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1.
BMC Plant Biol ; 22(1): 512, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36324083

RESUMO

BACKGROUND: Calcineurin B-like proteins (CBLs) are ubiquitous Ca2+ sensors that mediate plant responses to various stress and developmental processes by interacting with CBL-interacting protein kinases (CIPKs). CBLs and CIPKs play essential roles in acclimatization of crop plants. However, evolution of these two gene families in the genus Medicago is poorly understood. RESULTS: A total of 68 CBL and 135 CIPK genes have been identified in five genomes from Medicago. Among these genomes, the gene number of CBLs and CIPKs shows no significant difference at the haploid genome level. Phylogenetic and comprehensive characteristic analyses reveal that CBLs and CIPKs are classified into four clades respectively, which is validated by distribution of conserved motifs. The synteny analysis indicates that the whole genome duplication events (WGDs) have contributed to the expansion of both families. Expression analysis demonstrates that two MsCBLs and three MsCIPKs are specifically expressed in roots, mature leaves, developing flowers and nitrogen fixing nodules of Medicago sativa spp. sativa, the widely grown tetraploid species. In particular, the expression of these five genes was highly up-regulated in roots when exposed to salt and drought stress, indicating crucial roles in stress responses. CONCLUSIONS: Our study leads to a comprehensive understanding of evolution of CBL and CIPK gene families in Medicago, but also provides a rich resource to further address the functions of CBL-CIPK complexes in cultivated species and their closely related wild relatives.


Assuntos
Secas , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Medicago/metabolismo , Filogenia , Proteínas Serina-Treonina Quinases/genética , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Ligação ao Cálcio/genética
2.
J Agric Food Chem ; 70(46): 14633-14640, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36350751

RESUMO

Metabolomic studies on root uptake and transformation of bioactive compounds, like cereal benzoxazinoids (BXs) in non-BX producing plants, are very limited. Therefore, a targeted mass-spectrometry-based metabolomics study was performed to elucidate the root uptake of BXs in white clover (Trifolium repens L.) and the impact of absorbed BXs on intrinsic clover secondary metabolites. Clover plants grew in a medium containing 100 µM of individual BXs (five aglycone and one glycoside BXs) for 3 weeks. Subsequently, plant tissues were analyzed by liquid chromatography-tandem mass spectrometry to quantify the BXs and clover secondary metabolite concentrations. All BXs were taken up by clover roots and translocated to the shoots. Upon uptake of 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA), 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), 2-hydroxy-1,4-benzoxazin-3-one (HBOA), and 2-ß-d-glucopyranosyloxy-1,4-benzoxazin-3-one (HBOA-glc), the parent compounds and a range of transformation products were seen in the roots and shoots. The individual BX concentrations ranged from not detected (nd) to 469 µg/g of dry weight (dw) and from nd to 170 µg/g of dw in the roots and shoots, respectively. The root uptake of BXs altered the composition of intrinsic clover secondary metabolites. In particular, the concentration of flavonoids and the hormone abscisic acid increased substantially in comparison to control plants.


Assuntos
Benzoxazinas , Trifolium , Benzoxazinas/metabolismo , Grão Comestível/química , Ácido Abscísico/metabolismo , Trifolium/metabolismo , Medicago/metabolismo , Flavonoides/metabolismo , Raízes de Plantas/química
3.
Int J Mol Sci ; 23(21)2022 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-36361560

RESUMO

Heat shock transcription factors (HSF) are divided into classes A, B and C. Class A transcription factors are generally recognized as transcriptional activators, while functional characterization of class B and C heat shock transcription factors have not been fully developed in most plant species. We isolated and characterized a novel HSF transcription factor gene, TrHSFB2a (a class B HSF) gene, from the drought stress-sensitive forage crop species, white clover (Trifolium repens). TrHSFB2a was highly homologous to MtHSFB2b, CarHSFB2a, AtHSFB2b and AtHSFB2a. The expression of TrHSFB2a was strongly induced by drought (PEG6000 15% w/v), high temperature (35 °C) and salt stresses (200 mM L-1 NaCl) in white clover, while subcellular localization analysis showed that it is a nuclear protein. Overexpression of the white clover gene TrHSFB2a in Arabidopsis significantly reduced fresh and dry weight, relative water contents (RWC), maximum photosynthesis efficiency (Fv/Fm) and performance index on the absorption basis (PIABS), while it promoted leaf senescence, relative electrical conductivity (REC) and the contents of malondialdehyde (MDA) compared to a wild type under drought, heat and salt stress conditions of Arabidopsis plants. The silencing of its native homolog (AtHSFB2a) by RNA interference in Arabidopsis thaliana showed opposite trends by significantly increasing fresh and dry weights, RWC, maximum photosynthesis efficiency (Fv/Fm) and performance index on the absorption basis (PIABS) and reducing REC and MDA contents under drought, heat and salt stress conditions compared to wild type Arabidopsis plants. These phenotypic and physiological indicators suggested that the TrHSFB2a of white clover functions as a negative regulator of heat, salt and drought tolerance. The bioinformatics analysis showed that TrHSFB2a contained the core B3 repression domain (BRD) that has been reported as a repressor activator domain in other plant species that might repress the activation of the heat shock-inducible genes required in the stress tolerance process in plants. The present study explores one of the potential causes of drought and heat sensitivity in white clover that can be overcome to some extent by silencing the TrHSFB2a gene in white clover.


Assuntos
Arabidopsis , Trifolium , Secas , Arabidopsis/metabolismo , Trifolium/genética , Trifolium/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico/genética , Estresse Salino , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Medicago/metabolismo
4.
Theor Appl Genet ; 135(3): 853-864, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34817619

RESUMO

KEY MESSAGE: Transformation of MruGSTU39 in M. ruthenica and alfalfa enhanced growth and survival of transgenic plants by up-regulating GST and glutathione peroxidase activity to detoxify ROS under drought stress. Glutathione S-transferases (GSTs) are ubiquitous supergene family which play crucial roles in detoxification of reactive oxygen species (ROS). Despite studies on GSTs, few studies have focused on them in perennial, wild plant species with high tolerance to environmental stress. Here, we identified 66 MruGST genes from the genome of Medicago ruthenica, a perennial legume species native to temperate grasslands with high tolerance to environmental stress. These genes were divided into eight classes based on their conserved domains, phylogenetic tree and gene structure, with the tau class being the most numerous. Duplication analysis revealed that GST family in M. ruthenica was expanded by segmental and tandem duplication. Several drought-responsive MruGSTs were identified by transcriptomic analyses. Of them, expression of MruGSTU39 was up-regulated much more in a tolerant accession by drought stress. Transformation of MruGSTU39 in M. ruthenica and alfalfa (Medicago sativa) enhanced growth and survival of transgenic seedlings than their wild-type counterparts under drought. We demonstrated that MruGSTU39 can detoxify ROS to reduce its damage to membrane by up-regulating activities of GST and glutathione peroxidase. Our findings provide full-scale knowledge on GST family in the wild legume M. ruthenica with high tolerance to drought, and highlight improvement tolerance of legume forages to drought using genomic information of M. ruthenica.


Assuntos
Secas , Medicago sativa , Regulação da Expressão Gênica de Plantas , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Medicago/genética , Medicago/metabolismo , Medicago sativa/genética , Filogenia , Melhoramento Vegetal , Estresse Fisiológico/genética
5.
Int J Mol Sci ; 22(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063053

RESUMO

Increased soil salinity, and therefore accumulation of ions, is one of the major abiotic stresses of cultivated plants that negatively affect their growth and yield. Among Medicago species, only Medicago truncatula, which is a model plant, has been extensively studied, while research regarding salinity responses of two important forage legumes of Medicago sativa (M. sativa) and Medicago arborea (M. arborea) has been limited. In the present work, differences between M. arborea, M. sativa and their hybrid Alborea were studied regarding growth parameters and metabolomic responses. The entries were subjected to three different treatments: (1) no NaCl application (control plants), (2) continuous application of 100 mM NaCl (acute stress) and (3) gradual application of NaCl at concentrations of 50-75-150 mM by increasing NaCl concentration every 10 days. According to the results, M. arborea maintained steady growth in all three treatments and appeared to be more resistant to salinity. Furthermore, results clearly demonstrated that M. arborea presented a different metabolic profile from that of M. sativa and their hybrid. In general, it was found that under acute and gradual stress, M. sativa overexpressed saponins in the shoots while M. arborea overexpressed saponins in the roots, which is the part of the plant where most of the saponins are produced and overexpressed. Alborea did not perform well, as more metabolites were downregulated than upregulated when subjected to salinity stress. Finally, saponins and hydroxycinnamic acids were key players of increased salinity tolerance.


Assuntos
Hibridização Genética , Medicago/metabolismo , Medicago/fisiologia , Metaboloma , Tolerância ao Sal , Metabolismo Secundário , Análise de Variância , Medicago/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Caules de Planta/anatomia & histologia , Análise de Componente Principal
6.
Plant Physiol Biochem ; 165: 147-160, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34038811

RESUMO

S-adenosylmethionine decarboxylase (SAMDC) mediates the biosynthesis of polyamines (PAs) and plays a positive role in plants' response to adversity stress tolerance. In this study, we isolated a SAMDC gene from white clover, which is located in mitochondria. It was strongly induced when white clover exposed to drought (15% PEG6000), salinity (200 mM NaCl), 20 µM spermidine, 100 µM abscisic acid, and 10 mM H2O2, especially in leaves. The INVSc1 yeast introduced with TrSAMDC1 had tolerance to drought, salt, and oxidative stress. Overexpression of TrSAMDC1 in Arabidopsis showed higher fresh weight and dry weight under drought and salt treatment and without growth inhibition under normal conditions. Leaf senescence induced by drought and saline was further delayed in transgenic plants, regardless of cultivation in 1/2 MS medium and soil. During drought and salt stress, transgenic plants exhibited a significant increase in relative water content, maximum photosynthesis efficiency (Fv/Fm), performance index on the absorption basis (PIABS), activities of antioxidant protective enzymes such as SOD, POD, CAT, and APX, and a significant decrease in accumulation of MDA and H2O2 as compared to the WT. The concentrations of total PAs, putrescine, spermidine, and spermidine in transgenic lines were higher in transgenic plants than in WT under normal and drought conditions. These results suggested that TrSAMDC1 could effectively mitigate abiotic stresses without the expense of production and be a potential candidate gene for improving the drought and salt resistance of crops.


Assuntos
Arabidopsis , Secas , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio , Medicago/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética
7.
Plant Sci ; 303: 110664, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33487332

RESUMO

Flavin synthesis and secretion is an integral part of the toolbox of root-borne Fe facilitators used by Strategy I species upon Fe deficiency. The Fe-deficiency responses of the wild legume Medicago scutellata grown in nutrient solution have been studied at two different pH values (5.5 and 7.5). Parameters studied include leaf chlorophyll, nutrient solution pH, concentrations and contents of micronutrients, flavin accumulation in roots, flavin export to the medium, and root ferric chelate reductase and acidification activities. Results show that M. scutellata behaves upon Fe deficiency as a Strategy I species, with a marked capacity for synthesizing flavins (riboflavin and three hydroxylated riboflavin derivatives), which becomes more intense at high pH. Results also show that this species is capable of exporting a large amount of flavins to the external medium, both at pH 5.5 and 7.5. This is the first report of a species having a major flavin secretion at pH 7.5, in contrast with the very low flavin secretion found in other flavin-producing species such as Beta vulgaris and M. truncatula. These results provide further support to the hypothesis that flavin secretion is relevant for Fe acquisition at high pH, and open the possibility to improve the Fe-efficiency responses in legumes of agronomic interest.


Assuntos
Flavinas/biossíntese , Deficiências de Ferro , Medicago/metabolismo , Compostos Férricos/metabolismo , Flavinas/metabolismo , Concentração de Íons de Hidrogênio , Medicago/crescimento & desenvolvimento , Nutrientes/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Riboflavina/biossíntese , Riboflavina/metabolismo
8.
Chemosphere ; 263: 127918, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32822944

RESUMO

Some rhizosphere bacteria could colonize on the root surface of plants, or even form biofilm to promote plant growth, enhance plant resistance to harsh external environments and block the soil contamination. In this study, to explore the effects of pyrene-degrading bacterium on root surface on plant uptake of pyrene, a pyrene-degrading bacterium Mycolicibacterium sp. Pyr9 was isolated from the root surface of Eleusine indica L. Gaertn. in PAH-contaminated fields; after antibiotic labeling, it was colonized onto the root surface of white clover (Trifolium repens L.), and its distribution and performance were monitored under different levels of pyrene contamination. Strain Pyr9 could degrade 98% of pyrene (with an initial concentration of 50 mg L-1) in culture solution within 8 d; it also owns a variety of plant growth promoting characteristics and appreciable tolerance to harsh environments. The transcription of pyrene catabolic genes in Pyr9 enhanced obviously when induced by pyrene. Pyr9 colonized and grew well on the root surface of white clover via root inoculation; some cells could even enter into the root tissues and move to the shoots. Compared with the Pyr9-free treatment, the pyrene contents in the roots and shoots of Pyr9-inoculated white clover decreased by 25%-30% and 33%-42%, respectively. Correspondingly, the pyrene accumulation and translocation factors in white clover decreased as well. These results indicate that Pyr9 would be a good potential to circumvent plant pyrene pollution. This research may provide a theoretical basis and technical support for the safety of agricultural products and human health in PAH-contaminated sites.


Assuntos
Biodegradação Ambiental , Pirenos/metabolismo , Poluentes do Solo/metabolismo , Trifolium/metabolismo , Bactérias/metabolismo , Humanos , Medicago/metabolismo , Raízes de Plantas/metabolismo , Poluentes do Solo/análise , Trifolium/crescimento & desenvolvimento , Trifolium/microbiologia
9.
Plant Cell Physiol ; 61(10): 1818-1827, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32898258

RESUMO

Co-expressed genes tend to have regulatory relationships and participate in similar biological processes. Construction of gene correlation networks from microarray or RNA-seq expression data has been widely applied to study transcriptional regulatory mechanisms and metabolic pathways under specific conditions. Furthermore, since transcription factors (TFs) are critical regulators of gene expression, it is worth investigating TFs on the promoters of co-expressed genes. Although co-expressed genes and their related metabolic pathways can be easily identified from previous resources, such as EXPath and EXPath Tool, this information is not simultaneously available to identify their regulatory TFs. EXPath 2.0 is an updated database for the investigation of regulatory mechanisms in various plant metabolic pathways with 1,881 microarray and 978 RNA-seq samples. There are six significant improvements in EXPath 2.0: (i) the number of species has been extended from three to six to include Arabidopsis, rice, maize, Medicago, soybean and tomato; (ii) gene expression at various developmental stages have been added; (iii) construction of correlation networks according to a group of genes is available; (iv) hierarchical figures of the enriched Gene Ontology (GO) terms are accessible; (v) promoter analysis of genes in a metabolic pathway or correlation network is provided; and (vi) user's gene expression data can be uploaded and analyzed. Thus, EXPath 2.0 is an updated platform for investigating gene expression profiles and metabolic pathways under specific conditions. It facilitates users to access the regulatory mechanisms of plant biological processes. The new version is available at http://EXPath.itps.ncku.edu.tw.


Assuntos
Bases de Dados Genéticas , Regulação da Expressão Gênica de Plantas , Expressão Gênica , Arabidopsis/genética , Arabidopsis/metabolismo , Genes de Plantas , Ensaios de Triagem em Larga Escala , /metabolismo , Medicago/genética , Medicago/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Oryza/genética , Oryza/metabolismo , Soja/genética , Soja/metabolismo , Fatores de Transcrição/genética , Zea mays/genética , Zea mays/metabolismo
10.
Plant Biol (Stuttg) ; 22(5): 794-804, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32501628

RESUMO

Heat stress decreases crop growth and yield worldwide. Spermidine (Spd) is a small aliphatic amine and acts as a ubiquitous regulator for plant growth, development and stress tolerance. Objectives of this study were to determine effects of exogenous Spd on changes in endogenous polyamine (PA) and γ-aminobutyric acid (GABA) metabolism, oxidative damage, senescence and heat shock protein (HSP) expression in white clover subjected to heat stress. Physiological and molecular methods, including colorimetric assay, high performance liquid chromatography and qRT-PCR, were applied. Results showed that exogenous Spd significantly alleviated heat-induced stress damage. Application of Spd not only increased endogenous putrescine, Spd, spermine and total PA accumulation, but also accelerated PA oxidation and improved glutamic acid decarboxylase activity, leading to GABA accumulation in leaves under heat stress. The Spd-pretreated white clover maintained a significantly higher chlorophyll (Chl) content than untreated plants under heat stress, which could be related to the roles of Spd in up-regulating genes encoding Chl synthesis (PBGD and Mg-CHT) and maintaining reduced Chl degradation (PaO and CHLASE) during heat stress. In addition, Spd up-regulated HSP70, HSP70B and HSP70-5 expression, which might function in stabilizing denatured proteins and helping proteins to folding correctly in white clover under high temperature stress. In summary, exogenous Spd treatment improves the heat tolerance of white clover by altering endogenous PA and GABA content and metabolism, enhancing the antioxidant system and HSP expression and slowing leaf senescence related to an increase in Chl biosynthesis and a decrease in Chl degradation during heat stress.


Assuntos
Medicago , Poliaminas , Espermidina , Termotolerância , Ácido gama-Aminobutírico , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/genética , Resposta ao Choque Térmico/efeitos dos fármacos , Medicago/efeitos dos fármacos , Medicago/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Poliaminas/metabolismo , Espermidina/farmacologia , Termotolerância/efeitos dos fármacos , Ácido gama-Aminobutírico/metabolismo
11.
New Phytol ; 226(6): 1809-1821, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32048296

RESUMO

Root system architecture (RSA) influences the effectiveness of resources acquisition from soils but the genetic networks that control RSA remain largely unclear. We used rhizoboxes, X-ray computed tomography, grafting, auxin transport measurements and hormone quantification to demonstrate that Arabidopsis and Medicago CEP (C-TERMINALLY ENCODED PEPTIDE)-CEP RECEPTOR signalling controls RSA, the gravitropic set-point angle (GSA) of lateral roots (LRs), auxin levels and auxin transport. We showed that soil-grown Arabidopsis and Medicago CEP receptor mutants have a narrower RSA, which results from a steeper LR GSA. Grafting showed that CEPR1 in the shoot controls GSA. CEP receptor mutants exhibited an increase in rootward auxin transport and elevated shoot auxin levels. Consistently, the application of auxin to wild-type shoots induced a steeper GSA and auxin transport inhibitors counteracted the CEP receptor mutant's steep GSA phenotype. Concordantly, CEP peptides increased GSA and inhibited rootward auxin transport in wild-type but not in CEP receptor mutants. The results indicated that CEP-CEP receptor-dependent signalling outputs in Arabidopsis and Medicago control overall RSA, LR GSA, shoot auxin levels and rootward auxin transport. We propose that manipulating CEP signalling strength or CEP receptor downstream targets may provide means to alter RSA.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Medicago/genética , Medicago/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Receptores de Peptídeos/metabolismo
12.
J Sci Food Agric ; 100(2): 885-890, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31483055

RESUMO

BACKGROUND: The research focused on the evaluation of the impact of cover cropping on trace metals (Fe, Mn, Cu, Zn, Pb, Co and Cd) and nutrients in vineyard soils and Vitis vinifera L. For this purpose, two types of cover crops (Lolium perenne L. and Medicago sativa L.) and their mixture were planted between vine rows of Muscat white in the vineyard in South Crimea. Trace elements, nutrients and other parameters were analyzed in the soil layers, leaves and grapevines of control and cover cropped plots. RESULTS: The effect of cover cropping was dependent on applied plant species. Ryegrass (L. perenne L.) seems to compete with V. vinifera L. for nutrients - these were lower in the soil and vines of the treated plot. In parallel, lead (Pb) bioconcentration in grapevines was reduced. In contrast, under lucerne (M. sativa L.), nitrogen in the soil and vines, and trace metal bioconcentration (Fe, Pb and Co) were higher. CONCLUSIONS: Our results indicate that cover cropping can influence the chemical composition of soil and vines. This should be considered when selecting cover crops. © 2019 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Lolium/crescimento & desenvolvimento , Medicago/crescimento & desenvolvimento , Oligoelementos/análise , Vitis/química , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Lolium/metabolismo , Medicago/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Solo/química , Especificidade da Espécie , Oligoelementos/metabolismo , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
13.
Nat Prod Res ; 34(15): 2238-2242, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30887838

RESUMO

The main purpose of our study was to identify and compare secondary metabolites due to different mowing in order to make better use of Huaiyang Medicago polymorpha. The metabolite profiling of Huaiyang Medicago polymorpha with two mowing crops was performed using a rapid resolution liquid chromatography system with quadrupole time-of-flight mass spectrometer (RRLC-QTOFMS) followed by multivariate statistical analyses. Principal Component Analysis (PCA) results showed a clear distinction between two mowing crops. The major metabolites that contributed to mowing discrimination were identified. The results also showed that the content of major active compounds in Medicago polymorpha from the second crop are higher significantly than the first crop. This study suggests that the strategy is a reliable and simple method for the rapid discrimination of subtle variations due to different mowing crops.


Assuntos
Produtos Agrícolas , Medicago/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas , Metabolômica/métodos , Análise de Componente Principal
14.
Environ Sci Pollut Res Int ; 26(28): 29065-29073, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392616

RESUMO

Recently, due to increased drought risks, need for crops with higher water stress tolerance has increased strongly. Those crops have a wide range of uses such as supplying food as well as land restoration. Medicago scutellata (L.) Mill. is a Fabaceae widely cultivated for its capacity to produce high-quality forage. This study was designed as a factorial experiment based on a completely randomized design with three replications. Different cadmium levels were the first factor and included 0, 5, 25, 50, 100, and 125 mg kg-1. Second factor was the drought stress, which had three levels (100, 75, and 50% feed consumption). According to the results, Cd uptake in different organs increased with increasing Cd levels up to 100 mg kg-1 while the water stress had a negative effect on Cd uptake by M. scutellata. Average concentration of Cd in the leaves, stems, and roots were 63.16, 30.12, and 20.45 mg kg-1, respectively. The high value of translocation factor (TF) confirms the high ability of M. scutellata in translocation Cd from root to shoot. Fe, Zn, and K concentration of different organs significantly decreased with increasing Cd level. Fe and Zn concentration increased by increasing water stress levels in all organs and K concentration of roots decreased while in leaves and shoots increased by increasing water stress level. These results indicate that M. scutellata has a good ability for eliminating Cd from contaminated soil attribute to its powerful absorption and accumulation for Cd. It also showed a good performance under the co exposure of water stress and Cd indicated by accumulating proline and K in leaves.


Assuntos
Biodegradação Ambiental , Cádmio/toxicidade , Medicago/metabolismo , Poluentes do Solo/toxicidade , Cádmio/análise , Produtos Agrícolas , Desidratação , Folhas de Planta/química , Raízes de Plantas/efeitos dos fármacos , Solo , Poluentes do Solo/análise , Água
15.
Bioengineered ; 10(1): 218-228, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31138017

RESUMO

Intercropping can introduce greater plant diversity and functional complementarity in an arable crop system but inter- and intracompetition can between intercropped crops. The rhizo-box was established of apple-white clover intercropped system to examine the competitive relationship between intercropped crops on the Loess Plateau. The results showed that the competitive relationship between intercropped crops was dynamic and changed with the crop competitiveness. Crop competitiveness was characterized by root development, although intercropping inhibited the development and nutrient accumulation aboveground of apple trunks and branches, intercropped apples still maintained a larger root system than under monoculture and the root morphology of intercropped apples changed significantly. White clover had lower competitiveness than apple at the beginning of the year, which was reflected in the inhibited development in May. However in July and October, intercropped white clover had more biomass and nutrient accumulation than under monoculture.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Malus/crescimento & desenvolvimento , Malus/metabolismo , Biomassa , Medicago/crescimento & desenvolvimento , Medicago/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo
16.
Genetica ; 147(2): 185-196, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30905050

RESUMO

The amino acid/auxin permease (AAAP) gene family plays an important role in the long-distance amino acid transport pathway and takes part in various stages of plant growth and development. However, little is known about the AAAP gene family in Medicago truncatula. Here, we identified 86 putative MtAAAP family members using genome sequence information. Based on phylogenetic analysis, these MtAAAP genes were categorized into eight distinct subfamilies. The MtAAAP genes were mapped on 8 chromosomes and duplication events appeared widely, with 19 and 21 pairs of MtAAAP genes showing segment and tandem duplication events, respectively. Ratio of Ka/Ks indicated that duplicated genes underwent purifying selection. Analysis of RNA-seq data showed that MtAAAP genes exhibited specific expression patterns among different tissues and abiotic stress, indicating that MtAAAP members were involved in plant developmental regulation and stress responses. Expression patterns of 16 MtAAAP genes under abiotic stress were verified by qRT-PCR. The present study provides a foundation for the functional analysis of MtAAAPs in developmental regulation and stress responses.


Assuntos
Sistemas de Transporte de Aminoácidos/genética , Regulação da Expressão Gênica de Plantas , Medicago/genética , Proteínas de Plantas/genética , Sistemas de Transporte de Aminoácidos/metabolismo , Duplicação Gênica , Genoma de Planta , Medicago/metabolismo , Família Multigênica , Filogenia , Proteínas de Plantas/metabolismo , Seleção Genética , Estresse Fisiológico
17.
Plant J ; 98(4): 680-696, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30712282

RESUMO

Recent studies on E3 of endoplasmic reticulum (ER)-associated degradation (ERAD) in plants have revealed homologs in yeast and animals. However, it remains unknown whether the plant ERAD system contains a plant-specific E3 ligase. Here, we report that MfSTMIR, which encodes an ER-membrane-localized RING E3 ligase that is highly conserved in leguminous plants, plays essential roles in the response of ER and salt stress in Medicago. MfSTMIR expression was induced by salt and tunicamycin (Tm). mtstmir loss-of-function mutants displayed impaired induction of the ER stress-responsive genes BiP1/2 and BiP3 under Tm treatment and sensitivity to salt stress. MfSTMIR promoted the degradation of a known ERAD substrate, CPY*. MfSTMIR interacted with the ERAD-associated ubiquitin-conjugating enzyme MtUBC32 and Sec61-translocon subunit MtSec61γ. MfSTMIR did not affect MtSec61γ protein stability. Our results suggest that the plant-specific E3 ligase MfSTMIR participates in the ERAD pathway by interacting with MtUBC32 and MtSec61γ to relieve ER stress during salt stress.


Assuntos
Degradação Associada com o Retículo Endoplasmático/fisiologia , Medicago/enzimologia , Medicago/metabolismo , Estresse Salino/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Arabidopsis , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Medicago/genética , Chaperonas Moleculares , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estabilidade Proteica , Canais de Translocação SEC , Tunicamicina/farmacologia , Enzimas de Conjugação de Ubiquitina , Ubiquitina-Proteína Ligases/genética
18.
PLoS One ; 13(10): e0205968, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30372459

RESUMO

MOTIVATION: Modern analytical techniques such as LC-MS, GC-MS and NMR are increasingly being used to study the underlying dynamics of biological systems by tracking changes in metabolite levels over time. Such techniques are capable of providing information on large numbers of metabolites simultaneously, a feature that is exploited in non-targeted studies. However, since the dynamics of specific metabolites are unlikely to be known a priori this presents an initial subjective challenge as to where the focus of the investigation should be. Whilst a number of feed-forward software tools are available for manipulation of metabolomic data, no tool centralizes on clustering and focus is typically directed by a workflow that is chosen in advance. RESULTS: We present an interactive approach to time-course analyses and a complementary implementation in a software package, MetaboClust. This is presented through the analysis of two LC-MS time-course case studies on plants (Medicago truncatula and Alopecurus myosuroides). We demonstrate a dynamic, user-centric workflow to clustering with intrinsic visual feedback at all stages of analysis. The software is used to apply data correction, generate the time-profiles, perform exploratory statistical analysis and assign tentative metabolite identifications. Clustering is used to group metabolites in an unbiased manner, allowing pathway analysis to score metabolic pathways, based on their overlap with clusters showing interesting trends.


Assuntos
Redes e Vias Metabólicas , Metabolômica/métodos , Software , Vias Biossintéticas , Brassinosteroides/metabolismo , Análise por Conglomerados , Secas , Medicago/metabolismo , Fenótipo , Doenças das Plantas , Poaceae/metabolismo , Fatores de Tempo
19.
J Exp Bot ; 69(20): 4867-4880, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30295903

RESUMO

Medicago flowering, like that of Arabidopsis, is promoted by vernalization and long days, but alternative mechanisms are predicted because Medicago lacks the key regulators CO and FLC. Three Medicago SOC1-like genes, including MtSOC1a, were previously implicated in flowering control, but no legume soc1 mutants with altered flowering were reported. Here, reverse transciption-quantitative PCR (RT-qPCR) indicated that the timing and magnitude of MtSOC1a expression was regulated by the flowering promoter FTa1, while in situ hybridization indicated that MtSOC1a expression increased in the shoot apical meristem during the floral transition. A Mtsoc1a mutant showed delayed flowering and short primary stems. Overexpression of MtSOC1a partially rescued the flowering of Mtsoc1a, but caused a dramatic increase in primary stem height, well before the transition to flowering. Internode cell length correlated with stem height, indicating that MtSOC1a promotes cell elongation in the primary stem. However, application of gibberellin (GA3) caused stem elongation in both the wild type and Mtsoc1a, indicating that the mutant was not defective in gibberellin responsiveness. These results indicate that MtSOC1a may function as a floral integrator gene and promotes primary stem elongation. Overall, this study suggests that apart from some conservation with the Arabidopsis flowering network, MtSOC1a has a novel role in regulating aspects of shoot architecture.


Assuntos
Flores/crescimento & desenvolvimento , Proteínas de Domínio MADS/genética , Medicago/crescimento & desenvolvimento , Medicago/genética , Proteínas de Plantas/genética , Caules de Planta/crescimento & desenvolvimento , Sequência de Aminoácidos , Arabidopsis/genética , Flores/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Domínio MADS/química , Proteínas de Domínio MADS/metabolismo , Medicago/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Caules de Planta/genética , Alinhamento de Sequência
20.
Methods Mol Biol ; 1822: 145-159, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30043303

RESUMO

Here we describe an in situ hybridization (ISH) method using Invitrogen™ ViewRNA™ ISH Tissue Assay (ThermoFisher Scientific) optimized for Medicago root and nodules sections. The method is based on branched (b)DNA signal amplification technology originally developed for use in microplate format and further adapted for detection of (m)RNAs in mammalian tissue sections. Signal amplification is achieved via a series of sequential hybridizations of linking sequences which are anchored to complementary sequences present on specific oligonucleotide probes. The typical (m)RNA probe set contains ~20 synthetic adjacent oligonucleotide pairs. Each probe is composed of a 20bp primary sequence designed to target sequence of interest and a secondary extended sequence serving as a template for hybridization of a preamplifier oligonucleotide. The preamplifier forms a stable hybrid only if it hybridizes to two adjacent probes. By this principle, background is reduced. Other regions on the preamplifier are designed to hybridize to multiple bDNA amplifier molecules that create a branched structure. Finally, alkaline phosphatase (AP)-labeled oligonucleotides, which are complementary to bDNA amplifier sequences, bind to the bDNA molecule by hybridization. By adding Fast Red substrate, red punctuated precipitates are formed that can be detected by light bright and/or fluorescent microscope. ThermoFisher Scientific ( https://www.thermofisher.com/nl/en/home.html ) designs and synthesizes probe sets for a gene of interest and Invitrogen™ ViewRNA™ ISH Tissue Assay kits include all components required for pretreatment of plant tissues, hybridization and signal amplification.


Assuntos
Hibridização In Situ , Medicago/genética , RNA Mensageiro/genética , Histocitoquímica/métodos , Hibridização In Situ/métodos , Medicago/metabolismo , Microscopia , RNA Mensageiro/metabolismo , Fluxo de Trabalho
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