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1.
BMC Plant Biol ; 19(1): 341, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382871

RESUMO

BACKGROUND: Barley is a low phosphorus (P) demand cereal crop. Tibetan wild barley, as a progenitor of cultivated barley, has revealed outstanding ability of tolerance to low-P stress. However, the underlying mechanisms of low-P adaption and the relevant genetic controlling are still unclear. RESULTS: We identified low-P tolerant barley lines in a doubled-haploid (DH) population derived from an elite Tibetan wild barley accession and a high-yield cultivar. The tolerant lines revealed greater root plasticity in the terms of lateral root length, compared to low-P sensitive lines, in response to low-P stress. By integrating the QTLs associated with root length and root transcriptomic profiling, candidate genes encoding isoflavone reductase, nitrate reductase, nitrate transporter and transcriptional factor MYB were identified. The differentially expressed genes (DEGs) involved the growth of lateral root, Pi transport within cells as well as from roots to shoots contributed to the differences between low-P tolerant line L138 and low-P sensitive lines L73 in their ability of P acquisition and utilization. CONCLUSIONS: The plasticity of root system is an important trait for barley to tolerate low-P stress. The low-P tolerance in the elite DH line derived from a cross of Tibetan wild barley and cultivated barley is characterized by enhanced growth of lateral root and Pi recycling within plants under low-P stress.


Assuntos
Hordeum/fisiologia , Fósforo/metabolismo , Raízes de Plantas/fisiologia , Adaptação Fisiológica , Perfilação da Expressão Gênica , Genes de Plantas/genética , Genes de Plantas/fisiologia , Hordeum/genética , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Fósforo/deficiência , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Locos de Características Quantitativas/genética , Estresse Fisiológico
2.
An Acad Bras Cienc ; 91(3): e20181295, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31432907

RESUMO

The banana tree is associated with different species of endophytic bacteria that can stimulate plant growth. However, further studies are needed to better understand the relationships between this group of bacteria and the host plant. The objective of this study was to investigate the localization of the EB-40 (Bacillus sp.) through anatomical and ultrastructural analyses in micropropagated banana plantlets. The results demonstrated the effective colonization of the EB-40 isolate in the intercellular and intracellular spaces, as well as in the rhizosphere region. The wall of endophytic bacteria contains calcium and nitrogen. The EB-40 isolate was also observed to associate with the plasma membrane and cell wall. These results further our understanding of the mechanisms involved in the colonization of plant cells by endophytic bacteria in micropropagated banana plantlets.


Assuntos
Bacillus/fisiologia , Endófitos/ultraestrutura , Musa/microbiologia , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , Bacillus/ultraestrutura , Microscopia Eletrônica de Varredura , Musa/crescimento & desenvolvimento , Musa/ultraestrutura , Raízes de Plantas/crescimento & desenvolvimento
3.
Ying Yong Sheng Tai Xue Bao ; 30(6): 1993-2001, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257772

RESUMO

To understand the influence of roots of understory plant entering litter layer on litter decomposition in forest ecosystems, we examined the effects of different treatments of Lolium multiflorum root biomass on microorganisms and enzyme activities during leaf litter decomposition of Symplocos setchuensis, a dominant species in a mid-subtropical evergreen broad-leaved forest, through a litter bag simulation experiment. Results showed that diversity index of bacterial and fungal communities of leaf litter surface under three treatments, i.e. no root (N), less roots (L), more roots (M), in a 240-day decomposition process showed the following pattern: M > L > N. The effects of these different root biomass treatments on the composition and quantity of fungal community were more significant than those on bacterial community. The biomass of living roots growing in the litter bag gradually decreased at the end of the growing season of L. multiflorum. The impacts of root growth on the composition of the fungal community gradually decreased during decomposition. At the same decomposition stage, the activities of acid phosphatase, ß-glucosidase, polyphenol oxidase, and peroxidase on the litter surface were higher in the treatments with roots than that without roots. These results indicated that root growth could change the composition and quantity of microbial communities and increase the extracellular enzyme activities of microbes, and thus stimulating litter decomposition.


Assuntos
Florestas , Microbiota , Raízes de Plantas/crescimento & desenvolvimento , Microbiologia do Solo , Bactérias , Biomassa , Ecossistema , Folhas de Planta
4.
Bull Environ Contam Toxicol ; 103(2): 330-335, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31263937

RESUMO

The immobilization effect and mechanism of nano-hydroxyapatite(NHAP) on Pb in the ryegrass rhizosphere soil were studied by root-bag experiment. The speciation analysis results revealed that the residual Pb concentrations in the rhizosphere soil significantly increased after NHAP application. The acid-soluble and reducible Pb concentrations significantly decreased, indicating that NHAP had obviously immobilized Pb. Meanwhile, NHAP significantly promoted the secretion of tartaric acid from ryegrass roots, resulting the rhizosphere soil pH had been below that of the control group. This helped to relieve the stress of Pb on ryegrass, also promoted the dissolution of NHAP, resulting the formation of stable precipitation with more Pb ions. NHAP increased the rhizosphere soil pH by 0.03 to 0.17, which promoted the conversion of Pb to non-utilizable bioavailability. The total Pb mass balance indicated only a very small proportion Pb transferred to the shoots through ryegrass roots. The formation of pyromorphite by Pband NHAP in soil was accordingly to interpret the dominant mechanism for Pb immobilization.


Assuntos
Durapatita/química , Chumbo/análise , Lolium/crescimento & desenvolvimento , Nanoestruturas/química , Rizosfera , Poluentes do Solo/análise , Adsorção , Disponibilidade Biológica , Concentração de Íons de Hidrogênio , Chumbo/metabolismo , Lolium/metabolismo , Minerais/química , Modelos Teóricos , Fosfatos/química , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Tartaratos/metabolismo
5.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2226-2230, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359646

RESUMO

Using the White as basic medium, the effects of the exogenous IBA and endophytic fungal elicitor on the growth of in vitro roots cultures of Dysosma versipellis and production of podophyllotoxin were investigated in this study. The results showed that the IBA and the endophytic fungus Zasmidium syzygii elicitor could increase the content of podophyllotoxin of in vitro roots of D. versipellis after 3 weeks. The White medium added with 3 mg·L~(-1) IBA induced the highest increase of podophyllotoxin(1 830.86 µg·g~(-1)), which was 2.07 folds greater than the control, and followed by 1.5 mg·L~(-1) IBA, fungal elicitor, 1 mg·L~(-1) IBA, 0.5 mg·L~(-1) IBA and 4.5 mg·L~(-1) IBA, which was 1.82, 1.71, 1.63, 1.43 and 1.1 folds greater than the control, respectively. The results also showed that the growth of roots was certain positively correlated with the change of IBA concentration. Therefore, 3 mg·L~(-1) IBA was the most suitable for the production of podophyllotoxin in the in vitro roots of D. versipellis, and the stimulating effect of Z. syzygii fungal elicitor was between 1.5 mg·L~(-1) and 1 mg·L~(-1) IBA, which was a potential natural elicitor to induce the accumulation of podophyllotoxin in future production.


Assuntos
Ascomicetos , Berberidaceae/química , Raízes de Plantas/crescimento & desenvolvimento , Podofilotoxina/biossíntese , Técnicas de Cultura de Tecidos , Endófitos , Raízes de Plantas/efeitos dos fármacos
6.
Nat Commun ; 10(1): 2378, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31147541

RESUMO

Developmental plasticity of root system architecture is crucial for plant performance in nutrient-poor soils. Roots of plants grown under mild nitrogen (N) deficiency show a foraging response characterized by increased root length but mechanisms underlying this developmental plasticity are still elusive. By employing natural variation in Arabidopsis accessions, we show that the brassinosteroid (BR) signaling kinase BSK3 modulates root elongation under mild N deficiency. In particular, a proline to leucine substitution in the predicted kinase domain of BSK3 enhances BR sensitivity and signaling to increase the extent of root elongation. We further show that low N specifically upregulates transcript levels of the BR co-receptor BAK1 to activate BR signaling and stimulate root elongation. Altogether, our results uncover a role of BR signaling in root elongation under low N. The BSK3 alleles identified here provide targets for improving root growth of crops growing under limited N conditions.


Assuntos
Proteínas de Arabidopsis/genética , Nitrogênio/deficiência , Raízes de Plantas/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/genética , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Solo/química , Regulação para Cima
7.
BMC Plant Biol ; 19(1): 242, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174465

RESUMO

BACKGROUND: Recurrent drought associated with climate change is a major constraint to wheat (Triticum aestivum L.) productivity. This study aimed to (i) quantify the effects of addition/substitution/translocation of chromosome segments from wild relatives of wheat on the root, physiological and yield traits of hexaploid wheat under drought, and (ii) understand the mechanism(s) associated with drought tolerance or susceptibility in wheat-alien chromosome lines. METHODS: A set of 48 wheat-alien chromosome lines (addition/substitution/translocation lines) with Chinese Spring background were used. Seedling root traits were studied on solid agar medium. To understand the influence of drought on the root system of adult plants, these 48 lines were grown in 150-cm columns for 65 d under full irrigation or withholding water for 58 d. To quantify the effect of drought on physiological and yield traits, the 48 lines were grown in pots under full irrigation until anthesis; after that, half of the plants were drought stressed by withholding water for 16 d before recording physiological and yield-associated traits. RESULTS: The alien chromosome lines exhibited altered root architecture and decreased photochemical efficiency and seed yield and its components under drought. The wheat-alien chromosome lines T5DS·5S#3L (TA5088) with a chromosome segment from Aegilops speltoides (5S) and T5DL.5 V#3S (TA5638) with a chromosome segment from Dasypyrum villosum (5 V) were identified as drought tolerant, and the drought tolerance mechanism was associated with a deep, thin and profuse root system. CONCLUSIONS: The two germplasm lines (TA5088 and TA5638) could be used in wheat breeding programs to improve drought tolerance in wheat and understand the underlying molecular genetic mechanisms of root architecture and drought tolerance.


Assuntos
Cromossomos de Plantas/genética , Secas , Genes de Plantas/genética , Melhoramento Vegetal , Triticum/genética , Aegilops/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Poaceae/genética , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento
8.
J Agric Food Chem ; 67(25): 6911-6920, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31194542

RESUMO

Improving the root system architecture (RSA) under adverse environmental conditions by using biostimulants is emerging as a new way to boost crop productivity. Recently, we have reported the characterization of novel chitosan-based microparticles (CS-MPs) with promising biological properties as rooting agents in lettuce. In this work, we demonstrated that in contrast to bulk chitosan (CS), which exerts root growth inhibition, CS-MPs promoted root growth and development from 1 to 10 µg mL-1 without cytotoxicity effects at higher doses in Arabidopsis and lettuce seedlings. In addition, we studied the mechanistic mode of action of CS-MPs in the development of early RSA in the Arabidopsis model. CS-MPs unchained accurate and sustained spatio-temporal activation of the nuclear auxin signaling pathway. Our findings validated a promising scenario for the application of CS-MPs in the modulation of RSA to respond to changing soil environments and improve crop performance.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Ácidos Indolacéticos/farmacologia , Alface/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/efeitos dos fármacos , Alface/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
9.
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
10.
BMC Plant Biol ; 19(1): 284, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253081

RESUMO

BACKGROUND: Echinacea-endophyte interaction might affect plant secondary metabolites content and influence bacterial colonization specificity and plant growth, but the underlying mechanisms need deepening. An in vitro model, in which E. purpurea axenic plants as host species and E. angustifolia and Nicotiana tabacum as non-host species inoculated with single endophytes isolated from stem/leaf, root and rhizospheric soil, were used to investigate bacterial colonization. RESULTS: Colonization analysis showed that bacteria tended to reach tissues from which they were originally isolated (tissue-specificity) in host plants but not in non-host ones (species-specificity). Primary root elongation inhibition as well as the promotion of the growth of E. purpurea and E. angustifolia plants were observed and related to endophyte-produced indole-3-Acetic Acid. Bacteria-secreted substances affected plant physiology probably interacting with plant regulators. Plant metabolites played an important role in controlling the endophyte growth. CONCLUSIONS: The proposed in vitro infection model could be, generally used to identify novel bioactive compounds and/or to select specific endophytes contributing to the host metabolism properties.


Assuntos
Bactérias/crescimento & desenvolvimento , Echinacea/microbiologia , Endófitos/crescimento & desenvolvimento , Microbiologia do Solo , Echinacea/crescimento & desenvolvimento , Especificidade de Órgãos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Rizosfera , Tabaco/crescimento & desenvolvimento , Tabaco/microbiologia
11.
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
12.
Plant Sci ; 285: 214-223, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203886

RESUMO

Main Conclusion Root gravitropism of primary roots is assisted by curvature of the hypocotyl base. Root gravitropism is typically described as the sequence of signal perception, signal processing, and response that causes differential elongation and the establishment of a new gravitropic set-point angle. We describe two components of the graviresponse of Brassica seedlings that comprise a primary curvature of the root tip and a later onset but stronger curvature that occurs at the base of the hypocotyl. This second curvature is preceded by straightening of the tip region but leads to the completion of the alignment of the root axis. Curvature in both regions require a minimum displacement of 20 deg. The rate of tip curvature is a function of root length. After horizontal reorientation, tip curvature of five mm long roots curved twice as fast as 10 mm long roots (33.6 ±â€¯3.3 vs. 14.3 ±â€¯1.5 deg hr-1). The onset of curvature at the hypocotyl base is correlated with root length, but the rate of this curvature is independent of seedling length. Decapping of roots prevented tip curvature but the curvature at base of hypocotyl was unaffected. Endodermal cells at the root shoot junction show numerous, large and sedimenting amyloplasts, which likely serve as gravity sensors (statoliths). The amyloplasts at the hypocotyl were 3-4 µm in diameter, similar in size to those in the root cap, and twice the size of starch grains in the cortical layers of hypocotyl or elsewhere in the root. These data indicate that the root shoot reorientation of young seedlings is not limited to the root tip but includes more than one gravitropically responsive region.


Assuntos
Brassica rapa/crescimento & desenvolvimento , Gravitropismo , Hipocótilo/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Brassica rapa/fisiologia , Hipocótilo/fisiologia , Coifa/crescimento & desenvolvimento , Coifa/fisiologia
13.
Chemosphere ; 232: 70-75, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152905

RESUMO

Polycyclic aromatic hydrocarbons are an important group of pollutants that are widely distributed in the environment. The present study aimed to investigate the effect of salicylic acid (a phenolic phytohormone) and mycorrhizal fungi on the growth and phytoremediation ability of tall fescue in the soil contaminated by fluoranthene. The initial concentrations of fluoranthene in this study were 100, 200, and 300 mg kg-1. The experimental treatments were included: T0 uncultivated soil; T1 cultivated soil with tall fescue; T2 cultivated soil with tall fescue + salicylic acid application; T3 cultivated soil with tall fescue + application of mycorrhizal fungi; T4 cultivated soil with tall fescue + salicylic acid and mycorrhizal fungi application; and P planting tall fescue in uncontaminated soil. The removal of fluoranthene was measured after 90 days. Furthermore, at the end of the experiment, the amount of shoot and root biomass, soil bacteria, and dehydrogenase activity were measured. According to the results, in all levels of contamination, removal of fluoranthene in cultivated treatments significantly was higher than uncultivated treatments. Increasing the concentration of fluoranthene had a negative effect on the shoot and root biomass in different treatments. Salicylic acid and mycorrhizal fungi significantly increased the shoot and root biomass and also the number of soil bacteria, dehydrogenase activity, and fluoranthene removal in T2, T3, and T4 treatments compared to T1. At the highest concentration of fluoranthene, as a result of simultaneous application of salicylic acid and mycorrhizal fungi (T4), the fluoranthene removal increased by 63, 21, 13, and 16% in comparison with T0, T1, T2, and T3, respectively. Based on the results, salicylic acid and mycorrhizal fungi, either alone or in combination, have a significant effect on the improvement of phytoremediation potential in tall fescue.


Assuntos
Biodegradação Ambiental , Festuca/metabolismo , Micorrizas/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Ácido Salicílico/metabolismo , Poluentes do Solo/metabolismo , Biomassa , Festuca/microbiologia , Fluorenos , Reguladores de Crescimento de Planta , Raízes de Plantas/crescimento & desenvolvimento , Solo , Microbiologia do Solo , Simbiose
14.
Syst Appl Microbiol ; 42(4): 517-525, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31176475

RESUMO

Plant roots are inhabited by a large diversity of microbes, some of which are beneficial for the growth of plants and known as plant growth promoting rhizobacteria (PGPR). In this work, we designed a multispecies inoculum of PGPRs containing Rhizobium phaseoli, Sinorhizobium americanum and Azospirillum brasilense nitrogen-fixing strains and other plant-growth promoting bacteria such as Bacillus amyloliquefaciens and Methylobacterium extorquens. We evaluated the effect of this group of bacteria on the growth of one-month-old maize plants. The multispecies inoculum exerted a beneficial effect on maize plants that was greater than that obtained with single-bacteria. Using the same multispecies inoculant, acetylene reduction was recorded in 5-day-old roots indicating active nitrogen fixation by bacteria in maize. Azospirillum nitrogen fixation was lower than that obtained with the multispecies inoculum. We focused on the analysis of R. phaseoli gene expression in presence of other PGPRs. Many R. phaseoli up- regulated genes in roots in the presence of other bacteria are hypothetical, showing our poor knowledge of bacteria-bacteria interactions. Other genes indicated bacterial nutrient competition and R. phaseoli stress. Differentially expressed transcriptional regulators were identified that may be key in bacteria-bacteria interaction regulation. Additionally, gene expression was analyzed from Azospirillum but not from sinorhizobia and methylobacteria due to the low number of transcripts obtained from maize roots. The metatranscriptomic analysis from maize roots showed expression of Azospirillum nif genes in the presence of PGPR bacteria. Our hypothesis is that other bacteria stimulate Azospirillum capacity to fix nitrogen and this should be further explored.


Assuntos
Bactérias/genética , Interações Microbianas , Fixação de Nitrogênio/genética , Reguladores de Crescimento de Planta/genética , Zea mays/microbiologia , Bactérias/metabolismo , Proteínas de Bactérias/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Microbiota , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
15.
J Agric Food Chem ; 67(26): 7304-7314, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31180668

RESUMO

Morindae Officinalis Radix (MOR), the dried root of Morinda officinalis F.C. How (Rubiaceae), is a popular food supplement in southeastern China for bone protection, andrological, and gynecological healthcare. In clinical use, 3-4 year old MOR is commonly used and the xylem is sometimes removed. However, there is no scientific rationale for these practices so far. In this study, metabolomics and glycomics were integrated using multiple chromatographic and mass spectrometric techniques coupled with multivariate statistical analysis to investigate the qualitative and quantitative variations of secondary metabolome and glycome in different growth years (1-7 years) and tissues (xylem and cortex) of MOR. The results showed that various types of bioactive components reached a maximum between 3 and 4 years of growth and that the xylem contained more potentially toxic constituents but less bioactive components than the cortex. This study provides the chemical basis for the common practice of using 3-4 year old MOR with the xylem removed.


Assuntos
Medicamentos de Ervas Chinesas/química , Morinda/crescimento & desenvolvimento , Raízes de Plantas/química , China , Medicamentos de Ervas Chinesas/metabolismo , Glicômica , Metabolômica , Morinda/química , Morinda/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Fatores de Tempo , Xilema/química , Xilema/metabolismo
16.
J Agric Food Chem ; 67(26): 7232-7242, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184888

RESUMO

In the present study, the effect of imidacloprid uptake from contaminated soils on the growth of leaf vegetable Shanghaiqing was investigated. The result showed that during 35-day exposure, the concentration of imidacloprid (IMI) was in the order of vegetable shoots > vegetable roots > soil, indicating that IMI was more readily concentrated in vegetable shoots than in roots. Moreover, the biomass of IMI-treated vegetable shoots was comparable to that of the controls with early exposure, but was higher than that of the controls after 7-day exposure, showing that the test concentration of IMI could stimulate vegetable growth. The plant metabolic analysis of vegetable shoots using LC-QTOF/MS revealed that IMI may cause oxidative stress to the plant shoots with early exposure; however, the stressful situation of IMI seems to be relieved with the increase of some substances (such as spermidine and phenylalanine) with late exposure. Moreover, the upregulation of N-rich amino acids (glutamine, aspartate, and arginine) suggested that the process of fixing inorganic nitrogen in the plant should be enhanced, possibly contributing to enhanced growth rates. Additionally, four IMI's metabolites were identified by using MS-FINDER software, and the distribution of three metabolites in vegetable tissues was compared.


Assuntos
Inseticidas/farmacologia , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Poluentes do Solo/farmacologia , Verduras/efeitos dos fármacos , Aminoácidos/metabolismo , Transporte Biológico/efeitos dos fármacos , Inseticidas/análise , Espectrometria de Massas , Neonicotinoides/análise , Nitrocompostos/análise , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Solo/química , Poluentes do Solo/análise , Verduras/química , Verduras/crescimento & desenvolvimento , Verduras/metabolismo
17.
Ecotoxicol Environ Saf ; 181: 345-352, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202935

RESUMO

Nanomaterials are being used increasingly in various areas such as electronic devices manufacture, medicine, mechanical devices production, and even food industry. Therefore, the evaluation of their toxicity is mandatory. Graphene oxide (GO) has been shown to have both positive as well as negative impact on different crop plants, depending on species, dose, and duration of exposure. The current study evaluated the impact of GO sheets at different concentrations (500, 1000 and 2000 mg/L) on physiological, biochemical and genetic levels to determine the possible toxic action. Wheat caryopses were treated with GO for 48 h and 7 days. The germination rate and roots elongation decreased in a dose-response manner, except the sample treated with GO at a concentration of 1000 mg/L. Mitotic index has ascendant trend; its increase may be due to the accumulation of prophases GO induced significant accumulation of the cells with aberrations, their presence suggests a clastogenic/aneugenic effect of these carbon nanomaterials. Regarding enzymatic and non-enzymatic antioxidant system defence, the activity varied depending on the dose of GO. Thus, chlorophyll a pigments content decreased significantly at high dose (2000 mg/L), while the carotenoid pigments had lower content at 500 mg/L of GO, and no statistical difference encountered in case of chlorophyll b amount. The antioxidant enzyme activity (CAT, POD, and SOD) was higher at low dose of GO, indicating the presence of oxidative stress generated as a response to the GO treatment. Also, the free radical scavenging activity of the polyphenolic compounds was enhanced upon GO exposure. The GO accumulation has been identified by transmission electron microscopy only at plumules level, near the intercellular space.


Assuntos
Grafite/toxicidade , Nanoestruturas/toxicidade , Triticum/efeitos dos fármacos , Antioxidantes/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Germinação/efeitos dos fármacos , Estresse Oxidativo , Óxidos/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
18.
Plant Physiol Biochem ; 141: 225-230, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31185367

RESUMO

The present study evaluated the role of nitric oxide (NO) in mediating adventitious root (AR) growth, lignification and related enzymatic changes in the hypocotyls of Vigna radiata. To meet the objectives, the changes in AR growth, lignin content, and the activities of enzymes-peroxidases, polyphenol oxidases, and phenylalanine ammonia lyases- with NO donor and its scavenger were monitored. Hypocotyls were cultivated in aqueous solution supplemented with different concentrations of SNP (sodium nitroprusside, NO donor compound) and its scavenging compound (2,4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; cPTIO). Specifically, at low concentrations, SNP induced AR growth, increased the total lignin content and altered the activities of related oxidoreductases- peroxidases, polyphenol oxidases and phenylalanine ammonia lyases- which are involved in lignin biosynthesis pathway. At higher concentrations, a decline in AR growth and lignification was noticed. We analysed the function of NO in AR formation by depleting the endogenous NO using scavenging compound cPTIO. Hypocotyls grown in a medium supplemented with scavenger cPTIO exhibited significant decline in AR growth and the activities of lignin synthesizing enzymes. Application of NO scavenger showed that stimulatory properties on root lignification may be owing to NO itself. In addition, changes in AR growth were significantly correlated with these modified biochemical activities. Our analysis revealed that NO supplementation induces prominent alterations in lignin level during AR formation and this might be due to an alteration in the activity of lignin biosynthetic enzymes, which further affected the polymerization of monolignols and AR growth.


Assuntos
Hipocótilo/enzimologia , Lignina/química , Óxido Nítrico/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Vigna/enzimologia , Catecol Oxidase/metabolismo , Oxirredutases/metabolismo , Peroxidase/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Raízes de Plantas/enzimologia
19.
Plant Physiol Biochem ; 141: 291-299, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31202193

RESUMO

Silicon (Si) is reported to improve salt stress tolerance of cereals, but little is known about the effects of Si on flows and partitioning of sodium (Na+), chloride (Cl-), and essential mineral ions at the tissue and cellular level. Wheat (Triticum aestivum L.) was exposed to 200 mM NaCl for 30 d in hydroponics, with or without 2 mM Si. X-ray microanalysis coupled with scanning electron microscopy (SEM) was used to quantify the cell-specific ion profiles across root and leaf cells, paralleled by measurements of wheat growth and physiological responses. Under salt stress, higher Na+ and Cl- concentrations were detected in root epidermal, cortical and stelar cells, eventually increasing their concentrations in different leaf cells, being highest in the epidermal cells and lowest in the vascular bundle cells. The potassium (K+) and magnesium (Mg2+) profiles were generally opposite to those of Na+ and Cl-. NaCl-dependent deregulation of essential nutrient homeostasis and excessive toxic ions accumulation in leaves was correlated with enhanced electrolyte leakage index (ELI), decreased chlorophyll contents, photosynthesis and other physiological parameters, and ultimately hampered plant growth. Conversely, Si addition improved the growth and physiological performance of salinized wheat by reducing Na+ and Cl- concentration in root epidermal and cortical cells, and it improved root uptake and storage of K+ and Mg2+ ions and their loading into xylem for distribution to shoots. These results suggest that Si-mediated inhibition of Na+ uptake, maintained nutrient homeostasis and improved physiological parameters to contribute to wheat growth improvement under salt stress.


Assuntos
Tolerância ao Sal , Sais/química , Silício/química , Triticum/crescimento & desenvolvimento , Biomassa , Cloretos/química , Clorofila/química , Produtos Agrícolas/crescimento & desenvolvimento , Microanálise por Sonda Eletrônica , Genótipo , Homeostase , Hidroponia , Íons , Microscopia Eletrônica de Varredura , Minerais , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Potássio/química , Salinidade , Plântula/crescimento & desenvolvimento , Sódio/química , Água/química
20.
Plant Physiol Biochem ; 141: 343-352, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31207495

RESUMO

Plant U-box (PUB) E3 ubiquitin ligases play crucial roles in the plant response to abiotic stress and the phytohormone abscisic acid (ABA) signaling, but little is known about them in bryophytes. Here, a representative U-box armadillo repeat (PUB-ARM) ubiquitin E3 ligase from Antarctic moss Pohlia nutans (PnSAG1), was explored for its role in abiotic stress response in Arabidopsis thaliana and Physcomitrella patens. The expression of PnSAG1 was rapidly induced by exogenous abscisic acid (ABA), salt, cold and drought stresses. PnSAG1 was localized to the cytoplasm and showed E3 ubiquitin ligase activity by in vitro ubiquitination assay. The PnSAG1-overexpressing Arabidopsis enhanced the sensitivity with respect to ABA and salt stress during seed germination and early root growth. Similarly, heterogeneous overexpression of PnSAG1 in P. patens was more sensitive to the salinity and ABA in their gametophyte growth. The analysis by RT-qPCR revealed that the expression of salt stress/ABA-related genes were downregulated in PnSAG1-overexpressing plants after salt treatment. Taken together, our results indicated that PnSAG1 plays a negative role in plant response to ABA and salt stress.


Assuntos
Ácido Abscísico/farmacologia , Arabidopsis/fisiologia , Briófitas/enzimologia , Bryopsida/fisiologia , Estresse Salino , Ubiquitina-Proteína Ligases/genética , Regiões Antárticas , Arabidopsis/genética , Briófitas/genética , Bryopsida/genética , Biologia Computacional , Secas , Regulação da Expressão Gênica de Plantas , Células Germinativas Vegetais/metabolismo , Germinação , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/fisiologia , Transdução de Sinais
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