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1.
Int J Mol Sci ; 22(5)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800127

RESUMO

Heat stress causes huge losses in the yield of cereal crops. Temperature influences the rate of plant metabolic and developmental processes that ultimately determine the production of grains, with high temperatures causing a reduction in grain yield and quality. To ensure continued food security, the tolerance of high temperature is rapidly becoming necessary. Brassinosteroids (BR) are a class of plant hormones that impact tolerance to various biotic and abiotic stresses and regulate cereal growth and fertility. Fine-tuning the action of BR has the potential to increase cereals' tolerance and acclimation to heat stress and maintain yields. Mechanistically, exogenous applications of BR protect yields through amplifying responses to heat stress and rescuing the expression of growth promoters. Varied BR compounds and differential signaling mechanisms across cereals point to a diversity of mechanisms that can be leveraged to mitigate heat stress. Further, hormone transport and BR interaction with other molecules in plants may be critical to utilizing BR as protective agrochemicals against heat stress. Understanding the interplay between heat stress responses, growth processes and hormone signaling may lead us to a comprehensive dogma of how to tune BR application for optimizing cereal growth under challenging environments in the field.


Assuntos
Brassinosteroides/metabolismo , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Resposta ao Choque Térmico/fisiologia , Transdução de Sinais/fisiologia , Temperatura Alta
2.
DNA Cell Biol ; 40(3): 441-456, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33600242

RESUMO

IGT family genes function critically to regulate lateral organ orientation in plants. However, little information is available about this family of genes in Brassica napus. In this study, 27 BnIGT genes were identified on 16 chromosomes and divided into seven clades, namely LAZY1∼LAZY6 and TAC1 (Tiller Angle Control 1), based on their phylogenetic relationships. Duplication analysis revealed that 91.1% of the gene pairs were derived from whole-genome duplication. Most BnIGT genes had a similar structural pattern with one or two very short exons followed by a long and a shorter exon. Common and specific motifs were identified among the seven clades, and motif 1, containing the family-specific GφL(A/T)IGT sequence, was observed in all clades except LAZY5. Three types of cis-elements pertinent to transcription factor binding, light responses, and hormone signaling were detected in the BnIGT promoters. Intriguingly, more than half of the BnIGT genes exhibited no or very low expression in various tissues, and the LAZY1 and TAC1 clade members showed distinct tissue expression preferences. Coexpression analysis revealed that the LAZY1 members had strong associations with cell wall biosynthesis genes. This analysis provides a deeper understanding of the BnIGT gene family and will facilitate further deduction of their role in regulating plant architecture in B. napus.


Assuntos
Brassica napus , Regulação da Expressão Gênica de Plantas/fisiologia , Família Multigênica , Proteínas de Plantas , Tetraploidia , Brassica napus/genética , Brassica napus/metabolismo , Estudo de Associação Genômica Ampla , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética
3.
Nat Plants ; 7(2): 106-115, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33558755

RESUMO

Environmental pH is a critical parameter for innumerable chemical reactions, myriad biological processes and all forms of life. The mechanisms that underlie the perception of external pH (pHe) have been elucidated in detail for bacteria, fungi and mammalian cells; however, little information is available on whether and, if so, how pHe is perceived by plants. This is particularly surprising since hydrogen ion activity of the substrate is of paramount significance for plants, governing the availability of mineral nutrients, the structure of the soil microbiome and the composition of natural plant communities. Rapid changes in soil pH require constant readjustment of nutrient acquisition strategies, which is associated with dynamic alterations in gene expression. Referring to observations made in diverse experimental set-ups that unambiguously show that pHe per se affects gene expression, we hypothesize that sensing of pHe in plants is mandatory to prioritize responses to various simultaneously received environmental cues.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Concentração de Íons de Hidrogênio , Células Vegetais/química , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Solo/química
4.
Nat Commun ; 12(1): 735, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33531490

RESUMO

Nitrogen (N) and carbon (C) are essential elements for plant growth and crop yield. Thus, improved N and C utilisation contributes to agricultural productivity and reduces the need for fertilisation. In the present study, we find that overexpression of a single rice gene, Oryza sativa plasma membrane (PM) H+-ATPase 1 (OSA1), facilitates ammonium absorption and assimilation in roots and enhanced light-induced stomatal opening with higher photosynthesis rate in leaves. As a result, OSA1 overexpression in rice plants causes a 33% increase in grain yield and a 46% increase in N use efficiency overall. As PM H+-ATPase is highly conserved in plants, these findings indicate that the manipulation of PM H+-ATPase could cooperatively improve N and C utilisation, potentially providing a vital tool for food security and sustainable agriculture.


Assuntos
Membrana Celular/metabolismo , Oryza/enzimologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Compostos de Amônio/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/fisiologia , Fotossíntese/genética , Fotossíntese/fisiologia , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/enzimologia , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia
5.
Gene ; 764: 145078, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-32858175

RESUMO

In maize, eat rot and stalk rot caused by Fusarium verticillioides and Fusarium graminearum lead to contamination of moldy grains to produce mycotoxins. Identification of resistance genes against these pathogens for maize breeding is an effective way for disease control. Several 2-oxoglutarate-dependent dioxygenase (2OGD) proteins have been found to confer resistance to different pathogens in diverse plant species. However, little is known about the 2OGD superfamily in maize. Here, we identified 103 putative 2OGD genes in maize from a genome-wide analysis, and divided them into three classes - DOXA, DOXB, and DOXC. We further comprehensively investigated their gene structure, chromosome distribution, phylogenetic tree, gene-function enrichment, and expression profiles among different tissues. The genes encoding three 2OGD proteins, ACO, F3H, and NCS involved in ethylene biosynthesis, flavonoids biosynthesis, and alkaloids biosynthesis pathways, respectively, were identified to be induced by F. verticillioides and F. graminearum. The promoters of the three genes contain the binding sites for the transcription factor ZmDOF and ZmHSF, which are also induced by the two pathogens. The results imply that the three 2OGDs and the two transcription factors might be involved in the resistance to the two pathogens. This study provided a comprehensive understanding of the 2OGD superfamily in maize and laid the foundation for the further functional analysis of their roles in maize resistance to eat rot and stalk rot.


Assuntos
Dioxigenases/genética , Fusarium/imunologia , Proteínas de Plantas/genética , Zea mays/fisiologia , Sequência de Bases/genética , Sítios de Ligação/genética , Cromossomos de Plantas/genética , Coenzimas/metabolismo , Sequência Conservada/genética , Dioxigenases/imunologia , Dioxigenases/metabolismo , Resistência à Doença/genética , Evolução Molecular , Fusarium/patogenicidade , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas/fisiologia , Estudo de Associação Genômica Ampla , Ácidos Cetoglutáricos/metabolismo , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/imunologia , Proteínas de Plantas/metabolismo , Caules de Planta/enzimologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/microbiologia , Regiões Promotoras Genéticas/genética , RNA-Seq , Fatores de Transcrição/metabolismo , Zea mays/microbiologia
6.
Gene ; 770: 145353, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33333227

RESUMO

Since domestication, rice has cultivated in a wide range of latitudes with different day lengths. Selection of diverse natural variations in heading date and photoperiod sensitivity is critical for adaptation of rice to different geographical environments. To unravel the genetic architecture underlying natural variation of rice flowering time, we conducted a genome wide association study (GWAS) using several association analysis strategies with a diverse worldwide collection of 529 O. sativa accessions. Heading date was investigated in three environments under long-day or short-day conditions, and photosensitivity was evaluated. By dividing the whole association panel into subpopulations and performing GWAS with both linear mixed models and multi-locus mixed-models, we revealed hundreds of significant loci harboring novel candidate genes as well as most of the known flowering time genes. In total, 127 hotspots were detected in at least two GWAS. Universal genetic heterogeneity was found across subpopulations. We further detected abundant interactions between GWAS loci, especially in indica. Functional gene families were revealed from enrichment analysis of the 127 hotspots. The results demonstrated a rich of genetic interactions in rice flowering time genes and such epistatic interactions contributed to the large portions of missing heritability in GWAS. It suggests the increased complexity of genetic heterogeneity might discount the power of increasing the sample sizes in GWAS.


Assuntos
Epistasia Genética/fisiologia , Flores , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/fisiologia , Oryza , Flores/genética , Flores/crescimento & desenvolvimento , Estudo de Associação Genômica Ampla , Oryza/genética , Oryza/crescimento & desenvolvimento
7.
Gene ; 770: 145348, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33333230

RESUMO

Heat shock factors (Hsfs) and heat shock proteins (Hsps) play a critical role in the molecular mechanisms such as plant development and defense against abiotic. As an important food crop, maize is vulnerable to adverse environment such as heat stress and water logging, which leads to a decline in yield and quality. To date, very little is known regarding the structure and function of Hsf and Hsp genes in maize. Although some Hsf and Hsp genes have been characterized in maize, analysis of the entire Hsf and Hsp70 gene families were not completed following Maize (B73) Genome Sequencing Project. Therefore, studying their molecular mechanism and revealing their biological function in plant stress resistance process will contribute to reveal important theoretical significance and application value for improving corn yield and quality. In this study, we have identified 25 ZmHsf and 22 ZmHsp70 genes in maize. The structural characteristics and phylogenetic relationships of the Hsf and Hsp70 gene families of Arabidopsis thaliana, rice and maize were compared. The final 25 ZmHsf proteins and 22 ZmHsp70 proteins were divided into three and four subfamilies, respectively. In addition, chromosomal localization indicated that the ZmHsf and ZmHsp70 genes were unevenly distributed on the chromosome, and the gene structure map revealed the characteristics of their structures. Finally, transcriptome analysis indicated that most of the ZmHsf and ZmHsp70 genes showed different expression patterns at different developmental stages of maize. Further, by semi-quantitative RT-PCR and quantitative real-time PCR analysis, all 25 ZmHsf and 22 ZmHsp70 genes were confirmed to respond to heat stress treatment, indicating that they have potential effects in heat stress response. The analyses performed by combining co-expression network with protein-protein interaction network among the members of the Hsf and Hsp70 gene families in maize further enabled us to recognize components involved in the regulatory network associated with hsfs and hsp70s complex. The predicted subcellular location revealed that maize Hsp70 proteins exhibited a various subcellular distribution, which may be associated with functional diversification in heat stress response. Taken together, our study provides comprehensive information on the members of Hsf and Hsp70 gene families and will help in elucidating their exact function in maize.


Assuntos
Cromossomos de Plantas , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Choque Térmico HSP70 , Família Multigênica/fisiologia , Proteínas de Plantas , Zea mays , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Estudo de Associação Genômica Ampla , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Zea mays/genética , Zea mays/metabolismo
8.
Plant Sci ; 302: 110676, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288001

RESUMO

Ascorbic acid (AsA) is an antioxidant and enzyme co-factor that is vital to plant development and abiotic stress tolerance. However, the regulation mechanisms of AsA biosynthesis in plants remain poorly understood. Here, we report a basic helix-loop-helix 55 (ZmbHLH55) transcription factor that regulates AsA biosynthesis in maize. Analysis of publicly available transcriptomic data revealed that ZmbHLH55 is co-expressed with several genes of the GDP-mannose pathway. Experimental data showed that ZmbHLH55 forms homodimers localized to the cell nuclei, and it exhibits DNA binding and transactivation activity in yeast. Under salt stress conditions, knock down mutant (zmbhlh55) in maize accumulated lower levels of AsA compared with wild type, accompanied by lower antioxidant enzymes activity, shorter root length, and higher malondialdehyde (MDA) level. Gene expression data from the WT and zmbhlh55 mutant, showed that ZmbHLH55 positively regulates the expression of ZmPGI2, ZmGME1, and ZmGLDH, but negatively regulates ZmGMP1 and ZmGGP. Furthermore, ZmbHLH55-overexpressing Arabidopsis, under salt conditions, showed higher AsA levels, increased rates of germination, and elevated antioxidant enzyme activities. In conclusion, these results have identified previously unknown regulation mechanisms for AsA biosynthesis, indicating that ZmbHLH55 may be a potential candidate to enhance plant salt stress tolerance in the future.


Assuntos
Ácido Ascórbico/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Genes de Plantas/fisiologia , Guanosina Difosfato Manose/metabolismo , Redes e Vias Metabólicas/genética , Proteínas de Plantas/fisiologia , Tolerância ao Sal , Zea mays/metabolismo , Ácido Ascórbico/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Clonagem Molecular , Ensaio de Desvio de Mobilidade Eletroforética , Regulação da Expressão Gênica de Plantas/fisiologia , Técnicas de Silenciamento de Genes , Genes de Plantas/genética , Malondialdeído/metabolismo , Redes e Vias Metabólicas/fisiologia , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Técnicas do Sistema de Duplo-Híbrido , Zea mays/genética , Zea mays/fisiologia
9.
Plant Sci ; 302: 110716, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288022

RESUMO

Anther development is a complex process regulated by a myriad of transcription factors belonging to distinct protein families. In this study, we focus on the functional characterization of OsbHLH35, a basic Helix-Loop-Helix (bHLH) TF that regulates anther development in rice. Plants overexpressing OsbHLH35 presented small and curved anthers, leading to a reduction of 72 % on seed production. Rice transgenic plants expressing GUS reporter gene under the control of OsbHLH35 promoter (pOsbHLH35::GUS) showed that this TF specifically accumulates in anthers at the meiosis stage and in other spikelet tissues. Yeast one-hybrid screening identified three members of the Growth-Regulating Factor (GRF) family, OsGRF3, OsGRF4, and OsGRF11, as transcriptional regulators of OsbHLH35. Transactivation assay showed that OsGRF11 negatively regulates OsbHLH35 expression in Arabidopsis protoplasts. This regulation was also observed in planta through the analysis of transgenic plants overexpressing OsGRF11 (OsGRF11OE), confirming that OsGRF11 is a negative regulator of OsbHLH35 in rice. Our data suggest that OsbHLH35 plays an essential role in anther development in rice and the fine control of its expression is crucial to ensure proper seed production.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Flores/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Arabidopsis , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/crescimento & desenvolvimento , Técnicas do Sistema de Duplo-Híbrido
10.
Plant Sci ; 302: 110668, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288032

RESUMO

MYB transcription factors are important in abiotic stress responses; however, the detailed mechanisms are unclear. Tamarix hispida contains multiple MYB genes. The present study characterized T. hispida MYB8 (ThMYB8) during salt stress using transgenic T. hispida and Arabidopsis assays. ThMYB8 overexpression and ThMYB8 RNAi analysis demonstrated that ThMYB8 enhanced the salt stress tolerance. Transgenic Arabidopsis ectopic expression of ThMYB8 significantly increased root growth, fresh weight, and seed germination rate compared with that of the wild-type under salt stress. Physiological parameters analysis in T. hispida and Arabidopsis showed that ThMYB8 overexpressing plants had the lowest levels of O2, H2O2, cell death, malondialdehyde, and electrolyte leakage. Overexpression of ThMYB8 regulated Na+ and K+ concentrations in plant tissues while maintaining K+/Na+ homeostasis. Analysis using qRT-PCR and ChIP-PCR identified possible downstream ThMYB8-regulated genes. ThMYB8 regulated the expression of ThCYP450-2 (cytochrome p450-2), Thltk (leucine-rich repeat transmembrane protein kinase), and ThTIP (aquaporin TIP) by binding to the MBSI motif ('CAACTG') in their promoters. The results indicated that ThMYB8 enhanced salt stress tolerance in T. hispida by regulating gene expression related to the activation of stress-associated physiological changes, such as enhanced reactive oxygen species scavenging capability, maintaining K+/Na+ homeostasis, and decreasing the malondialdehyde content and lipid peroxidation cell membranes.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Proteínas Proto-Oncogênicas c-myb/fisiologia , Plantas Tolerantes a Sal/metabolismo , Tamaricaceae/fisiologia , Árabes , Imunoprecipitação da Cromatina , Perfilação da Expressão Gênica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estresse Salino , Plantas Tolerantes a Sal/genética , Análise de Sequência de DNA , Tamaricaceae/genética , Tamaricaceae/metabolismo , Técnicas do Sistema de Duplo-Híbrido
11.
EMBO J ; 40(2): e104559, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33372703

RESUMO

The transient elevation of cytosolic free calcium concentration ([Ca2+ ]cyt ) induced by cold stress is a well-established phenomenon; however, the underlying mechanism remains elusive. Here, we report that the Ca2+ -permeable transporter ANNEXIN1 (AtANN1) mediates cold-triggered Ca2+ influx and freezing tolerance in Arabidopsis thaliana. The loss of function of AtANN1 substantially impaired freezing tolerance, reducing the cold-induced [Ca2+ ]cyt increase and upregulation of the cold-responsive CBF and COR genes. Further analysis showed that the OST1/SnRK2.6 kinase interacted with and phosphorylated AtANN1, which consequently enhanced its Ca2+ transport activity, thereby potentiating Ca2+ signaling. Consistent with these results and freezing sensitivity of ost1 mutants, the cold-induced [Ca2+ ]cyt elevation in the ost1-3 mutant was reduced. Genetic analysis indicated that AtANN1 acts downstream of OST1 in responses to cold stress. Our data thus uncover a cascade linking OST1-AtANN1 to cold-induced Ca2+ signal generation, which activates the cold response and consequently enhances freezing tolerance in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Resposta ao Choque Frio/fisiologia , Membrana Celular/metabolismo , Temperatura Baixa , Congelamento , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas Quinases/metabolismo , Fatores de Transcrição/metabolismo
12.
Nucleic Acids Res ; 49(1): 190-205, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33332564

RESUMO

Secondary wall thickening in the sclerenchyma cells is strictly controlled by a complex network of transcription factors in vascular plants. However, little is known about the epigenetic mechanism regulating secondary wall biosynthesis. In this study, we identified that ARABIDOPSIS HOMOLOG of TRITHORAX1 (ATX1), a H3K4-histone methyltransferase, mediates the regulation of fiber cell wall development in inflorescence stems of Arabidopsis thaliana. Genome-wide analysis revealed that the up-regulation of genes involved in secondary wall formation during stem development is largely coordinated by increasing level of H3K4 tri-methylation. Among all histone methyltransferases for H3K4me3 in Arabidopsis, ATX1 is markedly increased during the inflorescence stem development and loss-of-function mutant atx1 was impaired in secondary wall thickening in interfascicular fibers. Genetic analysis showed that ATX1 positively regulates secondary wall deposition through activating the expression of secondary wall NAC master switch genes, SECONDARY WALL-ASSOCIATED NAC DOMAIN PROTEIN1 (SND1) and NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1). We further identified that ATX1 directly binds the loci of SND1 and NST1, and activates their expression by increasing H3K4me3 levels at these loci. Taken together, our results reveal that ATX1 plays a key role in the regulation of secondary wall biosynthesis in interfascicular fibers during inflorescence stem development of Arabidopsis.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Código das Histonas , Histona-Lisina N-Metiltransferase/fisiologia , Histonas/genética , Inflorescência/metabolismo , Proteínas de Plantas/genética , Caules de Planta/metabolismo , Fatores de Transcrição/fisiologia , Transcriptoma , Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/genética , Imunoprecipitação da Cromatina , Regulação da Expressão Gênica de Plantas/genética , Ontologia Genética , Genes de Plantas , Histonas/metabolismo , Lignina/metabolismo , Proteínas de Plantas/metabolismo , Caules de Planta/ultraestrutura , RNA de Plantas/biossíntese , RNA de Plantas/genética , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Xilanos/metabolismo
13.
Int J Mol Sci ; 21(24)2020 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-33322169

RESUMO

Crystal-bearing cells or idioblasts, which deposit calcium oxalate, are located in various tissues and organs of many plant species. The functional significance of their formation is currently unclear. Idioblasts in the leaf parenchyma and the development of crystal-bearing cells in the anther tissues of transgenic tomato plants (Solanum lycopersicon L.), expressing the heterologous FeSOD gene and which showed a decrease in fertility, were studied by transmission and scanning electron microscopy. The amount of calcium oxalate crystals was found to increase significantly in the transgenic plants compared to the wild type (WT) ones in idioblasts and crystal-bearing cells of the upper part of the anther. At the same time, changes in the size and shape of the crystals and their location in anther organs were noted. It seems that the interruption in the break of the anther stomium in transgenic plants was associated with the formation and cell death regulation of a specialized group of crystal-bearing cells. This disturbance caused an increase in the pool of these cells and their localization in the upper part of the anther, where rupture is initiated. Perturbations were also noted in the lower part of the anther in transgenic plants, where the amount of calcium oxalate crystals in crystal-bearing cells was reduced that was accompanied by disturbances in the morphology of pollen grains. Thus, the induction of the formation of crystal-bearing cells and calcium oxalate crystals can have multidirectional effects, contributing to the regulation of oxalate metabolism in the generative and vegetative organs and preventing fertility when the ROS balance changes, in particular, during oxidative stresses accompanying most abiotic and biotic environmental factors.


Assuntos
Oxalato de Cálcio/metabolismo , Flores/metabolismo , Frutas/metabolismo , Lycopersicon esculentum/metabolismo , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Pólen/metabolismo , Oxalato de Cálcio/efeitos adversos , Fertilidade/genética , Fertilidade/fisiologia , Flores/citologia , Flores/genética , Flores/ultraestrutura , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Lycopersicon esculentum/citologia , Microscopia Eletrônica de Transmissão e Varredura , Folhas de Planta/ultraestrutura , Pólen/citologia , Pólen/genética , Pólen/ultraestrutura , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
14.
Int J Mol Sci ; 21(24)2020 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-33322217

RESUMO

Aquaporins (AQPs) are universal membrane integrated water channel proteins that selectively and reversibly facilitate the movement of water, gases, metalloids, and other small neutral solutes across cellular membranes in living organisms. Compared with other organisms, plants have the largest number of AQP members with diverse characteristics, subcellular localizations and substrate permeabilities. AQPs play important roles in plant water relations, cell turgor pressure maintenance, the hydraulic regulation of roots and leaves, and in leaf transpiration, root water uptake, and plant responses to multiple biotic and abiotic stresses. They are also required for plant growth and development. In this review, we comprehensively summarize the expression and roles of diverse AQPs in the growth and development of various vegetative and reproductive organs in plants. The functions of AQPs in the intracellular translocation of hydrogen peroxide are also discussed.


Assuntos
Aquaporinas/metabolismo , Germinação , Desenvolvimento Vegetal , Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Transporte Biológico/genética , Transporte Biológico/fisiologia , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Dormência de Plantas/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Pólen/metabolismo , Sementes/metabolismo , Água/metabolismo
15.
Elife ; 92020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33315012

RESUMO

Floral transition, the onset of plant reproduction, involves changes in shape and identity of the shoot apical meristem (SAM). The change in shape, termed doming, occurs early during floral transition when it is induced by environmental cues such as changes in day-length, but how it is regulated at the cellular level is unknown. We defined the morphological and cellular features of the SAM during floral transition of Arabidopsis thaliana. Both cell number and size increased during doming, and these changes were partially controlled by the gene regulatory network (GRN) that triggers flowering. Furthermore, dynamic modulation of expression of gibberellin (GA) biosynthesis and catabolism enzymes at the SAM contributed to doming. Expression of these enzymes was regulated by two MADS-domain transcription factors implicated in flowering. We provide a temporal and spatial framework for integrating the flowering GRN with cellular changes at the SAM and highlight the role of local regulation of GA.


Assuntos
Ritmo Circadiano/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Meristema/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/metabolismo , Fenômenos Fisiológicos Vegetais , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Flores/crescimento & desenvolvimento , Flores/metabolismo , Redes Reguladoras de Genes , Meristema/metabolismo , Fotoperíodo
16.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322321

RESUMO

The present study was designed to serve as a comprehensive analysis of Citrus sinensis (C. sinensis) pectin acetylesterases (CsPAEs), and to assess the roles of these PAEs involved in the development of citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) infection. A total of six CsPAEs were identified in the genome of C. sinensis, with these genes being unevenly distributed across chromosomes 3, 6, and 9, and the unassembled scaffolds. A subset of CsPAEs were found to be involved in responses to Xcc infection. In particular, CsPAE2 was identified to be associated with such infections, as it was upregulated in CBC-susceptible variety Wanjincheng and inversely in CBC-resistant variety Calamondin. Transgenic citrus plants overexpressing CsPAE2 were found to be more susceptible to CBC, whereas the silencing of this gene was sufficient to confer CBC resistance. Together, these findings provide evolutionary insights into and functional information about the CsPAE family. This study also suggests that CsPAE2 is a potential candidate gene that negatively contributes to bacterial canker disease and can be used to breed CBC-resistant citrus plants.


Assuntos
Esterases/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Xanthomonas/patogenicidade , Esterases/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/enzimologia
17.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322339

RESUMO

Cyclins, together with highly conserved cyclin-dependent kinases (CDKs), play an important role in the process of cell cycle in plants, but less is known about the functions of cyclins in legume plants, especially Medicago truncatula. Our genome-wide analysis identified 58, 103, and 51 cyclin members in the M. truncatula, Glycine max, and Phaseolus vulgaris genomes. Phylogenetic analysis suggested that these cyclins could be classified into 10 types, and the CycB-like types (CycBL1-BL8) were the specific subgroups in M. truncatula, which was one reason for the expansion of the B-type in M. truncatula. All putative cyclin genes were mapped onto their own chromosomes of each genome, and 9 segmental duplication gene pairs involving 20 genes were identified in M. truncatula cyclins. Determined by quantitative real-time PCR, the expression profiling suggested that 57 cyclins in M. truncatula were differentially expressed in 9 different tissues, while a few genes were expressed in some specific tissues. Using the publicly available RNAseq data, the expression of Mtcyclins in the wild-type strain A17 and three nodule mutants during rhizobial infection showed that 23 cyclins were highly upregulated in the nodulation (Nod) factor-hypersensitive mutant sickle (skl) mutant after 12 h of rhizobium inoculation. Among these cyclins, six cyclin genes were also specifically expressed in roots and nodules, which might play specific roles in the various phases of Nod factor-mediated cell cycle activation and nodule development. Our results provide information about the cyclin gene family in legume plants, serving as a guide for further functional research on plant cyclins.


Assuntos
Medicago truncatula/genética , Ciclo Celular/genética , Ciclo Celular/fisiologia , Fabaceae/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Genoma de Planta/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo
18.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322385

RESUMO

The auxin response factor (ARF) transcription factors are a key component in auxin signaling and play diverse functions in plant growth, development, and stress response. ARFs are regulated at the transcript level and posttranslationally by protein modifications. However, relatively little is known regarding the control of ARF protein levels. We expressed five different ARFs with an HA (hemagglutinin) tag and observed that their protein levels under the same promoter varied considerably. Interestingly, their protein levels were affected by several hormonal and environmental conditions, but not by the auxin treatment. ABA (abscisic acid) as well as 4 °C and salt treatments decreased the levels of HA-ARF5, HA-ARF6, and HA-ARF10, but not that of HA-ARF19, while 37 °C treatment increased the levels of the four HA-ARFs, suggesting that the ARF protein levels are regulated by multiple factors. Furthermore, MG132 inhibited the reduction of HA-ARF6 level by ABA and 4 °C treatments, suggesting that these treatments decrease HA-ARF6 level through 26S proteasome-mediated protein degradation. It was also found that ABA treatment drastically increased HA-ARF6 ubiquitination, without strongly affecting the ubiquitination profile of the total proteins. Together, these results reveal another layer of control on ARFs, which could serve to integrate multiple hormonal and environmental signals into the ARF-regulated gene expression.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Ácidos Indolacéticos/farmacologia , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Temperatura , Fatores de Transcrição/genética , Ubiquitinação/efeitos dos fármacos
19.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322558

RESUMO

Drought stress is one of the major environmental problems in the growth of crops and woody perennials, but it is getting worse due to the global climate crisis. XERICO, a RING (Really Interesting New Gene) zinc-finger E3 ubiquitin ligase, has been shown to be a positive regulator of drought tolerance in plants through the control of abscisic acid (ABA) homeostasis. We characterized a poplar (Populus trichocarpa) RING protein family and identified the closest homolog of XERICO called PtXERICO. Expression of PtXERICO is induced by both salt and drought stress, and by ABA treatment in poplars. Overexpression of PtXERICO in Arabidopsis confers salt and ABA hypersensitivity in young seedlings, and enhances drought tolerance by decreasing transpirational water loss. Consistently, transgenic hybrid poplars overexpressing PtXERICO demonstrate enhanced drought tolerance with reduced transpirational water loss and ion leakage. Subsequent upregulation of genes involved in the ABA homeostasis and drought response was confirmed in both transgenic Arabidopsis and poplars. Taken together, our results suggest that PtXERICO will serve as a focal point to improve drought tolerance of woody perennials.


Assuntos
Arabidopsis/metabolismo , Proteínas de Plantas/metabolismo , Populus/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Populus/genética
20.
Int J Mol Sci ; 21(24)2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33327508

RESUMO

MicroRNAs are important regulators in plant developmental processes and stress responses. In this study, we generated a series of maize STTM166 transgenic plants. Knock-down of miR166 resulted in various morphological changes, including rolled leaves, enhanced abiotic stress resistance, inferior yield-related traits, vascular pattern and epidermis structures, tassel architecture, as well as abscisic acid (ABA) level elevation and indole acetic acid (IAA) level reduction in maize. To profile miR166 regulated genes, we performed RNA-seq and qRT-PCR analysis. A total of 178 differentially expressed genes (DEGs) were identified, including 118 up-regulated and 60 down-regulated genes. These DEGs were strongly enriched in cell and intercellular components, cell membrane system components, oxidoreductase activity, single organism metabolic process, carbohydrate metabolic process, and oxidation reduction process. These results indicated that miR166 plays important roles in auxin and ABA interaction in monocots, yet the specific mechanism may differ from dicots. The enhanced abiotic stress resistance is partly caused via rolling leaves, high ABA content, modulated vascular structure, and the potential changes of cell membrane structure. The inferior yield-related traits and late flowering are partly controlled by the decreased IAA content, the interplay of miR166 with other miRNAs and AGOs. Taken together, the present study uncovered novel functions of miR166 in maize, and provide insights on applying short tandem target mimics (STTM) technology in plant breeding.


Assuntos
MicroRNAs/fisiologia , Zea mays/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , MicroRNAs/genética , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Zea mays/fisiologia
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