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1.
Ying Yong Sheng Tai Xue Bao ; 30(9): 2955-2963, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529870

RESUMO

Light is a key factor affecting seed germination and seedling growth. In this study, seed germination and seedling growth of Cunninghamia lanceolata and Schima superba were compared under controlled conditions with five light treatments (100%, 60%, 40%, 15% and 5% of full sunlight). The results showed that light intensity significantly impacted seed germination and seedling growth of both species. With decreasing light intensity, the germination rate and germination index of C. lanceolata increased, while those of S. superba showed a trend which increased first and then decreased, with the maximum at 40% light intensity. The seedling survival rate of both species was 0 under full sunlight, while significantly decreased with decreasing light intensity from 60% to 5%. Root length, basal stem diameter and height showed a consistent trend with the change of light availability in both species. Root length significantly decreased, basal stem diameter and height increased first and then decreased with decreasing light intensity, with the minimum at 5% light intensity. With decreasing light intensity, root biomass, stem biomass, leaf biomass and total biomass of C. lanceolata seedlings declined, while high biomass accumulation of S. superba seedlings were observed in 15%-60% light intensities, and lowest at 5% light intensity. Biomass accumulation in each organ of S. superba seedlings was greater than that of C. lanceolata seedlings under the same light intensity. High stem biomass and leaf biomass, low root biomass and root to shoot ratio were a phenotypic response to low light intensity in C. lanceolata and S. superba seedlings grown under poor light condition. The growth of C. lanceolata is better under relatively high light intensity than S. superba. Whereas S. superba is moderately shade-tolerant at the seedling stage, thus is more suitable for planting under closed canopy.


Assuntos
Cunninghamia/fisiologia , Germinação/fisiologia , Plântula/crescimento & desenvolvimento , Theaceae , Sementes
2.
J Agric Food Chem ; 67(38): 10764-10773, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31487158

RESUMO

It has been hypothesized that the α-methylene-γ-lactone moiety of sesquiterpene lactones is a key unit for their bioactivity. As a consequence, modifications of these compounds have been focused on this fragment. In the work reported here, two sesquiterpene lactones, namely, dehydrocostuslactone and ß-cyclocostunolide, a eudesmanolide obtained by controlled cyclization of costunolide, were chosen for modification by Michael addition at C-13. On applying this reaction to both compounds, it was possible to introduce the functional groups alkoxy, amino, carbamoyl, hydroxy, and thiol to give products in good to high yields, depending on the base and solvent employed. In particular, the introduction of a thiol group at C-13 in both compounds was achieved with outstanding yields (>90%) and this is unprecedented for these sesquiterpene lactones. The bioactivities of the products were evaluated on etiolated wheat coleoptile elongation and germination of seeds of parasitic weeds, with significant activity observed on Orobanche cumana and Phelipanche ramosa. The structure-activity relationships are discussed.


Assuntos
Lactonas/química , Orobanchaceae/química , Orobanche/química , Extratos Vegetais/química , Plantas Daninhas/química , Sesquiterpenos/química , Germinação , Estrutura Molecular , Orobanchaceae/crescimento & desenvolvimento , Orobanche/crescimento & desenvolvimento , Plantas Daninhas/crescimento & desenvolvimento , Sementes/química , Sementes/crescimento & desenvolvimento , Compostos de Sulfidrila/química
3.
An Acad Bras Cienc ; 91(3): e20180504, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31432902

RESUMO

Somatic embryogenesis from explants from hermaphrodite papaya mother plants is an alternative for the production of true-to-type plants without the need for sexing. This study aimed to analyze hormonal and osmotic inducers in different somatic embryogenesis stages in the commercial hermaphrodite hybrid papaya UENF/Caliman 01. Leaf disks from in vitro shoots originated from ex vitro hermaphrodite plants were cultured in induction medium supplemented with different concentrations of 2,4-D (6, 9, 12, 15, and 18 µM) and 4-CPA (19, 22, 25, 28, and 31 µM). After 90 days, the formation of somatic embryos was verified. The 2,4-D induced the formation of light brown calli with low frequency (20%) of somatic embryogenesis. However, 4-CPA (25 µM) induced 96% of embryogenic calli, which were transferred to maturation medium (MM) and cultured for 30 days. The MM contained ABA (0.5 µM) and AC (15 g L-1) and produced 36.6 somatic embryos callus-1, mainly on cotyledonary stage. Cotyledonary embryos were transferred to germination medium supplemented with gibberellic acid (GA3) (0.0, 1.44, 2.88, and 4.32 µM), and the conversion into plantlets was enhanced with GA3 at 2.88 µM.


Assuntos
Carica/embriologia , Carica/fisiologia , Germinação/fisiologia , Técnicas de Embriogênese Somática de Plantas/métodos , Fatores de Tempo
4.
Oecologia ; 191(1): 165-175, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31372894

RESUMO

Alternative vegetation types that switch from one to another under contrasting fire regimes are termed fire-mediated alternative stable states (FMASS). Typically, pyrophylic communities (i.e., vegetation assemblages favored by burning) dominate under high frequencies or intensities of fire. Conversely, fire-sensitive (pyrophobic) vegetation types persist under long fire-free conditions. As the persistence traits of plants of FMASS systems are generally poorly researched, threshold levels of pyric disturbance that trigger 'state-switching' are often unknown. Dense thickets of the obligate-seeder shrub waputi (Aluta maisonneuvei ssp. maisonneuvei [Myrtaceae]) form fire-retarding woody islands within highly flammable spinifex (Triodia spp.) grasslands in arid Australia. To examine the tolerance of Aluta thickets to burning, we investigated: (1) the influence of post-fire rainfall and fire severity on recruitment (a field study); (2) soil seedbank densities (a field study); and (3) fire-related dormancy cues in seeds (a germination trial). We found a positive relationship between recruitment and post-fire rainfall volume, and much higher mean recruitment at sites with high- (5.9 seedlings/m2) than low-severity-burnt (2.2 seedlings/m2) and unburnt shrubs (0.03 seedlings/m2). Post-fire regeneration was mediated by dense soil-borne seedbanks, and the germination trial indicated that smoke promoted germination. Although Aluta shrubs are invariably fire-killed, high-severity fires are unlikely to lead to state shifts from shrubland to grassland because of the ability of mature stands to regenerate from dense, fire-cued seedbanks. Nevertheless, given that Aluta seedlings are exceptionally slow-growing, post-fire droughts combined with fire-return intervals less than the Aluta primary juvenile period of c. 5 years could drive conversion from Aluta- to Triodia-dominated vegetation.


Assuntos
Fogo , Austrália , Germinação , Sementes , Austrália Ocidental
5.
Food Chem ; 298: 125019, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260984

RESUMO

This study aims to investigate the postharvest physiology and texture of garlic cloves packaged in polyethylene terephthalate (PET), polyethylene (PE), aluminized kraft paper (AKP), single kraft paper (SKP), and mesh bag. Germination rate, electrical conductivity, respiration intensity, water content, and texture were determined during 180 d storage at -2 °C. Results showed that the germination of garlic cloves packaged in PET, PE, and AKP was effectively inhibited during storage. PE effectively reduced the degree of damage to the cell membranes of the garlic cloves. PE and SKP significantly inhibited respiratory intensity during storage. Garlic cloves water content did not change significantly in 90 d storage which packaged in PE and SKP. PE exhibited better effect on the texture and freshness of garlic cloves than the other materials. In conclusion, PE is the best packaging material for maintaining the quality attributes and extending the shelf lives of garlic cloves.


Assuntos
Embalagem de Alimentos , Alho/fisiologia , Polietileno , Condutividade Elétrica , Armazenamento de Alimentos , Germinação , Polietilenotereftalatos , Refrigeração , Água/análise
6.
Sheng Wu Gong Cheng Xue Bao ; 35(7): 1277-1285, 2019 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-31328484

RESUMO

Leaf water potential of peanut subjected to drought stress is positively related to the oil content of peanut kernels. The aim of this study was to directly screen the high oil mutants of peanut and create the new peanut varieties using hydroxyproline as water potential regulator. In vitro mutagenesis was carried out with the embryonic leaflets of peanut variety Huayu 20 as explants and pingyangmycin as a mutagen added into the somatic embryo formation medium. The formed somatic embryos were successively transferred to somatic embryo germination and selection medium containing 6 mmol/L hydroxyproline (at -2.079 MPa water potential ) to induce regeneration and directionally screen high oil content mutants. After that, these plantlets were grafted and transplanted to the experimental field and 132 high oil mutants with oil content over 55% were obtained from the offspring of regenerated plants. Finally, among them, the oil contents of 27 lines were higher than 58% and of 2 lines were higher than 60%. A new peanut variety Yuhua 9 with high yield and oil content was bred from the regenerated plant progenies combining the pedigree breeding method. The yield was 14.0% higher than that of the control cultivar in the testing new peanut varieties of Liaoning province, and also it has passed the national registration of non-major crop varieties. Yuhua 9 with an oil content of 61.05%, which was 11.55 percentage points higher than that of the parent Huayu 20, was the peanut cultivar with the highest oil content in the world. The result showed that it was an effective way for directional breeding of high oil peanut varieties by means of the three-step technique including in vitro mutagenesis, directional screening by reducing water potential in medium and pedigree selection of regenerated plant progenies.


Assuntos
Arachis , Germinação , Secas , Mutagênese , Melhoramento Vegetal
7.
Zhongguo Zhong Yao Za Zhi ; 44(12): 2444-2451, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359709

RESUMO

We studied the seed germination of Astragalus membranaceus under PEG and Na Cl osmotic stress gradients( 0,-0. 1,-0. 3,-0. 5,-0. 7 MPa) respectively applied with light( continuous light,light 12 h/dark 12 h circulation and continuous dark) and temperature( constant 15 ℃,15 ℃ 12 h/30 ℃ 12 h circulation and constant 30 ℃) treatments. The results showed as following: ① Under the light and temperature interactive treatments,total germination percentage( TGP) was restrained by high temperature and continuous light also decreased TGP under high temperature. Mean germination time( MGT) was not changed by light mode. Root development was enhanced by dark and low temperature. Shoot development was enhanced by light and high temperature. Hypocotyl length was enhanced by dark and high temperature. ② Under the light and temperature interactive treatments combined respectively with PEG and NaCl stress conditions,although the inhibitions of seed germination and growth were gradually strengthened with the increases of osmotic stresses,slight osmotic stress can promote seed germination. Under the same osmotic potential,the effects of PEG on TGPs and MGTs were stronger than that of NaCl. As the temperature increase,the seeds may change from photo-neutrality to photo-phobia. Decreased TGP under drought and continuous light interactive treatment is an adaptation strategy to avoiding drought. Hypocotyl growth accelerated under continuous dark treatment is an ecological trait which could increase dry matter input in stem and height for more light. Seed development under high concentration of NaCl treatment is better than that of PEG treatment due to low water potential caused by Na~+,which can enter into seed coat and promote water absorption.


Assuntos
Astragalus propinquus/fisiologia , Secas , Germinação , Estresse Salino , Sementes/fisiologia , Astragalus propinquus/efeitos da radiação , Luz , Sementes/efeitos da radiação , Temperatura Ambiente
8.
Food Chem ; 299: 125095, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31279124

RESUMO

Hydrogen gas (H2), a multifunctional signaling molecule, has received increasing attention in recent years. In the present study, hydrogen-rich water (HRW) (2 ppm) was used for the processing of sprouted black barley (Hordeum distichum L.), and the results showed that the HRW treatment could significantly increase the germination rate and growth rate of black barley (P < 0.05). A chemical component analysis showed that in sprouted black barley, the HRW treatment could change the distribution of phytochemicals (e.g., the ionic strength of guanosine), increase the concentrations of free vanillic acid, coumaric acid, sinapic acid, conjugated sinapic acid, Ca and Fe and the hydroxyl radical scavenging rate, and decrease the protein, fat, starch and dietary fibre contents compared with the results obtained after treatment with ultra-pure water (P < 0.05). HRW can be used for the processing of sprouted grains to effectively increase their germination efficiency and concentrations of bioactive phytochemicals.


Assuntos
Hordeum/química , Hordeum/crescimento & desenvolvimento , Hidrogênio/farmacologia , Antioxidantes/análise , Cromatografia Líquida , Fibras na Dieta/análise , Germinação/efeitos dos fármacos , Hordeum/efeitos dos fármacos , Radical Hidroxila/análise , Espectrometria de Massas , Proteínas de Vegetais Comestíveis/análise , Amido/análise , Água/química , Água/farmacologia
9.
Chemosphere ; 233: 905-912, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340418

RESUMO

We investigated the interconnected roles of reactive oxygen species (ROS) generated upon seed exposure to glyphosate and/or gibberellic acid (GA3), and the possible interaction between the herbicide and the plant hormone during germination of sorghum seeds. GA3 decreased antioxidant enzyme activity in embryos, and the over accumulation of hydrogen peroxide (H2O2) in 1000 mM GA3-treated seeds resulted in the lowest germinability among treatments. The deleterious effects of glyphosate on germination rate, in contrast, were not related to H2O2 accumulation, but to its interference with the mitochondrial electron transport chain. However, interactions among glyphosate, GA3 and H2O2 during seed germination were observed. Similar to paclobutrazol, glyphosate appears to interfere with the de novo synthesis of gibberellin, which modulates seed germination through oxidative metabolism. Seeds experiencing increased oxidative status due to GA3 (100 mM) or H2O2 (50 mM) applications had the effects of glyphosate on germination rate reversed. Since decreased ATP synthesis is a secondary effect of glyphosate, increased H2O2 concentrations in embryos must facilitate germination by decreasing the energy required by ATP-demanding metabolism. Our results showed that glyphosate affect seed germination of sorghum, and that the herbicide interacts with oxidative and gibberellin metabolisms.


Assuntos
Germinação/efeitos dos fármacos , Giberelinas/metabolismo , Glicina/análogos & derivados , Herbicidas/farmacologia , Peróxido de Hidrogênio/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Sorghum/metabolismo , Antioxidantes/metabolismo , Grão Comestível/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Glicina/farmacologia , Sementes/efeitos dos fármacos
10.
Chemosphere ; 233: 920-935, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340420

RESUMO

The current study aimed to investigate the impacts of different concentrations of GO/PANI nanocomposites (25, 50 and 100 mg L-1), in comparison with GO and PANI, on seed germination behaviors, morpho-physiological and biochemical traits in intact (mucilaginous) and demucilaged seeds, and young seedlings of the medicinal plant Salvia mirzayanii. Upon exposure to GO, seed germination was delayed and reduced, and growth attributes (root and shoot length, shoot fresh weight, and total chlorophyll content) declined, all of which could be attributed to the reductions in water uptake and oxidative stress particularly in demucilaged seeds. A hormetic dose-dependent response was observed for the growth traits in both intact and demucilaged seedlings upon exposure to GO/PANI concentrations, i.e. low-concentration stimulation and high-concentration repression. Elevated levels of H2O2 in shoot tissue of the seedlings exposed to GO and high concentration of GO/PANI, in comparison with those exposed to low levels of GO/PANI and control, were linked with the activities of the antioxidant enzymes SOD, CAT, POD, and total phenolics. Overall, the results showed high toxicity of GO on germination and early growth of S. mirzayani that was more evident in demucilaged seedlings, whereas GO/PANI stimulated germination, and the effects on seedling growth were stimulatory or inhibitory depending on the application dose and presence of mucilage. Furthermore, the capacity of GO/PANI nanocomposites to improve germination and cause a regular porosity pattern in roots accompanied by improved water uptake and early establishment of S. mirzayanii propose potential implications of GO/PANI nanocomposites for seeds/plants in drought-prone ecosystems.


Assuntos
Compostos de Anilina/toxicidade , Antioxidantes/farmacologia , Germinação/efeitos dos fármacos , Grafite/toxicidade , Salvia/metabolismo , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Catalase/metabolismo , Clorofila , Peróxido de Hidrogênio/farmacologia , Nanocompostos , Estresse Oxidativo/efeitos dos fármacos , Mucilagem Vegetal/metabolismo , Superóxido Dismutase/metabolismo , Água
11.
Pestic Biochem Physiol ; 157: 53-59, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31153477

RESUMO

Indian hedge mustard (Sisymbrium orientale) (IHM) is an important broadleaf weed across southern Australia. Resistance to sulfonylurea (SU) herbicides that inhibit acetohydroxyacid synthase (AHAS) is extensive in Australia, but resistance to imidazolinone (IMI) herbicides has only been reported recently. The AHAS-mutation profile of 65 IHM populations collected randomly from cropped fields was investigated to better understand the extent and types of resistance present. Resistance to SU herbicides was present in 40% of the populations and resistance to IMI herbicides in 11%. Mutations were identified in SoAHAS by sequence analysis, and included previously reported amino-acid substitutions at Pro197 and Trp574, but also new substitutions at Pro197 and Asp376 for this species. One population with possible non-target-site resistance was identified. Germination studies with fresh seed found no significant effect by mutations in SoAHAS on germination; however, population factors had a large effect on germination in S. orientale. Resistance to AHAS-inhibiting herbicides in populations of S. orientale is endowed by mutations in SoAHAS in all but one population examined. Mutations at Pro197 conferring resistance to SU herbicides were most common, while mutations at Trp574 that provide resistance to IMI herbicides are also present.


Assuntos
Acetolactato Sintase/genética , Herbicidas/farmacologia , Mostardeira/genética , Mutação/genética , Austrália , Germinação/efeitos dos fármacos , Germinação/genética , Mostardeira/efeitos dos fármacos
12.
J Sci Food Agric ; 99(13): 6089-6096, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31250437

RESUMO

BACKGROUND: Panax ginseng seeds have strong dormancy and a prolonged germination period in comparison to other seeds; thus, it is a great challenge to propagate ginseng. Seed longevity is closely associated with germination rate and viability, so we assumed that if a seed loses its viability, specific metabolic alterations regarding plant growth factors might occur. In this study, we divided ginseng seeds into normal and accelerated-aging groups. Both groups were treated with gibberellic acid, which is one of the most important plant-growth regulators. Afterward, gas chromatography-mass spectrometry (GC-MS) was used to analyze the samples, to identify the metabolic alterations between the two groups. RESULTS: Forty-four endogenous metabolites in normal and accelerated aging groups were putatively identified. To determine the differential significance of these metabolites, t-tests and fold-change analysis were conducted followed by principal component analysis and partial least-squares discriminant analysis to determine the metabolites that showed distinct responses between the groups. Among the differentially expressed metabolites (P value < 0.05 and FDR < 0.1), nine metabolites were selected as potential biomarker candidates for the prediction of seed longevity. CONCLUSION: Nine metabolites related to ginseng seed longevity were identified by comparing metabolomes. Our findings suggest that ginseng propagation can be facilitated by the regulation of these distinctive metabolic features of the seeds. © 2019 Society of Chemical Industry.


Assuntos
Panax/metabolismo , Extratos Vegetais/química , Sementes/química , Análise Discriminante , Cromatografia Gasosa-Espectrometria de Massas , Germinação , Giberelinas/farmacologia , Análise dos Mínimos Quadrados , Metabolômica , Panax/química , Panax/efeitos dos fármacos , Panax/crescimento & desenvolvimento , Extratos Vegetais/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
13.
Sci Total Environ ; 683: 737-748, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31150894

RESUMO

The presence of plastic bags on coastal dunes worldwide is well documented. Plastic bags contain additives that during rainfall events can leach out from bags into sand dune and be absorbed by seeds and roots of plants. Dune plants play a fundamental role in dune system formation, yet the possible impact of bag leaching on their establishment and development has been neglected. We assessed in laboratory whether (i) not biodegradable bags (high-density polyethylene, PE) and new generation of compostable bags (Mater-bi®, MB) would influence via leaching water chemical/physical properties and (ii) leachates would affect germination and seedling growth using Thinopyrum junceum and Glaucium flavum as models. Leachates were obtained from different amounts of not-exposed and bags exposed to beach or marine conditions simulating various pollution degrees (none, low, intermediate and high pollution). All water variables were affected by leaching. The magnitude of these alterations depended on bag type and environmental exposure. Seeds of T. junceum treated with the high concentration of marine-exposed MB bag leachate germinated later than controls while those of G. flavum treated with the remaining leachates germinated earlier. For both species, leachates from the low concentration of PE and MB marine-exposed bags increased seed germinability. A short radicle was observed in T. junceum seedlings treated with not-exposed MB bag leachates. Glaucium flavum seedlings treated with beach- and marine-exposed PE bags and not-exposed MB bags leachates showed a greater below-aboveground length ratio and those grown with the low concentration of not-exposed PE bag leachate had a longer hypocotyl compared to controls. Leachates from the high concentration of PE and MB bag caused seedling anomalies in both species. These findings indicate that not biodegradable and compostable bags may interact with abiotic/biotic factors and affect via leaching germination phenology, seedling establishment and plant interactions with consequences on dune community structure.


Assuntos
Plantas/efeitos dos fármacos , Plásticos/toxicidade , Resíduos/análise , Poluentes Químicos da Água/toxicidade , Ecossistema , Germinação , Raízes de Plantas , Plásticos/análise , Plântula , Sementes
14.
Ecotoxicol Environ Saf ; 180: 756-761, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154200

RESUMO

Nitrated polycyclic aromatic hydrocarbons (Nitro-PAHs) as important organic pollutants are ubiquitous in the atmospheric environment, agricultural soils and aquatic environments to pose a severe polluting risk. However, little is known about the mechanism of Nitro-PAHs genotoxicity in plants. We analyzed seeds germination, seedlings growth, and toxicity mechanism following 1-Nitropyrene treatment in Hordeum vulgare. Our results reveal that 1-NP treatment could be an inhibited agent on seeds germination and growth of roots and shoots. Additionally, the reduction of mitotic index and the increasing frequency of micronucleus suggest that 1-NP may pose a potential risk of genotoxicity in the plant. We further clarify that O2- and H2O2 radicals contribute to 1-NP stimulation induced oxidative damage. Our study provides insights into the role of Nitro-PAHs exposure on growth processing toxicity and genotoxicity in plant and provided a useful reference for the surveillance and risk management of Nitro-PAHs in environments.


Assuntos
Hordeum/efeitos dos fármacos , Mutagênicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes do Solo/toxicidade , Radicais Livres/metabolismo , Germinação/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Óxidos de Nitrogênio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Pirenos/toxicidade
15.
Environ Monit Assess ; 191(7): 465, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243568

RESUMO

The germination capacity of poplar seeds has never been studied in the context of metal(loid)-contaminated soils, even though poplars are present over a vast geographical area. In this study, black poplar seeds from the Loire Valley (France) were grown for 28 days in mesocosm on a heavily polluted soil that was subjected to different amendments. This phytomanagement process aimed to allow the revegetation of an As and Pb-contaminated mining soil by adding appropriate amendments, resulting in metal(loid) soil stabilisation and efficient plant growth. The objectives were to evaluate the effect of three amendments (garden soil, compost and biochar) when added alone or combined to a technosol on (i) the soil physicochemical properties, (ii) the mobility of As and Pb in the soil pore water (SPW), (iii) the capacity of poplar seeds to germinate and to grow and (iv) the metal(loid) distribution within the plant organs. The addition of amendments alone or combined allowed a 90% decrease in SPW Pb concentrations, while the arsenic concentrations were between 18 and 416 times higher. However, we were only able to obtain seed germination and plant growth on amended soils. These promising results will allow us to explore the use of such amendments in rehabilitating areas that are sources of significant metal(loid) dissemination, as well as allowing a natural plant recolonisation of these sites by seeds from the surrounding environment.


Assuntos
Carvão Vegetal/química , Compostagem , Germinação/efeitos dos fármacos , Mineração , Populus/efeitos dos fármacos , Poluentes do Solo/análise , Solo/química , Arsênico/análise , Monitoramento Ambiental , França , Chumbo/análise , Chumbo/toxicidade , Populus/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Poluentes do Solo/toxicidade
16.
Chemosphere ; 232: 439-452, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158639

RESUMO

This study investigated the role of an allochthonous Gram-positive wastewater bacterium (Bacillus sp. KUJM2) selected through rigorous screening, for the removal of potentially toxic elements (PTEs; As, Cd, Cu, Ni) and promotion of plant growth under PTE-stress conditions. The dried biomass of the bacterial strain removed PTEs (5 mg L-1) from water by 90.17-94.75 and 60.4-81.41%, whereas live cells removed 87.15-91.69 and 57.5-78.8%, respectively, under single-PTE and co-contaminated conditions. When subjected to a single PTE, the bacterial production of indole-3-acetic acid (IAA) reached the maxima with Cu (67.66%) and Ni (64.33%), but Cd showed an inhibitory effect beyond 5 mg L-1 level. The multiple-PTE treatment induced IAA production only up to 5 mg L-1 beyond which inhibition ensued. Enhanced germination rate, germination index and seed production of lentil plant (Lens culinaris) under the bacterial inoculation indicated the plant growth promotion potential of the microbial strain. Lentil plants, as a result of bacterial inoculation, responded with higher shoot length (7.1-27.61%), shoot dry weight (18.22-36.3%) and seed production (19.23-29.17%) under PTE-stress conditions. The PTE uptake in lentil shoots decreased by 67.02-79.85% and 65.94-78.08%, respectively, under single- and multiple-PTE contaminated conditions. Similarly, PTE uptake was reduced in seeds up to 72.82-86.62% and 68.68-85.94%, respectively. The bacteria-mediated inhibition of PTE translocation in lentil plant was confirmed from the translocation factor of the respective PTEs. Thus, the selected bacterium (Bacillus sp. KUJM2) offered considerable potential as a PTE remediating agent, plant growth promoter and regulator of PTE translocation curtailing environmental and human health risks.


Assuntos
Bacillus/crescimento & desenvolvimento , Lens (Planta)/crescimento & desenvolvimento , Poluentes do Solo/análise , Águas Residuárias/microbiologia , Bacillus/metabolismo , Biodegradação Ambiental , Germinação/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Lens (Planta)/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Poluentes do Solo/toxicidade
17.
Plant Sci ; 285: 34-43, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203892

RESUMO

Seed germination is a critical stage during the initiation of the plant lifecycle and is strongly affected by endogenous phytohormones and environmental stress. High temperature (HT) upregulates endogenous abscisic acid (ABA) to suppress seed germination, and ABA-INSENSITIVE 5 (ABI5) is the key positive regulator in the ABA signal-mediated modulation of seed germination. In plants, hydrogen sulfide (H2S) is a small gas messenger that participates in multiple physiological processes, but its role in seed germination thermotolerance has not been thoroughly elucidated to date. In this study, we found that H2S enhanced the seed germination rate under HT. Moreover, HT accelerates the efflux of the E3 ligase CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) from the nucleus to the cytoplasm, which results in increased nuclear accumulation of ELONG HYPCOTYL 5 (HY5) to activate the expression of ABI5 and thereby suppress seed germination. However, the H2S signal reversed the HT effect, as characterized by increased COP1 in the nucleus, which resulted in increased degradation of HY5 and reduced expression of ABI5 and thereby enhanced the seed germination thermotolerance. Thus, our findings reveal a novel role for the H2S signal in the modulation of seed germination thermotolerance through the nucleocytoplasmic partitioning of COP1 and the downstream HY5 and ABI5 pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Germinação/fisiologia , Sulfeto de Hidrogênio/metabolismo , Proteínas Nucleares/metabolismo , Sementes/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ácido Abscísico/metabolismo , Ácido Abscísico/fisiologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Núcleo Celular/enzimologia , Núcleo Celular/metabolismo , Giberelinas/metabolismo , Giberelinas/fisiologia , Temperatura Alta , Proteínas Nucleares/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Sementes/fisiologia , Transdução de Sinais/fisiologia , Termotolerância , Ubiquitina-Proteína Ligases/fisiologia
18.
Plant Sci ; 285: 79-90, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203896

RESUMO

Inactivation of abscisic acid (ABA) in vitro may be catalyzed either by ABA 8'-hydroxylase (ABA8'OH) or by ABA uridine diphosphate glucosyltransferase (ABAUGT), which conjugates ABA with glucose. However, the involvement of these enzymes in the control of ABA content in vivo, especially ABAUGT, has not been fully elucidated. In pea seeds, both PsABAUGT1 and PsABA8'OH1 contribute to the reduction of ABA content during seed maturation and imbibition; however, during the first hours of imbibition, a high expression of only PsABAUGT1 was observed. Imbibition of seeds with H2O2 increased the ABA content despite the oxygen availability and altered the expression of metabolic genes. The expression of the biosynthetic gene 9-cis-epoxycarotene dioxygenase (PsNCED2) was increased, while that of PsABAUGT1 was decreased in each H2O2 experiment despite O2 availability. Under hypoxia, only seeds imbibed with H2O2 germinated, while under nonlimiting oxygen conditions, the germination rate was not altered by H2O2. Under hypoxia, the germination rate of H2O2-imbibed seeds seemed to not depend on the absolute ABA content and rather on the balance between ABA and gibberellins (GA), as H2O2 increased the expression of GA synthesis genes. Overexpression of PsABAUGT1 in Arabidopsis decreases seed ABA content, accelerates germination and reduces seed sensitivity to exogenously applied ABA, confirming the ability of PsABAUGT1 to inactivate ABA. Thus, PsABAUGT1 is a new player in the regulation of ABA content in maturating and imbibed pea seeds, both under standard conditions and in response to H2O2.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas/fisiologia , Germinação , Peróxido de Hidrogênio/metabolismo , Ervilhas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/fisiologia , Sementes/metabolismo , Arabidopsis , Homeostase , Ervilhas/crescimento & desenvolvimento , Ervilhas/fisiologia , Plantas Geneticamente Modificadas , Sementes/crescimento & desenvolvimento
19.
J Plant Physiol ; 239: 61-70, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31200171

RESUMO

Seeds are the basis of propagation for the common beech (Fagus sylvatica L.), but the seed set of the beech is unsteady, with 5-10 years between abundant crops. Beech seeds are very difficult to store and lose their viability quickly even in optimum storage conditions. To date, it has not been possible to determine factors indicative of the aging process and the loss of viability of beech seeds during storage. To address this important economic challenge and interesting scientific problem, we analyzed the adjustment of the redox state during the development and storage of seeds. Many metabolic processes are based on reduction and oxidation reactions. Thiol proteins control and react to the redox state in the cells. The level of thiol proteins increased during seed maturation and decreased during storage. Gel-based redox proteomics identified 17 proteins in beech seeds during development. The proteins could be assigned to processes like metabolism and antioxidant functions. During storage, the number of proteins decreased to only six, i.e., oxidoreductases, peptidases, hydrolases and isomerases. The occurrence of peroxiredoxins (PRX) as thiol peroxidases and redox regulators indicates an important role of cytosolic 1CysPRX and PRXIIC, mitochondrial PRXIIF, and plastidic PRXIIE, 2CysPRX, and PRXQ in beech seeds during development and storage. Particularly, 2CysPRX was present in beech seeds during development and storage and may perform an important function in regulation of the redox state during both seed development and storage. The role of thiol proteins in the regulation of the redox state during the development and storage of beech seeds is discussed.


Assuntos
Fagus/metabolismo , Sementes/metabolismo , Compostos de Sulfidrila/metabolismo , Fagus/crescimento & desenvolvimento , Germinação , Oxirredução , Peroxirredoxinas/metabolismo , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento
20.
J Plant Physiol ; 239: 71-82, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31212099

RESUMO

Cryopreservation is a process whereby biological structures are preserved in liquid nitrogen (-196 °C) without losing their viability. Many cryopreservation techniques use the Plant Vitrification Solution 2 (PVS2) for cryoprotection. This study will therefore evaluate the influence of different exposure times to the cryoprotectant PVS2 and discuss the importance of the mobilization of reserves and the antioxidant metabolism during the germination of cryopreserved Passiflora ligularis embryos. The composition of P. ligularis seeds was analytically determined. We tested the germination capacity and the Germination Speed Index (GSI) of embryos (that is, seeds without external tegument) which were exposed to different PVS2 exposure times (0, 30, 60 and 120 min) at 30 days after thawing. Proline content, hydrogen peroxide, activity of isocitrate lyase (ICL), malate synthase (MSy), lipid peroxidation and antioxidant enzyme activities (SOD, CAT, APX) were measured at 7, 14 and 21 days after cryopreservation. The germination from cryopreserved embryos was maximal (85%) after 60 min PVS2 exposure with a GSI of 0.6. At 60 min, the highest activity of the enzymes involved in the glyoxylate cycle, ICL and MSy were recorded. We hypothesize that a 60 min exposure to PVS2 accelerates the reserve mobilization which correlates positively with germination. Until 60 min, there was a positive correlation between the PVS2 exposure time and the proline content, as well as the activity of antioxidant enzymes (SOD, CAT, APX), and a negative correlation with the lipid peroxidation. This study enables us to optimize the long-term conservation of this species. In conclusion, fundamental research is necessary to optimize the cryopreservation procedure, and this study offers an effective and efficient workflow which can be extrapolated to other (oil-rich) species.


Assuntos
Antioxidantes/metabolismo , Crioprotetores/metabolismo , Germinação/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Passiflora/fisiologia , Sementes/efeitos dos fármacos , Criopreservação , Sementes/crescimento & desenvolvimento
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