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1.
Plant Mol Biol ; 102(4-5): 537-551, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31916084

RESUMO

KEY MESSAGE: Silencing of SlCAND1 expression resulted in dwarfish, loss of apical dominance, early flowering, suppression of seed germination, and abnormal root architecture in tomato Cullin-RING E3 ligases (CRLs)-dependent ubiquitin proteasome system mediates degradation of numerous proteins that controls a wide range of developmental and physiological processes in eukaryotes. Cullin-associated Nedd8-dissociated protein 1 (CAND1) acts as an exchange factor allowing substrate recognition part exchange and plays a vital role in reactivating CRLs. The present study reports on the identification of SlCAND1, the only one CAND gene in tomato. SlCAND1 expression is ubiquitous and positively regulated by multiple plant hormones. Silencing of SlCAND1 expression using RNAi strategy resulted in a pleiotropic and gibberellin/auxin-associated phenotypes, including dwarf plant with reduced internode length, loss of apical dominance, early flowering, low seed germination percentage, delayed seed germination speed, short primary root, and increased lateral root proliferation and elongation. Moreover, application of exogenous GA3 or IAA could partly rescue some SlCAND1-silenced phenotypes, and the expression levels of gibberellin/auxin-related genes were altered in SlCAND1-RNAi lines. These facts revealed that SlCAND1 is required for gibberellin/auxin-associated regulatory network in tomato. Although SlCAND1 is crucial for multiple developmental processes during vegetative growth stage, SlCAND1-RNAi lines didn't exhibit visible effect on fruit development and ripening. Meanwhile, we discussed that multiple physiological functions of SlCAND1 in tomato are different to previous report of its ortholog in Arabidopsis. Our study adds a new perspective on the functional roles of CAND1 in plants, and strongly supports the hypothesis that CAND1 and its regulated ubiquitin proteasome system are pivotal for plant vegetative growth but possibly have different roles in diverse plant species.


Assuntos
Flores/fisiologia , Germinação , Lycopersicon esculentum/fisiologia , Proteínas de Plantas/fisiologia , Raízes de Plantas/fisiologia , Arabidopsis/genética , Proteínas Culina , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Lycopersicon esculentum/genética , Fenótipo , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Interferência de RNA , Sementes/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia
2.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-31969531

RESUMO

The Vietnamese Mekong delta is one of the largest rice-producing areas globally. Methylobacterium spp. are persistent colonizers of the rice plant and exert beneficial effects on plant growth and health. Sixty-one Methylobacterium strains belonging to seven species were predominantly isolated from the phyllosphere of rice cultivated in six Mekong delta provinces. Inoculation tests revealed that some strains exhibited plant growth-promoting activity. Moreover, three strains possessed the novel characteristics of inducing leaf bleaching and killing rice seedlings. These results revealed the complex diversity of Methylobacterium in Mekong delta rice and that healthy and productive rice cultivation requires a proper balance of Methylobacterium.


Assuntos
Variação Genética , Methylobacterium/genética , Oryza/microbiologia , Alface/crescimento & desenvolvimento , Alface/microbiologia , Methylobacterium/classificação , Methylobacterium/fisiologia , Oryza/crescimento & desenvolvimento , Componentes Aéreos da Planta/microbiologia , Reguladores de Crescimento de Planta/fisiologia , Vietnã
3.
BMC Genomics ; 20(1): 993, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856713

RESUMO

BACKGROUND: F-box proteins are substrate-recognition components of the Skp1-Rbx1-Cul1-F-box protein (SCF) ubiquitin ligases. By selectively targeting the key regulatory proteins or enzymes for ubiquitination and 26S proteasome mediated degradation, F-box proteins play diverse roles in plant growth/development and in the responses of plants to both environmental and endogenous signals. Studies of F-box proteins from the model plant Arabidopsis and from many additional plant species have demonstrated that they belong to a super gene family, and function across almost all aspects of the plant life cycle. However, systematic exploration of F-box family genes in the important fiber crop cotton (Gossypium hirsutum) has not been previously performed. The genome-wide analysis of the cotton F-box gene family is now possible thanks to the completion of several cotton genome sequencing projects. RESULTS: In current study, we first conducted a genome-wide investigation of cotton F-box family genes by reference to the published F-box protein sequences from other plant species. 592 F-box protein encoding genes were identified in the Gossypium hirsutume acc.TM-1 genome and, subsequently, we were able to present their gene structures, chromosomal locations, syntenic relationships with their parent species. In addition, duplication modes analysis showed that cotton F-box genes were distributed to 26 chromosomes, with the maximum number of genes being detected on chromosome 5. Although the WGD (whole-genome duplication) mode seems play a dominant role during cotton F-box gene expansion process, other duplication modes including TD (tandem duplication), PD (proximal duplication), and TRD (transposed duplication) also contribute significantly to the evolutionary expansion of cotton F-box genes. Collectively, these bioinformatic analysis suggest possible evolutionary forces underlying F-box gene diversification. Additionally, we also conducted analyses of gene ontology, and expression profiles in silico, allowing identification of F-box gene members potentially involved in hormone signal transduction. CONCLUSION: The results of this study provide first insights into the Gossypium hirsutum F-box gene family, which lays the foundation for future studies of functionality, particularly those involving F-box protein family members that play a role in hormone signal transduction.


Assuntos
Proteínas F-Box/genética , Gossypium/genética , Proteínas de Plantas/genética , Proteínas F-Box/classificação , Proteínas F-Box/metabolismo , Duplicação Gênica , Ontologia Genética , Genoma de Planta , Gossypium/metabolismo , Família Multigênica , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Proteínas Ligases SKP Culina F-Box/fisiologia , Transdução de Sinais
4.
BMC Plant Biol ; 19(1): 586, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881835

RESUMO

BACKGROUND: In soft fruits, the differential expression of many genes during development and ripening is responsible for changing their organoleptic properties. In strawberry fruit, although some genes involved in the metabolic regulation of the ripening process have been functionally characterized, some of the most studied genes correspond to transcription factors. High throughput transcriptomics analyses performed in strawberry red receptacle (Fragaria x ananassa) allowed us to identify a ripening-related gene that codes an atypical HLH (FaPRE1) with high sequence homology with the PACLOBUTRAZOL RESISTANCE (PRE) genes. PRE genes are atypical bHLH proteins characterized by the lack of a DNA-binding domain and whose function has been linked to the regulation of cell elongation processes. RESULTS: FaPRE1 sequence analysis indicates that this gene belongs to the subfamily of atypical bHLHs that also includes ILI-1 from rice, SlPRE2 from tomato and AtPRE1 from Arabidopsis, which are involved in transcriptional regulatory processes as repressors, through the blockage by heterodimerization of bHLH transcription factors. FaPRE1 presented a transcriptional model characteristic of a ripening-related gene with receptacle-specific expression, being repressed by auxins and activated by abscisic acid (ABA). However, its expression was not affected by gibberellic acid (GA3). On the other hand, the transitory silencing of FaPRE1 transcription by agroinfiltration in receptacle produced the down-regulation of a group of genes related to the ripening process while inducing the transcription of genes involved in receptacle growth and development. CONCLUSIONS: In summary, this work presents for the first time experimental data that support an important novel function for the atypical HLH FaPRE1 during the strawberry fruit ripening. We hypothesize that FaPRE1 modulates antagonistically the transcription of genes related to both receptacle growth and ripening. Thus, FaPRE1 would repress the expression of receptacle growth promoting genes in the ripened receptacle, while it would activate the expression of those genes related to the receptacle ripening process.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Fragaria/fisiologia , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fragaria/efeitos dos fármacos , Fragaria/genética , Fragaria/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Desenvolvimento Vegetal/genética , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triazóis/farmacologia
5.
Se Pu ; 37(8): 806-814, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31642250

RESUMO

Endogenous phytohormone is a kind of trace organic small molecule compound synthesized in plants. It plays important roles in regulating the growth and development of plants throughout their life cycles, and responding to external stimuli. With the development of analytical methods for the detection of phytohormone, the amount of analytical samples is gradually reduced. Moreover, the differences in the types and contents of phytohormones in different plant tissues (or organs) are constantly presented. These developments greatly promote the study of the physiological effects of plant hormones. In recent years, the temporal and spatial distribution of endogenous phytohormones in several plant samples has attracted more and more attention in plant hormone analysis. This review summarizes the research progress made in the study of the spatial and temporal distribution of endogenous phytohormones in the last five years. Mainly, the review summarizes and discusses the difficulties associated with analysis, the development of analytical methods, and the spatial and temporal distribution of major plant hormones. The sampling methods, sample preparation and detection methods for spatial and temporal distribution studies are discussed in detail with a special focus on our work in plant hormone detection. Finally, the future development of the plant hormone analysis research field analysis is prospected.


Assuntos
Reguladores de Crescimento de Planta/fisiologia , Plantas , Análise Espaço-Temporal
6.
J Plant Physiol ; 241: 153030, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31493717

RESUMO

Phytophthora cinnamomi (Pc) is a dangerous pathogen that causes root rot (ink disease) and threatens the production of chestnuts worldwide. Despite all the advances recently reported at molecular and physiological level, there are still gaps of knowledge that would help to unveil the defence mechanisms behind plant-Pc interactions. Bearing this in mind we quantified constitutive and Pc-induced stress-related signals (hormones and metabolites) complemented with changes in photosynthetic related parameters by exploring susceptible and resistant Castanea spp.-Pc interactions. In a greenhouse experiment, five days before and nine days after inoculation with Pc, leaves and fine roots from susceptible C. sativa and resistant C. sativa × C. crenata clonal 2-year-old plantlets were sampled (clones Cs14 and 111-1, respectively). In the resistant clone, stomatal conductance (gs) and net photosynthesis (A) decreased significantly and soluble sugars in leaves increased, while in the susceptible clone gs and A remained unchanged and proline levels in leaves increased. In the resistant clone, higher constitutive content of root SA and foliar ABA, JA and JA-Ile as compared to the susceptible clone were observed. Total phenolics and condensed tannins were highest in roots of the susceptible clone. In response to infection, a dynamic hormonal response in the resistant clone was observed, consisting of accumulation of JA, JA-Ile and ABA in roots and depletion of total phenolics in leaves. However, in the susceptible clone only JA diminished in leaves and increased in roots. Constitutive and Pc-induced levels of JA-Ile were only detectable in the resistant clone. From the hormonal profiles obtained in leaves and roots before and after infection, it is concluded that the lack of effective hormonal changes in C. sativa explains the lack of defence responses to Pc of this susceptible species.


Assuntos
Resistência à Doença , Fagaceae/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Phytophthora , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/fisiologia , Resistência à Doença/fisiologia , Fagaceae/imunologia , Fagaceae/microbiologia , Metaboloma/fisiologia , Phytophthora/fisiologia , Doenças das Plantas/imunologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/fisiologia
7.
Plant Sci ; 287: 110183, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481206

RESUMO

In plants, sugar acts as an essential signaling molecule that modulates various aspects of metabolism, growth and development, which are also controlled by phytohormones. However, the molecular mechanism of cross-talk between sugar and phytohormones still remains to be elucidated. We have identified gsm1 (glucose-hypersensitive mutant 1) as a mutant with impaired cotyledon development that shows sensitivity to exogenous abscisic acid (ABA). The addition of fluridone can reverse the glucose (Glc) inhibitory effect in gsm1, implying that endogenous ABA is involved in the Glc response of gsm1. In 4.5% Glc, the expression of Glc-induced ABA-responsive genes in gsm1-1 was nearly two times higher than that in the wild type. Compared to gsm1-1, the gsm1-1 abi4-1 double mutant exhibited reduced sensitivity to Glc and ABA, which was similar to the Glc and ABA insensitive phenotype of abi4-1, suggesting that ABI4 is epistatic to GSM1. In the treatment with 4.5% Glc, the GSM1 transcript level was greatly increased in abi4-1 by almost 4-fold of that in the wild type. These data suggest that GSM1 plays an important role in the ABI4-regulated Glc-ABA signaling cascade during Arabidopsis early seedling growth.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/fisiologia , RNA Helicases/fisiologia , Plântula/crescimento & desenvolvimento , Transdução de Sinais/fisiologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Clorofila/metabolismo , Glucose/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/metabolismo , Plântula/fisiologia , Fatores de Transcrição/fisiologia
8.
Plant Sci ; 287: 110168, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481214

RESUMO

Tiller production in grass species is controlled by both axillary bud initiation and bud outgrowth, which may be regulated by plant hormones. However, how gibberellic acid (GA) affects tillering in perennial grass species is still unclear. This study aims to elucidate the roles and the underlying mechanisms of GA in regulating tiller development. Tall fescue seedlings were treated with different concentrations of GA3 by foliar application, dose-dependent inhibitory effects of GA on tiller production were observed. GA3 (25 µM) slowed down the transition from axillary buds to tillers by specifically inhibiting the outgrowth of axillary buds. GA-inhibition of tillering were not related to endogenous content for auxin or strigolactone, but was mainly due to the antagonistic interaction with cytokinins (CK), as shown by the decreased CK content and up-regulation expression of CK degradation genes in GA3-treated plants. Furthermore, GA could act through regulating the expression of FaTB1 specifically expressed in axillary buds to repress bud outgrowth. These results provide insights for the regulatory mechanisms of GA for tiller bud outgrowth through crosstalks with CK and signaling of FaTB1 expression.


Assuntos
Citocininas/metabolismo , Festuca/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Citocininas/fisiologia , Festuca/genética , Festuca/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/genética , Giberelinas , Brotos de Planta/metabolismo , Receptor Cross-Talk
9.
Ecotoxicol Environ Saf ; 183: 109504, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31421537

RESUMO

Phytoremediation assisted by plant growth-promoting bacteria (PGPB) is an alternative method of cleaning up toxic metals from soil. However, the interactions among indigenous soil microorganisms following PGPB inoculation are far from fully understood, although these interactions are conducive to evaluate the effectiveness of PGPB. Here, we used Illumina Miseq sequencing and network analysis to decipher the co-occurrence patterns of bacterial communities following PGPB inoculation during phytoremediation of heavy metal contaminated soil. Miseq sequencing revealed that PGPB inoculation changed the bacterial community composition one day after inoculation, with minor changes continuing to be observed ten days after inoculation. This suggested that PGPB inoculants did not proliferate extensively in a new environment. Network analysis showed that PGPB inoculation altered the co-occurrence patterns, dominant modules and topological roles of individual OTUs. In the presence of PGPB inoculants the bacterial community had more complex and compact associations. Moreover, PGPB inoculation increased the percentage of connectors, indicating that PGPB may contribute to more intensified interactions among OTUs from different modules; consequently, the microbial community would be more ordered and efficient. The enhanced co-occurrence associations in the PGPB-inoculated bacterial network may contribute to the plant growth-promoting effects of PGPB during phytoremediation of heavy metal-contaminated soil.


Assuntos
Inoculantes Agrícolas/fisiologia , Metais Pesados/metabolismo , Interações Microbianas , Microbiota/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Microbiota/genética , Plantas/metabolismo , Solo/química , Microbiologia do Solo
10.
Ecotoxicol Environ Saf ; 183: 109573, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31442809

RESUMO

Aluminum (Al) bioaccumulation by a novel Al and drought tolerant Curtobacterium herbarum strain CAH5 isolated from rhizosphere soil of Beta vulgaris grown in acidic Andisols were examined. The rhizobacterial strain also presented important plant growth promoting traits even with Al and drought stresses under in-vitro conditions in broth. In experiments with a 2-6 mM as initial Al concentrations, the percentages of Al removal by bacteria were 89-93% and 78-91% within 72 h incubation under the normal and drought conditions, respectively. Cytogenotoxicity assay revealed that the toxicity of Al was reduced after bioaccumulation process. In the greenhouse study, formulated bio-inoculant CAH5 significantly improves the Lactuca sativa growth under Al and drought stress by reducing oxidative stress, lipid peroxidation and Al accumulation in plant parts. Our results highlighted that strain CAH5 could be used as a promising bioresource for restoration of agricultural soil with presence of phytotoxic Al improving crop production even under drought conditions.


Assuntos
Actinobacteria/fisiologia , Alumínio/metabolismo , Secas , Alface/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/fisiologia , Actinobacteria/metabolismo , Alumínio/toxicidade , Biodegradação Ambiental , Caryophyllales/crescimento & desenvolvimento , Caryophyllales/microbiologia , Alface/efeitos dos fármacos , Alface/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Rizosfera , Microbiologia do Solo , Estresse Fisiológico/efeitos dos fármacos
11.
Plant Physiol Biochem ; 142: 510-518, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31445476

RESUMO

As one of the most popular woody species that blooms in summer, Lagerstroemia speciosa has been used abundantly in urban landscape for its excellent floral beauty. For the first time, we discovered a double-flower variant with all petaloid stamens. To understand the molecular basis of this variation, we contrasted the transcriptomes of single- and double-flower buds at three stamen development stages. In total, 73,536 unigenes were mapped and 30,714 differently expressed genes (DEGs) were identified in the tissues. We focused on the DEGs expressing in both phenotypes and investigated the association of their expression profiles with their functions in transcription pathways. Furthermore, we performed WGCNA and identified co-expressed genes with four floral homeotic genes as hubs (MADS16, Unigene0026169; AP2, Unigene0042732; SOC1, Unigene0046314; AG, Unigene0056437). The expression of these hub genes has been conserved across the three developmental stages but significantly different between the two floral phenotypes. As a result, the robust transcriptional regulation of stamen petaloidy in double flowers was deduced. These findings will help to unravel the regulatory mechanisms of several specific genes, thereby providing a basis to study double-flower molecular breeding in L. speciosa.


Assuntos
Flores/crescimento & desenvolvimento , Lagerstroemia/crescimento & desenvolvimento , Flores/anatomia & histologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Lagerstroemia/anatomia & histologia , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia
12.
BMC Plant Biol ; 19(1): 312, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307379

RESUMO

BACKGROUND: The WOX (WUSCHEL-RELATED HOMEOBOX) gene family encodes a class of transcription factors that are unique to green plants, where they are involved in regulating the development of plant tissues and organs by determining cell fate. Although the importance of the WOX gene is well known, there are few studies describing their functions in cotton. RESULTS: In this study, 32 WOX genes were found in Gossypium hirsutum. Phylogenetic analysis showed that WOX proteins of cotton can be divided into three clades: the ancient, intermediate, and WUS clades. The number of WOX proteins in the WUS clade was greater than the sum of the proteins in the other two clades. Our analysis revealed that 20 GhWOX genes are distributed on 16 cotton chromosomes and that duplication events are likely to have contributed to the expansion of the GhWOX family. All GhWOX genes have introns, and each GhWOX protein contains multiple motifs. RNA-seq data and real-time PCR showed that GhWOX13 gene subfamily is specifically expressed at a high level in cotton fibers. We also identified putative GA, NAA, and BR response elements in the promoter regions of the GhWOX13 genes and GhWOX13 transcripts were significantly induced by GA, NAA, and BR. CONCLUSIONS: Our data provides a useful resource for future studies on the functional roles of cotton WOX genes and shows that the GhWOX13 genes may influence cotton fiber development. Our results also provide an approach for identifying and characterizing WOX protein genes in other species.


Assuntos
Fibra de Algodão , Genes de Plantas , Gossypium/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Gossypium/crescimento & desenvolvimento , Proteínas de Homeodomínio/genética , Filogenia , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética
13.
BMC Plant Biol ; 19(1): 329, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337346

RESUMO

BACKGROUND: Zinc finger proteins (ZFPs) containing only a single zinc finger domain play important roles in the regulation of plant growth and development, as well as in biotic and abiotic stress responses. To date, the evolutionary history and functions of the ZFP gene family have not been identified in cotton. RESULTS: In this paper, we identified 29 ZFP genes in Gossypium hirsutum. This gene family was divided into seven subfamilies, 22 of which were distributed over 17 chromosomes. Bioinformatic analysis revealed that 20 GhZFP genes originated from whole genome duplications and two originated from dispersed duplication events, indicating that whole genome duplication is the main force in the expansion of the GhZFP gene family. Most GhZFP8 subfamily genes, except for GhZFP8-3, were highly expressed during fiber cell growth, and were induced by brassinosteroids in vitro. Furthermore, we found that a large number of GhZFP genes contained gibberellic acid responsive elements, auxin responsive elements, and E-box elements in their promoter regions. Exogenous application of these hormones significantly stimulated the expression of these genes. CONCLUSIONS: Our findings reveal that GhZFP8 genes are involved in cotton fiber development and widely induced by auxin, gibberellin and BR, which provides a foundation for the identification of more downstream genes with potential roles in phytohormone stimuli, and a basis for breeding better cotton varieties in the future.


Assuntos
Gossypium/genética , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Dedos de Zinco/genética , Brassinosteroides/metabolismo , Mapeamento Cromossômico , Sequência Conservada/genética , Giberelinas/fisiologia , Gossypium/fisiologia , Ácidos Indolacéticos/metabolismo , Filogenia , Proteínas de Plantas/fisiologia , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Transcriptoma , Dedos de Zinco/fisiologia
14.
Plant Sci ; 285: 132-140, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203877

RESUMO

Xanthomonas campestris pv. campestris (Xcc)- responsive soluble and cell wall-bound hydroxycinnamic acids (HAs) and flavonoids accumulation in relation to hormonal changes in two Brassica napus cultivars contrasting disease susceptibility were interpreted with regard to the disease resistance. At 14-day post inoculation with Xcc, disease resistance in cv. Capitol was distinguished by an accumulation of specific (HAs) and flavonoids particularly in cell-wall bound form, and was characterized by higher endogenous jasmonic acid (JA) resulting in a decrease of JA-based balance with other hormones, as well as enhanced expression of JA signaling that was concurrently based on upregulation of PAP1 (production of anthocyanin pigment 1), MYB transcription factor, and phenylpropanoid biosynthetic genes. Fourier transform infrared spectra confirmed higher amounts of esterified phenolic acids in cv. Capitol. These results indicate that enhanced JA levels and signaling in resistant cultivar was associated with a higher accumulation of HAs and flavonoids, particularly in the cell wall-bound form, and vice versa in the susceptible cultivar (cv. Mosa) with enhanced SA-, ABA-, and CK- levels and signaling. Thus the JA-mediated phenolic metabolites accumulation is an important feature for the management and breeding program to develop disease-resistant B. napus cultivar.


Assuntos
Brassica napus/imunologia , Parede Celular/metabolismo , Ácidos Cumáricos/metabolismo , Ciclopentanos/metabolismo , Resistência à Doença , Oxilipinas/metabolismo , Fenóis/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Xanthomonas campestris , Brassica napus/metabolismo , Brassica napus/microbiologia , Brassica napus/fisiologia , Parede Celular/fisiologia , Resistência à Doença/fisiologia , Suscetibilidade a Doenças/microbiologia , Suscetibilidade a Doenças/fisiopatologia , Flavonoides/metabolismo , Peroxidação de Lipídeos , Microscopia Eletrônica de Varredura , Peptídeo Hidrolases/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Espécies Reativas de Oxigênio/metabolismo
15.
Plant Sci ; 285: 200-213, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203885

RESUMO

NONRACE-SPECIFIC DISEASE RESISTANCE (NDR1) is a widely characterized gene that plays a key role in defense against multiple bacterial, fungal, oomycete and nematode plant pathogens. NDR1 is required for activation of resistance by multiple NB and LRR-containing (NLR) protein immune sensors and contributes to basal defense. The role of NDR1 in positively regulating salicylic acid (SA)-mediated plant defense responses is well documented. However, ndr1-1 plants flower earlier and show accelerated development in comparison to wild type (WT) Arabidopsis plants, indicating that NDR1 is a negative regulator of flowering and growth. Exogenous application of gibberellic acid (GA) further accelerates the early flowering phenotype in ndr1-1 plants, while the GA biosynthesis inhibitor paclobutrazol attenuated the early flowering phenotype of ndr1-1, but not to WT levels, suggesting partial resistance to paclobutrazol and enhanced GA response in ndr1-1 plants. Mass spectroscopy analyses confirmed that ndr1-1 plants have 30-40% higher levels of GA3 and GA4, while expression of various GA metabolic genes and major flowering regulatory genes is also altered in the ndr1-1 mutant. Taken together this study provides evidence of crosstalk between the ndr1-1-mediated defense and GA-regulated developmental programs in plants.


Assuntos
Arabidopsis/genética , Flores/crescimento & desenvolvimento , Giberelinas/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Resistência à Doença/genética , Resistência à Doença/fisiologia , Giberelinas/metabolismo , Mutação/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Ácido Salicílico/metabolismo , Fatores de Transcrição/fisiologia , Transcriptoma , Verticillium
16.
Plant Sci ; 285: 34-43, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203892

RESUMO

Seed germination is a critical stage during the initiation of the plant lifecycle and is strongly affected by endogenous phytohormones and environmental stress. High temperature (HT) upregulates endogenous abscisic acid (ABA) to suppress seed germination, and ABA-INSENSITIVE 5 (ABI5) is the key positive regulator in the ABA signal-mediated modulation of seed germination. In plants, hydrogen sulfide (H2S) is a small gas messenger that participates in multiple physiological processes, but its role in seed germination thermotolerance has not been thoroughly elucidated to date. In this study, we found that H2S enhanced the seed germination rate under HT. Moreover, HT accelerates the efflux of the E3 ligase CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) from the nucleus to the cytoplasm, which results in increased nuclear accumulation of ELONG HYPCOTYL 5 (HY5) to activate the expression of ABI5 and thereby suppress seed germination. However, the H2S signal reversed the HT effect, as characterized by increased COP1 in the nucleus, which resulted in increased degradation of HY5 and reduced expression of ABI5 and thereby enhanced the seed germination thermotolerance. Thus, our findings reveal a novel role for the H2S signal in the modulation of seed germination thermotolerance through the nucleocytoplasmic partitioning of COP1 and the downstream HY5 and ABI5 pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Germinação/fisiologia , Sulfeto de Hidrogênio/metabolismo , Proteínas Nucleares/metabolismo , Sementes/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ácido Abscísico/metabolismo , Ácido Abscísico/fisiologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/fisiologia , Núcleo Celular/enzimologia , Núcleo Celular/metabolismo , Giberelinas/metabolismo , Giberelinas/fisiologia , Temperatura Alta , Proteínas Nucleares/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Sementes/fisiologia , Transdução de Sinais/fisiologia , Termotolerância , Ubiquitina-Proteína Ligases/fisiologia
17.
Syst Appl Microbiol ; 42(4): 517-525, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31176475

RESUMO

Plant roots are inhabited by a large diversity of microbes, some of which are beneficial for the growth of plants and known as plant growth promoting rhizobacteria (PGPR). In this work, we designed a multispecies inoculum of PGPRs containing Rhizobium phaseoli, Sinorhizobium americanum and Azospirillum brasilense nitrogen-fixing strains and other plant-growth promoting bacteria such as Bacillus amyloliquefaciens and Methylobacterium extorquens. We evaluated the effect of this group of bacteria on the growth of one-month-old maize plants. The multispecies inoculum exerted a beneficial effect on maize plants that was greater than that obtained with single-bacteria. Using the same multispecies inoculant, acetylene reduction was recorded in 5-day-old roots indicating active nitrogen fixation by bacteria in maize. Azospirillum nitrogen fixation was lower than that obtained with the multispecies inoculum. We focused on the analysis of R. phaseoli gene expression in presence of other PGPRs. Many R. phaseoli up- regulated genes in roots in the presence of other bacteria are hypothetical, showing our poor knowledge of bacteria-bacteria interactions. Other genes indicated bacterial nutrient competition and R. phaseoli stress. Differentially expressed transcriptional regulators were identified that may be key in bacteria-bacteria interaction regulation. Additionally, gene expression was analyzed from Azospirillum but not from sinorhizobia and methylobacteria due to the low number of transcripts obtained from maize roots. The metatranscriptomic analysis from maize roots showed expression of Azospirillum nif genes in the presence of PGPR bacteria. Our hypothesis is that other bacteria stimulate Azospirillum capacity to fix nitrogen and this should be further explored.


Assuntos
Bactérias/genética , Interações Microbianas , Fixação de Nitrogênio/genética , Reguladores de Crescimento de Planta/genética , Zea mays/microbiologia , Bactérias/metabolismo , Proteínas de Bactérias/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Microbiota , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
18.
Plant Cell Physiol ; 60(7): 1581-1594, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31058993

RESUMO

Lateral root (LR) formation and development play a vital role in plant development by permitting the establishment of branched root systems. It is well known that nutrient availability controls LR development. Moreover, LR development is fine-tuned by a myriad of hormonal signals. Many transcription factors (TFs) participate in LR development. Here, we discuss the TFs involved in the nitrate and auxin signaling pathways and how these function in the regulation of LR formation and development in chrysanthemum. AtTCP20 is a plant-specific TF, which can modulate LR development in response to nitrate. The roles of CmTCP20 in LR development were identified by overexpression in chrysanthemum and heterologous expression in Arabidopsis. Overexpression of CmTCP20 significantly increased the number and average length of LRs compared with the wild type in chrysanthemum and Arabidopsis. We also found that CmTCP20 positively influenced auxin accumulation in the LRs at least partly by improving auxin biosynthesis, transport and response, thereby promoting LR development. Moreover, we found that CmTCP20 interacts with an auxin response factor, CmARF8, which also can be induced by nitrate and combined to proximal sites in the upstream promoter region of CmCYCB1;1 to positively regulate the cell cycle. The CmTCP20-CmARF8 heterodimer links nitrate and auxin signaling and converts cell-cycle signals to regulate LR initiation and growth.


Assuntos
Chrysanthemum/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Nitratos/metabolismo , Proteínas de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Fatores de Transcrição/fisiologia , Arabidopsis , Chrysanthemum/metabolismo , Chrysanthemum/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Transdução de Sinais , Fatores de Transcrição/metabolismo
19.
Curr Microbiol ; 76(7): 888-895, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31093691

RESUMO

Lindane is an organochlorine pesticide that is highly persistent in the environment. The amassing of lindane has been identified worldwide and has been found to be very toxic to the environment, human, and animal health. Therefore, urgent consideration and management of the problem is necessary. The current study intends to isolate and identify lindane degrading rhizospheric bacteria from Phragmites karka and to study its degradation kinetics. Also, plant growth promoting potential of the bacterium was evaluated in the presence and absence of studied pesticide. Rhizospheric bacteria were isolated by standard enrichment technique in Mineral Salt Medium. Microbacterium sp. P27 showed the highest degradation percentage, 82.7 ± 1.79% for 50 mg l-1 lindane, after 15 days. Degradation was also studied at different concentrations of lindane. Maximum degradation was achieved at 10 mg l-1 followed by 50 mg l-1 and 100 mg l-1 lindane. Microbacterium sp. P27 showed positive result for Indole-3-acetic acid production, ammonia production, and 1-aminocyclopropane-1-carboxylate deaminase activity. Presence of lindane revealed a concentration-dependent decrease in plant growth promoting activity. Since the isolated bacterial strain possesses lindane degrading capacity and also other characters that help in plant growth promotion, the isolate can be an important candidate for the progress of bioremediation strategy.


Assuntos
Actinomycetales/fisiologia , Hexaclorocicloexano/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Plantas/microbiologia , Rizosfera , Microbiologia do Solo , Poluentes do Solo/metabolismo , Actinomycetales/metabolismo , Biodegradação Ambiental , Hexaclorocicloexano/toxicidade , Inseticidas/metabolismo , Inseticidas/toxicidade , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Planta/metabolismo , Poaceae/microbiologia , Poluentes do Solo/toxicidade
20.
Plant Cell Physiol ; 60(7): 1619-1629, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31073591

RESUMO

Although exogenous applications of gibberellins (GAs) delay tomato ripening, the regulatory mechanisms of GAs in the process have never been well recognized. Here, we report that the concentration of endogenous GAs is declined before the increase of ethylene production in mature-green to breaker stage fruits. We further demonstrate that reductions in GA levels via overexpression of a GA catabolism gene SlGA2ox1 specifically in fruit tissues lead to early ripening. Consistently, we have also observed that application of a GA biosynthetic inhibitor, prohexadione-calcium, at the mature-green stage accelerates fruit ripening, while exogenous GA3 application delays the process. Furthermore, we demonstrate that ethylene biosynthetic gene expressions and ethylene production are activated prematurely in GA-deficient fruits but delayed/reduced in exogenous GA3-treated WT fruits. We also show that the GA deficiency-mediated activation of ethylene biosynthesis is due to the activation of the ripening regulator genes RIN, NOR and CNR. In conclusion, our results demonstrate that GAs play a negative role in tomato fruit ripening.


Assuntos
Frutas/crescimento & desenvolvimento , Giberelinas/fisiologia , Lycopersicon esculentum/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/fisiologia , Etilenos/biossíntese , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/fisiologia
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