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1.
Plant Physiol Biochem ; 167: 723-737, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34500197

RESUMO

It was aimed to assess that up to what extent endogenous nitric oxide (NO) and its sources are involved in glutathione (GSH)-mediated tolerance of maize plants to cadmium (Cd) stress. The Cd-stressed maize plants were sprayed with or without GSH (1.0 mM) once every week for two weeks. Before initiating the stress treatment, the Cd-stressed plants sprayed with GSH were supplied with or without 0.1 mM, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO; a NO scavenger) for two weeks or with 0.1 mM sodium tungstate (ST; a nitrate reductase inhibitor), or 0.1 mM NG-nitro-L-arginine methyl ester hydrochloride (L-NAME). Cadmium stress suppressed the activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glyoxalase II, while increased leaf NO, Cadmium content, proline, oxidative stress, the activities of glutathione reductase, ascorbate peroxidase, the key enzymes of oxidative defense system, glyoxalase I, NR and NOS. GSH reduced oxidative stress and tissue Cd2+ content, but it improved growth, altered water relations, and additionally increased proline levels, activities of the AsA-GSH cycle, key enzymatic antioxidants, glyoxalase I and II, NR and NOS as well as NO content. The cPTIO and ST supplementation abolished the beneficial effects of GSH by reducing the activities of NO and NR. However, L-NAME did not retreat the favorable effects of GSH, although it reduced the NOS activity without eliminating NO content, suggesting that NR might be a prospective source of NO generated by GSH in Cd-stressed plants, which in turn accelerated the activities of antioxidant enzymes.


Assuntos
Cádmio , Glutationa , Antioxidantes , Ácido Ascórbico , Cádmio/toxicidade , Glutationa/metabolismo , Óxido Nítrico , Estresse Oxidativo , Estudos Prospectivos , Zea mays/metabolismo
2.
Plant Physiol Biochem ; 167: 840-850, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34534799

RESUMO

As one of the largest families of transcription factors in plants, the WRKY proteins play crucial roles in plant growth and development, defense regulation and stress responses. In this research, ZmWRKY86 encoding a WRKY transcription factor was cloned from maize (Zea mays L.). ZmWRKY86 expression was up-regulated by salt stress. ZmWRKY86 is a nuclear protein and has no transcriptional activation ability in yeast. ZmWRKY86 can specifically bind to W-box (TTGACC), which was confirmed by electrophoretic mobility shift assay (EMSA) and dual-LUC experiments. As compared with control, the wrky86 mutants showed enhanced plant tolerance to salt stress with higher survival rate, catalase activity and K+ content, but lower malondialdehyde accumulation, relative electrical leakage level and Na+ content under salt-stress condition. Transcriptome and quantitative real-time PCR analyses indicated that the mutation of ZmWRKY86 led to significant changes in the expression of stress-related genes in maize. Further assays showed that ZmWRKY86 directly interacted with the promoter of two salt stress-related genes Zm00001d020840 and Zm00001d046813. In summary, we identified a WRKY transcription factor ZmWRKY86 that participates in salt stress regulation through controlling the expression of stress-related genes.


Assuntos
Arabidopsis , Zea mays , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Estresse Salino , Estresse Fisiológico/genética , Zea mays/genética , Zea mays/metabolismo
3.
BMC Plant Biol ; 21(1): 434, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556041

RESUMO

BACKGROUND: Kernel development and starch formation are the primary determinants of maize yield and quality, which are considerably influenced by drought stress. To clarify the response of maize kernel to drought stress, we established well-watered (WW) and water-stressed (WS) conditions at 1-30 days after pollination (dap) on waxy maize (Zea mays L. sinensis Kulesh). RESULTS: Kernel development, starch accumulation, and activities of starch biosynthetic enzymes were significantly reduced by drought stress. The morphology of starch granules changed, whereas the grain filling rate was accelerated. A comparative proteomics approach was applied to analyze the proteome change in kernels under two treatments at 10 dap and 25 dap. Under the WS conditions, 487 and 465 differentially accumulated proteins (DAPs) were identified at 10 dap and 25 dap, respectively. Drought induced the downregulation of proteins involved in the oxidation-reduction process and oxidoreductase, peroxidase, catalase, glutamine synthetase, abscisic acid stress ripening 1, and lipoxygenase, which might be an important reason for the effect of drought stress on kernel development. Notably, several proteins involved in waxy maize endosperm and starch biosynthesis were upregulated at early-kernel stage under WS conditions, which might have accelerated endosperm development and starch synthesis. Additionally, 17 and 11 common DAPs were sustained in the upregulated and downregulated DAP groups, respectively, at 10 dap and 25 dap. Among these 28 proteins, four maize homologs (i.e., A0A1D6H543, B4FTP0, B6SLJ0, and A0A1D6H5J5) were considered as candidate proteins that affected kernel development and drought stress response by comparing with the rice genome. CONCLUSIONS: The proteomic changes caused by drought were highly correlated with kernel development and starch accumulation, which were closely related to the final yield and quality of waxy maize. Our results provided a foundation for the enhanced understanding of kernel development and starch formation in response to drought stress in waxy maize.


Assuntos
Secas , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Amido/metabolismo , Ceras/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , China , Desidratação/metabolismo , Proteômica , Água/metabolismo
4.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502218

RESUMO

Phosphorus (P) deficiency is an important challenge the world faces while having to increase crop yields. It is therefore necessary to select maize (Zea may L.) genotypes with high phosphorus use efficiency (PUE). Here, we extensively analyzed the biomass, grain yield, and PUE-related traits of 359 maize inbred lines grown under both low-P and normal-P conditions. A significant decrease in grain yield per plant and biomass, an increase in PUE under low-P condition, as well as significant correlations between the two treatments were observed. In a genome-wide association study, 49, 53, and 48 candidate genes were identified for eleven traits under low-P, normal-P conditions, and in low-P tolerance index (phenotype under low-P divided by phenotype under normal-P condition) datasets, respectively. Several gene ontology pathways were enriched for the genes identified under low-P condition. In addition, seven key genes related to phosphate transporter or stress response were molecularly characterized. Further analyses uncovered the favorable haplotype for several core genes, which is less prevalent in modern lines but often enriched in a specific subpopulation. Collectively, our research provides progress in the genetic dissection and molecular characterization of PUE in maize.


Assuntos
Regulação da Expressão Gênica de Plantas , Fósforo/metabolismo , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Estresse Fisiológico , Zea mays/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Estudo de Associação Genômica Ampla , Fenótipo , Proteínas de Plantas/genética , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
5.
J Plant Physiol ; 265: 153507, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34478919

RESUMO

Dihydroxyacid dehydratase (EC 4.2.1.9) participates in metabolism of branched chain amino acids, in CoA biosynthesis and in the conversion of hydroxycitric acid that accumulates in several plants. In maize (Zea mays L.), this enzyme is encoded by the two genes (Dhad1 and Dhad2), having different patterns of their expression during germination. We have demonstrated the inhibition of Dhad1 expression by light and the opposite effect of light on Dhad2. These effects were phytochrome-dependent and involved methylation/demethylation of promoters. Incubation of maize plants in a nitrogen atmosphere resulted in Dhad1 activation peaking at 12 h, which coincided with the decrease in promoter methylation. The gene Dhad2 was activated only during the first 6 h of anoxia, with no correlation with the level of promoter methylation. Salt stress (150 mM NaCl) caused the activation of expression of Dhad2 while the expression of Dhad1 was inhibited in the first hour and then after 12 h incubation with NaCl. We conclude that the expression of two genes encoding dihydroxyacid dehydratase reveals the opposite or different patterns of regulation by light, anoxia and salinity. The mechanisms underlying these modifications involve promoter methylation and result in corresponding changes in the enzymatic activity of the conversion of hydroxycitrate to 2-oxoglutarate.


Assuntos
Adaptação Ocular/genética , Hidroliases/genética , Hipóxia/genética , Hipóxia/metabolismo , Estresse Salino/genética , Estresse Salino/fisiologia , Zea mays/genética , Zea mays/metabolismo , Adaptação Ocular/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Hidroliases/metabolismo
6.
Plant Physiol Biochem ; 167: 901-910, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34544007

RESUMO

Maize (Zea mays) plants over-expressing or suppressing the class 1 Phytoglobin (ZmPgb1.1) were evaluated for their ability to cope with low temperature stress. Cold treatment (10 °C day/4 °C night) depressed several gas exchange parameters including photosynthetic rate, stomatal conductance and transpiration, while elevated the levels of reactive oxygen species (ROS) and ROS-induced damage. These effects were attenuated by the over-expression of ZmPgb1.1, and aggravated when the level of the same gene was suppressed. Combination of transcriptomic and pharmacological studies revealed that over-expression of ZmPgb1.1 suppressed the level of nitric oxide (NO), which lowers the transcription of several Brassinosteroid (BR) biosynthetic and response genes. Cellular BR was required to induce the expression of ZmMPK5, a component of the mitogen-activated protein kinase (MAPK) cascade, which is known to be involved in the regulation of ROS-producing pathways. Experimental reduction of NO content, suppression of BR or inhibition of ZmMPK5 reverted the beneficial effects of ZmPgb1.1 over-expression, and increased plant susceptibility to cold stress through accumulation of ROS. Conversely, tolerance to cold was augmented in the ZmPgb1.1 down-regulating line when the levels of NO or BR were elevated. Together, this study demonstrates a novel role of ZmPgb1.1 in modulating plant performance to cold stress, and integrates the ZmPgb1.1 response in a model requiring NO and BR to alleviate oxidative stress through ZmMPK5.


Assuntos
Resposta ao Choque Frio , Zea mays , Brassinosteroides , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Óxido Nítrico/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Zea mays/genética , Zea mays/metabolismo
7.
Plant Physiol Biochem ; 167: 958-969, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34571389

RESUMO

Melatonin is a pleiotropic regulatory molecule in plants and is involved in regulating plant tolerance to drought stress. Here, we conducted transcriptomic and physiological analyses to identify metabolic processes associated with the enhanced tolerance of the melatonin-treated maize (Zea mays L.) seedlings to water deficit. Maize seedlings were foliar sprayed with either 50 µM melatonin or water and exposed to drought stress for 12 d in growth chambers. Drought stress significantly suppressed seedling growth, and melatonin application partially alleviated this growth inhibition. RNA-Seq analysis revealed that genes whose expression was significantly altered by melatonin were mainly related to carbon (C) and nitrogen (N) metabolism. Analysis of transcriptomics, enzyme activity, and metabolite content data, melatonin-treated plants exhibited a higher level of relatively stable C and N metabolism than untreated plants; this phenotype of melatonin-treated plants was associated with their higher photosynthesis, sucrose biosynthesis, N assimilation, and protein biosynthesis capacities under drought stress. Overall, our results suggest that melatonin enhances drought stress tolerance in maize through coordinated regulation of C and N metabolism.


Assuntos
Secas , Melatonina , Carbono/metabolismo , Regulação da Expressão Gênica de Plantas , Melatonina/farmacologia , Nitrogênio/metabolismo , Plântula/metabolismo , Estresse Fisiológico , Zea mays/metabolismo
8.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360681

RESUMO

The function and regulation of lipid metabolic genes are essential for plant male reproduction. However, expression regulation of lipid metabolic genic male sterility (GMS) genes by noncoding RNAs is largely unclear. Here, we systematically predicted the microRNA regulators of 34 maize white brown complex members in ATP-binding cassette transporter G subfamily (WBC/ABCG) genes using transcriptome analysis. Results indicate that the ZmABCG26 transcript was predicted to be targeted by zma-miR164h-5p, and their expression levels were negatively correlated in maize B73 and Oh43 genetic backgrounds based on both transcriptome data and qRT-PCR experiments. CRISPR/Cas9-induced gene mutagenesis was performed on ZmABCG26 and another lipid metabolic gene, ZmFAR1. DNA sequencing, phenotypic, and cytological observations demonstrated that both ZmABCG26 and ZmFAR1 are GMS genes in maize. Notably, ZmABCG26 proteins are localized in the endoplasmic reticulum (ER), chloroplast/plastid, and plasma membrane. Furthermore, ZmFAR1 shows catalytic activities to three CoA substrates in vitro with the activity order of C12:0-CoA > C16:0-CoA > C18:0-CoA, and its four key amino acid sites were critical to its catalytic activities. Lipidomics analysis revealed decreased cutin amounts and increased wax contents in anthers of both zmabcg26 and zmfar1 GMS mutants. A more detailed analysis exhibited differential changes in 54 monomer contents between wild type and mutants, as well as between zmabcg26 and zmfar1. These findings will promote a deeper understanding of miRNA-regulated lipid metabolic genes and the functional diversity of lipid metabolic genes, contributing to lipid biosynthesis in maize anthers. Additionally, cosegregating molecular markers for ZmABCG26 and ZmFAR1 were developed to facilitate the breeding of male sterile lines.


Assuntos
Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Aldeído Oxirredutases/genética , Flores/metabolismo , Metabolismo dos Lipídeos , MicroRNAs/metabolismo , Zea mays/metabolismo , Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Aldeído Oxirredutases/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas , Pólen/crescimento & desenvolvimento , Pólen/metabolismo , RNA-Seq , Zea mays/genética , Zea mays/crescimento & desenvolvimento
9.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445334

RESUMO

The aim of the study was to demonstrate the biostimulating effect of exogenous melatonin (MEL) applied to seeds via hydroconditioning. It was indicated that only well-chosen application technique and MEL dose guarantees success concerning seed germination and young seedlings growth under stress conditions. For maize seed, 50 µM of MEL appeared to be the optimal dose. It improved seed germination and embryonic axes growth especially during chilling stress (5 °C/14 days) and during regeneration after its subsided. Unfortunately, MEL overdosing lowered IAA level in dry seeds and could disrupt the ROS-dependent signal transduction pathways. Very effective antioxidant MEL action was confirmed by low level of protein oxidative damage and smaller quantity of lipid oxidation products in embryonic axes isolated from seeds pre-treated with MEL and then exposed to cold. The stimulatory effects of MEL on antioxidant enzymes: SOD, APX and GSH-PX and on GST-a detoxifying enzyme, was also demonstrated. It was indicated for the first time, that MEL induced defence strategies against stress at the cytological level, as appearing endoreplication in embryonic axes cells even in the seeds germinating under optimal conditions (preventive action), but very intensively in those germinating under chilling stress conditions (intervention action), and after stress removal, to improve regeneration.


Assuntos
Resposta ao Choque Frio , Melatonina/farmacologia , Zea mays , Agricultura/métodos , Antioxidantes/metabolismo , Resposta ao Choque Frio/efeitos dos fármacos , Resposta ao Choque Frio/genética , Endorreduplicação/efeitos dos fármacos , Germinação/efeitos dos fármacos , Germinação/genética , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Temperatura , Zea mays/efeitos dos fármacos , Zea mays/genética , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
10.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445561

RESUMO

Among numerous contaminants, the ubiquitous occurrence of nonsteroidal anti-inflammatory drugs (NSAIDs) in the environment and their plausible harmful impact on nontarget organisms have made them one of the most important areas of concern in recent years. Crop plants can also potentially be exposed to NSAIDs, since the concentration of these pharmaceuticals is constantly rising in the surface water and soil. Our goal was to evaluate the stress response of two crop plants, maize and tomato, to treatment with selected NSAIDs, naproxen and diclofenac. The focus of the research was on the growth response, photosynthetic efficiency, selected oxidative stress factors (such as the H2O2 level and the rate of lipid peroxidation) as well as the total phenolic content, which represents the non-enzymatic protectants against oxidative stress. The results indicate that susceptibility to the NSAIDs that were tested is dependent on the plant species. A higher sensitivity of tomato manifested in growth inhibition, a decrease in the content of the photosynthetic pigments and a reduction in the maximum quantum efficiency of PSII and the activity of PSII, which was estimated using the Fv/Fm and Fv/F0 ratios. Based on the growth results, it was also possible to reveal that diclofenac had a more toxic effect on tomato. In contrast to tomato, in maize, neither the content of the photosynthetic pigments nor growth appeared to be affected by DFC and NPX. However, both drugs significantly decreased in maize Fv and Fm, which are particularly sensitive to stress. A higher H2O2 concentration accompanied, in most cases, increasing lipid peroxidation, indicating that oxidative stress occurred in response to the selected NSAIDs in the plant species that were studied. The higher phenolic content of the plants after NSAIDs treatment may, in turn, indicate the activation of defense mechanisms in response to the oxidative stress that is triggered by these drugs.


Assuntos
Diclofenaco/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Naproxeno/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Peróxido de Hidrogênio/farmacologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Oxidantes/farmacologia , Fenóis/farmacologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
11.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361051

RESUMO

DNA methylation is important for plant growth, development, and stress response. To understand DNA methylation dynamics in maize roots under water stress (WS), we reanalyzed DNA methylation sequencing data to profile DNA methylation and the gene expression landscape of two inbred lines with different drought sensitivities, as well as two of their derived recombination inbred lines (RILs). Combined with genotyping-by-sequencing, we found that the inheritance pattern of DNA methylation between RILs and parental lines was sequence-dependent. Increased DNA methylation levels were observed under WS and the methylome of drought-tolerant inbred lines were much more stable than that of the drought-sensitive inbred lines. Distinctive differentially methylated genes were found among diverse genetic backgrounds, suggesting that inbred lines with different drought sensitivities may have responded to stress in varying ways. Gene body DNA methylation showed a negative correlation with gene expression but a positive correlation with exon splicing events. Furthermore, a positive correlation of a varying extent was observed between small interfering RNA (siRNA) and DNA methylation, which at different genic regions. The response of siRNAs under WS was consistent with the differential DNA methylation. Taken together, our data can be useful in deciphering the roles of DNA methylation in plant drought-tolerance variations and in emphasizing its function in alternative splicing.


Assuntos
Processamento Alternativo , Metilação de DNA , Estresse Fisiológico , Zea mays/genética , Secas , Regulação da Expressão Gênica de Plantas , Zea mays/metabolismo
12.
J Chem Ecol ; 47(8-9): 799-809, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34347233

RESUMO

Fall armyworm (Spodoptera frugiperda) is a major global pest of many crops, including maize (Zea mays). This insect is known to use host plant-derived volatile organic compounds to locate suitable hosts during both its adult and larval stages, yet the function of individual compounds remains mostly enigmatic. In this study, we use a combination of volatile profiling, electrophysiological assays, pair-wise choice behavioral assays, and chemical supplementation treatments to identify and assess specific compounds from maize that influence S. frugiperda host location. Our findings reveal that methyl salicylate and (E)-alpha-bergamotene are oviposition attractants for adult moths but do not impact larval behavior. While geranyl acetate can act as an oviposition attractant or repellent depending on the host volatile context and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) is an oviposition deterrent. These compounds can also be attractive to the larvae when applied to specific maize inbreds. These data show that S. frugiperda uses different plant volatile cues for host location in its adult and larval stage and that the background volatile context that specific volatiles are perceived in, alters their impact as behavioral cues.


Assuntos
Herbivoria/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Spodoptera/fisiologia , Compostos Orgânicos Voláteis/farmacologia , Zea mays/química , Animais , Compostos Bicíclicos com Pontes/isolamento & purificação , Compostos Bicíclicos com Pontes/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Larva/fisiologia , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal , Salicilatos/isolamento & purificação , Salicilatos/farmacologia , Spodoptera/crescimento & desenvolvimento , Terpenos/isolamento & purificação , Terpenos/farmacologia , Compostos Orgânicos Voláteis/química , Zea mays/metabolismo
13.
Molecules ; 26(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34443651

RESUMO

Caraway (Carum carvi L.) essential oil is a candidate for botanical herbicides. A hypothesis was formulated that the sand-applied maltodextrin-coated caraway oil (MCEO) does not affect the growth of maize (Zea mays L.). In the pot experiment, pre-emergence application of five doses of MCEO was tested on four maize cultivars up to the three-leaf growth stage. The morphological analyses were supported by the measurements of relative chlorophyll content (SPAD), two parameters of chlorophyll a fluorescence, e.g., Fv/Fm and Fv/F0, and fluorescence emission spectra. The analyzed MCEO contained 6.5% caraway EO with carvone and limonene as the main compounds, constituting 95% of the oil. The MCEO caused 7-day delays in maize emergence from the dose of 0.9 g per pot (equal to 96 g m-2). Maize development at the three-leaf growth stage, i.e., length of roots, length of leaves, and biomass of shoots and leaves, was significantly impaired already at the lowest dose of MCEO: 0.4 g per pot, equal to 44 g m-2. A significant drop of both chlorophyll a fluorescence parameters was noted, on average, from the dose of 0.7 g per pot, equal to 69 g m-2. Among the tested cultivars, cv. Rywal and Pomerania were less susceptible to the MCEO compared to the cv. Kurant and Podole. In summary, maize is susceptible to the pre-emergence, sand-applied MCEO from the dose of 44 g m-2.


Assuntos
Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Biomassa , Carum/química , Clorofila A/metabolismo , Monoterpenos Cicloexânicos/química , Monoterpenos Cicloexânicos/farmacologia , Fluorescência , Herbicidas/farmacologia , Limoneno/química , Limoneno/farmacologia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Zea mays/metabolismo
14.
Plant Mol Biol ; 106(6): 555-567, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275101

RESUMO

KEY MESSAGE: Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. The size and architecture of the root system is functionally relevant for the access to water and soil nutrients. A great number of mostly unknown genes are involved in regulating root architecture complicating targeted breeding of plants with a larger root system. Here, we have explored whether root-specific degradation of the hormone cytokinin, which is a negative regulator of root growth, can be used to genetically engineer maize (Zea mays L.) plants with a larger root system. Root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE (CKX) gene of Arabidopsis caused the formation of up to 46% more root dry weight while shoot growth of these transgenic lines was similar as in non-transgenic control plants. The concentration of several elements, in particular of those with low soil mobility (K, P, Mo, Zn), was increased in leaves of transgenic lines. In kernels, the changes in concentration of most elements were less pronounced, but the concentrations of Cu, Mn and Zn were significantly increased in at least one of the three independent lines. Our data illustrate the potential of an increased root system as part of efforts towards achieving biofortification. Taken together, this work has shown that root-specific expression of a CKX gene can be used to engineer the root system of maize and alter shoot element composition.


Assuntos
Proteínas de Arabidopsis/genética , Citocininas/metabolismo , Proteínas de Membrana/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Folhas de Planta/genética , Raízes de Plantas/genética , Zea mays/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Cobre/metabolismo , Regulação da Expressão Gênica de Plantas , Engenharia Genética/métodos , Manganês/metabolismo , Proteínas de Membrana/metabolismo , Minerais/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transgenes/genética , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Zinco/metabolismo
15.
Plant Physiol Biochem ; 166: 645-656, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34214775

RESUMO

Nickel (Ni) is involved in several physiological processes in plants but its excess in environment has many phytotoxic effects. Silicon (Si), an element required for optimal plant performance, has been shown to have beneficial effects for plants coping with various types of stresses. Here we studied the alleviative potential of Si (2.5 mM) added to hydroponically grown maize (Zea mays L.) plants under Ni (100 µM) stress. Ni decreased most of the growth parameters, total chlorophyll (Chl) and leaf relative water content (RWC), and catalase (CAT; EC 1.11.1.6) activity, while leaf water loss (LWL), contents of proline (Pro), hydrogen peroxide (H2O2) and ascorbate (AsA), membrane lipid peroxidation and activities of peroxidase (POX; EC 1.11.1.7) and superoxide dismutase (SOD; EC 1.15.1.1) were increased. Supplementation of Si to Ni-treated plants enhanced the leaf area, Chl content, RWC, CAT and POX (only in younger leaf) activities and decreased LWL, the contents of Pro (in younger leaf), H2O2 (roots) and AsA, lipid peroxidation and POX and SOD activities. We may conclude that Si mitigated the Ni-induced stress in maize by amelioration of the leaf water deficient status (Pro, RWC, LWL), enhancing membrane stability (MDA) and influencing enzymatic (SOD, POX, CAT) and non-enzymatic (Pro, AsA) defence systems. The increased Chl content and leaf area improve overall plant performance.


Assuntos
Silício , Zea mays , Antioxidantes , Catalase/metabolismo , Peróxido de Hidrogênio , Malondialdeído , Níquel/farmacologia , Estresse Oxidativo , Silício/farmacologia , Superóxido Dismutase/metabolismo , Zea mays/metabolismo
16.
Plant Physiol Biochem ; 166: 1121-1130, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34328870

RESUMO

Silicon (Si)-mediated growth promotion of various grasses is well documented. In the present study, Si-induced changes in maize shoot growth and its underlying mechanisms were studied. Maize plants were grown with various concentrations of Si (0-3 mM) in the nutrient solution. Silicon nutrition improved plant expansion growth. Silicon-supplied maize plants (0.8 and 1.2 mM) showed higher plant height and leaf area compared to no-Si amended plants. It was assumed that Si-induced expansion growth was due to positive Si effects on plasma membrane (PM) H+-ATPase. In this context, western blot analysis revealed an increase in PM H+-ATPase abundance by 77% under Si nutrition. However, in vitro measurements of enzyme activities showed no significant effect on apoplast pH, proton pumping, passive H+ efflux and enzyme kinetics such as Km, Vmax, and activation energy. Further, these results were confirmed by in vivo ratiometric analysis of apoplastic pH, which showed non-significant changes upon Si supply. In contrast, 1 mM Si altered the relative transcripts of specific PM H+-ATPase isoforms. Silicon application resulted in a significant decrease of MHA3, and this decrease in transcription seems to be compensated by an increased concentration of H+-ATPase protein. From these results, it can be concluded that changes in cell wall composition and PM H+-ATPase may be responsible for Si-mediated growth improvement in maize.


Assuntos
Silício , Zea mays , Membrana Celular/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Silício/farmacologia , Zea mays/metabolismo
17.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206810

RESUMO

Recently, crop breeders have widely adopted a new biotechnology-based process, termed Seed Production Technology (SPT), to produce hybrid varieties. The SPT does not produce nuclear male-sterile lines, and instead utilizes transgenic SPT maintainer lines to pollinate male-sterile plants for propagation of nuclear-recessive male-sterile lines. A late-stage pollen-specific promoter is an essential component of the pollen-inactivating cassette used by the SPT maintainers. While a number of plant pollen-specific promoters have been reported so far, their usefulness in SPT has remained limited. To increase the repertoire of pollen-specific promoters for the maize community, we conducted a comprehensive comparative analysis of transcriptome profiles of mature pollen and mature anthers against other tissue types. We found that maize pollen has much less expressed genes (>1 FPKM) than other tissue types, but the pollen grain has a large set of distinct genes, called pollen-specific genes, which are exclusively or much higher (100 folds) expressed in pollen than other tissue types. Utilizing transcript abundance and correlation coefficient analysis, 1215 mature pollen-specific (MPS) genes and 1009 mature anther-specific (MAS) genes were identified in B73 transcriptome. These two gene sets had similar GO term and KEGG pathway enrichment patterns, indicating that their members share similar functions in the maize reproductive process. Of the genes, 623 were shared between the two sets, called mature anther- and pollen-specific (MAPS) genes, which represent the late-stage pollen-specific genes of the maize genome. Functional annotation analysis of MAPS showed that 447 MAPS genes (71.7% of MAPS) belonged to genes encoding pollen allergen protein. Their 2-kb promoters were analyzed for cis-element enrichment and six well-known pollen-specific cis-elements (AGAAA, TCCACCA, TGTGGTT, [TA]AAAG, AAATGA, and TTTCT) were found highly enriched in the promoters of MAPS. Interestingly, JA-responsive cis-element GCC box (GCCGCC) and ABA-responsive cis-element-coupling element1 (ABRE-CE1, CCACC) were also found enriched in the MAPS promoters, indicating that JA and ABA signaling likely regulate pollen-specific MAPS expression. This study describes a robust and straightforward pipeline to discover pollen-specific promotes from publicly available data while providing maize breeders and the maize industry a number of late-stage (mature) pollen-specific promoters for use in SPT for hybrid breeding and seed production.


Assuntos
Perfilação da Expressão Gênica/métodos , Melhoramento Vegetal/métodos , Pólen/genética , Transcriptoma , Zea mays/genética , Regulação da Expressão Gênica de Plantas , Infertilidade das Plantas/genética , Pólen/metabolismo , Regiões Promotoras Genéticas , Sementes/genética , Sementes/metabolismo , Zea mays/metabolismo
18.
BMC Plant Biol ; 21(1): 309, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210268

RESUMO

BACKGROUND: Phytohormone abscisic acid (ABA) is involved in the regulation of a wide range of biological processes. In Arabidopsis, it has been well-known that SnRK2s are the central components of the ABA signaling pathway that control the balance between plant growth and stress response, but the functions of ZmSnRK2 in maize are rarely reported. Therefore, the study of ZmSnRK2 is of great importance to understand the ABA signaling pathways in maize. RESULTS: In this study, 14 ZmSnRK2 genes were identified in the latest version of maize genome database. Phylogenetic analysis revealed that ZmSnRK2s are divided into three subclasses based on their diversity of C-terminal domains. The exon-intron structures, phylogenetic, synteny and collinearity analysis indicated that SnRK2s, especially the subclass III of SnRK2, are evolutionally conserved in maize, rice and Arabidopsis. Subcellular localization showed that ZmSnRK2 proteins are localized in the nucleus and cytoplasm. The RNA-Seq datasets and qRT-PCR analysis showed that ZmSnRK2 genes exhibit spatial and temporal expression patterns during the growth and development of different maize tissues, and the transcript levels of some ZmSnRK2 genes in kernel are significantly induced by ABA and sucrose treatment. In addition, we found that ZmSnRK2.10, which belongs to subclass III, is highly expressed in kernel and activated by ABA. Overexpression of ZmSnRK2.10 partially rescued the ABA-insensitive phenotype of snrk2.2/2.3 double and snrk2.2/2.3/2.6 triple mutants and led to delaying plant flowering in Arabidopsis. CONCLUSION: The SnRK2 gene family exhibits a high evolutionary conservation and has expanded with whole-genome duplication events in plants. The ZmSnRK2s expanded in maize with whole-genome and segmental duplication, not tandem duplication. The expression pattern analysis of ZmSnRK2s in maize offers important information to study their functions. Study of the functions of ZmSnRK.10 in Arabidopsis suggests that the ABA-dependent members of SnRK2s are evolutionarily conserved in plants. Our study elucidated the structure and evolution of SnRK2 genes in plants and provided a basis for the functional study of ZmSnRK2s protein in maize.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas , Transdução de Sinais , Zea mays/genética , Zea mays/metabolismo , Arabidopsis/genética , Sequência de Bases , Núcleo Celular/metabolismo , Cromossomos de Plantas/genética , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica de Plantas , Mutação/genética , Fenótipo , Filogenia , Transdução de Sinais/genética , Frações Subcelulares/metabolismo , Sintenia/genética
19.
Molecules ; 26(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208534

RESUMO

Endothelial cell dysfunction is considered to be one of the major causes of vascular complications in diabetes. Polyphenols are known as potent antioxidants that can contribute to the prevention of diabetes. Corn silk has been reported to contain polyphenols and has been used in folk medicine in China for the treatment of diabetes. The present study aims to investigate the potential protective role of the phenolic-rich fraction of corn silk (PRF) against injuries to vascular endothelial cells under high glucose conditions in vitro and in vivo. The protective effect of PRF from high glucose toxicity was investigated using human umbilical vein endothelial cells (HUVECs). The protective effect of PRF was subsequently evaluated by using in vivo methods in streptozotocin (STZ)-induced diabetic rats. Results showed that the PRF significantly reduced the cytotoxicity of glucose by restoring cell viability in a dose-dependent manner. PRF was also able to prevent the histological changes in the aorta of STZ-induced diabetic rats. Results suggested that PRF might have a beneficial effect on diabetic patients and may help to prevent the development and progression of diabetic complications such as diabetic nephropathy and atherosclerosis.


Assuntos
Células Endoteliais/efeitos dos fármacos , Polifenóis/farmacologia , Zea mays/metabolismo , Animais , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , China , Citoproteção/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Células Endoteliais/metabolismo , Glucose/efeitos adversos , Glucose/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Masculino , Extratos Vegetais/farmacologia , Polifenóis/química , Ratos , Ratos Sprague-Dawley , Estreptozocina/farmacologia
20.
BMC Plant Biol ; 21(1): 347, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301191

RESUMO

BACKGROUND: Tomato (Solanum lycopersicum) is one of the most important horticultural crops, with a marked preference for nitrate as an inorganic nitrogen source. The molecular mechanisms of nitrate uptake and assimilation are poorly understood in tomato. NIN-like proteins (NLPs) are conserved, plant-specific transcription factors that play crucial roles in nitrate signaling. RESULTS: In this study, genome-wide analysis identified six NLP members in tomato genome. These members were clustered into three clades in a phylogenetic tree. Comparative genomic analysis showed that SlNLP genes exhibited collinear relationships to NLPs in Arabidopsis, canola, maize and rice, and that the expansion of the SlNLP family mainly resulted from segmental duplications in the tomato genome. Tissue-specific expression analysis showed that one of the close homologs of AtNLP6/7, SlNLP3, was strongly expressed in roots during both the seedling and flowering stages, that SlNLP4 and SlNLP6 exhibited preferential expression in stems and leaves and that SlNLP6 was expressed at high levels in fruits. Furthermore, the nitrate uptake in tomato roots and the expression patterns of SlNLP genes were measured under nitrogen deficiency and nitrate resupply conditions. Four SlNLPs, SlNLP1, SlNLP2, SlNLP4 and SlNLP6, were upregulated after nitrogen starvation. And SlNLP1 and SlNLP5 were induced rapidly and temporally by nitrate. CONCLUSIONS: These results provide significant insights into the potential diverse functions of SlNLPs to regulate nitrate uptake.


Assuntos
Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Nitratos/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Transdução de Sinais/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Brassica napus/genética , Brassica napus/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Oryza/genética , Oryza/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Zea mays/genética , Zea mays/metabolismo
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