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1.
Plant Mol Biol ; 102(1-2): 143-158, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31782079

RESUMO

KEY MESSAGE: Zinc finger protein transcription factor ZFP5 positively regulates root hair elongation in response to Pi and potassium deficiency by mainly activating the expression of EIN2 in Arabidopsis. Phosphate (Pi) and potassium (K+) are major plant nutrients required for plant growth and development, and plants respond to low-nutrient conditions via metabolic and morphology changes. The C2H2 transcription factor ZFP5 is a key regulator of trichome and root hair development in Arabidopsis. However, its role in regulating root hair development under nutrient deprivations remains unknown. Here, we show that Pi and potassium deficiency could not restore the short root hair phenotype of zfp5 mutant and ZFP5 RNAi lines to wild type level. The deprivation of either of these nutrients also induced the expression of ZFP5 and the activity of an ethylene reporter, pEBS:GUS. The significant reduction of root hair length in ein2-1 and ein3-1 as compared to wild-type under Pi and potassium deficiency supports the involvement of ethylene in root hair elongation. Furthermore, the application of 1-aminocyclopropane-1-carboxylic acid (ACC) significantly enhanced the expression level of ZFP5 while the application of 2-aminoethoxyvinyl glycine (AVG) had the opposite effect when either Pi or potassium was deprived. Further experiments reveal that ZFP5 mainly regulates transcription of ETHYLENE INSENSITIVE 2 (EIN2) to control deficiency-mediated root hair development through ethylene signaling. Generally, these results suggest that ZFP5 regulates root hair elongation by interacting with ethylene signaling mainly through regulates the expression of EIN2 in response to Pi and potassium deficiency in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Fosfatos/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Deficiência de Potássio/metabolismo , Transdução de Sinais , Aminoácidos Cíclicos/farmacologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glicina/análogos & derivados , Glicina/farmacologia , Desnutrição/tratamento farmacológico , Mutação , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Deficiência de Potássio/tratamento farmacológico , Interferência de RNA , Receptores de Superfície Celular/metabolismo , Fatores de Transcrição
2.
Food Chem ; 309: 125705, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31670122

RESUMO

Red-peeled huyou has a distinct red peel color due mainly to the presence of red apocarotenoid ß-citraurin as well as the increase in amount of total carotenoids. The expression level of carotenoid cleavage dioxygenase 4b1 (CCD4b1) accounted for 99.0% of total transcript abundance of CCD4s in red-peeled huyou peel and was nearly 100 times higher than that in ordinary huyou. ß-Citraurin accumulation and peel coloration was mostly favored at 15 °C but strongly inhibited at moderately high temperatures 20 °C and 25 °C. Exogenous ethylene application for 3 d had no obvious effect on ß-citraurin accumulation in red-peeled huyou but holding fruit at moderately higher temperatures (20 °C and 25 °C) for 3 d had a significant adverse effect on ß-citraurin accumulation. The expression of phytoene synthase 1 (PSY1) and CCD4b1 was higher at 10 °C and 15 °C and significantly lower at 20 °C and 25 °C. The mechanisms governing the accumulation of ß-citraurin are discussed.


Assuntos
Citrus/efeitos dos fármacos , Etilenos/farmacologia , Armazenamento de Alimentos/métodos , Carotenoides/análise , Carotenoides/isolamento & purificação , Citrus/química , Citrus/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Frutas/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Extração Líquido-Líquido , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura Ambiente , beta Caroteno/análogos & derivados , beta Caroteno/análise , beta Caroteno/isolamento & purificação
3.
J Agric Food Chem ; 67(49): 13706-13717, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31693347

RESUMO

Tomato storage conditions are difficult largely due to Botrytis cinerea infection which causes gray mold disease. However, the effects of the volatile organic compounds (VOCs) emitted by postharvest tomatoes on this fungus remain unclear. We analyzed the effects of tomato-emitted VOCs on B. cinerea pathogenicity, germination, and hyphal growth with bioassay, predicted the causative active compounds by principle component analysis, identified G-protein-coupled receptors (GPCRs) which captured chemical signals in the B. cinerea genome by stimulating molecular docking, tested the binding affinities of these receptors for the active compounds by fluorescence binding competition assay, and identified an associated signaling pathway by RNA interfere. The VOCs emitted by postharvest tomatoes inhibited B. cinerea; ethylene and benzaldehyde were the active compounds causing this effect. One of the identified GPCRs in B. cinerea, BcGPR3, bound tightly to both active compounds. Two genes associated with the cAMP signaling pathway (BcRcn1 and BcCnA) were downregulated in wild-type B. cinerea exposed to the active compounds, as well as in the ΔBcgpr3 B. cinerea mutant. Exposure to postharvest tomato VOCs reduces B. cinerea pathogenicity due to ethylene and benzaldehyde volatiles. The BcGPR3 protein is inactivated by the active compounds, and thus fails to transmit signals to the cAMP pathway, thereby inhibiting B. cinerea.


Assuntos
Benzaldeídos/farmacologia , Botrytis/efeitos dos fármacos , AMP Cíclico/metabolismo , Etilenos/farmacologia , Proteínas Fúngicas/metabolismo , Lycopersicon esculentum/química , Receptores Acoplados a Proteínas-G/metabolismo , Benzaldeídos/metabolismo , Botrytis/genética , Botrytis/metabolismo , Etilenos/metabolismo , Proteínas Fúngicas/genética , Lycopersicon esculentum/metabolismo , Simulação de Acoplamento Molecular , Doenças das Plantas/microbiologia , Receptores Acoplados a Proteínas-G/genética , Transdução de Sinais/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
4.
Nat Commun ; 10(1): 4020, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488841

RESUMO

Timely perception of adverse environmental changes is critical for survival. Dynamic changes in gases are important cues for plants to sense environmental perturbations, such as submergence. In Arabidopsis thaliana, changes in oxygen and nitric oxide (NO) control the stability of ERFVII transcription factors. ERFVII proteolysis is regulated by the N-degron pathway and mediates adaptation to flooding-induced hypoxia. However, how plants detect and transduce early submergence signals remains elusive. Here we show that plants can rapidly detect submergence through passive ethylene entrapment and use this signal to pre-adapt to impending hypoxia. Ethylene can enhance ERFVII stability prior to hypoxia by increasing the NO-scavenger PHYTOGLOBIN1. This ethylene-mediated NO depletion and consequent ERFVII accumulation pre-adapts plants to survive subsequent hypoxia. Our results reveal the biological link between three gaseous signals for the regulation of flooding survival and identifies key regulatory targets for early stress perception that could be pivotal for developing flood-tolerant crops.


Assuntos
Arabidopsis/metabolismo , Etilenos/metabolismo , Etilenos/farmacologia , Hipóxia , Óxido Nítrico/metabolismo , Estresse Fisiológico/fisiologia , Aclimatação/genética , Aclimatação/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Inundações , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hemoglobinas/metabolismo , Oxigênio/metabolismo , Proteólise , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo
5.
Int J Mol Sci ; 20(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31510080

RESUMO

In Arabidopsis basal hypocotyls of dark-grown seedlings, xylary cells may form from the pericycle as an alternative to adventitious roots. Several hormones may induce xylogenesis, as Jasmonic acid (JA), as well as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) auxins, which also affect xylary identity. Studies with the ethylene (ET)-perception mutant ein3eil1 and the ET-precursor 1-aminocyclopropane-1-carboxylic acid (ACC), also demonstrate ET involvement in IBA-induced ectopic metaxylem. Moreover, nitric oxide (NO), produced after IBA/IAA-treatments, may affect JA signalling and interact positively/negatively with ET. To date, NO-involvement in ET/JA-mediated xylogenesis has never been investigated. To study this, and unravel JA-effects on xylary identity, xylogenesis was investigated in hypocotyls of seedlings treated with JA methyl-ester (JAMe) with/without ACC, IBA, IAA. Wild-type (wt) and ein3eil1 responses to hormonal treatments were compared, and the NO signal was quantified and its role evaluated by using NO-donors/scavengers. Ectopic-protoxylem increased in the wt only after treatment with JAMe(10 µM), whereas in ein3eil1 with any JAMe concentration. NO was detected in cells leading to either xylogenesis or adventitious rooting, and increased after treatment with JAMe(10 µM) combined or not with IBA(10 µM). Xylary identity changed when JAMe was applied with each auxin. Altogether, the results show that xylogenesis is induced by JA and NO positively regulates this process. In addition, NO also negatively interacts with ET-signalling and modulates auxin-induced xylary identity.


Assuntos
Acetatos/farmacologia , Arabidopsis/efeitos dos fármacos , Ciclopentanos/farmacologia , Ácidos Indolacéticos/farmacologia , Óxido Nítrico/metabolismo , Oxilipinas/farmacologia , Xilema/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hipocótilo/efeitos dos fármacos , Hipocótilo/genética , Hipocótilo/metabolismo , Mutação , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/metabolismo , Xilema/citologia , Xilema/metabolismo
6.
ACS Appl Mater Interfaces ; 11(37): 33734-33747, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31436081

RESUMO

Due to insufficient biomedical functions of hydrogels for wound management, the exploitation of available methods to expand the biomedical functions of hydrogels always becomes the cutting-edge research. Here, we report on the use of the silver-ethylene interaction and 3D printing technique to develop the antibacterial superporous polyacrylamide (PAM)/hydroxypropyl methylcellulose (HPMC) hydrogel dressings. Experiments demonstrated that the silver-ethylene interaction played significant roles in mediating the formation, dispersion, and cross-linking of silver nanoparticles (AgNPs) in the hydrogel matrix as well as the cross-linking of the PAM networks. At the same time, such organometallic complexes also controlled the release of AgNPs to balance the cytocompatibility and antibacterial activity of the AgNP-cross-linked hydrogels. On the other hand, the use of 3D printed templates and HPMC as the pore-making materials demonstrated could tailor hydrogels into 91.4% porosity and the formed pores into open channels, endowing hydrogels with rapid water uptake rate and 14 times dead-weight of uptake capacity. Furthermore, experiments showed that the regular large pores arisen from 3D printed templates could buffer the swelling of superporous hydrogel dressings, thus decreasing the detachment risk of dressings from wounds. In vivo experiments demonstrated that the AgNP-cross-linked superporous hydrogel dressings could promote the healing of the infected wounds and restrain scar tissue formation.


Assuntos
Antibacterianos , Bandagens , Etilenos , Hidrogéis , Impressão Tridimensional , Prata , Infecção dos Ferimentos , Ferimentos e Lesões , Animais , Antibacterianos/química , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Linhagem Celular , Etilenos/química , Etilenos/farmacocinética , Etilenos/farmacologia , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia , Ratos , Ratos Sprague-Dawley , Prata/química , Prata/farmacocinética , Prata/farmacologia , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Ferimentos e Lesões/tratamento farmacológico , Ferimentos e Lesões/microbiologia
7.
BMC Plant Biol ; 19(1): 285, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253103

RESUMO

BACKGROUND: Sugarcane is a major crop producing about 80% of sugar globally. Increasing sugar content is a top priority for sugarcane breeding programs worldwide, however, the progress is extremely slow. Owing to its commercial significance, the physiology of sucrose accumulation has been studied extensively but it did not lead to any significant practical outcomes. Recent molecular studies are beginning to recognize genes and gene networks associated with this phenomenon. To further advance our molecular understanding of sucrose accumulation, we altered sucrose content of sugarcane genotypes with inherently large variation for sucrose accumulation using a sugarcane ripener, ethylene, and studied their transcriptomes to identify genes associated with the phenomenon. RESULTS: Sucrose content variation in the experimental genotypes was substantial, with the top-performing clone producing almost 60% more sucrose than the poorest performer. Ethylene treatment increased stem sucrose content but that occurred only in low-sugar genotype. Transcriptomic analyses have identified about 160,000 unigenes of which 86,000 annotated genes were classified into functional groups associated with carbohydrate metabolism, signaling, localization, transport, hydrolysis, growth, catalytic activity, membrane and storage, suggesting the structural and functional specification, including sucrose accumulation, occurring in maturing internodes. About 25,000 genes were differentially expressed between all genotypes and treatments combined. Genotype had a dominant effect on differential gene expression than ethylene treatment. Sucrose and starch metabolism genes were more responsive to ethylene treatment in low-sugar genotype. Ethylene caused differential gene expression of many stress-related transcription factors, carbohydrate metabolism, hormone metabolism and epigenetic modification. Ethylene-induced expression of ethylene-responsive transcription factors, cytosolic acid- and cell wall-bound invertases, and ATPase was more pronounced in low- than in high-sugar genotype, suggesting an ethylene-stimulated sink activity and consequent increased sucrose accumulation in low-sugar genotype. CONCLUSION: Ethylene-induced sucrose accumulation is more pronounced in low-sugar sugarcane genotype, and this is possibly achieved by the preferential activation of genes such as invertases that increase sink strength in the stem. The relatively high enrichment of differentially expressed genes associated with hormone metabolism and signaling and stress suggests a strong hormonal regulation of source-sink activity, growth and sucrose accumulation in sugarcane.


Assuntos
Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/farmacologia , Saccharum/fisiologia , Sacarose/metabolismo , Genótipo , Saccharum/crescimento & desenvolvimento , Transcriptoma
8.
Planta ; 250(1): 347-366, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31037486

RESUMO

MAIN CONCLUSION: The involvement of a WRKY transcription factor in the regulation of lignan biosynthesis in flax using a hairy root system is described. Secoisolariciresinol is the main flax lignan synthesized by action of LuPLR1 (pinoresinol-lariciresinol reductase 1). LuPLR1 gene promoter deletion experiments have revealed a promoter region containing W boxes potentially responsible for the response to Fusarium oxysporum. W boxes are bound by WRKY transcription factors that play a role in the response to stress. A candidate WRKY transcription factor, LuWRKY36, was isolated from both abscisic acid and Fusarium elicitor-treated flax cell cDNA libraries. This transcription factors contains two WRKY DNA-binding domains and is a homolog of AtWRKY33. Different approaches confirmed LuWRKY36 binding to a W box located in the LuPLR1 promoter occurring through a unique direct interaction mediated by its N-terminal WRKY domain. Our results propose that the positive regulator action of LuWRKY36 on the LuPLR1 gene regulation and lignan biosynthesis in response to biotic stress is positively mediated by abscisic acid and inhibited by ethylene. Additionally, we demonstrate a differential Fusarium elicitor response in susceptible and resistant flax cultivars, seen as a faster and stronger LuPLR1 gene expression response accompanied with higher secoisolariciresinol accumulation in HR of the resistant cultivar.


Assuntos
Linho/genética , Fusarium/fisiologia , Lignanas/biossíntese , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/farmacologia , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Etilenos/farmacologia , Linho/metabolismo , Linho/microbiologia , Biblioteca Gênica , Modelos Biológicos , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Regiões Promotoras Genéticas/genética , Estresse Fisiológico , Fatores de Transcrição/genética
9.
J Plant Physiol ; 238: 63-71, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31146183

RESUMO

This study aimed to investigate the firmness retention by ethylene treatment in olive fruit, as observed earlier. Ethylene concentrations up to 1000 µL L-1 were applied to dark green 'Konservolia' olives harvested shortly before the green maturation and exposed to 20 °C for up to 9 d. Surprisingly, the results indicated a tendency to fruit firmness increases in concentration-dependent manner in a non-climacteric fruit. The highest concentration increased the firmness within 12 h by approximately 1.35-fold, but transiently for approximately up to 5 d; all ethylene inhibitors tested, either of synthesis (ethoxyvinyl glycine or AVG), or perception (1 -methyl-cyclopropene or 1-MCP, and silver nitrate) prevented the firmness increase. Texture was evaluated by firmness and changes in lignin, cellulose (CL), total pectins (TPC), water soluble pectins (WSP) and total non-cellulosic sugars (total sugars) concentrations, and in pectin esterification degree (DE) in the alcohol insoluble residue (AIR) of 'Konservolia' fruit pericarp during 1.5-d, 5-d and 10-d treatments with 1000 µL L-1 ethylene at 20 °C. Pectins in AIR were also extracted sequentially with cyclohexane-trans-1,2-diaminetetra-acetate (CDTA), Na2CO3, 1 M and 4 M KOH. The results showed that on day 1.5, the increased firmness was consistent with increased CL (crystalline formation, as observed by microscopy), total sugars and DE levels, but reduced WSP, whereas softening reversed the changes and lowered TPC and CDTA-soluble pectins in all fruit on day 10. However, on day 5 ethylene-treated olives exhibited a transitional phase during softening, characterized by retention of high TPC concentration and energy demand, as indicated by elevated respiration rates. The inhibitor 1-MCP, applied before ethylene, did inhibit the responses to ethylene treatment. Ethylene firming effect and the respective cell wall changes in olives are demonstrated for first time. The experiments could be used for research on perception and transcription responses to ethylene in olive, a non-climacteric fruit. In practice, high ethylene concentrations could also be beneficial for firmness increase and/or short storage of dark green olives.


Assuntos
Parede Celular/metabolismo , Ciclopropanos/farmacologia , Etilenos/metabolismo , Frutas/metabolismo , Olea/metabolismo , Parede Celular/efeitos dos fármacos , Celulose/metabolismo , Produção Agrícola/métodos , Relação Dose-Resposta a Droga , Etilenos/antagonistas & inibidores , Etilenos/farmacologia , Qualidade dos Alimentos , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Lignina/metabolismo , Olea/efeitos dos fármacos , Olea/crescimento & desenvolvimento , Pectinas/metabolismo
10.
BMC Plant Biol ; 19(1): 219, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31132986

RESUMO

BACKGROUND: Mature fruit cracking during the normal season in African Pride (AP) atemoya is a major problem in postharvest storage. Our current understanding of the molecular mechanism underlying fruit cracking is limited. The aim of this study was to unravel the role starch degradation and cell wall polysaccharide metabolism in fruit ripening and cracking after harvest through transcriptome analysis. RESULTS: Transcriptome analysis of AP atemoya pericarp from cracking fruits of ethylene treatments and controls was performed. KEGG pathway analysis revealed that the starch and sucrose metabolism pathway was significantly enriched, and approximately 39 DEGs could be functionally annotated, which included starch, cellulose, pectin, and other sugar metabolism-related genes. Starch, protopectin, and soluble pectin contents among the different cracking stages after ethylene treatment and the controls were monitored. The results revealed that ethylene accelerated starch degradation, inhibited protopectin synthesis, and enhanced the soluble pectin content, compared to the control, which coincides with the phenotype of ethylene-induced fruit cracking. Key genes implicated in the starch, pectin, and cellulose degradation were further investigated using RT-qPCR analysis. The results revealed that alpha-amylase 1 (AMY1), alpha-amylase 3 (AMY3), beta-amylase 1 (BAM1), beta-amylase 3 (BAM3), beta-amylase 9 (BAM9), pullulanase (PUL), and glycogen debranching enzyme (glgX), were the major genes involved in starch degradation. AMY1, BAM3, BAM9, PUL, and glgX all were upregulated and had higher expression levels with ethylene treatment compared to the controls, suggesting that ethylene treatment may be responsible for accelerating starch degradation. The expression profile of alpha-1,4-galacturonosyltransferase (GAUT) and granule-bound starch synthase (GBSS) coincided with protopectin content changes and could involve protopectin synthesis. Pectinesterase (PE), polygalacturonase (PG), and pectate lyase (PEL) all involved in pectin degradation; PE was significantly upregulated by ethylene and was the key enzyme implicated pectin degradation. CONCLUSION: Both KEGG pathway enrichment analysis of DEGs and material content analysis confirmed that starch decomposition into soluble sugars and cell wall polysaccharides metabolism are closely related to the ripening and cracking of AP atemoya. A link between gene up- or downregulation during different cracking stages of atemoya fruits and how their expression affects starch and pectin contents were established by RT-qPCR analysis.


Assuntos
Annona/genética , Etilenos/farmacologia , Frutas/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/farmacologia , Polissacarídeos/metabolismo , Annona/metabolismo , Etilenos/administração & dosagem , Frutas/genética , Frutas/metabolismo , Perfilação da Expressão Gênica , Genes de Plantas , Redes e Vias Metabólicas/genética
11.
BMC Plant Biol ; 19(1): 92, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30832566

RESUMO

BACKGROUND: Hydrogen cyanide (HCN) is a small gaseous molecule that is predominantly produced as an equimolar co-product of ethylene (ET) biosynthesis in plants. The function of ET is of great concern and is well studied; however, the function of HCN is largely unknown. Similar to ET, HCN is a simple and diffusible molecule that has been shown to play a regulatory role in the control of some metabolic processes in plants. Nevertheless, it is still controversial whether HCN should be regarded as a signalling molecule, and the cross-talk between HCN and ET in gene expression regulation remains unclear. In this study, RNA sequencing (RNA-seq) was performed to compare the differentially expressed genes (DEGs) between HCN and ET in Arabidopsis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were subsequently performed to investigate the function and pathway enrichment of DEGs. Parts of key genes were confirmed by quantitative real-time PCR. RESULTS: The results showed that at least 1305 genes and 918 genes were significantly induced by HCN and ET, respectively. Interestingly, a total of 474 genes (|log2 FC| ≥1) were co-regulated by HCN and ET. GO and KEGG analyses indicated that the co-regulated genes by HCN and ET were enriched in plant responses to stress and plant hormone signal transduction pathways, indicating that HCN may cooperate with ET and participate in plant growth and development and stress responses. However, a total of 831 genes were significantly induced by HCN but not by ET, indicating that in addition to ET, HCN is in essence a key signalling molecule in plants. Importantly, our data showed that the possible regulatory role of a relatively low concentration of HCN does not depend on ET feedback induction, although there are some common downstream components were observed. CONCLUSION: Our findings provide a valuable resource for further exploration and understanding of the molecular regulatory mechanisms of HCN in plants and provide novel insight into HCN cross-talk with ET and other hormones in the regulation of plant growth and plant responses to environmental stresses.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Cianeto de Hidrogênio/farmacologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Etilenos/biossíntese , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Análise de Sequência de RNA/métodos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
12.
Plant Biol (Stuttg) ; 21 Suppl 1: 103-108, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29996004

RESUMO

Soil water-logging and flooding are common environmental stress conditions that can impair plant fitness. Roots are the first organs to be confronted with reduced oxygen tension as a result of flooding. While anatomical and morphological adaptations of roots are extensively studied, the root system architecture is only now becoming a focus of flooding research. Adventitious root (AR) formation shifts the root system higher up the plant, thereby facilitating supply with oxygen, and thus improving root and plant survival. We used Arabidopsis knockout mutants and overexpressors of ERFVII transcription factors to study their role in AR formation under hypoxic conditions and in response to ethylene. Results show that ethylene inhibits AR formation. Hypoxia mainly promotes AR elongation rather than formation mediated by ERFVII transcription factors, as indicated by reduced AR elongation in erfVII seedlings. Overexpression of HRE2 induces AR elongation to the same degree as hypoxia, while ethylene overrides HRE2-induced AR elongation. The ERFVII transcription factors promote establishment of an AR system that is under negative control by ethylene. Inhibition of growth of the main root system and promotion of AR elongation under hypoxia strengthens the root system in upper soil layers where oxygen shortage may last for shorter time periods.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Hipóxia/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas
13.
J Exp Bot ; 70(1): 115-131, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30239815

RESUMO

The common fig bears a unique closed inflorescence structure, the syconium, composed of small individual drupelets that develop from the ovaries, which are enclosed in a succulent receptacle of vegetative origin. The fig ripening process is traditionally classified as climacteric; however, recent studies have suggested that distinct mechanisms exist in its reproductive and non-reproductive parts. We analysed ABA and ethylene production, and expression of ABA-metabolism, ethylene-biosynthesis, MADS-box, NAC, and ethylene response-factor genes in inflorescences and receptacles of on-tree fruit treated with ABA, ethephon, fluridone, and nordihydroguaiaretic acid (NDGA). Exogenous ABA and ethephon accelerated fruit ripening and softening, whereas fluridone and NDGA had the opposite effect, delaying endogenous ABA and ethylene production compared to controls. Expression of the ABA-biosynthesis genes FcNCED2 and FcABA2, ethylene-biosynthesis genes FcACS4, FcACOL, and FcACO2, FcMADS8, 14, 15, FcNAC1, 2, 5, and FcERF9006 was up-regulated by exogenous ABA and ethephon. NDGA down-regulated FcNCED2 and FcABA2, whereas fluridone down-regulated FcABA2; both down-regulated the ethylene-related genes. These results demonstrate the key role of ABA in regulation of ripening by promoting ethylene production, as in the climacteric model plant tomato, especially in the inflorescence. However, increasing accumulation of endogenous ABA until full ripeness and significantly low expression of ethylene-biosynthesis genes in the receptacle suggests non-climacteric, ABA-dependent ripening in the vegetative-originated succulent receptacle part of the fruit.


Assuntos
Ácido Abscísico/farmacologia , Ficus/crescimento & desenvolvimento , Masoprocol/farmacologia , Compostos Organofosforados/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Piridonas/farmacologia , Ácido Abscísico/antagonistas & inibidores , Etilenos/farmacologia , Ficus/genética , Ficus/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Inflorescência/crescimento & desenvolvimento , Inflorescência/metabolismo , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
14.
Ultrason Sonochem ; 50: 289-301, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30274889

RESUMO

Postharvest treatments such as wounding, ultrasound (US) and the exogenous application of ethylene (ET) and methyl jasmonate (MJ) have been studied as an effective tool to improve the content of secondary metabolites in fresh produce. The present study evaluated the immediate and late response (storage for 72 h at 15 °C) to US treatment (20 min, frequency 24 kHz, amplitude 100 µm) alone and combined with exogenous MJ (250 ppm) and/or ET (1000 ppm) on glucosinolates, isothiocyanates, phenolic compounds and ascorbic acid content in broccoli florets. US treatment increased the extractability of glucosinolates [glucoraphanin (795%), 4-hydroxy glucobrassicin (153%), glucobrassicin (78.6%)] and phenolics [1-sinapoyl-2-feruloylgentiobiose (57.23%)] as compared with the control (CT). The combined application of MJ and US in broccoli florets, induced a synergistic effect on the accumulation of 4-hydroxy glucobrassicin (187.1%), glucoerucin (111.92%), gluconasturtiin (755.9%), neoglucobrassicin (232.8%), 3-O-caffeoylquinic acid (73.4%), 1-sinapoyl-2-ferulolylgentiobiose (56.0%), and 1,2,2-trisinapoylgentiobiose (136.7%) at 72 h of storage. Interestingly, when the three stressors were applied together the synergistic effect of US + MJ observed on the accumulation of glucosinolates and phenolics was repressed. In general, the ascorbic acid content was not affected by US treatment and decreased in most samples during storage. However, when MJ + ET were applied, the content of total ascorbic acid was significantly reduced in CT + MJ + ET and US + MJ + ET samples after 72 h of storage by 53.4% and 86.6%, respectively, as compared with CT 0 h samples. Based on the results herein obtained, the application of US can be an effective tool to enhance the extractability of certain glucocosinolate and phenolic compounds in broccoli. Moreover, due to the synergistic effect observed on the accumulation of bioactive compounds, the combined application of US and MJ could be a practical approach to yield higher levels of glucosinolates and phenolic compounds in broccoli during storage.


Assuntos
Brassica/metabolismo , Flores/metabolismo , Conservação de Alimentos , Reguladores de Crescimento de Planta/farmacologia , Ondas Ultrassônicas , Acetatos/farmacologia , Cromatografia Líquida de Alta Pressão , Ciclopentanos/farmacologia , Suplementos Nutricionais , Etilenos/farmacologia , Glucosinolatos/isolamento & purificação , Glucosinolatos/metabolismo , Oxilipinas/farmacologia , Fenóis/isolamento & purificação , Fenóis/metabolismo
15.
Nitric Oxide ; 82: 25-34, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30465876

RESUMO

The current review focuses on the significant role of nitric oxide (NO) in modulating ethylene-induced fruit ripening responses in plants. In this context, hydrogen sulfide (H2S) and melatonin mediated crosstalk mechanisms have been discussed with recent updates. Physiological and biochemical events associated with climacteric fruit ripening involves a plethora of effects mediated by these biomolecules. In the last few years of progress in fruit ripening physiology, the involvement of hydrogen sulfide in relation to NO remains as a nascent field of research. The importance of nitric oxide as a freely diffusible and membrane permeable biomolecule leads to its applications in post-harvest fruit storage. The process of field to market transition of edible fruits involves various intermediate stages of post-harvest storage and transport. Fruits harvested in the pre-climacteric stage are intended to be stored and transported for longer durations. However, this does not confer proper development of aroma and flavor in the post-harvest stages. Nitric oxide and ethylene crosstalk is mediated by hydrogen sulfide and melatonin activity which regulate various metabolic pathways associated with fruit ripening. A surge in the reactive nitrogen species (RNS), sugar metabolism, and plastid biogenesis are the plausible effects of NO-ethylene crosstalk. NO-mediated regulations of carbon metabolism and phytohormone levels are essential components of fruit ripening process. Melatonin by the virtue of its functional group possesses strong anti-oxidative properties. Recent updates suggest crosstalk mechanisms associated with melatonin-ethylene and nitric oxide in plants. The present review briefly summarizes the current understandings of fruit ripening physiology manifested by the effects of NO, H2S and melatonin signaling. The agri-horticultural applications of exogenous NO/H2S donors and melatonin treatment impose major benefits for delaying postharvest fruit senescence.


Assuntos
Etilenos/farmacologia , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Sulfeto de Hidrogênio/farmacologia , Melatonina/farmacologia , Óxido Nítrico/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Transdução de Sinais/efeitos dos fármacos
16.
J Sci Food Agric ; 99(2): 854-860, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30006943

RESUMO

BACKGROUND: Tannins are frequently a main focus in the investigation of de-astringency treatments of persimmon, and the effect of a controlled atmosphere on other phytochemicals is often overlooked. In the present study, changes in the content of total soluble and insoluble phenolics, soluble tannins, saponins, and carotenoids, as well as changes in primary metabolites, were monitored. RESULTS: Generally, treatment with ethylene induced a decrease in total phenolic content, whereas, when treated with CO2 , the content of total phenolics remained unchanged compared to the level of total phenolics before treatment. Treatment with apple-sourced ethylene did not significantly affect the level of total phenolics. Additionally, for both varieties, 'Kaki Tipo' and 'Rojo Brillante', the share of insoluble phenolics strongly increased when treated with CO2 , whereas, when treated with ethylene, the same change applied for the ratio of soluble phenolics. The content of carotenoids varied markedly among treatments and varieties, whereas the content of total saponins remained unchanged, regardless of the treatment and variety. CONCLUSION: The results obtained in the present study show that the content of metabolites in persimmon was affected markedly and variedly using post-harvest technology. Apart from the treatment used, changes in the content of metabolites are also affected markedly by the persimmon variety. © 2018 Society of Chemical Industry.


Assuntos
Diospyros/química , Conservação de Alimentos/métodos , Frutas/química , Diospyros/efeitos dos fármacos , Diospyros/metabolismo , Etilenos/farmacologia , Conservação de Alimentos/instrumentação , Frutas/efeitos dos fármacos , Frutas/metabolismo , Fenóis/análise , Fenóis/metabolismo , Saponinas/análise , Saponinas/metabolismo , Taninos/análise , Taninos/metabolismo
17.
New Phytol ; 222(2): 820-836, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30511456

RESUMO

Ethylene is the main hormone controlling climacteric fruit ripening; however, the mechanisms underlying the developmental transition leading to the initiation of the ripening process remain elusive, although the presumed role of active hormone interplay has often been postulated. To unravel the putative role of auxin in the unripe-to-ripe transition, we investigated the dynamics of auxin activity in tomato fruit and addressed the physiological significance of Sl-SAUR69, previously identified as a RIN target gene, using reverse genetics approaches. Auxin signalling undergoes dramatic decline at the onset of ripening in wild-type fruit, but not in the nonripening rin mutant. Sl-SAUR69 exhibits reduced expression in rin and its up-regulation results in premature initiation of ripening, whereas its down-regulation extends the time to ripening. Overexpression of Sl-SAUR69 reduces proton pump activity and polar auxin transport, and ectopic expression in Arabidopsis alters auxin transporter abundance, further arguing for its active role in the regulation of auxin transport. The data support a model in which Sl-SAUR69 represses auxin transport, thus generating auxin minima, which results in enhanced ethylene sensitivity. This defines a regulation loop, fed by ethylene and auxin as the main hormonal signals and by RIN and Sl-SAUR69 as modulators of the balance between the two hormones.


Assuntos
Etilenos/farmacologia , Frutas/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , RNA de Plantas/metabolismo , Arabidopsis/metabolismo , Transporte Biológico/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Frutas/efeitos dos fármacos , Frutas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Bombas de Próton/metabolismo , Transdução de Sinais , Transcrição Genética/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
18.
Plant Cell Environ ; 42(1): 85-97, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29486054

RESUMO

During soil waterlogging, plants experience O2 deficits, elevated ethylene, and high CO2 in the root-zone. The effects on chickpea (Cicer arietinum L.) and faba bean (Vicia faba L.) of ethylene (2 µL L-1 ), CO2 (2-20% v/v) or deoxygenated stagnant solution were evaluated. Ethylene and high CO2 reduced root growth of both species, but O2 deficiency had the most damaging effect and especially so for chickpea. Chickpea suffered root tip death when in deoxygenated stagnant solution. High CO2 inhibited root respiration and reduced growth, whereas sugars accumulated in root tips, of both species. Gas-filled porosity of the basal portion of the primary root of faba bean (23%, v/v) was greater than for chickpea (10%), and internal O2 movement was more prominent in faba bean when in an O2 -free medium. Ethylene treatment increased the porosity of roots. The damaging effects of low O2 , such as death of root tips, resulted in poor recovery of root growth upon reaeration. In conclusion, ethylene and high CO2 partially inhibited root extension in both species, but low O2 in deoxygenated stagnant solution had the most damaging effect, even causing death of root tips in chickpea, which was more sensitive to the low O2 condition than faba bean.


Assuntos
Dióxido de Carbono/farmacologia , Cicer/metabolismo , Etilenos/farmacologia , Raízes de Plantas/metabolismo , Vicia faba/metabolismo , Cicer/efeitos dos fármacos , Cicer/crescimento & desenvolvimento , Oxigênio/metabolismo , Consumo de Oxigênio , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Vicia faba/efeitos dos fármacos , Vicia faba/crescimento & desenvolvimento
19.
Int J Mol Sci ; 20(1)2018 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-30583536

RESUMO

Alfalfa is the most extensively cultivated forage legume worldwide. However, the molecular mechanisms underlying alfalfa responses to exogenous abscisic acid (ABA) are still unknown. In this study, the first global transcriptome profiles of alfalfa roots under ABA treatments for 1, 3 and 12 h (three biological replicates for each time point, including the control group) were constructed using a BGISEQ-500 sequencing platform. A total of 50,742 isoforms with a mean length of 2541 bp were generated, and 4944 differentially expressed isoforms (DEIs) were identified after ABA deposition. Metabolic analyses revealed that these DEIs were involved in plant hormone signal transduction, transcriptional regulation, antioxidative defense and pathogen immunity. Notably, several well characterized hormone signaling pathways, for example, the core ABA signaling pathway, was activated, while salicylic acid, jasmonate and ethylene signaling pathways were mainly suppressed by exogenous ABA. Moreover, the physiological work showed that catalase and peroxidase activity and glutathione and proline content were increased after ABA deposition, which is in accordance with the dynamic transcript profiles of the relevant genes in antioxidative defense system. These results indicate that ABA has the potential to improve abiotic stress tolerance, but that it may negatively regulate pathogen resistance in alfalfa.


Assuntos
Ácido Abscísico/farmacologia , Perfilação da Expressão Gênica , Medicago sativa/efeitos dos fármacos , Medicago sativa/fisiologia , Raízes de Plantas/efeitos dos fármacos , Ciclopentanos/farmacologia , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas/genética , Medicago sativa/genética , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Ácido Salicílico/farmacologia , Estresse Fisiológico/efeitos dos fármacos
20.
BMC Plant Biol ; 18(1): 358, 2018 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-30558543

RESUMO

BACKGROUND: Understanding the mechanisms involved in climacteric fruit ripening is key to improve fruit harvest quality and postharvest performance. Kiwifruit (Actinidia deliciosa cv. 'Hayward') ripening involves a series of metabolic changes regulated by ethylene. Although 1-methylcyclopropene (1-MCP, inhibitor of ethylene action) or ozone (O3) exposure suppresses ethylene-related kiwifruit ripening, how these molecules interact during ripening is unknown. RESULTS: Harvested 'Hayward' kiwifruits were treated with 1-MCP and exposed to ethylene-free cold storage (0 °C, RH 95%) with ambient atmosphere (control) or atmosphere enriched with O3 (0.3 µL L- 1) for up to 6 months. Their subsequent ripening performance at 20 °C (90% RH) was characterized. Treatment with either 1-MCP or O3 inhibited endogenous ethylene biosynthesis and delayed fruit ripening at 20 °C. 1-MCP and O3 in combination severely inhibited kiwifruit ripening, significantly extending fruit storage potential. To characterize ethylene sensitivity of kiwifruit following 1-MCP and O3 treatments, fruit were exposed to exogenous ethylene (100 µL L- 1, 24 h) upon transfer to 20 °C following 4 and 6 months of cold storage. Exogenous ethylene treatment restored ethylene biosynthesis in fruit previously exposed in an O3-enriched atmosphere. Comparative proteomics analysis showed separate kiwifruit ripening responses, unraveled common 1-MCP- and O3-dependent metabolic pathways and identified specific proteins associated with these different ripening behaviors. Protein components that were differentially expressed following exogenous ethylene exposure after 1-MCP or O3 treatment were identified and their protein-protein interaction networks were determined. The expression of several kiwifruit ripening related genes, such as 1-aminocyclopropane-1-carboxylic acid oxidase (ACO1), ethylene receptor (ETR1), lipoxygenase (LOX1), geranylgeranyl diphosphate synthase (GGP1), and expansin (EXP2), was strongly affected by O3, 1-MCP, their combination, and exogenously applied ethylene. CONCLUSIONS: Our findings suggest that the combination of 1-MCP and O3 functions as a robust repressive modulator of kiwifruit ripening and provide new insight into the metabolic events underlying ethylene-induced and ethylene-independent ripening outcomes.


Assuntos
Actinidia/fisiologia , Ciclopropanos/farmacologia , Etilenos/farmacologia , Frutas/fisiologia , Ozônio/farmacologia , Actinidia/efeitos dos fármacos , Etilenos/metabolismo , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ozônio/metabolismo , Proteínas de Plantas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
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