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1.
J Sci Food Agric ; 101(15): 6434-6442, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33987837

RESUMO

BACKGROUND: The years after planting play an important role in the above-ground biomass and nutritive value of alfalfa. Zhonglan No. 2 (Medicago sativa L. cv. Zhonglan No. 2) is a new breeding alfalfa cultivar characterized by high drought tolerance and high yield. To determine the optimum time for utilization of Zhonglan No. 2, we examined growth traits, chlorophyll content, photosynthetic and fluorescence parameters, and composition and nutritive values at the late vegetative and early flowering stages of the first stubble in the second, third, fourth, sixth, and eleventh years after planting. RESULTS: In general, the height and leaf area decreased with increasing number of years after planting. At the late vegetative stage, the fourth-year alfalfa exhibited higher stomatal conductance (Gs) and intercellular CO2 concentration (Ci), and better water use efficiency, and at the early flowering stage, the fourth-year alfalfa had the highest (P < 0.05) leaf net photosynthetic rate (Pn) and carboxylation efficiency (CE). Total digestible nutrients did not differ among years, but, in the early flowering stage, crude protein content decreased with years (P < 0.05). Malondialdehyde (MDA) content and total antioxidant capacity did not differ among years after planting, suggesting aging did not impose oxidative stress on this alfalfa cultivar. CONCLUSIONS: Based on height, chlorophyll content, crude protein (CP) content, and photosynthetic and fluorescence parameters, the fourth year after planting, at the early flowering stage, was the best for using Zhonglan No. 2. © 2021 Society of Chemical Industry.


Assuntos
Flores/crescimento & desenvolvimento , Medicago sativa/química , Fotossíntese , Antioxidantes/análise , Antioxidantes/metabolismo , Clorofila/análise , Clorofila/metabolismo , Flores/química , Flores/metabolismo , Malondialdeído/análise , Malondialdeído/metabolismo , Medicago sativa/classificação , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo , Valor Nutritivo , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
2.
Molecules ; 26(5)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802449

RESUMO

Seven-day-old sprouts of fenugreek (Trigonella foenum-graecum L.), lentil (Lens culinaris L.), and alfalfa (Medicagosativa L.) were studied. The legume seeds and then sprouts were soaked each day for 30 min during 6 days with water (control) or mixture of Fe-EDTA and sodium silicate (Optysil), or sodium silicate (Na-Sil) alone. Germination and sprout growing was carried out at temperature 20 ± 2 °C in 16/8 h (day/night) conditions. Phenolic compounds (free, ester, and glycosides) content were determined by HPLC-ESI-MS/MS using a multiple reaction monitoring of selected ions. Flavonoids and phenolic acids were released from their esters after acid hydrolysis and from glycosides by alkaline hydrolysis. The presence and high content of (-)-epicatechin (EC) in fenugreek sprouts was demonstrated for the first time. Applied elicitors decreased the level of free EC in fenugreek and alfalfa sprouts but enhanced the content of its esters. Besides, elicitors decreased the content of quercetin glycosides in lentil and fenugreek sprouts but increased the content of quercetin and apigenin glycosides in alfalfa sprouts. The applied elicitors decreased the glycoside levels of most phenolic acids in lentil and p-hydroxybenzoic acid in fenugreek, while they increased the content of this acid in alfalfa. The mixture of iron chelate and sodium silicate had less effect on changes in flavonoid and phenolic acid content in legume sprouts than silicate alone. In general, the used elicitors increased the content of total phenolic compounds in fenugreek and alfalfa sprouts and decreased the content in lentil sprouts. Among the evaluated elicitors, Optysil seems to be worth recommending due to the presence of iron chelate, which can be used to enrich sprouts with this element.


Assuntos
Quelantes de Ferro/farmacologia , Lens (Planta)/metabolismo , Medicago sativa/metabolismo , Fenóis/análise , Sementes/metabolismo , Silicatos/farmacologia , Trigonella/metabolismo , Flavonoides/análise , Germinação , Lens (Planta)/efeitos dos fármacos , Lens (Planta)/crescimento & desenvolvimento , Medicago sativa/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Trigonella/efeitos dos fármacos , Trigonella/crescimento & desenvolvimento
3.
PLoS One ; 16(4): e0250926, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33914821

RESUMO

Alfalfa (Medicago sativa L.) is an important legume crop for forage, agriculture, and environment in the world. Ascorbic acid (AsA) plays positive roles in plants. However, its effects on germination and salt-tolerance of alfalfa are unknown. The effects of AsA applications on seed germination and seedling salt-tolerance of alfalfa were investigated. The results revealed that 0.1 and 1 mmol L-1 of exogenous AsA increased germination, amylase, and protease, as well as seedling length, fresh weight (FW), dry weight (DW), and endogenous AsA both in the shoots and roots, except that 1 mmol L-1 AsA reduced the activities of α-amylase, ß-amylase and protease on day 3. However, 10 and 100 mmol L-1 AsA inhibited these parameters and even caused serious rot. It indicates that 0.1 mmol L-1 AsA has the optimal effects, whereas 100 mmol L-1 AsA has the worst impacts. Another part of the results showed that 0.1 mmol L-1 AsA not only enhanced stem elongation, FW and DW, but also increased chlorophyll and carotenoids both under non-stress and 150 mmol L-1 NaCl stress. Furthermore, 0.1 mmol L-1 AsA mitigated the damages of membrane permeability, malondialdehyde, and excessive reactive oxygen species (ROS) and ions both in the shoots and roots under 150 mmol L-1 NaCl stress. Hence, 0.1 mmol L-1 AsA improves growth and induces salt-tolerance by inhibiting excessive ROS, down-regulating the ion toxicity and up-regulating the antioxidant system. The principal component analysis included two main components both in the shoots and roots, and it explained the results well. In summary, the optimum concentration of 0.1 mmol L-1 AsA can be implemented to improve the seed germination and seedling growth of alfalfa under salt stress.


Assuntos
Amilases/metabolismo , Ácido Ascórbico/farmacologia , Medicago sativa/crescimento & desenvolvimento , Peptídeo Hidrolases/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Medicago sativa/efeitos dos fármacos , Medicago sativa/metabolismo , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
4.
Plant Physiol ; 185(2): 424-440, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721890

RESUMO

Orobanche cumana is a holoparasitic plant that attaches to host-plant roots and seriously reduces the yield of sunflower (Helianthus annuus L.). Effective control methods are lacking with only a few known sources of genetic resistance. In this study, a seed-soak agroinoculation (SSA) method was established, and recombinant tobacco rattle virus vectors were constructed to express RNA interference (RNAi) inducers to cause virus-induced gene silencing (VIGS) in sunflower. A host target gene HaTubulin was systemically silenced in both leaf and root tissues by the SSA-VIGS approach. Trans-species silencing of O. cumana genes were confirmed for 10 out of 11 target genes with silencing efficiency of 23.43%-92.67%. Knockdown of target OcQR1, OcCKX5, and OcWRI1 genes reduced the haustoria number, and silencing of OcEXPA6 caused further phenotypic abnormalities such as shorter tubercles and necrosis. Overexpression of OcEXPA6 caused retarded root growth in alfalfa (Medicago sativa). The results demonstrate that these genes play an important role in the processes of O. cumana parasitism. High-throughput small RNA (sRNA) sequencing and bioinformatics analyses unveiled the distinct features of target gene-derived siRNAs in O. cumana such as siRNA transitivity, strand polarity, hotspot region, and 21/22-nt siRNA predominance, the latter of which was confirmed by Northern blot experiments. The possible RNAi mechanism is also discussed by analyzing RNAi machinery genes in O. cumana. Taken together, we established an efficient host-induced gene silencing technology for both functional genetics studies and potential control of O. cumana. The ease and effectiveness of this strategy could potentially be useful for other species provided they are amenable to SSA.


Assuntos
Resistência à Doença/genética , Helianthus/genética , Orobanche/fisiologia , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Biologia Computacional , Expressão Gênica , Inativação Gênica , Helianthus/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Medicago sativa/genética , Medicago sativa/crescimento & desenvolvimento , Necrose , Orobanche/genética , Folhas de Planta/genética , Folhas de Planta/imunologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Vírus de Plantas/genética , Interferência de RNA , Sementes/genética , Sementes/imunologia , Análise de Sequência de RNA , Tubulina (Proteína)/genética
5.
Food Microbiol ; 97: 103414, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33653513

RESUMO

Microbial contamination of sprouts commonly occurs because of the pathogens present on and in the seeds and the optimal conditions for bacteria growth provided during the germination and sprouting processes. This study examined the decontamination effect of slightly acidic electrolyzed water (SAEW), a 'generally recognized as safe' (GRAS) disinfectant, in the production process of alfalfa sprouts. SAEW with various available chlorine concentrations (ACC, 25, 35, 45 mg/L) and different pH levels (5.0, 5.7 and 6.4) was used to soak seeds for different length of time (0.5 and 6 h), after which the variations in natural Enterobacteriaceae, water absorption and seed germination (germination rate, weight and length of sprouts) were determined. The results showed that when the seeds were soaked with SAEW, albeit with different ACC (25, 35 and 45 mg/L) and pH levels (5.0, 5.7 and 6.4), a significant reduction of Enterobacteriaceae and no negative effect on sprout quality was observed. The water absorption and germination rates were also not significantly adversely affected by SAEW soaking. These findings suggest that SAEW could be used to decontaminate natural Enterobacteriaceae in the production of alfalfa sprouts, with no negative side effects on the alfalfa seeds.


Assuntos
Desinfetantes/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Medicago sativa/microbiologia , Sementes/crescimento & desenvolvimento , Água/química , Cloro/química , Cloro/farmacologia , Contagem de Colônia Microbiana , Desinfetantes/química , Eletrólise , Enterobacteriaceae/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Medicago sativa/crescimento & desenvolvimento , Sementes/microbiologia , Verduras/crescimento & desenvolvimento , Verduras/microbiologia
6.
Ecotoxicol Environ Saf ; 211: 111942, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33476850

RESUMO

In this work, the internalization and distribution of citric acid-coated magnetite nanoparticles (here, Fe3O4-NPs) in soybean and alfalfa tissues and their effects on plant growth were studied. Both legumes were germinated in pots containing an inert growing matrix (vermiculite) to which Hoagland solution without (control, C), with Fe3O4-NPs (50 and 100 mgironL-1, NP50 and NP100), or with the same amount of soluble iron supplied as Fe-EDTA (Fe50, Fe100) was added once before sowing. Then, plants were watered with the standard nutrient solution. The observation of superparamagnetic signals in root tissues at harvest (26 days after emergence) indicated Fe3O4-NPs uptake by both legumes. A weak superparamagnetic signal was also present in the stems and leaves of alfalfa plants. These findings suggest that Fe3O4-NPs are readily absorbed but not translocated (soybean) or scarcely translocated (alfalfa) from the roots to the shoots. The addition of both iron sources resulted in increased root weight; however, only the addition of Fe3O4-NPs resulted in significantly higher root surface; shoot weight also increased significantly. As a general trend, chlorophyll content enhanced in plants grown in vermiculite supplemented with extra iron at pre-sowing; the greatest increase was observed with NP50. The only antioxidant enzyme significantly affected by our treatments was catalase, whose activity increased in the roots and shoots of both species exposed to Fe3O4-NPs. However, no symptoms of oxidative stress, such as increased lipid peroxidation or reactive oxygen species accumulation, were evidenced in any of these legumes. Besides, no evidence of cell membrane damage or cell death was found. Our results suggest that citric acid-coated Fe3O4-NPs are not toxic to soybean and alfalfa; instead, they behave as plant growth stimulators.


Assuntos
Ácido Cítrico/química , Nanopartículas de Magnetita/química , Medicago sativa/crescimento & desenvolvimento , Soja/crescimento & desenvolvimento , Clorofila/metabolismo , Ácido Cítrico/metabolismo , Germinação , Ferro/metabolismo , Nanopartículas de Magnetita/toxicidade , Medicago sativa/metabolismo , Nanopartículas/metabolismo , Desenvolvimento Vegetal , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Soja/metabolismo
7.
Food Microbiol ; 96: 103708, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33494890

RESUMO

Microbial contamination of fresh produce is a major public health concern, with the number of associated disease outbreaks increasing in recent years. The consumption of sprouted beans and seeds is of particular concern, as these foodstuffs are generally consumed raw, and are produced in conditions favourable for the growth of zoonotic pathogens, if present in seeds prior to sprouting or in irrigation water. This work aimed to evaluate the activity of plasma activated water (PAW) as a disinfecting agent for alfalfa (Medicago sativa) and mung bean (Vigna radiata) seeds, during seed soaking. Each seed type was inoculated with Escherichia coli O157, E. coli O104, Listeria monocytogenes or Salmonella Montevideo, and treated with PAW for different times. A combination of PAW and ultrasound treatment was also evaluated. The germination and growth rate of both seeds were assessed after PAW treatments. PAW was demonstrated to have disinfecting ability on sprouted seeds, with reductions of up to Log10 1.67 cfu/g in alfalfa seeds inoculated with E. coli O104, and a reduction of Log10 1.76 cfu/g for mung bean seeds inoculated with E. coli O157 observed. The germination and growth rate of alfalfa and mung bean sprouts were not affected by the PAW treatments. The combination of a PAW treatment and ultrasound resulted in increased antimicrobial activity, with a reduction of Log10 3.48 cfu/g of S. Montevideo in mung bean seeds observed. These results demonstrate the potential for PAW to be used for the inactivation of pathogenic microorganisms which may be present on sprouted seeds and beans, thereby providing greater assurance of produce safety.


Assuntos
Desinfetantes/farmacologia , Desinfecção/métodos , Escherichia coli O157/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Medicago sativa/microbiologia , Salmonella/efeitos dos fármacos , Vigna/microbiologia , Água/química , Desinfetantes/química , Desinfecção/instrumentação , Escherichia coli O157/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Germinação , Listeria monocytogenes/crescimento & desenvolvimento , Medicago sativa/crescimento & desenvolvimento , Salmonella/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Vigna/crescimento & desenvolvimento , Água/farmacologia
8.
BMC Plant Biol ; 21(1): 8, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407121

RESUMO

BACKGROUND: Alfalfa (Medicago sativa L.) is a perennial legume extensively planted throughout the world as a high nutritive value livestock forage. Flowering time is an important agronomic trait that contributes to the production of alfalfa hay and seeds. However, the underlying molecular mechanisms of flowering time regulation in alfalfa are not well understood. RESULTS: In this study, an early-flowering alfalfa genotype 80 and a late-flowering alfalfa genotype 195 were characterized for the flowering phenotype. Our analysis revealed that the lower jasmonate (JA) content in new leaves and the downregulation of JA biosynthetic genes (i.e. lipoxygenase, the 12-oxophytodienoate reductase-like protein, and salicylic acid carboxyl methyltransferase) may play essential roles in the early-flowering phenotype of genotype 80. Further research indicated that genes encode pathogenesis-related proteins [e.g. leucine rich repeat (LRR) family proteins, receptor-like proteins, and toll-interleukin-like receptor (TIR)-nucleotide-binding site (NBS)-LRR class proteins] and members of the signaling receptor kinase family [LRR proteins, kinases domain of unknown function 26 (DUF26) and wheat leucine-rich repeat receptor-like kinase10 (LRK10)-like kinases] are related to early flowering in alfalfa. Additionally, those involved in secondary metabolism (2-oxoglutarate/Fe (II)-dependent dioxygenases and UDP-glycosyltransferase) and the proteasome degradation pathway [really interesting new gene (RING)/U-box superfamily proteins and F-box family proteins] are also related to early flowering in alfalfa. CONCLUSIONS: Integrated phenotypical, physiological, and transcriptomic analyses demonstrate that hormone biosynthesis and signaling pathways, pathogenesis-related genes, signaling receptor kinase family genes, secondary metabolism genes, and proteasome degradation pathway genes are responsible for the early flowering phenotype in alfalfa. This will provide new insights into future studies of flowering time in alfalfa and inform genetic improvement strategies for optimizing this important trait.


Assuntos
Flores/crescimento & desenvolvimento , Flores/genética , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/genética , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Ciclopentanos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Variação Genética , Genótipo , Oxilipinas/metabolismo , Fenótipo
9.
Int J Mol Sci ; 22(2)2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33419062

RESUMO

Forisomes are giant fusiform protein complexes composed of sieve element occlusion (SEO) protein monomers, exclusively found in sieve elements (SEs) of legumes. Forisomes block the phloem mass flow by a Ca2+-induced conformational change (swelling and rounding). We studied the forisome reactivity in four different legume species-Medicago sativa, Pisum sativum, Trifolium pratense and Vicia faba. Depending on the species, we found direct relationships between SE diameter, forisome surface area and distance from the leaf tip, all indicative of a developmentally tuned regulation of SE diameter and forisome size. Heat-induced forisome dispersion occurred later with increasing distance from the stimulus site. T. pratense and V. faba dispersion occurred faster for forisomes with a smaller surface area. Near the stimulus site, electro potential waves (EPWs)-overlapping action (APs), and variation potentials (VPs)-were linked with high full-dispersion rates of forisomes. Distance-associated reduction of forisome reactivity was assigned to the disintegration of EPWs into APs, VPs and system potentials (SPs). Overall, APs and SPs alone were unable to induce forisome dispersion and only VPs above a critical threshold were capable of inducing forisome reactions.


Assuntos
Fabaceae/fisiologia , Proteínas de Plantas/metabolismo , Cálcio/metabolismo , Fenômenos Eletrofisiológicos , Fabaceae/crescimento & desenvolvimento , Fabaceae/metabolismo , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo , Ervilhas/crescimento & desenvolvimento , Ervilhas/metabolismo , Floema/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Especificidade da Espécie , Temperatura , Vicia faba/crescimento & desenvolvimento , Vicia faba/metabolismo
10.
Chem Biodivers ; 18(2): e2000897, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33410569

RESUMO

The chemical profile and phytotoxic action of Hibiscus trionum essential oil (EO) was studied. In total 17 compounds were identified via GC/MS, representing 94.18 % of the entire oil, with phytol (40.37 %) being the dominant constituent. Bioassay revealed that the EO inhibited root elongation of Medicago sativa and Amaranthus retroflexus by 32.66 % and 61.86 % at 5 mg/mL, respectively; meanwhile, the major component phytol also exhibited significant phytotoxic activity, suppressing radical elongation of Pennisetum alopecuroides, M. sativa and A. retroflexus by 26.08 %, 27.55 % and 43.96 % at 1 mg/mL, respectively. The fact that the EO showed weaker activity than phytol implied that some constituents might trigger antagonistic action to decrease the oil's activity. Our study is the first on the chemical profile and phytotoxic effect of H. trionum EO.


Assuntos
Hibiscus/química , Óleos Voláteis/química , Fitol/química , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Cromatografia Gasosa-Espectrometria de Massas , Hibiscus/toxicidade , Medicago sativa/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Óleos Voláteis/toxicidade , Fitol/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Testes de Toxicidade
11.
Plant Cell Physiol ; 62(1): 28-42, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32976554

RESUMO

A novel late embryogenesis abundant (LEA) gene, MsLEA-D34, was cloned from alfalfa (Medicago sativa L.). Its function and gene regulatory pathways were studied via overexpression (OE) and RNA interference (RNAi) of the gene in Arabidopsis and in hairy roots of alfalfa, as well as via analyzing key genes related to MsLEA-D34 during developmental phases in alfalfa. The results showed that MsLEA-D34 was a typical intrinsically disordered protein with a high capability for protein protection. Overexpression of MsLEA-D34 increased plant tolerance to osmotic and salt stresses, and caused Arabidopsis early flowering under drought and well-watered conditions. Overexpressing MsLEA-D34 induced up-regulation of FLOWERING LOCUS T (FT) and GIGANTEA (GI) at the flowering phase of Arabidopsis and hairy roots of alfalfa, but only FT was down-regulated in MsLEA-D34-RNAi lines. A positive effect of MsLEA-D34 on FT accumulation was demonstrated in alfalfa hairy roots. An ABA-responsive element (ABRE)-binding transcription factor (MsABF2), a novel transcription factor cloned from alfalfa, directly bound to the RY element in the MsLEA-D34 promoter and activated MsLEA-D34 expression. The above results indicate that MsLEA-D34 can regulate abiotic stress response in plants and influence flowering time of Arabidopsis.


Assuntos
Flores/crescimento & desenvolvimento , Genes de Plantas/fisiologia , Medicago sativa/genética , Arabidopsis , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/fisiologia , Pressão Osmótica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Tolerância ao Sal , Estresse Fisiológico
12.
Plant Signal Behav ; 15(12): 1832373, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33073686

RESUMO

In order to explore the main limiting factors affecting the growth and physiological function of alfalfa under salt and alkali stress, the effect of the salt and alkali stress on the growth and physiological function of alfalfa was studied. The results showed that effects of the excessive salt concentration (100 and 200 mM) on the growth and physiological characteristics were significantly greater than that of pH (7.0 and 9.0). Under 100 mM salt stress, there was no significant difference in the growth and photosynthetic function between pH 9.0 and pH 7.0. Under the 200 mM salt concentration the absorption of Na+ by alfalfa treated at the pH 9.0 did not increase significantly compared with absorption at the pH 7.0. However, the higher pH directly reduced the root activity, leaf's water content, and N-P-K content also decreased significantly. The PSII and PSI activities decreased with increasing the salt concentration, especially the damage degree of PSI. Although the photoinhibition of PSII was not significant, PSII donor and electron transfer from the Q A to Q B of the PSII receptor sides was inhibited. In a word, alfalfa showed relatively strong salt tolerance capacity, at the 100 mM salt concentration, even when the pH reached 9.0. Thus, the effect on the growth and photosynthetic function was not significant. However, at 200 mM salt concentration, pH 9.0 treatment caused damage to root system and the photosynthetic function in leaves of alfalfa was seriously injured.


Assuntos
Medicago sativa/crescimento & desenvolvimento , Nitrogênio/metabolismo , Fósforo/metabolismo , Processos Fotoquímicos , Desenvolvimento Vegetal/efeitos dos fármacos , Folhas de Planta/metabolismo , Cloreto de Sódio/farmacologia , Biomassa , Fluorescência , Concentração de Íons de Hidrogênio , Medicago sativa/efeitos dos fármacos , Oxigênio/metabolismo , Processos Fotoquímicos/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Água/metabolismo
13.
DNA Cell Biol ; 39(11): 1976-1989, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33001712

RESUMO

The Dof transcription factor is a plant-specific transcriptional regulator that plays important roles in plant development and acts as a mediator in plant external stress responses. However, Dofs have previously been identified in several plants but not in alfalfa (Medicago sativa L.), one of the most widely cultivated forage legumes. In the present study, a total of 40 MsDof genes were identified, and the phylogenetic reconstruction, classification, conserved motifs, and expression patterns under abscisic acid (ABA), cold, heat, drought and salt stresses of these Dof genes were comprehensively analyzed. The Dof genes family in alfalfa could be classified into eight classes. Gene ontology (GO) and tissue-specific analysis indicated that most MsDof genes may be involved in biological functions during plant growth. Moreover, the expression profiles and quantitative real-time PCR analysis indicated that eight candidate abiotic tolerance genes were induced in response to four abiotic stresses. This study identified the possibility of abiotic tolerance candidate genes playing various roles in stress resistance at the whole genome level, which would provide new information on the Dof family in alfalfa.


Assuntos
Medicago sativa/genética , Filogenia , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Ácido Abscísico/efeitos adversos , Temperatura Baixa/efeitos adversos , Secas , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Resposta ao Choque Térmico/genética , Medicago sativa/crescimento & desenvolvimento , Família Multigênica/genética , Sais/efeitos adversos , Fatores de Transcrição/classificação
14.
Ecotoxicol Environ Saf ; 202: 111011, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800236

RESUMO

Boron (B) deficiency and surplus are the main factors that affect plant growth and yield. A better understanding of the response mechanisms of plant reproductive organs to stress induced by B deficiency and surplus could provide new insights to potential strategies for improving seed yield and quality. In this study, we aimed to elucidate the mechanisms of tolerance to B-induced stress in the reproductive organs of alfalfa (Medicago sativa L. cv. 'Aohan'). We initially used five B concentrations (0 mg B L-1, 400 mg B L-1, 800 mg B L-1, 1200 mg B L-1, and 1600 mg B L-1) to determine the B deficient, sufficient, and surplus levels in the field. Secondly, we examined changes in metabolite profiles of alfalfa 'Aohan' reproductive organs in response to B deficiency (0 mg B L-1), B sufficiency (800 mg B L-1), and B surplus (1600 mg B L-1) conditions using gas chromatography-mass spectrometry (GC-MS). Flowers and seeds from alfalfa 'Aohan' showed different metabolite profiles and resistance capacity under B deficiency and surplus conditions. B deficiency led to the excessive accumulation of sugars and phenolic compounds in alfalfa 'Aohan' and seeds, respectively, thus causing abscission or the abortion of reproductive organs. In contrast, B surplus severely reduced the levels of metabolites associated with amino acid and carbohydrate metabolism, resulting in the flowers falling and, therefore, low seed yield. Overall, B deficiency predominantly reduced seed yield and quality of alfalfa 'Aohan', while B surplus mainly affected seed yield of alfalfa 'Aohan'.


Assuntos
Boro/deficiência , Boro/toxicidade , Células Germinativas Vegetais/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Poluentes do Solo/toxicidade , Aminoácidos/metabolismo , Metabolismo dos Carboidratos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Células Germinativas Vegetais/metabolismo , Medicago sativa/metabolismo , Metabolômica , Sementes/metabolismo , Poluentes do Solo/metabolismo
15.
Int J Mol Sci ; 21(16)2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32824876

RESUMO

Albendazole (ABZ), a widely used anthelmintic drug, enters the environment mainly via livestock excrements. To evaluate the environmental impact of ABZ, the knowledge of its uptake, effects and metabolism in all non-target organisms, including plants, is essential. The present study was designed to identify the metabolic pathway of ABZ and to test potential ABZ phytotoxicity in fodder plant alfalfa, with seeds and in vitro regenerants used for these purposes. Alfalfa was chosen, as it may meet manure from ABZ-treated animals in pastures and fields. Alfalfa is often used as a feed of livestock, which might already be infected with helminths. The obtained results showed that ABZ did not inhibit alfalfa seed germination and germ growth, but evoked stress and a toxic effect in alfalfa regenerants. Alfalfa regenerants were able to uptake ABZ and transform it into 21 metabolites. UHPLC-MS/MS analysis revealed three new ABZ metabolites that have not been described yet. The discovery of the parent compound ABZ together with the anthelmintically active and instable metabolites in alfalfa leaves shows that the contact of fodder plants with ABZ-containing manure might represent not only a danger for herbivorous invertebrates, but also may cause the development of ABZ resistance in helminths.


Assuntos
Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Medicago sativa/efeitos dos fármacos , Metaboloma , Ração Animal , Germinação , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo
16.
Plant Biol (Stuttg) ; 22(6): 1140-1149, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32609937

RESUMO

In Northeastern China, the intensive cropping system and increased use of chemical fertilizer has caused severe problems in terms of sustainable agricultural development. Therefore, to improve agricultural sustainability and crop productivity the farming system needs to be modified in the region. A pot experiment was conducted to evaluate the effect of maize-alfalfa intercropping on the physiological characteristics, nitrogen (N) uptake and yield of the maize crops in northeast China in 2017-2018. The study findings showed that intercropping under N fertilization progressively improved the physio-agronomic indices of the maize crop as compared to mono-cropping. The grain yield, 100 seed weight and biomass dry matter of maize crop improved in intercropping when it was practiced with N fertilizer. Furthermore, intercropping with N fertilization increased the chlorophyll content of the maize crop at bell-mouthed, silking, filing and mature stages by 19%, 44%, 12%, and 9% in 2017 and by 23%, 43%, 15%, and 11% in 2018, respectively, as compared with the monocropping system. Unlike monocropping, intercropping with N fertilization increased the photosynthesis rate (14% and 15%), stomatal conductance (74% and 98%) and transpiration rate (74% and 75%) in 2017 and 2018, respectively. However, intercropping reduced intercellular CO2 (Ci ). Moreover, intercropping with N fertilization increased the maize N content of grain and leaves as well as total N uptake by 49%, 31% and 93% in 2017 and 53%, 34% and 132%, respectively, in 2018 as compared to monocropping. In conclusion, our results suggest that maize-alfalfa intercropping with optimal N fertilization provides a practical method for improving growth, yield and N accumulation in the maize crop.


Assuntos
Produção Agrícola , Medicago sativa , Nitrogênio , Zea mays , China , Produção Agrícola/métodos , Fertilizantes , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo , Nitrogênio/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
17.
Antonie Van Leeuwenhoek ; 113(9): 1263-1278, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32564275

RESUMO

Plant growth-promoting rhizobacteria are a group of free-living bacteria that colonize plant rhizosphere and benefit plant root growth, thereby increasing host plant to cope with salinity induced stress. The aim of this study was to (1) isolate and characterize auxin-producing bacteria showing a high plant growth-promoting (PGP) potential, and (2) evaluate the PGP effects on the growth of Medicago sativa L under salinity stress (130 mM NaCl). Of thirteen isolates, Bacillus megaterium NRCB001 (NRCB001), B. subtilis subsp. subtilis NRCB002 (NRCB002) and B. subtilis NRCB003 (NRCB003) had the ability to produce auxin, which ranged from 47.53 to 154.38 µg ml-1. The three auxin-producing bacterial strains were shown multiple PGP traits, such as producing siderophore and NH3, showing ACC deaminase activity, solubilize phosphate and potassium. Furthermore, NRCB001, NRCB002, and NRCB003 could survive in LB medium containing 1750 mM NaCl. The three auxin-producing with salinity tolerance strains were selected for further analyses. In greenhouse experiments, when inoculated with NRCB001, NRCB002 and NRCB003, dry weight of alfalfa significantly (P < 0.05) increased by 24.1%, 23.1% and 38.5% respectively, compared with those of non-inoculated control seedlings under normal growth condition. When inoculated with NRCB002 and NRCB003, dry weight of alfalfa significantly (P < 0.05) increased by 96.9 and 71.6% respectively, compared with those of non-inoculated control seedlings under 130 mM NaCl condition. Our results indicated that NRCB002 and NRCB003 having PGP traits are promising candidate strains to develop biofertilizers, especially used under salinity stress conditions.


Assuntos
Bacillus megaterium/fisiologia , Bacillus subtilis/fisiologia , Ácidos Indolacéticos/metabolismo , Medicago sativa/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Salinidade , Bacillus megaterium/classificação , Bacillus megaterium/isolamento & purificação , Bacillus subtilis/classificação , Bacillus subtilis/isolamento & purificação , DNA Bacteriano/genética , Medicago sativa/microbiologia , Filogenia , Desenvolvimento Vegetal , RNA Ribossômico 16S/genética , Rizosfera , Cloreto de Sódio , Microbiologia do Solo
18.
Int J Mol Sci ; 21(12)2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32585890

RESUMO

Increasing photosynthetic ability as a whole is essential for acquiring higher crop yields. Nonleaf green organs (NLGOs) make important contributions to photosynthate formation, especially under stress conditions. However, there is little information on the pod wall in legume forage related to seed development and yield. This experiment is designed for alfalfa (Medicago sativa) under drought stress to explore the photosynthetic responses of pod walls after 5, 10, 15, and 20 days of pollination (DAP5, DAP10, DAP15, and DAP20) based on ultrastructural, physiological and proteomic analyses. Stomata were evidently observed on the outer epidermis of the pod wall. Chloroplasts had intact structures arranged alongside the cell wall, which on DAP5 were already capable of producing photosynthate. The pod wall at the late stage (DAP20) still had photosynthetic ability under well-watered (WW) treatments, while under water-stress (WS), the structure of the chloroplast membrane was damaged and the grana lamella of thylakoids were blurry. The chlorophyll a and chlorophyll b concentrations both decreased with the development of pod walls, and drought stress impeded the synthesis of photosynthetic pigments. Although the activity of ribulose-1,5-bisphosphate carboxylase (RuBisCo) decreased in the pod wall under drought stress, the activity of phosphoenolpyruvate carboxylase (PEPC) increased higher than that of RuBisCo. The proteomic analysis showed that the absorption of light is limited due to the suppression of the synthesis of chlorophyll a/b binding proteins by drought stress. Moreover, proteins involved in photosystem I and photosystem II were downregulated under WW compared with WS. Although the expression of some proteins participating in the regeneration period of RuBisCo was suppressed in the pod wall subjected to drought stress, the synthesis of PEPC was induced. In addition, some proteins, which were involved in the reduction period of RuBisCo, carbohydrate metabolism, and energy metabolism, and related to resistance, including chitinase, heat shock protein 81-2 (Hsp81-2), and lipoxygenases (LOXs), were highly expressed for the protective response to drought stress. It could be suggested that the pod wall in alfalfa is capable of operating photosynthesis and reducing the photosynthetic loss from drought stress through the promotion of the C4 pathway, ATP synthesis, and resistance ability.


Assuntos
Secas , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/ultraestrutura , Fotossíntese , Proteínas de Plantas/metabolismo , Proteoma/análise , Estresse Fisiológico , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Medicago sativa/metabolismo
19.
Molecules ; 25(10)2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32429231

RESUMO

Identification and quantification of polyphenols in plant material are of great interest since they make a significant contribution to its total bioactivity. In the present study, an UPLC-Orbitrap-MS/MS approach using the variable data acquisition mode (vDIA) was developed and applied for rapid separation, identification, and quantification of the main polyphenolic compounds in Medicago sativa L. and Trifolium pratense L. sprouts in different germination stages. Based on accurate MS data and fragment ions identification strategy, a total of 29 compounds were identified by comparing their accurate masses, fragment ions, retention times, and literatures. Additionally, a number of 30 compounds were quantified by comparing to the reference standards. Data were statistically analysed. For both plant species, the sprouts of the third germination day are valuable sources of bioactive compounds and could be used in phytotherapy and nutrition. Although Trifolium pratense L. (Red Clover) is considered to be a reference for natural remedies in relieving menopause disorders, alfalfa also showed a high level of biological active compounds with estrogenic activity.


Assuntos
Flavonoides/química , Medicago sativa/química , Polifenóis/química , Plântula/química , Trifolium/química , Cromatografia Líquida de Alta Pressão , Flavonoides/classificação , Flavonoides/isolamento & purificação , Germinação/fisiologia , Limite de Detecção , Espectrometria de Massas , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo , Extratos Vegetais/química , Polifenóis/classificação , Polifenóis/isolamento & purificação , Padrões de Referência , Plântula/metabolismo , Fatores de Tempo , Trifolium/crescimento & desenvolvimento , Trifolium/metabolismo
20.
Ecotoxicol Environ Saf ; 196: 110537, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32272346

RESUMO

The objective of the study was to explore the influences of arbuscular mycorrhizae (AM), phosphorus (P) fertiliser, biochar application (BC) and their interactions on Medicago sativa growth, nutrient, Cd content and AM fungi-plant symbioses. Applications of both P fertiliser and BC significantly increased total biomass and P and potassium (K) uptake, regardless of AM. When no P fertiliser or BC was used, the shoot biomass and nitrogen (N), P, and K contents in the +AM treatments were 1.39, 1.54, 4.53 and 2.06 times higher than those in the -AM treatments, respectively. AM fungi only elevated the total P uptake by 44.03% when P fertiliser was applied at a rate of 30 mg P kg-1 in the absence of BC addition. With BC application or high-P fertiliser input (100 mg P kg-1), the soil available P was significantly higher than that in the other treatments, and AM fungi significantly reduced the shoot biomass. The minimum Cd concentration occurred in the shoots of alfalfas treated with BC and high-P fertiliser inputs; this concentration was lower than the maximum permitted concentration in China. Although the BC and high-P inputs could eliminate the positive mycorrhizal response, the results suggested that BC application in combination with high-P fertiliser input could not only increase forage yields but also lower Cd concentrations to meet the forage safety standards by the dilution effect.


Assuntos
Cádmio/metabolismo , Carvão Vegetal/farmacologia , Medicago sativa/crescimento & desenvolvimento , Micorrizas/fisiologia , Fósforo/farmacologia , Biomassa , Carvão Vegetal/análise , Fertilizantes/análise , Medicago sativa/efeitos dos fármacos , Medicago sativa/metabolismo , Medicago sativa/microbiologia , Nutrientes/metabolismo , Fósforo/análise , Fósforo/metabolismo , Poluentes do Solo/metabolismo , Simbiose/efeitos dos fármacos
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