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1.
Int J Mol Sci ; 22(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34445383

RESUMO

As crucial signal transducers, G-proteins and G-protein-coupled receptors (GPCRs) have attracted increasing attention in the field of signal transduction. Research on G-proteins and GPCRs has mainly focused on animals, while research on plants is relatively rare. The mode of action of G-proteins is quite different from that in animals. The G-protein α (Gα) subunit is the most essential member of the G-protein signal cycle in animals and plants. The G-protein is activated when Gα releases GDP and binds to GTP, and the relationships with the GPCR and the downstream signal are also achieved by Gα coupling. It is important to study the role of Gα in the signaling pathway to explore the regulatory mechanism of G-proteins. The existence of a self-activated Gα in plants makes it unnecessary for the canonical GPCR to activate the G-protein by exchanging GDP with GTP. However, putative GPCRs have been found and proven to play important roles in G-protein signal transduction. The unique mode of action of G-proteins and the function of putative GPCRs in plants suggest that the same definition used in animal research cannot be used to study uncanonical GPCRs in plants. This review focuses on the different functions of the Gα and the mode of action between plants and animals as well as the functions of the uncanonical GPCR. This review employs a new perspective to define uncanonical GPCRs in plants and emphasizes the role of uncanonical GPCRs and Gα subunits in plant stress resistance and agricultural production.


Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Plantas/metabolismo , Estresse Fisiológico , Animais , Regulação da Expressão Gênica de Plantas , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Desenvolvimento Vegetal , Proteínas de Plantas/metabolismo , Transdução de Sinais
2.
BMC Plant Biol ; 21(1): 340, 2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-34273968

RESUMO

BACKGROUND: TLPs (Tubby-like proteins) are widespread in eukaryotes and highly conserved in plants and animals. TLP is involved in many biological processes, such as growth, development, biotic and abiotic stress responses, while the underlying molecular mechanism remains largely unknown. In this paper we characterized the biological function of cucumber (Cucumis sativus L.) Tubby-like protein 8 (CsTLP8) in Arabidopsis. RESULTS: In cucumber, the expression of the tubby-like protein CsTLP8 was induced by NaCl treatment, but reduced by PEG (Polyethylene Glycol) and ABA (Abscisic Acid) treatment. Subcellular localization and transcriptional activation activity analysis revealed that CsTLP8 possessed two characteristics of classical transcription factors: nuclear localization and trans-activation activity. Yeast two-hybrid assay revealed interactions of CsTLP8 with CsSKP1a and CsSKP1c, suggesting that CsTLP8 might function as a subunit of E3 ubiquitin ligase. The growth activity of yeast with ectopically expressed CsTLP8 was lower than the control under NaCl and mannitol treatments. Under osmotic and salt stresses, overexpression of CsTLP8 inhibited seed germination and the growth of Arabidopsis seedlings, increased the content of MDA (Malondialdehyde), and decreased the activities of SOD (Superoxide Dismutase), POD (Peroxidase) and CAT (Catalase) in Arabidopsis seedlings. Overexpression of CsTLP8 also increased the sensitivity to ABA during seed germination and ABA-mediated stomatal closure. CONCLUSION: Under osmotic stress, CsTLP8 might inhibit seed germination and seedling growth by affecting antioxidant enzymes activities. CsTLP8 acts as a negative regulator in osmotic stress and its effects may be related to ABA.


Assuntos
Ácido Abscísico/metabolismo , Cucumis sativus/metabolismo , Germinação , Pressão Osmótica , Proteínas de Plantas/metabolismo , Sementes , Transdução de Sinais , Antioxidantes/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/embriologia , Cloreto de Sódio , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
3.
Plant Sci ; 301: 110683, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33218644

RESUMO

The LATERAL ORGAN BOUNDARIES DOMAIN (LBD)-containing genes are plant-specific genes that play important roles in lateral organ development. In this study, we identified LBD40 (Solyc02g085910), which belongs to subfamily II of the LBD family of genes in tomato. LBD40 was highly expressed in roots and fruit. LBD40 expression was significantly induced by PEG and salt. Moreover, SlLBD40 expression was induced by methyl jasmonate treatment, while SlLBD40 expression could not be induced in the jasmonic acid-insensitive1 (jai1) mutant or MYC2-silenced plants, in which jasmonic acid (JA) signaling was disrupted. These findings demonstrate that SlLBD40 expression was dependent on JA signaling and that it might be downstream of SlMYC2, which is the master transcription factor in the JA signal transduction pathway. Overexpressing and CRISPR/Cas9 mediated knockout transgenic tomato plants were generated to explore SlLBD40 function. The drought tolerance test showed that two SlLBD40 knockout lines wilted slightly, while SlLBD40 overexpressing plants suffered severe wilting. The statistical water loss rate and midday leaf water potential also confirmed that knockout of SlLBD40 improved the water-holding ability of tomato under drought conditions. Taken together, our study demonstrates that SlLBD40, involved in JA signaling, was a negative regulator of drought tolerance and that knockout of SlLBD40 enhanced drought tolerance in tomato. This study also provides a novel function of SlLBD40, which belongs to subfamily II of LBD genes.


Assuntos
Lycopersicon esculentum/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Acetatos/metabolismo , Sistemas CRISPR-Cas , Ciclopentanos/metabolismo , Secas , Frutas/genética , Frutas/fisiologia , Lycopersicon esculentum/fisiologia , Mutagênese , Oxilipinas/metabolismo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Plant Sci ; 298: 110580, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32771141

RESUMO

In tomato, red color is a key commercial trait and arises from the accumulation of carotenoids. Previous studies have revealed that melatonin promotes lycopene accumulation and ethylene production. However, it is unclear if melatonin similarly increases other carotenoids, and whether any increase of carotenoids in tomato fruit is directly related to ethylene production. In this study, changes in carotenoid profiles during fruit ripening were investigated in control (CK) and in fruits treated with melatonin (M50). The α, ß-carotene, and lycopene levels were significantly increased in M50, and there was increased carotenoid biosynthetic gene expression. We also observed up-regulated transcript levels of SlRIN, SlCNR, and SlNOR in M50 compared to CK. To better understand the regulation of carotenoid biosynthesis by melatonin and its potential response to endogenous ethylene, we tested an ethylene-insensitive mutant, Never ripe (Nr). Melatonin-treated Nr failed to accumulate more carotenoids compared to CK, although there was significantly changed ethylene production. Additionally, there was no general upregulation of expression of ripening-related genes in this mutant under melatonin treatment. These results suggest melatonin function might require ethylene to promote carotenoid synthesis in tomato.


Assuntos
Carotenoides/metabolismo , Expressão Gênica , Licopeno/metabolismo , Lycopersicon esculentum/metabolismo , Melatonina/metabolismo , beta Caroteno/metabolismo , Frutas/química , Melatonina/administração & dosagem , Regulação para Cima
5.
Plant Cell Environ ; 43(11): 2666-2679, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32799324

RESUMO

Improving plant water-use efficiency (WUE) is important to plant survival and crop yield in the context of water limitation. In this study, SlTLFP8 (Tubby-like F-box protein 8) was identified as an osmotic-induced gene in tomato. Transgenic tomato with up-regulated expression of SlTLFP8 showed enhanced water-deficient resistance, whereas knockout mutants generated by CRISPR/Cas9 were more sensitive to water deficit. SlTLFP8 overexpression significantly enhanced WUE by suppressing transpiration under both water-sufficient and water-deficient conditions. Further study showed that overexpressing SlTLFP8 significantly increased leaf epidermal cell size and thereby decreased stomatal density 10-20%, conversely SlTLFP8 knockout resulted in decreased cell size and thereby increased stomatal density 20-50%. SlTLFP8 overexpression and knockout modulated ploidy levels in leaf cells. Changes in expression of cell cycle related genes also indicated that SlTLFP8 affected cell size and stomatal density through endocycle transition. Despite changes in stomata density and transpiration, altering the expression of SlTLFP8 did not change photosynthesis. Additionally, biomass was not altered and there was little difference in fruit yield for transgenic and wild type lines under water-sufficient and water-deficient conditions. Our results demonstrate the effect of SlTLFP8 on endoreduplication and the potential of SlTLFP8 for improvement of WUE. BRIEF SUMMERY: This work found a new mechanism of TLP (Tubby like protein) response to water-deficient stress. SlTLFP8, a member of TLP family, regulates water-deficient resistance by modulating water loss via affecting stomatal density. Expression of SlTLFP8 was induced by osmotic stress. Transgenic tomato lines with SlTLFP8 overexpression or SlTLFP8 knockout showed significantly differences in water-use efficiency (WUE) and water-deficient resistance. The difference of leaf water loss caused by transpiration is the main explanation of the difference in WUE and water-deficient resistance. Additionally, overexpressing SlTLFP8 significantly decreased stomatal density, while SlTLFP8 knockout resulted in increased stomatal density, and SlTLFP8 affected stomatal density through endoreduplication and altered epidermal cell size. Despite changes in stomata density, altering the expression of SlTLFP8 did not result in distinct changes in photosynthesis, biomass and yield of tomato.


Assuntos
Endorreduplicação , Proteínas F-Box/fisiologia , Proteínas de Plantas/fisiologia , Estômatos de Plantas/anatomia & histologia , Transpiração Vegetal , Água/metabolismo , Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Tamanho Celular , Proteínas F-Box/metabolismo , Técnicas de Silenciamento de Genes , Lycopersicon esculentum/genética , Lycopersicon esculentum/fisiologia , Proteínas de Plantas/metabolismo , Estômatos de Plantas/fisiologia , Reação em Cadeia da Polimerase em Tempo Real
6.
Plant Physiol Biochem ; 154: 409-418, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32650255

RESUMO

The WRKY transcription factors (TFs) are involved in aluminum (Al) stress and jasmonic acid (JA)-regulated resistance responses. WRKYs act as regulators of Al-activated malate transporter (ALMT) proteins (anion channels) by directly binding to their promoters and altering malate efflux, thereby regulating Al ion toxicity in plant roots. JA enhances Al-induced root growth inhibition in Arabidopsis. However, the relationship between WRKY and ALMT genes and their involvement in JA-mediated root growth inhibition during Al stress in tomato remain unknown. Here, we demonstrate a similar phenomenon that JA enhances Al-induced root growth inhibition in tomato (Solanum lycopersicum). By analyzing RNA-seq data and tissue-specific expression data from public databases, we selected 17 WRKY and 6 ALMT family genes to identify the genes participated in this process. The promoters of many of the selected genes contained MeJA responsive element, G-box (target site of MYC2, a core TF of JA signaling), and W-box (target site for WRKY). Quantitative real-time PCR was performed to evaluate the expression levels of selected WRKY and ALMT genes under AlCl3 and Methyl jasmonate (MeJA) treatment. SlMYC2-VIGS seedlings and jasmonic acid-insensitive1 (jai1) mutant were also employed to analyze the expression patterns of selected genes. We find that SlALMT3 is responsible for the crosstalk regulatory mechanism between Al and JA in root growth inhibition, and 6 SlWRKYs may act as the upstream regulators of SlALMT3 in this crosstalk response. This study is initial and informative in exploring the crosstalk regulatory mechanism between JA and Al in tomato.


Assuntos
Alumínio/farmacologia , Ciclopentanos/farmacologia , Lycopersicon esculentum/crescimento & desenvolvimento , Oxilipinas/farmacologia , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Fatores de Transcrição/genética , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Raízes de Plantas/efeitos dos fármacos
7.
Materials (Basel) ; 13(5)2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32182744

RESUMO

This study aimed to investigate the shear capacity performance for eight deep beams with HTRB600 reinforced high strength concrete under concentrated load to enable a better understanding of the effects of shear span-depth ratio, longitudinal reinforcement ratio, vertical stirrup ratio and in order to improve design procedures. The dimension of eight test specimens is 1600 mm × 200 mm × 600 mm. The effective span to height ratio l0/h is 2.0, the shear span-depth ratio λ is 0.3, 0.6 and 0.9, respectively. In addition, the longitudinal reinforcement ratio ρs is set to 0.67%, 1.05%, 1.27%, and the vertical stirrup ratio is taken to be 0%, 0.25%, 0.33%, 0.5%. Through measuring the strain of steel bar, the strain of concrete and the deflection of mid-span, the characteristics of the full process of shear capacity, the failure mode and the load deflection deformation curve were examined. The test results showed that the failure mode of deep beams with small shear span-depth ratio is diagonal compression failure, which is influenced by the layout and quantity of web reinforcement. The diagonal compression failure could be classified into two forms: crushing-strut and diagonal splitting. With decreasing of shear span-depth ratio and increasing longitudinal reinforcement ratio, the shear capacity of deep beams increases obviously, while the influence of vertical web reinforcement ratio on shear capacity is negligible. Finally, the shear capacity of eight deep beams based on GB 50010-2010 is calculated and compared with the calculation results of ACI 318-14, EN 1992-1-1:2004 and CSA A23.3-04, which are based on strut-and-tie model. The obtained results in this paper show a very good agreement with GB50010-2010 and ACI 318-14, while the results of EN 1992-1-1:2004 and CSA A23.3-04 are approved to be conservative.

8.
Plant Cell Physiol ; 61(5): 909-921, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32065633

RESUMO

The SNAT enzyme participates in the biosynthesis of melatonin, which is reported to regulate thermotolerance in many plants. However, the mechanistic basis of this regulation remains unclear. In this study, we identified the SlSNAT gene, which is responsible for melatonin biosynthesis in tomato. SlSNAT expression levels were 3- and 5-fold higher in SlSNAT overexpression lines OX-2 and OX-6, respectively. The melatonin levels were 3- and 4-fold higher than those in wild type. The melatonin levels decreased by 50% when the expression of SlSNAT was downregulated to 40%. Overexpression of SlSNAT in tomato plants provided significantly enhanced thermotolerance with better growth performance in Photosystem II (PSII) maximum photochemical quantum yield (Fv/Fm) and alleviated heat injury. Both exogenous melatonin treatment and endogenous melatonin manipulation by SlSNAT overexpression decreased the levels of reactive oxygen species�accumulation and Fv/Fm. The SlSNAT overexpression line showed protected ribulose bisphosphate carboxylase oxygenase proteins and upregulated response of heat transcription factors and heat shock proteins under heat stress. HSP40, a DnaJ-type chaperone, was found to interact with SlSNAT in the chloroplast. Downregulation of HSP40 showed lower melatonin synthesis under heat stress. HSP40 functions as a chaperone to protect the SNAT enzyme during melatonin synthesis under heat stress. HSP40 interacted with SlSNAT and together participated in melatonin-related thermotolerance regulation in tomato.


Assuntos
Proteínas de Choque Térmico HSP40/metabolismo , Lycopersicon esculentum/fisiologia , Melatonina/biossíntese , Proteínas de Plantas/metabolismo , Termotolerância/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico HSP40/genética , Resposta ao Choque Térmico/genética , Lycopersicon esculentum/genética , Modelos Biológicos , Proteínas de Plantas/genética , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Termotolerância/genética
9.
Front Oncol ; 9: 1110, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31696058

RESUMO

Expression patterns of estrogen receptors [ERα, ERß, and G-protein associated ER (GPER)] in melanoma and skin may suggest their differential roles in carcinogenesis. Phytoestrogenic compound cyanidin-3-o-glucoside (C3G) has been shown to inhibit the growth and metastatic potential of melanoma, although the underlying molecular mechanism remains unclear. The aim of this study was to clarify the mechanism of action of C3G in melanoma in vitro and in vivo, as well as to characterize the functional expressions of ERs in melanoma. In normal skin or melanoma (n = 20/each), no ERα protein was detectable, whereas expression of ERß was high in skin but weak focal or negative in melanoma; and finally high expression of GPER in all skin vs. 50% melanoma tissues (10/20) was found. These results correspond with our analysis of the melanoma survival rates (SRs) from Human Protein Atlas and The Cancer Genome Atlas GDC (362 patients), where low ERß expression in melanoma correlate with a poor relapse-free survival, and no correlations were observed between SRs and ERα or GPER expression in melanoma. Furthermore, we demonstrated that C3G treatment arrested the cell cycle at the G2/M phase by targeting cyclin B1 (CCNB1) and promoted apoptosis via ERß in both mouse and human melanoma cell lines, and inhibited melanoma cell growth in vivo. Our study suggested that C3G elicits an agonistic effect toward ERß signaling enhancement, which may serve as a potential novel therapeutic and preventive approach for melanoma.

10.
Plant Sci ; 283: 385-395, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128709

RESUMO

High temperature is a major environmental factor affecting plant growth. Heat shock proteins (Hsps) are molecular chaperones that play important roles in improving plant thermotolerance during heat stress. Spinach (Spinacia oleracea) is very sensitive to high temperature; however, the specific function of Hsps in spinach is unclear. In this study, cytosolic heat shock 70 protein (SoHSC70), which was induced by heat stress, was cloned from spinach. Overexpressing SoHSC70 in spinach calli and Arabidopsis enhanced their thermotolerance. In contrast, spinach seedlings with silenced SoHSC70 by virus-induced gene silencing (VIGS) showed more sensitivity to heat stress. Further analysis revealed that overexpressing SoHSC70 altered relative electrical conductivity (REC), malondialdehyde (MDA) content, photosynthetic rate, reactive oxygen species (ROS) accumulation and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) after the heat treatment. Taken together, our results suggest that overexpressing SoHSC70 positively affects heat tolerance by reducing membrane damage and ROS accumulation and improving activities of antioxidant enzymes.


Assuntos
Antioxidantes/metabolismo , Membrana Celular/metabolismo , Proteínas de Choque Térmico/fisiologia , Proteínas de Plantas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Spinacia oleracea/metabolismo , Termotolerância , Arabidopsis , Membrana Celular/fisiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Malondialdeído/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Análise de Sequência de DNA , Spinacia oleracea/genética , Spinacia oleracea/fisiologia
11.
Plant Sci ; 280: 66-76, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30824030

RESUMO

Switchgrass (Panicum virgatum L.) is a bioenergy crop; thus, it is important to improve biomass to effectively produce bioethanol, particularly under adverse stress conditions. NAC transcription factors are involved in the abiotic stress response. PvNAC1 was isolated in the nucleus of switchgrass, with its C-terminal region containing a transcriptional activation domain. PvNAC1 expression was induced by dehydration, salt, H2O2, and abscisic acid treatments. Overexpressing (OE) PvNAC1 improved growth performance, leading to significantly taller and heavier (dry weight) plants. Moreover, cellulose content was significantly higher in OE plants, indicating that PvNAC1 plays an important role regulating growth and bioethanol production. PvNAC1 RNA interference (RNAi) switchgrass plants exhibited reduced dry weight and cellulose content. OE PvNAC1 enhanced tolerance to salt stress, through higher reactive oxygen species scavenging ability and less Na+ and more K+ accumulation in roots and shoots. RNAi plants were more sensitive to salt stress. The quantitative polymerase chain reaction results revealed that some stress responsive genes, three antioxidant enzymatic genes, and an ion homeostasis-related gene were upregulated in OE plants and downregulated in RNAi plants. These results show that PvNAC1 functions as a transcriptional activator in response to salt stress and growth.


Assuntos
Panicum/metabolismo , Sódio/metabolismo , Biomassa , Celulose/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal
12.
Plant Cell Physiol ; 60(3): 562-574, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30496548

RESUMO

Melatonin plays an important role in stress tolerance in plants. In this study, exogenous melatonin significantly alleviated the dwarf phenotype and inhibited the decrease of plant fresh weight induced by excess copper (Cu2+). Our results indicated that melatonin alleviated Cu2+ toxicity by improving Cu2+ sequestration, carbon metabolism and ROS (reactive oxygen species) scavenging, rather than by influencing the Cu2+ uptake under excess Cu2+ conditions. Transcriptome analysis showed that melatonin broadly altered gene expression under Cu2+ stress. Melatonin increased the levels of glutathione and phytochelatin to chelate excess Cu2+ and promoted cell wall trapping, thus keeping more Cu2+ in the cell wall and vacuole. Melatonin inhibited ROS production and enhanced antioxidant systems at the transcriptional level and enzyme activities, thus building a line of defense in response to excess Cu2+. The distribution of nutrient elements was recovered by melatonin which was disturbed by Cu2+. In addition, melatonin activated carbon metabolism, especially glycolysis and the pentose phosphate pathway, to generate more ATP, an intermediate for biosynthesis. Taken together, melatonin alleviated Cu2+ toxicity in cucumber via multiple mechanisms. These results will help to resolve the toxic effects of Cu2+ stress on plant growth and development. These results can be used for new strategies to solve problems associated with Cu2+ stress.


Assuntos
Cucumis sativus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peroxidação de Lipídeos/genética , Peroxidação de Lipídeos/fisiologia , Melatonina/metabolismo , Melatonina/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma/genética
13.
Sci Rep ; 8(1): 13349, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30190519

RESUMO

NACs are one of the largest transcription factor families in plants and are involved in the response to abiotic stress. BoNAC019, a homologue of AtNAC019, was isolated from cabbage (Brassica oleracea). BoNAC019 was localized in the nucleus and functioned as a transcriptional activator. The expression of BoNAC019 was induced by dehydration, salt, abscisic acid (ABA), and H2O2 treatments. BoNAC019 overexpressing plants were generated to explore the function of BoNAC019 in response to drought stress. Overexpression (OE) of BoNAC019 reduced drought tolerance with lower survival rate, higher water loss rate, lower proline content and ABA content. The seed germination and root length assays of BoNAC019-OE plants showed decreased sensitivity to ABA. Under drought condition, antioxidant enzymes and anthocyanin content decreased in BoNAC019 -OE plants, resulting in the accumulation of more reactive oxygen species (ROS), which cause damage to plants. Several stress-responsive genes, antioxidant enzymatic genes, anthocyanin biosynthetic genes and ABA signaling genes were down-regulated under drought condition while the ABA catabolism genes were induced in BoNAC019-OE plants under both normal and drought conditions. Our results demonstrated that BoNAC019 might participated in regulating drought tolerance by inducing ABA catabolism genes and decreasing ABA content.


Assuntos
Antocianinas , Arabidopsis , Brassica/genética , Proteínas de Plantas , Plantas Geneticamente Modificadas , Fatores de Transcrição , Antocianinas/biossíntese , Antocianinas/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Desidratação/genética , Desidratação/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Plant Physiol Biochem ; 130: 80-88, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29980096

RESUMO

Marine alginate-derived oligosaccharides (ADOs) are prepared from degraded alginate. Our experiments were carried out to determine the mechanism of ADOs to improve resistance to water stress in cucumber (Cucumis sativus L.). We evaluated the effects of ADOs on physiological indices, photosynthesis, reactive oxygen species (ROS) levels, antioxidant enzyme activities, and relative expression levels of drought resistance genes. The growth of drought stressed cucumber decreased markedly. However, treatment with ADOs significantly improved the diameter, fresh weight, photosynthetic rate, transpiration rate, stomatal conductance, maximum quantum yield of photosystem II (Fv/Fm) and chlorophyll degradation; thus, reversing the effects of drought stress. Moreover, the antioxidant levels and ROS scavenging enzyme activities also increased in response to the ADOs. Additionally, the genes involved in abscisic aid (ABA) signaling and the drought stress response, such as superoxide dismutase [Cu-Zn] (CsSOD(Cu-Zn)), the peroxidase superfamily protein (CsPOD3), ABA deficient 2 (CsABA2), responsive to ABA 18 (CsRAB18), abscisic acid insensitive 5 (CsABI5), responsive to dehydration 22 (CsRD22), and responsive to dehydration 29A (CsRD29A) were upregulated by ADOs. The ABA content was also improved by ADOs. Our results suggest that ADOs induced the expression of some antioxidant enzyme synthetic genes involved in the ABA signaling pathway by stimulating ABA synthesis to improve the drought resistance capacity in cucumber.


Assuntos
Alginatos/química , Cucumis sativus/efeitos dos fármacos , Oligossacarídeos/farmacologia , Água/metabolismo , Antioxidantes/metabolismo , Clorofila/fisiologia , Cucumis sativus/metabolismo , Fluorescência , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oligossacarídeos/química , Fotossíntese , Espécies Reativas de Oxigênio , Estresse Fisiológico
15.
Plant Cell Physiol ; 59(5): 930-945, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29415202

RESUMO

The NAC transcription factors play vital roles in responding to drought stress in plants; however, the molecular mechanisms remain largely unknown in cucumber. Suppression of CsATAF1 via RNA interference (RNAi) weakened drought stress tolerance in cucumber due to a higher water loss rate in leaves, a higher level of hydrogen peroxide (H2O2) and superoxide radicals (O2·-), increased malondialdehyde (MDA) content, lower Fv/Fm ratios and lower antioxidant enzyme activity. The analysis of root length and stomatal apertures showed that CsATAF1-RNAi cucumber plants were less responsive to ABA. In contrast, CsATAF1-overexpression (OE) plants showed increased drought stress tolerance and sensitivity to ABA. Quantitative PCR (qPCR) analysis showed that expression of several stress-responsive genes was significantly up-regulated in CsATAF1-OE transformants and down-regulated in CsATAF1-RNAi transformants. CsABI5, CsCu-ZnSOD and CsDREB2C were verified as direct target genes of CsATAF1. Yeast one-hybrid analysis and electrophoretic mobility shift assay (EMSA) further substantiated that CsATAF1 bound to the promoters of CsABI5, CsCu-ZnSOD and CsDREB2C. Transient expression in tobacco leaves and cucumber protoplasts showed that CsATAF1 directly up-regulated the expression of CsABI5, CsCu-ZnSOD and CsDREB2C. Our results demonstrated that CsATAF1 functioned as a positive regulator in response to drought stress by an ABA-dependent pathway and decreasing reactive oxygen species (ROS) accumulation in cucumber.


Assuntos
Ácido Abscísico/farmacologia , Adaptação Fisiológica , Cucumis sativus/fisiologia , Secas , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Adaptação Fisiológica/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Cucumis sativus/genética , Cucumis sativus/crescimento & desenvolvimento , Sequestradores de Radicais Livres/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Germinação/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transporte Proteico/efeitos dos fármacos , Interferência de RNA , Análise de Sequência de DNA , Estresse Fisiológico/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética
16.
Sci Rep ; 7(1): 503, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28356562

RESUMO

Seed germination is a critical and complex process in the plant life cycle. Although previous studies have found that melatonin can promote seed germination under salt stress, the involvement of melatonin in the regulation of proteomic changes remains poorly understood. In this study, a total of 157 proteins were significantly influenced (ratio ≥ 2 or ≤ -2) by melatonin during seed germination under salt stress using a label-free quantitative technique. Our GO analysis revealed that several pathways were obviously regulated by melatonin, including ribosome biosynthesis, lipid metabolism, carbohydrate metabolism, and storage protein degradation. Not only stress-tolerant proteins but also proteins that produce ATP as part of glycolysis, the citric acid cycle, and the glyoxylate cycle were upregulated by melatonin. Overall, this study provides new evidence that melatonin alleviates the inhibitory effects of NaCl stress on seed germination by promoting energy production. This study is the first to provide insights at the proteomic level into the molecular mechanism of melatonin in response to salt stress in cucumber seeds. This may be helpful to further understand the role of melatonin in cucumber seed germination under stress conditions.


Assuntos
Cucumis sativus/fisiologia , Metabolismo Energético , Germinação , Melatonina/metabolismo , Proteômica , Salinidade , Sementes/fisiologia , Estresse Fisiológico , Redes e Vias Metabólicas , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Proteômica/métodos
17.
Sci Rep ; 7: 41397, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28169290

RESUMO

Cellulose is the major component of cell wall materials. A 300 bp specific fragment from the cDNA fragment was chosen to insert into vector pFGC1008 at forward and reverse orientations to construct the recombinant RNAi vector. Knockdown of BoiCesA caused "dwarf" phenotype with smaller leaves and a loss of the content of cellulose. Moreover, RT-PCR analysis confirmed that the expression of the RNAi apparatus could repress expression of the CesA gene. Meanwhile, examination of the leaves from the T3 of RNAi transformants indicated reduction of cell expansion in vascular bundles, particularly on their abaxial surface. The proline and soluble sugar content increased contrarily. Under the salt stress, the T3 of RNAi plants showed significant higher resistance. The expression levels of some salt tolerance related genes (BoiProH, BoiPIP2;2, BoiPIP2;3) were significantly changed in T3 of RNAi plants. The results showed that the hairpin structure of CesA specific fragment inhibited the endogenous gene expression and it was proved that the cDNA fragment was relevant to the cellulose biosynthesis. Moreover, modulation cellulose synthesis probably was an important influencing factor in polysaccharide metabolism and adaptations of plants to stresses. This will provide technological possibilities for the further study of modulation of the cellulose content of crops.


Assuntos
Adaptação Fisiológica/genética , Brassica/enzimologia , Brassica/genética , Celulose/metabolismo , Técnicas de Silenciamento de Genes , Glucosiltransferases/genética , Folhas de Planta/anatomia & histologia , Cloreto de Sódio/farmacologia , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Aminoácidos , Brassica/efeitos dos fármacos , Brassica/fisiologia , Parede Celular/metabolismo , Clonagem Molecular , DNA Complementar/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Glucosiltransferases/química , Glucosiltransferases/metabolismo , Especificidade de Órgãos/genética , Pectinas/metabolismo , Fenótipo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/ultraestrutura , Plantas Geneticamente Modificadas , Prolina/metabolismo , Interferência de RNA , Análise de Sequência de DNA , Solubilidade , Açúcares/metabolismo , Transcrição Genética
18.
Front Plant Sci ; 8: 2156, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29410672

RESUMO

Aluminum (Al) is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104) was cloned from cabbage (Brassica oleracea). BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent cations lanthanum (La), cadmium (Cd), zinc (Zn), or copper (Cu). Subcellular localization studies were performed in onion epidermal cells and revealed that BoALMT1 was localized at the plasma membrane. Scanning Ion-selective Electrode Technique was used to analyze H+ flux. Xenopus oocytes and Arabidopsis thaliana expressing BoALMT1 excreted more H+ under Al treatment. Overexpressing BoALMT1 in transgenic Arabidopsis resulted in enhanced Al tolerance and increased malate secretion. The results suggested that BoALMT1 functions as an Al-resistant gene and encodes a malate transporter. Expressing BoALMT1 in Xenopus oocytes or A. thaliana indicated that BoALMT1 could increase malate secretion and H+ efflux to resist Al tolerance.

19.
Front Plant Sci ; 7: 1804, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27990149

RESUMO

Genistein (GNT), an isoflavone, is used in the clinical treatment of various health disorders. GNT is found in primary food source plants and some medical plants. However, studies on the functions of GNT in plants are rarely reported. In this study, we demonstrated that GNT plays an important role in promoting anthocyanin accumulation in red cabbage. GNT solutions (10, 20, 30, 40, and 50 mg/L) as foliar fertilizers were applied to red cabbage. Consequently, anthocyanin accumulation in red cabbage increased in a light-dependent manner. GNT solution at 30 mg/L exhibited the optimal effect on anthocyanin accumulation, which was twice that of the control. Quantitative real-time PCR analysis indicated that GNT application upregulated the expression of all structural genes, contributing to anthocyanin biosynthesis under light conditions. Under dark conditions, GNT exerted no significant promotive effect on anthocyanin accumulation; only early biosynthetic genes of anthocyanin biosynthesis responded to GNT. The promotive effect of GNT on anthocyanin biosynthesis is directly attributable to the regulation of structural gene expression. Transcription factors exhibited no response to GNT. The levels of anthocyanin in red cabbage positively correlated with the enzyme activities of antioxidant systems. This finding correlation suggested that the promotive effect of GNT on anthocyanin levels was correlated with improved antioxidant activity in the red cabbage.

20.
Oncotarget ; 7(42): 68864-68882, 2016 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-27655695

RESUMO

Anthocyanins have been shown to inhibit the growth and metastatic potential of breast cancer (BC) cells. However, the effects of individual anthocyanins on triple-negative breast cancer (TNBC) have not yet been studied. In this study, we found that cyanidin-3-o-glucoside (Cy-3-glu) preferentially promotes the apoptosis of TNBC cells, which co-express the estrogen receptor alpha 36 (ERα36) and the epidermal growth factor receptor (EGFR). We demonstrated that Cy-3-glu directly binds to the ligand-binding domain (LBD) of ERα36, inhibits EGFR/AKT signaling, and promotes EGFR degradation. We also confirmed the therapeutic efficacy of Cy-3-glu on TNBC in the xenograft mouse model. Our data indicates that Cy-3-glu could be a novel preventive/therapeutic agent against the TNBC co-expressed ERα36/EGFR.


Assuntos
Antocianinas/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptor alfa de Estrogênio/metabolismo , Glucosídeos/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antocianinas/química , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Microcirculação , Mitocôndrias/metabolismo , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Superóxido Dismutase/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo
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