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1.
Plant Sci ; 286: 28-36, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300139

RESUMO

MYB family genes act as important regulators modulating the response to abiotic stress in plants. However, much less is known about MYB proteins in cotton. Here, we found that a cotton MYB gene, GhMYB73, was induced by NaCl and abscisic acid (ABA). Silencing GhMYB73 expression in cotton increased sensitivity to salt stress. The cotyledon greening rate of Arabidopsis thaliana over-expressing GhMYB73 under NaCl or mannitol treatment was significantly enhanced during the seedling germination stage. What's more, several osmotic stress-induced genes, such as AtNHX1, AtSOS3 and AtP5CS1, were more highly induced in the over-expression lines than in wild type under salt treatment, supporting the hypothesis that GhMYB73 contributes to salinity tolerance by improving osmotic stress resistance. Arabidopsis lines over-expressing GhMYB73 had superior germination and cotyledon greening under ABA treatment, and some abiotic stress-induced genes involved in ABA pathways (AtPYL8, AtABF3, AtRD29B and AtABI5), had increased transcription levels under salt-stress conditions in these lines. Furthermore, we found that GhMYB73 physically interacts with GhPYL8 and AtPYL8, suggesting that GhMYB73 regulates ABA signaling during salinity stress response. Taken together, over-expression of GhMYB73 significantly increases tolerance to salt and ABA stress, indicating that it can potentially be used in transgenic technology approaches to improve cotton salt tolerance.


Assuntos
Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Gossypium/fisiologia , Proteínas de Plantas/genética , Estresse Salino/genética , Fatores de Transcrição/genética , Arabidopsis/genética , Inativação Gênica , Genes myb , Gossypium/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Fatores de Transcrição/metabolismo
2.
Gene ; 713: 143976, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306715

RESUMO

Naturally evolved saline tolerant rice landraces found along the coastline of India are a valuable genomic resource to explore the complex, polygenic nature of salinity tolerance. In the present study, a set of 28 genome wide SSR markers, 11 salt responsive genic SSR markers and 8 Saltol QTL linked SSR markers were used to estimate genetic relatedness and population structure within a collection of 47 rice landraces (including a tolerant and 2 sensitive checks) originating from geographically divergent coastal regions of India. All three marker types identified substantial genetic variation among the landraces, as evident from their higher PIC values (0.53 for genomic SSRs, 0.43 for Genic SSRs and 0.59 for Saltol SSRs). The markers RM431, RM484 (Genomic SSRs), OsCAX (D), OsCAX (T) (Genic SSRs) and RM562 (Saltol SSR) were identified as good candidates to be used in breeding programs for improving salinity tolerance in rice. STRUCTURE analysis divided the landraces into five distinct populations, with classification correlating with their geographical locations. Principal coordinate and hierarchical cluster analyses (UPGMA and neighbor joining) are in close agreement with STRUCTURE results. AMOVA analysis indicated a higher magnitude of genetic differentiation within individuals of groups (58%), than among groups (42%). We also report the development and validation of a new Cleavage Amplified Polymorphic Sequence (CAPS) marker (OsHKT1;5V395) that targets a codon in the sodium transporter gene OsHKT1;5 (Saltol/SKC1 locus) that is associated with sodium transport rates in the above rice landraces. The CAPS marker was found to be present in all landraces except in IR29, Kamini, Gheus, Matla 1 and Matla 2. Significant molecular genetic diversity established among the analyzed salt tolerant rice landraces will aid in future association mapping; the CAPS marker, OsHKT1;5V395 can be used to map rice landraces for the presence of the SNP (Single Nucleotide Polymorphism) associated with increased sodium transport rates and concomitant salinity tolerance in rice.


Assuntos
Marcadores Genéticos , Variação Genética , Repetições de Microssatélites , Oryza/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Sódio/metabolismo , Genótipo , Filogenia
3.
J Plant Physiol ; 239: 38-51, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31181407

RESUMO

Reaumuria trigyna (Reaumuria Linn genus, family Tamaricaceae), an endangered dicotyledonous shrub with the features of a recretohalophyte, is endemic to the Eastern Alxa-Western Ordos area of China. Based on R. trigyna transcriptome data and expression pattern analysis of RtWRKYs, RtWRKY23, a Group II WRKY transcription factor, was isolated from R. trigyna cDNA. RtWRKY23 was mainly expressed in the stem and was induced by salt, drought, cold, ultraviolet radiation, and ABA treatments, but suppressed by heat treatment. Overexpression of RtWRKY23 in Arabidopsis increased chlorophyll content, root length, and fresh weight of the transgenic lines under salt stress. Real-time quantitative PCR (qPCR) analysis and yeast one-hybrid analysis demonstrated that RtWRKY23 protein directly or indirectly modulated the expression levels of downstream genes, including stress-related genes AtPOD, AtPOD22, AtPOD23, AtP5CS1, AtP5CS2, and AtPRODH2, and reproductive development-related genes AtMAF5, AtHAT1, and AtANT. RtWRKY23 transgenic Arabidopsis had higher proline content, peroxidase activity, and superoxide anion clearance rate, and lower H2O2 and malondialdehyde content than WT plants under salt stress conditions. Moreover, RtWRKY23 transgenic Arabidopsis exhibited later flowering and shorter pods, but little change in seed yield, compared with WT plants under salt stress. Our study demonstrated that RtWRKY23 not only enhanced salt stress tolerance through maintaining the ROS and osmotic balances in plants, but also participated in the regulation of flowering under salt stress.


Assuntos
Flores/crescimento & desenvolvimento , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Tamaricaceae/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência , Tamaricaceae/genética , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
4.
BMC Plant Biol ; 19(1): 213, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31117942

RESUMO

BACKGROUND: Atriplex canescens is a typical C4 secretohalophyte with salt bladders on the leaves. Accumulating excessive Na+ in tissues and salt bladders, maintaining intracellular K+ homeostasis and increasing leaf organic solutes are crucial for A. canescens survival in harsh saline environments, and enhanced photosynthetic activity and water balance promote its adaptation to salt. However, the molecular basis for these physiological mechanisms is poorly understood. Four-week-old A. canescens seedlings were treated with 100 mM NaCl for 6 and 24 h, and differentially expressed genes in leaves and roots were identified, respectively, with Illumina sequencing. RESULTS: In A. canescens treated with 100 mM NaCl, the transcripts of genes encoding transporters/channels for important nutrient elements, which affect growth under salinity, significantly increased, and genes involved in exclusion, uptake and vacuolar compartmentalization of Na+ in leaves might play vital roles in Na+ accumulation in salt bladders. Moreover, NaCl treatment upregulated the transcripts of key genes related to leaf organic osmolytes synthesis, which are conducive to osmotic adjustment. Correspondingly, aquaporin-encoding genes in leaves showed increased transcripts under NaCl treatment, which might facilitate water balance maintenance of A. canescens seedlings in a low water potential condition. Additionally, the transcripts of many genes involved in photosynthetic electron transport and the C4 pathway was rapidly induced, while other genes related to chlorophyll biosynthesis, electron transport and C3 carbon fixation were later upregulated by 100 mM NaCl. CONCLUSIONS: We identified many important candidate genes involved in the primary physiological mechanisms of A. canescens salt tolerance. This study provides excellent gene resources for genetic improvement of salt tolerance of important crops and forages.


Assuntos
Atriplex/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/fisiologia , Transcriptoma , Atriplex/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/fisiologia , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Plantas Tolerantes a Sal/genética , Transcriptoma/efeitos dos fármacos
5.
Plant Mol Biol ; 100(4-5): 379-390, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30968308

RESUMO

KEY MESSAGE: Functions of most splice isoforms that are generated by alternative splicing are unknown. We show that two splice variants that encode proteins differing in only eight amino acids have distinct functions in a stress response. Serine/arginine-rich (SR) and SR-like proteins, a conserved family of RNA binding proteins across eukaryotes, play important roles in pre-mRNA splicing and other post-transcriptional processes. Pre-mRNAs of SR and SR-like proteins undergo extensive alternative splicing in response to diverse stresses and produce multiple splice isoforms. However, the functions of most splice isoforms remain elusive. Alternative splicing of pre-mRNA of Arabidopsis SR45, which encodes an SR-like splicing regulator, generates two isoforms (long-SR45.1 and short-SR45.2). The proteins encoded by these two isoforms differ in eight amino acids. Here, we investigated the role of SR45 and its splice variants in salt stress tolerance. The loss of SR45 resulted in enhanced sensitivity to salt stress and changes in expression and splicing of genes involved in regulating salt stress response. Interestingly, only the long isoform (SR45.1) rescued the salt-sensitive phenotype as well as the altered gene expression and splicing patterns in the mutant. These results suggest that SR45 positively regulates salt tolerance. Furthermore, only the long isoform is required for SR45-mediated salt tolerance.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Proteínas de Ligação a RNA/fisiologia , Tolerância ao Sal/genética , Processamento Alternativo , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Homeostase , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Estresse Fisiológico
6.
Mol Biotechnol ; 61(6): 442-450, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30980224

RESUMO

Soil salinity imposes a serious threat to the productivity of agricultural crops. Among several other transporters, high-affinity K+ transporter (HKT)'s play an important role in reducing the phytotoxicity of Na+. Expression of Eutrema salsugineum (a halophyte) HKT1;2 is induced upon salt exposure. To elucidate the role of its promoter, we compared the sequences of HKT1;2 promoters from E. salsugineum (1822 bp) and E. botschantzevii (1811 bp) with Arabidopsis thaliana HKT1;1 (846 bp) promoter. In silico analysis predicted several cis-acting regulatory elements (GT-1 elements, core motifs of DRE/CRT, MYC/MYB-recognition sites and ACGT elements). Activities of the three promoters were analyzed by measuring HKT1;1 and/or HKT1;2 transcript level in the Athkt1;1 mutant plants. NaCl tolerance of the transgenics was also assessed. Our results depicted that expressing either AtHKT1;1 or EsHKT1;2 coding regions under the control of AtHKT1;1 promoter, almost reversed the hypersensitivity of the mutant for salt, on contrarily, when AtHKT1;1 coding sequence expressed under either Es or EbHKT1;2 promoters did not. Changes in shoot Na+/K+ concentrations under salt exposure is significantly consistent with the complementation ability of the mutant. The transcript concentration for genes under the control of either of Eutrema promoters, at control level was very less. This may suggest that either an important upstream response motif is missed or that A. thaliana misses a transcriptional regulator that is essential for salt-inducible HKT1 expression in Eutrema.


Assuntos
Arabidopsis/genética , Brassicaceae/genética , Proteínas de Transporte de Cátions/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Simportadores/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Sequência de Bases , Brassicaceae/efeitos dos fármacos , Brassicaceae/crescimento & desenvolvimento , Brassicaceae/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Teste de Complementação Genética , Transporte de Íons/efeitos dos fármacos , Mutação , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Potássio/metabolismo , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Sódio/metabolismo , Cloreto de Sódio/farmacologia , Especificidade da Espécie , Estresse Fisiológico/genética , Simportadores/metabolismo
7.
BMC Genomics ; 20(1): 318, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31023240

RESUMO

BACKGROUND: Salinity is an abiotic stress that negatively affects soybean [Glycine max (L.) Merr.] seed yield. Although a major gene for salt tolerance was identified and consistently mapped to chromosome (Chr.) 3 by linkage mapping studies, it does not fully explain genetic variability for tolerance in soybean germplasm. In this study, a genome-wide association study (GWAS) was performed to map genomic regions for salt tolerance in a diverse panel of 305 soybean accessions using a single nucleotide polymorphism (SNP) dataset derived from the SoySNP50K iSelect BeadChip. A second GWAS was also conducted in a subset of 234 accessions using another 3.7 M SNP dataset derived from a whole-genome resequencing (WGRS) study. In addition, three gene-based markers (GBM) of the known gene, Glyma03g32900, on Chr. 3 were also integrated into the two datasets. Salt tolerance among soybean lines was evaluated by leaf scorch score (LSS), chlorophyll content ratio (CCR), leaf sodium content (LSC), and leaf chloride content (LCC). RESULTS: For both association studies, a major locus for salt tolerance on Chr. 3 was confirmed by a number of significant SNPs, of which three gene-based SNP markers, Salt-20, Salt14056 and Salt11655, had the highest association with all four traits studied. Also, additional genomic regions on Chrs. 1, 8, and 18 were found to be associated with various traits measured in the second GWAS using the WGRS-derived SNP dataset. CONCLUSIONS: A region identified on Chr. 8 was identified to be associated with all four traits and predicted as a new minor locus for salt tolerance in soybean. The candidate genes harbored in this minor locus may help reveal the molecular mechanism involved in salt tolerance and to improve tolerance in soybean cultivars. The significant SNPs will be useful for marker-assisted selection for salt tolerance in soybean breeding programs.


Assuntos
Estudo de Associação Genômica Ampla , Tolerância ao Sal/genética , Soja/genética , Mapeamento Cromossômico , Genótipo , Desequilíbrio de Ligação , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Locos de Características Quantitativas
8.
Plant Genome ; 12(1)2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30951087

RESUMO

Many agricultural lands in the western United States consist of soil with high concentrations of salt, which is detrimental to alfalfa ( L.) growth and production, especially in the region where water resource is limited. Developing alfalfa varieties with salt tolerance is imperative for sustainable production under increasing soil salinity. In the present study, we used advanced alfalfa breeding populations and evaluated five traits related to salt tolerance including biomass dry weight (DW) and fresh weight (FW), plant height (PH), leaf relative water content (RWC), and stomatal conductance (SC) under control and salt stress. Stress susceptibility index (SSI) of each trait and single-nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS) were used for genome-wide association studies (GWAS) to identify loci associated with salt tolerance. A total of 53 significant SNPs associated with salt tolerance were identified and they were located at 49 loci through eight chromosomes. A Basic Local Alignment Search Tool (BLAST) search of the regions surrounding the SNPs revealed 21 putative candidate genes associated with salt tolerance. The genetic architecture for traits related to salt tolerance characterized in this report could help in understanding the genetic mechanism by which salt stress affects plant growth and production in alfalfa. The markers and candidate genes identified in the present study would be useful for marker-assisted selection (MAS) in breeding salt-tolerant alfalfa after validation of the markers.


Assuntos
Genoma de Planta , Medicago sativa/genética , Tolerância ao Sal/genética , Loci Gênicos , Marcadores Genéticos , Variação Genética , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Desequilíbrio de Ligação , Fenótipo , Melhoramento Vegetal , Tetraploidia
9.
Mol Biotechnol ; 61(6): 421-426, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30937688

RESUMO

The B-box proteins (BBXs) are zinc finger proteins containing one or two B-box domain(s) and involved in regulation of development processes as transcription factors in plants. Here, seven BBX genes in Malus domestica genome (MdBBXs) were identified and found to be up-regulated under abiotic stresses, with 2-12 folds in roots. All recombinant MdBBXs expressed in Escherichia coli (E. coli) enhanced the cell's tolerance to salt and osmotic stresses, respectively. Deficiency of B-box domain of MdBBX10 led to the loss of anti-stress functions. Five conservative cysteines in B-box domain played crucial roles in stress resistance, which are involved in two of metal iron binding sites of zinc finger motifs in BBXs. All the above results suggested MdBBXs confer stress tolerance to E. coli cell against abiotic stresses.


Assuntos
Escherichia coli/genética , Regulação da Expressão Gênica de Plantas , Malus/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Clonagem Molecular , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Malus/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Polietilenoglicóis/farmacologia , Domínios Proteicos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologia , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo , Dedos de Zinco/genética
10.
Genome Biol ; 20(1): 79, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30999938

RESUMO

BACKGROUND: Pistachio (Pistacia vera), one of the most important commercial nut crops worldwide, is highly adaptable to abiotic stresses and is tolerant to drought and salt stresses. RESULTS: Here, we provide a draft de novo genome of pistachio as well as large-scale genome resequencing. Comparative genomic analyses reveal stress adaptation of pistachio is likely attributable to the expanded cytochrome P450 and chitinase gene families. Particularly, a comparative transcriptomic analysis shows that the jasmonic acid (JA) biosynthetic pathway plays an important role in salt tolerance in pistachio. Moreover, we resequence 93 cultivars and 14 wild P. vera genomes and 35 closely related wild Pistacia genomes, to provide insights into population structure, genetic diversity, and domestication. We find that frequent genetic admixture occurred among the different wild Pistacia species. Comparative population genomic analyses reveal that pistachio was domesticated about 8000 years ago and suggest that key genes for domestication related to tree and seed size experienced artificial selection. CONCLUSIONS: Our study provides insight into genetic underpinning of local adaptation and domestication of pistachio. The Pistacia genome sequences should facilitate future studies to understand the genetic basis of agronomically and environmentally related traits of desert crops.


Assuntos
Adaptação Biológica , Domesticação , Evolução Molecular , Genoma de Planta , Pistacia/genética , Família Multigênica , Tolerância ao Sal/genética , Transcriptoma
11.
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
12.
Ecotoxicol Environ Saf ; 174: 245-254, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30831473

RESUMO

Salinity decreases the yield and quality of crops. Silicon (Si) has been widely reported to have beneficial effects on plant growth and development under salt stress. However, the mechanism is still poorly understood. In an attempt to identify genes or gene networks that may be orchestrated to improve salt tolerance of cucumber plants, we sequenced the transcriptomes of both control and salt-stressed cucumber leaves in the presence or absence of added Si. Seedlings of cucumber 'JinYou 1' were subjected to salt stress (75 mM NaCl) without or with addition of 0.3 mM Si. Plant growth, photosynthetic gas exchange and transcriptomic dynamics were investigated. The results showed that Si addition improved the growth and photosynthetic performance of cucumber seedlings under salt stress. The comparative transcriptome analysis revealed that Si played an important role in shaping the transcriptome of cucumber: the expressions of 1469 genes were altered in response to Si treatment in the control conditions, and these genes were mainly involved in ion transport, hormone and signal transduction, biosynthetic and metabolic processes, and stress and defense responses. Under salt stress alone, 1482 genes with putative functions associated with metabolic processes and responses to environmental stimuli have changed their expression levels. Si treatment shifted the transcriptome of salt-stressed cucumber back to that of the control, as evidenced that among the 708 and 774 genes that were up- or down-regulated under salt stress, a large majority of them (609 and 595, respectively) were reverted to the normal expression levels. These results suggest that Si may act as an elicitor to precondition cucumber plants and induce salt tolerance. The study may help us understand the mechanism for silicon-mediated salt tolerance and provide a theoretical basis for silicon application in crop production in saline soils.


Assuntos
Cucumis sativus/efeitos dos fármacos , Estresse Salino/efeitos dos fármacos , Silicatos/farmacologia , Transcriptoma/efeitos dos fármacos , Cucumis sativus/genética , Cucumis sativus/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Modelos Teóricos , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Desenvolvimento Vegetal/efeitos dos fármacos , Desenvolvimento Vegetal/genética , Salinidade , Estresse Salino/genética , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Cloreto de Sódio/administração & dosagem
13.
Genes Genomics ; 41(5): 599-612, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30840180

RESUMO

BACKGROUND: Sinonovacula constricta is an economically important bivalve species in China, Korea and Japan that widely resides in estuarine and coastal areas where salinity fluctuates rapidly. However, little is known about its adaptation mechanisms to acute salt stresses. OBJECTIVE: To reveal the underlying molecular mechanisms involved in acute salt stresses in juvenile S. constricta. METHODS: Nine cDNA libraries (triplicate each trial) were established from juvenile S. constricta, which were subjected to low salinity (5 psu), optimal salinity (15 psu) and high salinity (25 psu) for 6 h, respectively. RESULTS: Illumina sequencing generated 478,587,310 clean reads totally, which were assembled into 427,057 transcripts of 246,672 unigenes. Compared with the control, 1259 and 2163 differentially expressed genes (DEGs) were identified under acute low and high salt stresses, respectively. GO and KEGG enrichment analyses of DEGs revealed that several key metabolic modulations were mainly responsible for the acute salt stresses. According to the significantly highlighted KEGG pathways, some key DEGs were identified and discussed in details. Notably, based on which, some potential osmolytes were further speculated. CONCLUSION: Here, we carried out a unique report of comparative transcriptome analyses in juvenile S. constricta in response to acute salt stresses. The identified DEGs and their significantly enriched GO terms and KEGG pathways were critical for understanding and further investigating the underlying the physical and biochemical performances, and ultimately facilitated S. constricta breeding. Besides, the transcriptome data greatly enriched the genetic information of S. constricta, which were valuable for promoting its molecular biology researches.


Assuntos
Bivalves/genética , Perfilação da Expressão Gênica/métodos , Estresse Salino/genética , Adaptação Biológica/genética , Animais , Bivalves/fisiologia , China , Japão , Anotação de Sequência Molecular/métodos , República da Coreia , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia
14.
World J Microbiol Biotechnol ; 35(3): 50, 2019 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-30852675

RESUMO

A halophilic Gram-negative eubacterium was isolated from the Iroise Sea and identified as an efficient producer of polyhydroxyalkanoates (PHA). The strain, designated SF2003, was found to belong to the Halomonas genus on the basis of 16S rRNA gene sequence similarity. Previous biochemical tests indicated that the Halomonas sp. strain SF2003 is capable of supporting various culture conditions which sometimes can be constraining for marine strains. This versatility could be of great interest for biotechnological applications. Therefore, a complete bacterial genome sequencing and de novo assembly were performed using a PacBio RSII sequencer and Hierarchical Genome Assembly Process software in order to predict Halomonas sp. SF2003 metabolisms, and to identify genes involved in PHA production and stress tolerance. This study demonstrates the complete genome sequence of Halomonas sp. SF2003 which contains a circular 4,36 Mbp chromosome, and replaces the strain in a phylogenetic tree. Genes related to PHA metabolism, carbohydrate metabolism, fatty acid metabolism and stress tolerance were identified and a comparison was made with metabolisms of relative species. Genes annotation highlighted the presence of typical genes involved in PHA biosynthesis such as phaA, phaB and phaC and enabled a preliminary analysis of their organization and characteristics. Several genes of carbohydrates and fatty acid metabolisms were also identified which provided helpful insights into both a better knowledge of the intricacies of PHA biosynthetic pathways and of production purposes. Results show the strong versatility of Halomonas sp. SF2003 to adapt to various temperatures and salinity which can subsequently be exploited for industrial applications such as PHA production.


Assuntos
Halomonas/genética , Halomonas/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Sequenciamento Completo do Genoma , Composição de Bases , Biotecnologia , Metabolismo dos Carboidratos/genética , DNA Bacteriano , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Genes Bacterianos/genética , Tamanho do Genoma , Halomonas/classificação , Halomonas/isolamento & purificação , Redes e Vias Metabólicas/genética , Filogenia , Poli-Hidroxialcanoatos/genética , RNA Ribossômico 16S/genética , Salinidade , Tolerância ao Sal/genética , Estresse Fisiológico
15.
Plant Sci ; 280: 1-11, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30823987

RESUMO

Abscisic acid (ABA) and jasmonates (JAs) are the primary plant hormones involved in mediating salt tolerance. In addition, these two plant hormones exert a synergistic effect to inhibit seed germination. However, the molecular mechanism of the interaction between ABA signalling and JA signalling is still not well documented. Here, a moss jasmonate ZIM-domain gene (PnJAZ1), which encodes a nucleus-localized protein with conserved ZIM and Jas domains, was cloned from Pohlia nutans. PnJAZ1 expression was rapidly induced by various abiotic stresses. The PnJAZ1 protein physically interacted with MYC2 and was degraded by exogenous 12-oxo-phytodienoic acid (OPDA) treatment, implying that the JAZ protein-mediated signalling pathway is conserved in plants. Transgenic Arabidopsis and Physcomitrella plants overexpressing PnJAZ1 showed increased tolerance to salt stress and decreased ABA sensitivity during seed germination and early development. The overexpression of PnJAZ1 inhibited the expression of ABA pathway genes related to seed germination and seedling growth. Moreover, the transgenic Arabidopsis lines exhibited enhanced tolerance to auxin (IAA) and glucose, mimicking the phenotypes of abi4 or abi5 mutants. These results suggest that PnJAZ1 acts as a repressor, mediates JA-ABA synergistic crosstalk and enhances plant growth under salt stress.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Tolerância ao Sal/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Tolerância ao Sal/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
16.
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
17.
Plant Sci ; 281: 19-30, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824052

RESUMO

The manipulation of APETALA2/ethylene responsive factor (AP2/ERF) genes in plants makes great contributions on resistance to abiotic stresses. Here, we cloned an AP2/ERF gene from the salt-tolerant sweetpotato line ND98 and named IbRAP2-12. IbRAP2-12 protein expressed in nuclear revealed by transient expression in tobacco epidermal cells, and IbRAP2-12 exhibited transcriptional activation using heterologous expression assays in yeast. IbRAP2-12 was induced by NaCl (200 mM), 20% polyethylene glycol (PEG) 6000, 100 µM abscisic acid (ABA), 100 µM ethephon and 100 µM methyl jasmonate (MeJA). IbRAP2-12-overexpressing Arabidopsis lines were more tolerant to salt and drought stresses than wild type plants. Transcriptome analysis showed that genes involved in the ABA signalling, JA signalling, proline biosynthesis and reactive oxygen species (ROS) scavenging processes were up-regulated in IbRAP2-12 overexpression lines under salt and drought stresses. In comparing with WT, the contents of ABA, JA and proline were significantly increased, while hydrogen peroxide (H2O2) and the rate of water loss were significantly reduced in transgenic lines under salt and drought stresses. All these results demonstrated the roles of IbRAP2-12 in enhancing salt and drought tolerance in transgenic Arabidopsis lines. Thus, this IbRAP2-12 gene can be used to increase the tolerance ability during abiotic stresses in plants.


Assuntos
Arabidopsis/metabolismo , Secas , Ipomoea batatas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Ipomoea batatas/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Prolina/metabolismo , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia
18.
Plant Sci ; 281: 72-81, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30824063

RESUMO

Salinity is a major abiotic stress limiting plant growth and development that has caused severe damage to yield and quality of cotton fiber. Uncovering the mechanisms of response to salt stress is important in breeding salt-tolerant cotton varieties. Transcriptome analysis identified 2356 differentially expressed genes in cotton under salt stress, of which 9.4% were predicted transcription factors (TFs). Approximately 17.6% (39 out of 222) of the differentially expressed TFs belonged to the ethylene response factor (ERF) family. Expression pattern analysis showed significant changes in these ERFs during salt stress. Moreover, the number of down-regulated ERFs was more than that of the up-regulated ERFs. Two of the ERFs, GhERF4L and GhERF54L, showed increased (12-15 times) expression after 12 h of salt treatment. Silencing of GhERF4L and GhERF54L significantly reduced salt tolerance of cotton seedlings, indicating their role in regulating cotton response to salt stress. This study revealed the essential role of ERF transcription factors in the salt response mechanism of plants, and provided important genetic resources for breeding salt-tolerant cotton.


Assuntos
Gossypium/metabolismo , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Gossypium/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Fatores de Transcrição/genética
19.
Nat Commun ; 10(1): 857, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787279

RESUMO

Microtubules are filamentous structures necessary for cell division, motility and morphology, with dynamics critically regulated by microtubule-associated proteins (MAPs). Here we outline the molecular mechanism by which the MAP, COMPANION OF CELLULOSE SYNTHASE1 (CC1), controls microtubule bundling and dynamics to sustain plant growth under salt stress. CC1 contains an intrinsically disordered N-terminus that links microtubules at evenly distributed points through four conserved hydrophobic regions. By NMR and live cell analyses we reveal that two neighboring residues in the first hydrophobic binding motif are crucial for the microtubule interaction. The microtubule-binding mechanism of CC1 is reminiscent to that of the prominent neuropathology-related protein Tau, indicating evolutionary convergence of MAP functions across animal and plant cells.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Tolerância ao Sal/fisiologia , Proteínas tau/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Celulose/biossíntese , Glucosiltransferases/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Proteínas Associadas aos Microtúbulos/genética , Tolerância ao Sal/genética , Plântula/crescimento & desenvolvimento
20.
Int J Mol Sci ; 20(4)2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30769802

RESUMO

Sodium chloride (NaCl) induced expression of a jacalin-related mannose-binding lectin (JRL) gene in leaves, roots, and callus cultures of Populus euphratica (salt-resistant poplar). To explore the mechanism of the PeJRL in salinity tolerance, the full length of PeJRL was cloned from P. euphratica and was transformed into Arabidopsis. PeJRL was localized to the cytoplasm in mesophyll cells. Overexpression of PeJRL in Arabidopsis significantly improved the salt tolerance of transgenic plants, in terms of seed germination, root growth, and electrolyte leakage during seedling establishment. Under NaCl stress, transgenic plants retained K⁺ and limited the accumulation of Na⁺. PeJRL-transgenic lines increased Na⁺ extrusion, which was associated with the upward regulation of SOS1, AHA1, and AHA2 genes encoding plasma membrane Na⁺/proton (H⁺) antiporter and H⁺-pumps. The activated H⁺-ATPases in PeJRL-overexpressed plants restricted the channel-mediated loss of K⁺ that was activated by NaCl-induced depolarization. Under salt stress, PeJRL⁻transgenic Arabidopsis maintained reactive oxygen species (ROS) homeostasis by activating the antioxidant enzymes and reducing the production of O2- through downregulation of NADPH oxidases. Of note, the PeJRL-transgenic Arabidopsis repressed abscisic acid (ABA) biosynthesis, thus reducing the ABA-elicited ROS production and the oxidative damage during the period of salt stress. A schematic model was proposed to show the mediation of PeJRL on ABA response, and ionic and ROS homeostasis under NaCl stress.


Assuntos
Arabidopsis/genética , Lectinas de Ligação a Manose/genética , Plantas Geneticamente Modificadas/genética , Estresse Salino/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Citoplasma/efeitos dos fármacos , Citoplasma/genética , Regulação da Expressão Gênica de Plantas , Homeostase , Lectinas de Ligação a Manose/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Lectinas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Populus , Espécies Reativas de Oxigênio/química , Tolerância ao Sal/genética , Cloreto de Sódio/efeitos adversos
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