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1.
J Agric Food Chem ; 67(32): 8905-8918, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31380641

RESUMO

NAC TFs play crucial roles in response to abiotic stresses in plants. Here, ZmNAC071 was identified as a nuclear located transcriptional repressor. Overexpression of ZmNAC071 in Arabidopsis enhanced sensitivity of transgenic plants to ABA and osmotic stress. The expression levels of SODs, PODs, P5CSs, and AtMYB61 were inhibited by ZmNAC071, which results in reduced ROS scavenging and proline content, increased ROS level, and water loss. Besides, the expression levels of some ABA or abiotic stress-related genes, like ABIs, RD29A, DREBs, and LEAs were also significantly inhibited by ZmNAC071. Yeast one-hybrid assay demonstrated that ZmNAC071 specifically bound to the cis-acting elements containing CGT[G/A] core sequences in the promoter of stress-related genes, suggesting that ZmNAC071 may participate in the regulation of transcription of these genes through recognizing the core sequences CGT[G/A]. These results will facilitate further studies concerning the cis-elements and downstream genes targeted by ZmNAC071 in maize.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Ácido Ascórbico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/fisiologia , Fatores de Transcrição/genética , Zea mays/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação para Baixo/efeitos dos fármacos , Pressão Osmótica , Plantas Geneticamente Modificadas/genética , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Fatores de Transcrição/metabolismo
2.
J Agric Food Chem ; 67(21): 5997-6006, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31056906

RESUMO

A fluoride export gene ( CsFEX) was newly found and isolated from Camellia sinensis, and its functions in detoxifying F were investigated in transgenic Escherichia coli and Arabidopsis thaliana. CsFEX contains two crcB domains, which is the typical structure in plants. The expression of CsFEX in C. sinensis is tissue-specific and related to maturity of leaves, and its expression is significantly induced by F treatments in different tissues of C. sinensis, particularly in leaves. Additionally, the growth of C. sinensis, E. coli, and A. thaliana can all be inhibited by F treatment. However, the growth of CsFEX-overexpression E. coli was increased with lower F content under F treatment compared to the control. Similarly, the germination and growth of CsFEX-overexpression A. thaliana were enhanced with lower F content under F treatment compared to the wild type. CsFEX relieves F toxicity in the transgenic E. coli and A. thaliana by alleviating F accumulation.


Assuntos
Arabidopsis/metabolismo , Camellia sinensis/genética , Escherichia coli/metabolismo , Fluoretos/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Transporte Biológico , Camellia sinensis/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fluoretos/toxicidade , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética
3.
Molecules ; 24(8)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027270

RESUMO

The use of natural products that can serve as natural herbicides and insecticides is a promising direction because of their greater safety for humans and environment. Secondary metabolites of plants that are toxic to plants and insects-allelochemicals-can be used as such products. Woody plants can produce allelochemicals, but they are studied much less than herbaceous species. Meanwhile, there is a problem of interaction of woody species with neighboring plants in the process of introduction or invasion, co-cultivation with agricultural crops (agroforestry) or in plantation forestry (multiclonal or multispecies plantations). This review describes woody plants with the greatest allelopathic potential, allelochemicals derived from them, and the prospects for their use as biopesticides. In addition, the achievement of and the prospects for the use of biotechnology methods in relation to the allelopathy of woody plants are presented and discussed.


Assuntos
Herbicidas/farmacologia , Árvores/efeitos dos fármacos , Produtos Biológicos/química , Plantas Geneticamente Modificadas/efeitos dos fármacos
4.
Plant Physiol Biochem ; 139: 435-445, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30999131

RESUMO

Recent years have witnessed a renewed interest in introns as a tool to increase gene expression. We previously isolated TdSHN1 gene encoding a transcription factor in durum wheat. Here we show that TdSHN1 intron contains many CT-stretches and the motif CGATT known to be important for IME. When subjected to bioinformatics analysis using IMEter software, TdSHN1 intron obtained a score of 17.04 which indicates that it can moderately enhance gene expression. TdSHN1 gene including its intron was placed under the control of TdSHN1 endogenous salt and drought-inducible promoter or the constitutive 35S promoter and transferred into tobacco. Transgenic lines were obtained and designated gD (with 35S promoter) and PI (with native promoter). A third construct was also used in which intron-less cDNA was driven by the 35S promoter (cD lines). Results showed that, gD lines exhibited lower stomatal density than cD lines. When subjected to drought and salt stresses, gD lines outperformed intron-less cD lines and WT. Indeed, gD lines exhibited longer roots, higher biomass production, retained more chlorophyll, produced less ROS and MDA and had higher antioxidant activity. qRT-PCR analysis revealed that gD lines had higher TdSHN1 expression levels than cD lines. In addition, expression of ROS-scavengering, stress-related and wax biosynthesis tobacco genes was higher in gD lines compared to cD lines and WT. Interestingly, under stress conditions, PI transgenic lines showed higher TdSHN1 expression levels and outperformed gD lines. These results suggest that TdSHN1 intron enhances gene expression when used alone or in combination with TdSHN1 endogenous promoter.


Assuntos
Íntrons/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Tabaco/genética , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Tabaco/efeitos dos fármacos , Tabaco/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Plant Cell Rep ; 38(6): 731-739, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30903268

RESUMO

KEY MESSAGE: OsIAAGLU could catalyze the reaction of IAA with glucose to generate IAA-glucose. Overexpression of OsIAAGLU in rice resulted in altered rice shoot architecture and root gravitropism. The distribution and levels of indole-3-acetic acid (IAA) within plant tissues are well known to play vital roles in plant growth and development. An important mechanism of regulating free IAA levels in monocots is formation of IAA ester conjugates. In this study, a cytosol-localized protein encoded by the rice gene of indole-3-acetic acid glucosyltransferase (OsIAAGLU) was found to catalyze the reaction of free IAA with glucose to generate IAA-glucose. Expression of OsIAAGLU could be induced by IAA and NAA. The number of tillers and leaf angle was significantly increased with a concomitant decrease in plant height and panicle length in the transgenic rice lines overexpressing OsIAAGLU compared to the wild-type (WT) plants. Phenotypes of iaaglu mutants constructed using the CRISPR/Cas9 system had no obvious differences with WT plants. Furthermore, overexpression of OsIAAGLU resulted in reduced sensitivity to IAA/NAA and altered gravitropic response of the roots in the transgenic plants. Free IAA contents in the leaves, root tips, and lamina joint of OsIAAGLU-overexpressing transgenic lines were lower than those of WT plants. These results support that OsIAAGLU could play a regulatory role in IAA homeostasis and rice architecture.


Assuntos
Glucose/química , Glucose/farmacologia , Ácidos Indolacéticos/química , Ácidos Indolacéticos/farmacologia , Oryza/efeitos dos fármacos , Oryza/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética
6.
Plant Physiol Biochem ; 139: 239-245, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30921735

RESUMO

Abscisic acid (ABA) is the key hormone that regulating plant responses to abiotic stresses. Several basic helix-loop-helix (bHLH) transcription factors have been reported to regulate ABA signaling in Arabidopsis. Paclobutrazol Resistances (PREs) are non-DNA binding bHLH transcription factors involved in the regulation of plant response to several different plant hormones including gibberellin, brassinosteroid and auxin. Here, we show that PREs are involved in the regulation of ABA and salt responses in Arabidopsis. Quantitative RT-PCR results showed that the expression levels of PRE6 as well as several other PRE genes were reduced in response to ABA treatment, but increased to salt treatment. Seed germination assays indicated that ABA sensitivity is reduced in the pre6 mutants, but increased in transgenic plants overexpressing PRE6. On the other hand, the 35S:PRE6 transgenic plants showed enhanced tolerance to salt, whereas little, if any changes were observed in the pre6 mutants. Similar responses to ABA and salt treatments were observed in the pre2 mutants and the transgenic plants overexpressing PRE2, and a slight increased resistance to ABA in seed germination was observed in the pre2 pre6 double mutants. Taken together, our results suggest that at least some of the PRE genes are ABA responsive genes, and PREs may function redundantly to regulate ABA and salt responses in Arabidopsis.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cloreto de Sódio/farmacologia , Triazóis/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/efeitos dos fármacos
7.
Phytopathology ; 109(7): 1257-1269, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30920357

RESUMO

Ubiquitin (Ub) extension proteins (UEPs) are fusion proteins of a Ub at the N terminus to a ribosomal protein. They are the main source of Ub and the only source of extension ribosomal protein. Although important roles of the Ub-26S proteasome system in various biological processes have been well established, direct evidence for the role of UEP genes in plant defense is rarely reported. In this study, we cloned a Ub-S27a-type UEP gene (NbUEP1) from Nicotiana benthamiana and demonstrated its function in cell death and disease resistance. Virus-induced gene silencing of NbUEP1 led to intensive cell death, culminating in whole-seedling withering. Transient RNA interference (RNAi) of NbUEP1 caused strong cell death in infiltrated areas, while stable NbUEP1-RNAi tobacco plants constitutively formed necrotic lesions in leaves. NbUEP1-RNAi plants exhibited increased resistance to the oomycete Pythium aphanidermatum and viruses Tobacco mosaic virus and Cucumber mosaic virus while displaying decreased resistance to the nematode Meloidogyne incognita compared with non-RNAi control plants. Transcription profiling analysis indicated that jasmonate and ethylene pathways, lipid metabolism, copper amine oxidase-mediated active species generation, glycine-rich proteins, vacuolar processing enzyme- and RD21-mediated cell death and defense regulation, and autophagy might be associated with NbUEP1-mediated cell death and resistance. Our results provided evidence for the important roles of plant UEPs in modulating plant cell death and disease resistance.


Assuntos
Doenças das Plantas/microbiologia , Proteínas de Plantas , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Tabaco , Animais , Morte Celular , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Tabaco/crescimento & desenvolvimento , Ubiquitinas
8.
Plant Sci ; 280: 164-174, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30823994

RESUMO

MADS-box family transcription factors play essential roles in the growth and development of plants, and some MADS-box genes have also been found to participate in the stress-response. At present, little information regarding stress-related MADS-box genes is available in pepper. We isolated a MADS-box transcription factor gene from Capsicum annuum, which we named CaMADS. CaMADS expression is induced by low and high temperature, salt, and osmotic stress, and also by abscisic acid (ABA), salicylic acid (SA), methyl-jasmonic acid (MeJA), and CaCl2. To understand the function of CaMADS in the abiotic stress response, we generated pepper plants in which CaMADS expression was down-regulated using VIGS (Virus-induced Gene Silencing), and also transgenic Arabidopsis plants overexpressing CaMADS. We found that CaMADS-down-regulated seedlings were more seriously injured than WT after cold, NaCl, and mannitol treatment, and showed increased electrolyte leakage, malondialdehyde (MDA) levels, and lower chlorophyll content. CaMADS-overexpressing Arabidopsis plants were more tolerant to these stresses than WT, and showed significantly high survival rates and lower H2O2 and super oxide radical contents after cold treatment. CaMADS-overexpressing plants had higher germination rates and percentages of green cotyledons following NaCl and mannitol treatment. Root lengths and fresh weight in CaMADS-overexpressing plants were also significantly longer and higher, respectively, than in WT plants. Taken together, our results suggest that CaMADS functions as a positive stress-responsive transcription factor in the cold, salt, and osmotic stress signaling pathways.


Assuntos
Capsicum/efeitos dos fármacos , Capsicum/metabolismo , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Capsicum/genética , Temperatura Baixa , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Pressão Osmótica/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/fisiologia , Fatores de Transcrição/genética
9.
Plant Sci ; 281: 1-8, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824042

RESUMO

Transcription factor (TF) genes play a critical role in plant abiotic and biotic stress responses. In this study, we cloned a poplar TF NAC13 gene (Potri.001G404100.1), which is significantly up-regulated to salt stress. Then we developed gene overexpression and antisense suppression constructions driven by CaMV35S, and successfully transferred them to a poplar variety 84 K (Populus alba × P. glandulosa), respectively. Evidence from molecular assay indicated that NAC13 overexpression and antisense suppression fragments have been integrated into the poplar genome. The morphological and physiological characterization and salt treatment results indicated the NAC13-overexpressing transgenic plants enhance salt tolerance significantly, compared to wide type. In contrast, the NAC13-suppressing transgenic plants are significantly sensitive to salt stress, compared to wide type. Evidence from transgenic Arabidopsis expressing GUS gene indicated that the gene driven by NAC13 promoter is mainly expressed in the roots and leaves of young plants. These studies indicate that the NAC13 gene plays a vital role in salt stress response.


Assuntos
Proteínas de Plantas/metabolismo , Populus/metabolismo , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Populus/efeitos dos fármacos , Populus/genética , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Cloreto de Sódio/farmacologia , Fatores de Transcrição/genética
10.
Plant Sci ; 281: 113-121, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824044

RESUMO

As an essential regulatory process of post-translational modifications, Sumoylation has been shown to play a central role in stress responses in higher plants. However, the mechanisms underlying the involvement of the Sumoylation in stress responses in crops are largely unknown. In this study, a putative SUMO conjugating enzyme ortholog from Zea mays (ZmSCE1e) was isolated. Sequence alignments and phylogenetic analysis showed that ZmSCE1e possesses a central active domain similar to known SCE1 proteins, but is the cereal-specific isoform.The transcript levels of ZmSCE1e were markedly up-regulated by salt or drought stress. Over-expression of ZmSCE1e in tobacco plants increased levels of SUMO conjugates and enhanced their tolerances to salt and drought stresses. ZmSCE1e-transgenic plants showed higher activities of key antioxidant enzymes but lower hydrogen peroxide (H2O2) and malondialdehyde (MDA) accumulations under salt or drought stress. Furthermore, expression of several stress defense genes was significantly elevated as revealed by qPCR in the ZmSCE1e-transgenic lines. Together, these data have demonstrated that ZmSCE1e improved salt and drought tolerance likely by modulating Sumoylation levels, antioxidant capability, and stress defense gene expression in transgenic plants. This study may facilitate our understanding of the biological roles of SCE-mediated Sumoylation under stress conditions in higher plants and accelerate genetic improvement of crop plants tolerant to environmental stresses.


Assuntos
Secas , Tabaco/efeitos dos fármacos , Tabaco/metabolismo , Zea mays/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Cloreto de Sódio/farmacologia , Sumoilação/efeitos dos fármacos , Sumoilação/genética , Tabaco/genética , Zea mays/genética
11.
Plant Sci ; 281: 213-222, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824054

RESUMO

Eukaryotic nucleases are involved in processes such as DNA restriction digestion, repair, recombination, transposition, and programmed cell death (PCD). Studies on the role of nucleases have mostly focused on PCD during plant development, while the information on nucleases involved in responses to different abiotic stress conditions remains limited. Here, we identified a Ca2+-dependent nuclease, AtCaN2, in Arabidopsis thaliana and characterized its activity, expression patterns, and involvement in plant responses to salt stress. AtCaN2 showed a dual endonuclease and exonuclease activity, being able to degrade circular plasmids, RNA, single-stranded DNA, and double-stranded DNA. Expression analysis showed that AtCaN2 was strongly induced in senescent siliques and by salt stress. Overexpression of AtCaN2 decreased the plant tolerance to salt stress conditions, leading to an excessive H2O2 accumulation. However, an atcan2 mutant showed better tolerance to salt stress and a lower level of H2O2 accumulation. Moreover, the expression of several genes (AtAPX1, AtGPX8, and AtSOD1), encoding reactive oxygen species-scavenging enzymes (ascorbate peroxidase 1, glutathione peroxidase 8, and superoxide dismutase 1, respectively), was highly induced in the atcan2 mutant under salt stress conditions. In addition, salt-stress-induced cell death was increased in the AtCaN2-overexpressing transgenic plant but decreased in the atcan2 mutant. On the basis of these findings, we conclude that AtCaN2 plays a negative role in plant tolerance to salt stress. A AtCaN2 knock out could reduce ROS accumulation, decrease ROS-induced PCD, and improve overall plant tolerance.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Endonucleases/genética , Endonucleases/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Peróxido de Hidrogênio/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/genética
12.
Planta ; 249(5): 1521-1533, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30712129

RESUMO

MAIN CONCLUSION: OsbZIP42 is a positive regulator of ABA signaling and drought stress tolerance. The activation of OsbZIP42 depends on stress-/ABA-activated protein kinase 4 (SAPK4) and an additional ABA-dependent modification of OsbZIP42. Basic leucine zipper transcription factors (bZIP TFs) play important roles in the ABA signaling pathway in plants. Rice OsbZIP42 is a member of the group E bZIP, which is an ortholog of Arabidopsis group A bZIP. This latter group includes abscisic acid-responsive element (ABRE)-binding factors (ABFs) involved in abiotic stress tolerance. The expression of OsbZIP42 was induced by ABA treatment, although it was not induced by drought and salt stresses. Unlike other bZIP TFs, OsbZIP42 contained two transcriptional activation domains. Although the full-length OsbZIP42 protein did not, the N-terminus of the protein interacted with SAPK4. Our results suggest that the activation of OsbZIP42 by SAPK4 requires another ABA-dependent modification of OsbZIP42. Transgenic rice overexpressing OsbZIP42 (OsbZIP42-OX) exhibited a rapidly elevated expression of the ABA-responsive LEA3 and Rab16 genes and was hypersensitive to ABA. Analyses of the OsbZIP42-OX plants revealed enhanced tolerance to drought stress. These results suggest that OsbZIP42 is a positive regulator of ABA signaling and drought stress tolerance depending on its activation, which is followed by an additional ABA-dependent modification. We propose that OsbZIP42 is an important player in rice for conferring ABA-dependent drought tolerance.


Assuntos
Ácido Abscísico/farmacologia , Oryza/efeitos dos fármacos , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
13.
J Agric Food Chem ; 67(5): 1443-1452, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30653319

RESUMO

Dicamba, a broad-spectrum and highly efficient herbicide, is an excellent target herbicide for the engineering of herbicide-resistant crops. In this study, a new tetrahydrofolate (THF)-dependent dicamba methyltransferase gene, dmt50, was cloned from the dicamba-degrading strain Rhizorhabdus dicambivorans Ndbn-20. Dmt50 catalyzed the methyl transfer from dicamba to THF, generating the herbicidally inactive product 3,6-dichlorosalicylic acid (3,6-DCSA) and 5-methyl-THF. A dmt50 transgenic Arabidopsis thaliana clearly showed dicamba resistance (560 g/ha, the normal field application rate). However, Dmt50 demethylation activity was inhibited by the product 5-methyl-THF. Mthfr66, encoded by the 5,10-methylene-THF reductase gene mthfr66 could relieve the inhibition by removing 5-methyl-THF in vitro. Compared with expression of dmt50 alone, simultaneous expression of dmt50 and mthfr66 further improved the dicamba resistance (1120 g/ha) of transgenic A. thaliana. This study provides new genes for dicamba detoxification and a strategy for the engineering of dicamba-resistant crops.


Assuntos
Arabidopsis/efeitos dos fármacos , Proteínas de Bactérias/genética , Dicamba/farmacologia , Resistência a Herbicidas , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metiltransferases/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Sphingomonadaceae/enzimologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Bactérias/metabolismo , Herbicidas/farmacologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Metiltransferases/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Sphingomonadaceae/genética
14.
BMC Plant Biol ; 19(1): 17, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30626336

RESUMO

BACKGROUND: Despite increasing characterization of DEAD-box RNA helicases (RHs) in chloroplast gene expression regulation at posttranscriptional levels in plants, their functional roles in growth responses of crops, including rice (Oryza sativa), to abiotic stresses are yet to be characterized. In this study, rice OsRH58 (LOC_Os01g73900), a chloroplast-localized DEAD-box RH, was characterized for its expression patterns upon stress treatment and its functional roles using transgenic Arabidopsis plants under normal and abiotic stress conditions. RESULTS: Chloroplast localization of OsRH58 was confirmed by analyzing the expression of OsRH58-GFP fusion proteins in tobacco leaves. Expression of OsRH58 in rice was up-regulated by salt, drought, or heat stress, whereas its expression was decreased by cold, UV, or ABA treatment. The OsRH58-expressing Arabidopsis plants were taller and had more seeds than the wild type under favorable conditions. The transgenic plants displayed faster seed germination, better seedling growth, and a higher survival rate than the wild type under high salt or drought stress. Importantly, levels of several chloroplast proteins were increased in the transgenic plants under salt or dehydration stress. Notably, OsRH58 harbored RNA chaperone activity. CONCLUSIONS: These findings suggest that the chloroplast-transported OsRH58 possessing RNA chaperone activity confers stress tolerance by increasing translation of chloroplast mRNAs.


Assuntos
Arabidopsis/metabolismo , Cloroplastos/metabolismo , RNA Helicases DEAD-box/metabolismo , Secas , Oryza/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Cloreto de Sódio/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cloroplastos/efeitos dos fármacos , Cloroplastos/genética , RNA Helicases DEAD-box/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Estresse Fisiológico
15.
Transgenic Res ; 28(2): 165-176, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30656492

RESUMO

Wheat is the most widely grown cereal grain, occupying a significant portion of the total cultivated land. As drought is the major environmental stressor affecting crop production, yield maintenance under water deficit conditions appears as a highly desirable phenotype for crop improvement. The HaHB4 (Helianthus annuus homeobox 4) gene from sunflower encodes for a transcription factor involved in tolerance to environmental stress. The introduction of HaHB4 in wheat led to the development of event IND-ØØ412-7 (HB4® wheat), which displayed higher yield in production environments of low productivity potential. Compositional analysis of IND-ØØ412-7 wheat, including 41 nutrients and 2 anti-nutrients for grain and 10 nutrients in forage, was performed. Results of these studies indicated that IND-ØØ412-7 is compositionally equivalent to non-transgenic wheat.


Assuntos
Aminobutiratos/farmacologia , Lipídeos/análise , Metaboloma/efeitos dos fármacos , Plantas Geneticamente Modificadas/metabolismo , Triticum/metabolismo , Herbicidas/farmacologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Triticum/efeitos dos fármacos , Triticum/genética
16.
Ecotoxicol Environ Saf ; 168: 230-240, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30388541

RESUMO

Cadmium (Cd) induces cell death in plant roots. Mitogen-activated protein kinase (MAPK) plays a role in the regulation of cell death induced by Cd in plant roots. In this study, MhMAPK4 was isolated from the roots of Malus hupehensis. Subcellular localization showed that the MhMAPK4 protein was located in the cell membrane and cytoplasm and is a transmembrane protein that is characterized by hydrophily. The expression of MhMAPK4 in the roots of M. hupehensis was up-regulated by Cd sulfate and Cd chloride. Phenotypic comparison under Cd stress showed that the growth of wild-type (WT) tobacco was lower than the transgenic lines overexpressing MhMAPK4. The fresh weight and the root length of WT also was lower than that of the transgenic tobacco. The net Cd2+ influx in the tobacco roots was decreased by the overexpression of MhMAPK4, as was root Cd accumulation. The recovery time of the Cd2+ influx to stable state in the transgenic tobacco was also shorter than the WT. The expression of iron-regulated transporter 1 (NtIRT1) and natural resistance associated macrophage protein 5 (NtNRAMP5) was relatively low in the transgenic lines under Cd stress. Cell death and apoptosis in the tobacco roots was reduced following the overexpression of MhMAPK4. The activity of vacuolar processing enzyme (VPE) and the transcript level of VPE in the transgenic tobacco was lower than that of WT under Cd stress. In addition, the electrolyte leakage and malondialdehyde and hydrogen peroxide contents in the transgenic tobacco were lower than those of WT, whereas the antioxidant enzyme activity and expression were higher. These results suggest that MhMAPK4 regulates Cd accumulation by mediating Cd2+ uptake by the roots, and controls Cd-caused cell death by adjusting VPE activity.


Assuntos
Cádmio/toxicidade , Morte Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Malus/enzimologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Sequência de Aminoácidos , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Clonagem Molecular , MAP Quinases Reguladas por Sinal Extracelular/genética , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Malus/genética , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Tabaco/metabolismo
17.
Chemosphere ; 214: 371-378, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30267910

RESUMO

Parasitoids acting as biocontrol agents provide farmers with valuable ecosystem services, but are sensitive to insecticides applied against pests. Besides lethal effects of insecticides, sublethal effects observed among survivors may further influence parasitoids' performance. However, information on sublethal effects is scattered across case studies, without a quantitative synthesis and evaluation of generality of respective data. We conducted an analysis of 85 primary empirical datasets to quantify sublethal effects of insecticide application on two key parameters of parasitoid fitness, offspring production and proportion of females among offspring (i.e. sex ratio). To create a direct link to existing agricultural practices, we primarily focused on studies in which parasitoids were exposed to field-recommended concentrations of insecticides. Insecticide-exposed females produced substantially fewer and more male-biased offspring, accounting for an average of about 28% cumulative loss in parasitoid reproductive capacity per generation. The magnitude of sublethal effects was significantly affected by insecticide mode of action, with broad-spectrum insecticides being particularly harmful to parasitoid reproductive performance. Transgenic crops and toxins derived from such plants were generally associated with weaker sublethal effects than majority of synthetic insecticides. Nevertheless, species responses, even to the same insecticides and transgenic crops, showed high variability, cautioning against extrapolating results from individual studies to a wider range of species. Overall, our results indicate that sublethal side-effects on parasitoid reproductive performance represent a significant and widespread cost of insecticides that should explicitly be taken into account when evaluating their harmfulness. Linking laboratory results to field situations remains a key challenge for future research.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Interações Hospedeiro-Parasita/efeitos dos fármacos , Himenópteros/crescimento & desenvolvimento , Inseticidas/toxicidade , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Reprodução , Animais , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/parasitologia , Feminino , Himenópteros/efeitos dos fármacos , Dose Letal Mediana , Masculino , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/parasitologia , Fatores Sexuais
18.
Ecotoxicol Environ Saf ; 170: 627-634, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30579163

RESUMO

Bisphenol A (BPA) is an estrogenic endocrine disruptor which disturbs a normal animal development. We generated an indicator plant that senses and provides a clear visual indicator of an estrogen-like compound BPA in the environment. We developed transgenic Arabidopsis lines expressing a construct designed to synthesize anthocyanin (thus showing a red color) in response to BPA. We transformed Arabidopsis with a recombinant vector containing the chimeric estrogen receptor (XVE region), LAP and coding region of PtrMYB119 (transcription factor involved in anthocyanin biosynthesis in poplar and Arabidopsis). Upon binding of the estrogen compound to the ligand-binding domain of E (estrogen receptor) in XVE, the XV domain binds to LAP promoter and triggering the transcription of PtrMYB119 with a subsequent enhancement of anthocyanin biosynthetic gene expression, resulting in anthocyanin synthesis. The leaves of the transgenic Arabidopsis line XVE-PtrMYB119 turned red in the presence of 10 ppm BPA. The transcript level of PtrMYB119 peaked at day 3 of BPA exposure, then decreased to its minimal level at day 5. Similar expression patterns to that of PtrMYB119 were detected for genes encoding the anthocyanin biosynthetic enzymes chalcone synthase, chalcone flavanone isomerase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, anthocyanidin synthase, and UFGT (UGT78D2). The leaves of transgenic plants did not turn red in response to BPA at concentrations below 10 ppm, but PtrMYB119 expression was induced by BPA at concentrations as low as 1 ppt BPA. Since this transgenic plant turns red in the presence of BPA without any experimental procedures, this line can be easily used by non-scientists.


Assuntos
Antocianinas/biossíntese , Arabidopsis/efeitos dos fármacos , Compostos Benzidrílicos/análise , Técnicas Biossensoriais/métodos , Disruptores Endócrinos/análise , Fenóis/análise , Plantas Geneticamente Modificadas/efeitos dos fármacos , Antocianinas/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Compostos Benzidrílicos/toxicidade , Colorimetria/métodos , Disruptores Endócrinos/toxicidade , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fenóis/toxicidade , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/genética
19.
Acta Biol Hung ; 69(4): 464-480, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30587018

RESUMO

We aimed to examine the response of three tomato introgression lines (IL925.3, IL925.5 and IL925.6) to NaCl stress. These lines originated from a cross between M82 (Solanum lycopersicum) and the wild salttolerant tomato Solanum pennellii, each line containing a different fragment of the S.pennellii genome. Salt-sensitive phenotypes related to plant growth and physiology, and the response of antioxidants, pigments and antioxidant enzymes were measured. In general, salt stress decreased the fresh weight of leaves, leaf area and leaf number and an increase of Na+ accumulation in aerial parts was observed, which caused a reduction in the absorption of K+ and Ca2+. Salt stress also induced a decrease in chlorophyll, carotenoids and lipid peroxidation (MDA) and an increase in anthocyanins and reduced ascorbate, although some differences were seen between the lines, for example for carotenoid levels. Guaiacol peroxidase, catalase and glutathione reductase activity enhanced in aerial parts of the lines, but again some differences were seen between the three lines. It is concluded that IL925.5 might be the most sensitive line to salt stress as its dry weight loss was the greatest in response to salt and this line showed the highest Na+ ion accumulation in leaves.


Assuntos
Lycopersicon esculentum/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Tolerância ao Sal , Cloreto de Sódio/farmacologia , Antocianinas/metabolismo , Ácido Ascórbico/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Cruzamentos Genéticos , Enzimas/metabolismo , Genótipo , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Cloreto de Sódio/metabolismo
20.
Int J Mol Sci ; 20(1)2018 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-30583543

RESUMO

SBP-box (Squamosa-promoter binding protein) genes are a type of plant-specific transcription factor and play important roles in plant growth, signal transduction and stress response. However, little is known about the SBP-box genes in pepper (CaSBP), especially in the process of Phytophthora capsici infection. In this study, a novel gene (CaSBP12) was selected from the CaSBP gene family, which was isolated from the pepper genome database in our previous study. The CaSBP12 gene was located in the nucleus of the cell and its silencing in the pepper plant enhanced the defense response against Phytophthora capsici infection. After inoculation with Phytophthora capsici, the root activity of the CaSBP12-silenced plants is compared to control plants, while malondialdehyde (MDA) content is compared viceversa. Additionally, the expression of defense related genes (CaPO1, CaSAR8.2, CaBPR1, and CaDEF1) in the silenced plants were induced to different degrees and the peak of CaSAR8.2 and CaBPR1 were higher than that of CaDEF1. The CaSBP12 over-expressed Nicotiana benthamiana plants were more susceptible to Phytophthora capsici infection with higher EC (electrical conductivity) and MDA contents as compared to the wild-type. The relative expression of defense related genes (NbDEF, NbNPR1, NbPR1a, and NbPR1b) in transgenic and wild-type Nicotiana benthamiana plants were induced, especially the NbPR1a and NbPR1b. In conclusion, these results indicate that CaSBP12 gene negative regulates the defense response against Phytophthora capsici infection which suggests their potentially significant role in plant defense. To our knowledge, this is the first report on CaSBP gene which negative regulate defense response.


Assuntos
Capsicum/fisiologia , Resistência à Doença/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Phytophthora/patogenicidade , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Fatores de Transcrição/metabolismo , Acetatos/farmacologia , Capsicum/efeitos dos fármacos , Capsicum/genética , Ciclopentanos/farmacologia , Resistência à Doença/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oxilipinas/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/parasitologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Ácido Salicílico/farmacologia , Fatores de Transcrição/genética
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