rate were reduced, with harmful effects on plant growth. Thus, from the losses in dry matter production of the shoot, the order of limiting of macronutrients in bean plants was N < P < Ca < S < Mg < K, with a decrease of up to 86.2%, 80.1%, 51.2%, 46.5%, 25.6%, and 19.3%, respectively. The nitrogen deficiency is more evident, proven by symptoms such as chlorosis in the lower and upper third leaves and necrosis of the lower third leaves.


Assuntos
Nitrogênio/metabolismo , Nutrientes/metabolismo , Phaseolus/crescimento & desenvolvimento , Fotossíntese/genética , Ambiente Controlado , Hidroponia , Nutrientes/fisiologia , Phaseolus/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Potássio/metabolismo
20.
Ecotoxicol Environ Saf ; 201: 110822, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32534334

RESUMO

Boron (B) toxicity is an important abiotic constraint that limits crop productivity mainly in arid and semi-arid areas of the world. High levels of B in soil disturbs several physiological and biochemical processes in plant. The aim of this study was to investigate the function of melatonin (Mel) in the regulation of carbohydrate and proline (Pro) metabolism, photosynthesis process and antioxidant system of wheat seedlings under B toxicity conditions. High levels of B inhibited net photosynthetic rate (PN), stomatal conductance (gs), content of chlorophyll (Chl) a, b, δ-aminolevulinic acid (δ-ALA), nitrogen (N) and phosphorus (P), and increased accumulation of B, Chl degradation and activity of chlorophyllase (Chlase; a Chl degrading enzyme), and downregulated the activity of enzymes (δ-ALAD; δ-aminolevulinic acid dehydratase) involved in the biosynthesis of photosynthesis pigments, photosynthesis (carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase) and carbohydrate metabolism (cell wall invertase, CWI) in wheat seedlings. Also, high levels of B caused oxidative damage by increasing the content of malondialdehyde, superoxide anion and H2O2, and activity of glycolate oxidase (an H2O2-producing enzyme) in leaves of seedlings. However, foliar application of Mel significantly improved photosynthetic pigments concentration by increasing δ-ALA, δ-ALAD and decreasing Chl degradation and Chlase activity and led to an increase of plant growth attributes under both B toxicity and non-toxicity conditions. Under normal and B toxicity conditions, exogenous Mel also improved content of N, P, total soluble carbohydrates (TSCs) and Pro, and upregulated activity of CWI and Δ1-pyrroline-5-carboxylate synthetase. Mel significantly suppressed the adverse effects of excess B by alleviating cellular oxidative damage through enhanced reactive oxygen species scavenging by superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and lipoxygenase, and content of total phenolic compounds (TPC), ascorbate and reduced glutathione. These results postulate that Mel induced plant defense mechanisms by enhancing Pro, TSCs, TPC, nutrients (N and P) uptake and enzymatic and non-enzymatic antioxidants.


Assuntos
Antioxidantes/metabolismo , Boro/toxicidade , Melatonina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Metabolismo dos Carboidratos/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
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