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1.
BMC Genomics ; 25(1): 593, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867153

RESUMO

BACKGROUND: Terpenes are important components of plant aromas, and terpene synthases (TPSs) are the key enzymes driving terpene diversification. In this study, we characterized the volatile terpenes in five different Chrysanthemum nankingense tissues. In addition, genome-wide identification and expression analysis of TPS genes was conducted utilizing an improved chromosome-scale genome assembly and tissue-specific transcriptomes. The biochemical functions of three representative TPSs were also investigated. RESULTS: We identified tissue-specific volatile organic compound (VOC) and volatile terpene profiles. The improved Chrysanthemum nankingense genome assembly was high-quality, including a larger assembled size (3.26 Gb) and a better contig N50 length (3.18 Mb) compared to the old version. A total of 140 CnTPS genes were identified, with the majority representing the TPS-a and TPS-b subfamilies. The chromosomal distribution of these TPS genes was uneven, and 26 genes were included in biosynthetic gene clusters. Closely-related Chrysanthemum taxa were also found to contain diverse TPS genes, and the expression profiles of most CnTPSs were tissue-specific. The three investigated CnTPS enzymes exhibited versatile activities, suggesting multifunctionality. CONCLUSIONS: We systematically characterized the structure and diversity of TPS genes across the Chrysanthemum nankingense genome, as well as the potential biochemical functions of representative genes. Our results provide a basis for future studies of terpene biosynthesis in chrysanthemums, as well as for the breeding of improved chrysanthemum varieties.


Assuntos
Alquil e Aril Transferases , Chrysanthemum , Genoma de Planta , Família Multigênica , Terpenos , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Chrysanthemum/genética , Chrysanthemum/enzimologia , Terpenos/metabolismo , Filogenia , Compostos Orgânicos Voláteis/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma
2.
J Cell Physiol ; 2023 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-37393608

RESUMO

Anthraquinones are polycyclic compounds with an unsaturated diketone structure (quinoid moiety). As important secondary metabolites of plants, anthraquinones play an important role in the response of many biological processes and environmental factors. Anthraquinones are common in the human diet and have a variety of biological activities including anticancer, antibacterial, and antioxidant activities that reduce disease risk. The biological activity of anthraquinones depends on the substitution pattern of their hydroxyl groups on the anthraquinone ring structure. However, there is still a lack of systematic summary on the distribution, classification, and biosynthesis of plant anthraquinones. Therefore, this paper systematically reviews the research progress of the distribution, classification, biosynthesis, and regulation of plant anthraquinones. Additionally, we discuss future opportunities in anthraquinone research, including biotechnology, therapeutic products, and dietary anthraquinones.

3.
Molecules ; 23(9)2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30149578

RESUMO

The genus Sanguisorba, which contains about 30 species around the world and seven species in China, is the source of the medicinal plant Sanguisorba officinalis, which is commonly used as a hemostatic agent as well as to treat burns and scalds. Here we report the complete chloroplast (cp) genome sequences of four Sanguisorba species (S. officinalis, S. filiformis, S. stipulata, and S. tenuifolia var. alba). These four Sanguisorba cp genomes exhibit typical quadripartite and circular structures, and are 154,282 to 155,479 bp in length, consisting of large single-copy regions (LSC; 84,405⁻85,557 bp), small single-copy regions (SSC; 18,550⁻18,768 bp), and a pair of inverted repeats (IRs; 25,576⁻25,615 bp). The average GC content was ~37.24%. The four Sanguisorba cp genomes harbored 112 different genes arranged in the same order; these identical sections include 78 protein-coding genes, 30 tRNA genes, and four rRNA genes, if duplicated genes in IR regions are counted only once. A total of 39⁻53 long repeats and 79⁻91 simple sequence repeats (SSRs) were identified in the four Sanguisorba cp genomes, which provides opportunities for future studies of the population genetics of Sanguisorba medicinal plants. A phylogenetic analysis using the maximum parsimony (MP) method strongly supports a close relationship between S. officinalis and S. tenuifolia var. alba, followed by S. stipulata, and finally S. filiformis. The availability of these cp genomes provides valuable genetic information for future studies of Sanguisorba identification and provides insights into the evolution of the genus Sanguisorba.


Assuntos
Genoma de Cloroplastos , Sanguisorba/classificação , Sanguisorba/genética , Composição de Bases , Códon , Biologia Computacional/métodos , Éxons , Variação Genética , Genômica/métodos , Íntrons , Repetições de Microssatélites , Anotação de Sequência Molecular , Filogenia
4.
ACS Sens ; 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38908004

RESUMO

Infection with drug-resistant bacteria poses a significant threat to human health. Judicious use of antibiotics could reduce the likelihood of bacterial resistance, which can be evaluated through antibiotic susceptibility testing (AST). This paper focuses on the application of a needle-like nanocapillary tip filled with chitosan (CS)/polyethylene pyrrolidone (PVP) hydrogel based on its specific pH-sensitive properties. The gel-filled nanocapillary has the potential to be used for electrical pH detection with a sensitivity of 3.06 nA/pH and a linear range from 7.3 to 4.3. Such sensitivity for pH measurement could be extended for monitoring of bacterial (such as Escherichia coli and Streptococcus salivarius) growth because of the relationship between pH and bacterial growth. Bacterial growth curves obtained using the hydrogel-filled nanocapillary showed good agreement with the OD600 method. Moreover, this device could be applied for rapid AST for tetracycline and norfloxacin on E. coli with minimum inhibitory concentrations of 2 and 0.125 µg/mL, respectively. This study expands the application of the hydrogel-based nanocapillary for bacterial research by monitoring changes in pH values.

5.
Plant Physiol Biochem ; 210: 108591, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583314

RESUMO

Fresh lotus seeds are gaining favor with consumers for their crunchy texture and natural sweetness. However, the intricacies of sugar accumulation in lotus seeds remain elusive, which greatly hinders the quality improvement of fresh lotus seeds. This study endeavors to elucidate this mechanism by identifying and characterizing the sucrose synthase (SUS) gene family in lotus. Comprising five distinct members, namely NnSUS1 to NnSUS5, each gene within this family features a C-terminal glycosyl transferase1 (GT1) domain. Among them, NnSUS1 is the predominately expressed gene, showing high transcript abundance in the floral organs and cotyledons. NnSUS1 was continuously up-regulated from 6 to 18 days after pollination (DAP) in lotus cotyledons. Furthermore, NnSUS1 demonstrates co-expression relationships with numerous genes involved in starch and sucrose metabolism. To investigate the function of NnSUS1, a transient overexpression system was established in lotus cotyledons, which confirmed the gene's contribution to sugar accumulation. Specifically, transient overexpression of NnSUS1 in seed cotyledons leads to a significant increase in the levels of total soluble sugar, including sucrose and fructose. These findings provide valuable theoretical insights for improving sugar content in lotus seeds through molecular breeding methods.


Assuntos
Cotilédone , Glucosiltransferases , Lotus , Proteínas de Plantas , Cotilédone/genética , Cotilédone/metabolismo , Cotilédone/enzimologia , Regulação da Expressão Gênica de Plantas , Glucosiltransferases/metabolismo , Glucosiltransferases/genética , Lotus/genética , Lotus/enzimologia , Lotus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismo , Sementes/enzimologia , Sacarose/metabolismo , Açúcares/metabolismo
6.
Food Chem ; 449: 139183, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38604028

RESUMO

Tartary buckwheat, celebrated as the "king of grains" for its flavonoid and phenolic acid richness, has health-promoting properties. Despite significant morphological and metabolic variations in mature achenes, research on their developmental process is limited. Utilizing Liquid chromatography-mass spectrometry and atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry imaging, we conducted spatial-temporal metabolomics on two cultivars during achene development. Metabolic profiles including 17 phenolic acids and 83 flavonoids are influenced by both varietal distinctions and developmental intricacies. Notably, flavonols, as major flavonoids, accumulated with achene ripening and showed a tissue-specific distribution. Specifically, flavonol glycosides and aglycones concentrated in the embryo, while methylated flavonols and procyanidins in the hull. Black achenes at the green achene stage have higher bioactive compounds and enhanced antioxidant capacity. These findings provide insights into spatial and temporal characteristics of metabolites in Tartary buckwheat achenes and serve as a theoretical guide for selecting optimal resources for food production.


Assuntos
Fagopyrum , Metabolômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fagopyrum/química , Fagopyrum/crescimento & desenvolvimento , Fagopyrum/metabolismo , Flavonoides/metabolismo , Flavonoides/química , Flavonoides/análise , Cromatografia Líquida de Alta Pressão , Extratos Vegetais/metabolismo , Extratos Vegetais/química , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Espectrometria de Massa com Cromatografia Líquida
7.
Food Chem ; 457: 139925, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38917567

RESUMO

Blueberry leaves (BBL) are a natural source with strong antioxidant activity, but bioactive compounds and their seasonal variation remain vague. Here, two major classes of compounds including four caffeoylquinic acids and eight flavonoids were identified in two southern highbush cultivars ("Lanmei" #1 and "Jewel") grown in China. Major bioactive compounds were discovered using an online HPLC post-column derivatization system and determined as neochlorogenic acid (NeoCA), chlorogenic acid (CA), rutin, hyperoside, and isoquercitrin. CA contributed the most to the BBL antioxidant activity. "Lanmei" showed significant advantages in terms of rutin content and antioxidant activity over "Jewel" (P < 0.05). The highest CA content (CAC) of juvenile "Jewel" leaves reached 17.9%. July was the optimum harvest time for both cultivars after fruiting stage. Total phenolic content (TPC) and Trolox equivalent antioxidant capacity (TEAC) of fresh BBL were accurately predicted by a portable near-infrared (NIR) device in a rapid, low-cost, and non-destructive way in situ.

8.
J Exp Bot ; 64(5): 1413-25, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23382554

RESUMO

Foliar NH4(+) exposure is linked to inhibition of lateral root (LR) formation. Here, the role of shoot ethylene in NH4(+)-induced inhibition of LR formation in Arabidopsis was investigated using wild-type and mutant lines that show either blocked ethylene signalling (etr1) or enhanced ethylene synthesis (eto1, xbat32). NH4(+) exposure of wild-type Arabidopsis led to pronounced inhibition of LR production chiefly in the distal root, and triggered ethylene evolution and enhanced activity of the ethylene reporter EBS:GUS in the shoot. It is shown that shoot contact with NH4(+) is necessary to stimulate shoot ethylene evolution. The ethylene antagonists Ag(+) and aminoethoxyvinylglycine (AVG) mitigated LR inhibition under NH4(+) treatment. The decrease in LR production was significantly greater for eto1-1 and xbat32 and significantly less for etr1-3. Enhanced shoot ethylene synthesis/signalling blocked recovery of LR production when auxin was applied in the presence of NH4(+) and negatively impacted shoot AUX1 expression. The findings highlight the important role of shoot ethylene evolution in NH4(+)-mediated inhibition of LR formation.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Etilenos/biossíntese , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Compostos de Amônio Quaternário/farmacologia , Arabidopsis/efeitos dos fármacos , Glucuronidase/metabolismo , Ácidos Indolacéticos/farmacologia , Oniocompostos/farmacologia , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Transdução de Sinais/efeitos dos fármacos , Tioureia/análogos & derivados , Tioureia/farmacologia
9.
Gene ; 852: 147054, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36395971

RESUMO

Blueberry (Vaccinium corymbosum L.), a woody perennial bush in the genus Vaccinium, is an economically important and popular fruit crop worldwide. Development the superior cultivars, which including excellent fruit traits, not only means higher yielding and economic efficiency, but also produce fruit that to meet the preferences of different consumers. Excavating fruit quality-related genes, studying their functions, and using transgenic or molecular-assisted breeding are beneficial to the development of excellent blueberry varieties. Genetic transformation is an excellent way to study the function of genes in plants, however, it is a labor-intensive and time-consuming process to genetically transform many woody plants, including blueberry. Virus-induced gene silencing (VIGS) provides an efficient approach to knock-down the expression of target genes for functional analysis. In this study, tobacco rattle virus induced genes silencing (TRV-VIGS) was established in blueberry fruits using the VcANS gene as a reporter. The silenced sector of the skin of blueberry fruits injected with pTRV2 (plasmid Tobacco Rattle Virus, TRV-RNA2)::VcANS remained green or white at 25 days after agroinfiltration. In agroinfiltrated materials, the VcANS transcript levels were much lower in fruits with phenotypic changes (delayed color change) than in those infiltrated with the pTRV2 empty vector. Silencing of VcANS also affected the expression of other genes involved in the anthocyanin synthesis pathway. The experimental results support that VcANS can be used as an effective marker gene for VIGS system. In addition, the TRV-VIGS system has been successfully established in blueberry fruits, which provided an effective verification method for functional identification of unknown genes in blueberry fruits.


Assuntos
Mirtilos Azuis (Planta) , Vírus de Plantas , Inativação Gênica , Mirtilos Azuis (Planta)/genética , Frutas/genética , Nicotiana/genética , Vetores Genéticos , Vírus de Plantas/genética , Regulação da Expressão Gênica de Plantas
10.
Int J Biol Macromol ; 233: 123543, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36740124

RESUMO

Mitogen-activated protein kinase (MAPK) cascade signaling pathway plays pivotal roles in various plant biological processes. However, systematic study of MAPK cascade gene families is yet to be conducted in lotus. Herein, 198 putative MAPK genes, including 152 MAP3Ks, 15 MKKs, and 31 MPKs genes were identified in Nelumbo. Segmental duplication was identified as the predominant factor driving MAPK cascade gene family expansion in lotus. MAPK cascade genes in N. nucifera and N. lutea shared high degree of sequence homologies, with 84, 9, and 19 homologous MAP3K, MKK, and MPK gene pairs being detected between the two species, respectively, with most genes predominantly undergoing purifying selection. Gene expression profiling indicated that NnMAPK cascade genes were extensively involved in plant development and submergence stress response. Co-expression analysis revealed potential interaction between transcription factors (TFs) and NnMAPK cascade genes in various biological processes. NnMKK showed predicted interactions with multiple NnMAP3K or NnMPK proteins, which suggested that functional diversity of MAPK cascade genes could be as a result of their complex protein interaction mechanisms. This first systematic analysis of MAPK cascade families in lotus provides deeper insights into their evolutionary dynamics and functional properties, which potentially could be crucial for lotus genetic improvement.


Assuntos
Nelumbo , Nelumbo/genética , Genoma de Planta/genética , Sistema de Sinalização das MAP Quinases/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Família Multigênica , Filogenia , Regulação da Expressão Gênica de Plantas
11.
J Plant Physiol ; 280: 153891, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36495813

RESUMO

1,9-decanediol (1,9-D) is a biological nitrification inhibitor secreted in roots, which effectively inhibits soil nitrifier activity and reduces nitrogen loss from agricultural fields. However, the effects of 1,9-D on plant root growth and the involvement of signaling pathways in the plant response to 1,9-D have not been investigated. Here, we report that 1,9-D, in the 100-400 µM concentration range, promotes primary root length in Arabidopsis seedlings at 3d and 5d, by 10.1%-33.3% and 6.9%-32.6%, and, in a range of 50-200 µM, leads to an increase in the number of lateral roots. 150 µM 1,9-D was found optimum for the positive regulation of root growth. qRT-PCR analysis reveals that 1,9-D can significantly increase AtABA3 gene expression and that a mutation in ABA3 results in insensitivity of root growth to 1,9-D. Moreover, through pharmacological experiments, we show that exogenous addition of ABA (abscisic acid) with 1,9-D enhances primary root length by 23.5%-63.3%, and an exogenous supply of 1,9-D with the ABA inhibitor Flu reduces primary root length by 1.0%-14.3%. Primary root length of the pin2/eir1-1 is shown to be insensitive to both exogenous addition of 1,9-D and ABA, indicating that the auxin carrier PIN2/EIR1 is involved in promotion of root growth by 1,9-D. These results suggest a novel for 1,9-D in regulating plant root growth through ABA and auxin signaling.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Oryza , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Oryza/metabolismo , Nitrificação , Raízes de Plantas/metabolismo , Ácidos Indolacéticos/farmacologia , Ácidos Indolacéticos/metabolismo , Regulação da Expressão Gênica de Plantas
12.
Environ Pollut ; 317: 120805, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36470457

RESUMO

Microplastics (MPs) accumulation in farmland has attracted global concern. Smallholder farming is the dominant type in China's agriculture. Compared with large-scale farming, smallholder farming is not constrained by restrictive environmental policies and public awareness about pollution. Consequently, the degree to which smallholder farming is associated with MP pollution in soils is largely unknown. Here, we collected soil samples from both smallholder and large-scale vegetable production systems to determine the distribution and characteristics of MPs. MP abundance in vegetable soils was 147.2-2040.4 MP kg-1 (averaged with 500.8 MP kg-1). Soil MP abundance under smallholder cultivation (730.9 MP kg-1) was twice that found under large-scale cultivation (370.7 MP kg-1). MP particle sizes in smallholder and large-scale farming were similar, and were mainly <1 mm. There were also differences in MP characteristics between the two types of vegetable soils: fragments (60%) and fibers (34%) were dominant under smallholder cultivation, while fragments (42%), fibers (42%), and films (11%) were dominant under large-scale cultivation. We observed a significant difference in the abundance of fragments and films under smallholder versus large-scale cultivation; the main components of MPs under smallholder cultivation were PP (34%), PE (28%), and PE-PP (10%), while these were PE (29%), PP (16%), PET (16%), and PE-PP (13%) under large-scale cultivation. By identifying the shape and composition of microplastics, it can be inferred that agricultural films were not the main MP pollution source in vegetable soil. We show that smallholder farming produces more microplastics pollution than large-scale farming in vegetable soil.


Assuntos
Microplásticos , Plásticos , Fazendas , Verduras , Agricultura , Solo , Monitoramento Ambiental
13.
Hortic Res ; 10(2): uhac276, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36789257

RESUMO

Lotus (Nelumbo nucifera), an ancient aquatic plant, possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids (BIAs). However, only few genes and enzymes involved in BIA biosynthesis in N. nucifera have been isolated and characterized. In the present study we identified the regiopromiscuity of an O-methyltransferase, designated NnOMT6, isolated from N. nucifera; NnOMT6 was found to catalyze the methylation of monobenzylisoquinoline 6-O/7-O, aporphine skeleton 6-O, phenylpropanoid 3-O, and protoberberine 2-O. We further probed the key residues affecting NnOMT6 activity via molecular docking and molecular dynamics simulation. Verification using site-directed mutagenesis revealed that residues D316, N130, L135, N176A, D269, and E328 were critical for BIA O-methyltransferase activities; furthermore, N323A, a mutant of NnOMT6, demonstrated a substantial increase in catalytic efficiency for BIAs and a broader acceptor scope compared with wild-type NnOMT6. To the best of our knowledge, this is the first study to report the O-methyltransferase activity of an aporphine skeleton without benzyl moiety substitutions in N. nucifera. The study findings provide biocatalysts for the semisynthesis of related medical compounds and give insights into protein engineering to strengthen O-methyltransferase activity in plants.

14.
Heliyon ; 9(6): e16138, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37251486

RESUMO

Benzylisoquinoline alkaloids in lotus (Nelumbo nucifera) seed plumules and leaves exhibit significant tissue specificity for their pharmacological effects and potential nutritional properties. Herein, 46 benzylisoquinoline alkaloids were identified via UPLC-QTOF-HRMS, of which 9 were annotated as glycosylated monobenzylisoquinoline alkaloids concentrated in the seed plumules. The spatial distribution of targeted benzylisoquinoline alkaloids in leaves, seed plumules, and milky sap was determined via MALDI-MSI. Furthermore, 37 Nelumbo cultivars were investigated using targeted metabolomics to provide insights into functional tea development. While aporphine alkaloids comprised the main compounds present in lotus leaves, bisbenzylisoquinoline alkaloids were the main compounds in lotus plumules, where glycosylation primarily occurs. These findings can help understand the distribution of benzylisoquinoline alkaloids in lotus tissue and the directional breeding of varieties enriched with specific chemical functional groups for nutritional and pharmacological applications.

15.
Planta ; 235(2): 239-52, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21866344

RESUMO

Ammonium (NH(4)(+)) toxicity is a significant agricultural problem globally, compromising crop growth and productivity in many areas. However, the molecular mechanisms of NH(4)(+) toxicity are still poorly understood, in part due to a lack of valuable genetic resources. Here, a novel Arabidopsis mutant, amos2 (ammonium overly sensitive 2), displaying hypersensitivity to NH(4) (+) in both shoots and roots, was isolated. The mutant exhibits the hallmarks of NH(4)(+) toxicity at significantly elevated levels: severely suppressed shoot biomass, increased leaf chlorosis, and inhibition of lateral root formation. Amos2 hypersensitivity is associated with excessive NH(4)(+) accumulation in shoots and a reduction in tissue potassium (K(+)), calcium (Ca(2+)), and magnesium (Mg(2+)). We show that the lesion is specific to the NH(4)(+) ion, is independent of NH(4)(+) metabolism, and can be partially rescued by elevated external K(+). The amos2 lesion was mapped to a 16-cM interval on top of chromosome 1, where no similar mutation has been previously mapped. Our study identifies a novel locus controlling cation homeostasis under NH(4)(+) stress and provides a tool for the future identification of critical genes involved in the development of NH(4)(+) toxicity.


Assuntos
Sulfato de Amônio/farmacologia , Arabidopsis/genética , Genes de Plantas , Compostos de Amônio Quaternário/metabolismo , Sulfato de Amônio/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Cálcio/metabolismo , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Meios de Cultura/metabolismo , Homeostase , Magnésio/metabolismo , Mutação , Fenótipo , Doenças das Plantas/induzido quimicamente , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Potássio/metabolismo , Potássio/farmacologia , Especificidade da Espécie
16.
J Exp Bot ; 63(10): 3777-88, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22407650

RESUMO

Root gravitropism is affected by many environmental stresses, including salinity, drought, and nutrient deficiency. One significant environmental stress, excess ammonium (NH(4)(+)), is well documented to inhibit root elongation and lateral root formation, yet little is known about its effects on the direction of root growth. We show here that inhibition of root elongation upon elevation of external NH(4)(+) is accompanied by a loss in root gravitropism (agravitropism) in Arabidopsis. Addition of potassium (K(+)) to the treatment medium partially rescued the inhibition of root elongation by high NH(4)(+) but did not improve gravitropic root curvature. Expression analysis of the auxin-responsive reporter gene DR5::GUS revealed that NH(4)(+) treatment delayed the development of gravity-induced auxin gradients across the root cap but extended their duration once initiated. Moreover, the ß-glucuronidase (GUS) signal intensity in root tip cells was significantly reduced under high NH(4)(+) treatment over time. The potassium carrier mutant trh1 displayed different patterns of root gravitropism and DR5::GUS signal intensity in root apex cells compared with the wild type in response to NH(4)(+). Together, the results demonstrate that the effects of NH(4)(+) on root gravitropism are related to delayed lateral auxin redistribution and the TRH1 pathway, and are largely independent of inhibitory effects on root elongation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Regulação para Baixo , Gravitropismo , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Compostos de Amônio Quaternário/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
17.
Front Plant Sci ; 13: 1099689, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36605956

RESUMO

Syringic acid (SA) is a novel biological nitrification inhibitor (BNIs) discovered in rice root exudates with significant inhibition of Nitrosomonas strains. However, the inhibitory effect of SA on nitrification and nitrous oxide (N2O) emissions in different soils and the environmental factors controlling the degree of inhibition have not been studied. Using 14-day microcosm incubation, we investigated the effects of different concentrations of SA on nitrification activity, abundance of ammonia-oxidizing microorganisms, and N2O emissions in three typical agricultural soils. The nitrification inhibitory efficacy of SA was strongest in acidic red soil, followed by weakly acidic paddy soil, with no significant effect in an alkaline calcareous soil. Potential nitrification activity (PNA) were also greatly reduced by SA additions in paddy and red soil. Pearson correlation analysis showed that the inhibitory efficacy of SA might be negatively correlated with soil pH and positively correlated with clay percentage. SA treatments significantly reduced N2O emissions by 69.1-79.3% from paddy soil and by 40.8%-46.4% from red soil, respectively, but no effect was recorded in the calcareous soil. SA addition possessed dual inhibition of both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) abundance in paddy and red soil. Structural equation modelling revealed that soil ammonium (NH4 +) and dissolved organic carbon content (DOC) were the key variables explaining AOA and AOB abundance and subsequent N2O emissions. Our results support the potential for the use of the BNI SA in mitigating N2O emissions and enhancing N utilization in red and paddy soils.

18.
Front Genet ; 13: 901838, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35754820

RESUMO

NAC (NAM, ATAF, and CUC) is a ubiquitously expressed plant-specific transcription factor (TF) family which is involved in the regulation of various biological processes. However, a systematic characterization of NAC gene family is yet to be reported in lotus. Here, 82 NnNAC genes which included five predicted membrane-bound NAC proteins were identified in the lotus genome. Phylogenetic analysis revealed seven-subfamily clusters (I-VII) of NnNAC proteins, with homologous gene pairs displaying similar conserved motifs and gene structure characteristics. Transactivation assay of NnNAC proteins revealed an extensive transcriptional activation capacity which is mediated by the highly divergent C-terminal activation domain (AD). Expression analysis of NnNAC genes in lotus tissues showed high transcript levels in root, stamen, petal and seed coat. In addition, 30 and 29 differentially expressed NnNAC candidate genes putatively involved in lotus seed development and response to complete submergence stress, respectively, were identified. Overall, our study provides potentially useful candidate gene resources for future molecular breeding of lotus varieties with novel agronomic traits.

19.
Food Chem ; 379: 132124, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35065486

RESUMO

Untargeted metabolomics was performed to study the profiles of 101 chemicals in lotus seeds using ultrahigh-performance liquid chromatography-photodiode array detection-high-resolution tandem mass spectrometry. Among them, 16 dimeric, 18 trimeric, and 4 tetrameric proanthocyanidins were theoretically identified based on the degree of polymerization, and the number of linkages and the presence of two dihydroflavonols and three glycosylated alkaloids were determined for the first time. The proanthocyanidin, flavonoid, amino acid, and total compound contents were quantified, revealing decreases in their levels during maturation as well as a polymerization process formation of polymers from monomers during seed maturation. Interestingly, glycosylated alkaloids were only detected in seed cotyledons being highest at green-brown stage, whereas proanthocyanidins were present at a concentration of 8,226.19 ± 249.96 µg/g (dry weight) in green-brown stage of seed coats. Our findings may provide insights into the utilization of lotus seeds as a functional food.


Assuntos
Alcaloides , Proantocianidinas , Antioxidantes , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Proantocianidinas/análise
20.
Food Chem X ; 14: 100295, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35372824

RESUMO

Tartary buckwheat sprouts have a high nutritional value and are gluten-free, and polyphenols are their main active constituents. However, information regarding the active constituents' difference of Tartary buckwheat sprouts grown from seeds with different morphology, at different developmental stages and environments is limited. Here, we developed a LC-MS-based targeted metabolomics approach to analyze polyphenols (46 flavonoids and 6 anthraquinones) in 40 Tartary buckwheat sprouts varieties. Both flavonoids and anthraquinones contributed to significant differences in sprouts grown from seed with different color or shape. Twenty-seven differential compounds were all at a higher level in 3-day-old sprouts, and the fold change from 3-day-old to 8-day-old sprouts was 1.42-6.64. A total of 25 differential compounds were all significantly upregulated upon UV-B radiation, especially for epicatechin. This study is valuable not only for better breeding cultivars of Tartary buckwheat sprouts, but also assessing their metabolic quality.

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