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1.
BMC Plant Biol ; 19(1): 335, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370805

RESUMO

BACKGROUND: Drought is a serious causal factor of reduced crop yields than any other abiotic stresses. As one of the most widely distributed crops, maize plants frequently suffer from drought stress, which causes great losses in the final kernel yield. Drought stress response in plants showed tissue- and developmental stage-specific characteristics. RESULTS: In this study, the ears at the V9 stage, kernels and ear leaf at the 5DAP (days after pollination) stage of maize were used for morphological, physiological and comparative transcriptomics analysis to understand the different features of "sink" or "source" organs and the effects on kernel yield under drought stress conditions. The ABA-, NAC-mediate signaling pathway, osmotic protective substance synthesis and protein folding response were identified as common drought stress response in the three organs. Tissue-specific drought stress responses and the regulators were identified, they were highly correlated with growth, physiological adaptation and yield loss under drought stress. For ears, drought stress inhibited ear elongation, led to the abnormal differentiation of the paired spikelet, and auxin signaling involved in the regulation of cell division and growth and primordium development changes. In the kernels, reduced kernel size caused by drought stress was observed, and the obvious differences of auxin, BR and cytokine signaling transduction appeared, which indicated the modification in carbohydrate metabolism, cell differentiation and growth retardation. For the ear leaf, dramatically and synergistically reduced the expression of photosynthesis genes were observed when suffered from drought stress, the ABA- and NAC- mediate signaling pathway played important roles in the regulation of photosynthesis. CONCLUSIONS: Transcriptomic changes caused by drought were highly correlated with developmental and physiological adaptation, which was closely related to the final yield of maize, and a sketch of tissue- and developmental stage-specific responses to drought stress in maize was drafted.


Assuntos
Zea mays/fisiologia , Produção Agrícola , Desidratação , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/fisiologia , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
2.
BMC Plant Biol ; 19(1): 338, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375063

RESUMO

BACKGROUND: In native environments plants frequently experience simultaneous or sequential unfavourable abiotic and biotic stresses. The plant's response to combined stresses is usually not the sum of the individual responses. Here we investigated the impact of cold on plant defense against subsequent herbivory by a generalist and specialist insect. RESULTS: We determined transcriptional responses of Arabidopsis thaliana to low temperature stress (4 °C) and subsequent larval feeding damage by the lepidopteran herbivores Mamestra brassicae (generalist), Pieris brassicae (specialist) or artificial wounding. Furthermore, we compared the performance of larvae feeding upon cold-experienced or untreated plants. Prior experience of cold strongly affected the plant's transcriptional anti-herbivore and wounding response. Feeding by P. brassicae, M. brassicae and artificial wounding induced transcriptional changes of 1975, 1695, and 2239 genes, respectively. Of these, 125, 360, and 681 genes were differentially regulated when cold preceded the tissue damage. Overall, prior experience of cold mostly reduced the transcriptional response of genes to damage. The percentage of damage-responsive genes, which showed attenuated transcriptional regulation when cold preceded the tissue damage, was highest in M. brassicae damaged plants (98%), intermediate in artificially damaged plants (89%), and lowest in P. brassicae damaged plants (69%). Consistently, the generalist M. brassicae performed better on cold-treated than on untreated plants, whereas the performance of the specialist P. brassicae did not differ. CONCLUSIONS: The transcriptional defense response of Arabidopsis leaves to feeding by herbivorous insects and artificial wounding is attenuated by a prior exposure of the plant to cold. This attenuation correlates with improved performance of the generalist herbivore M. brassicae, but not the specialist P. brassicae, a herbivore of the same feeding guild.


Assuntos
Arabidopsis/fisiologia , Herbivoria , Animais , Arabidopsis/metabolismo , Borboletas/fisiologia , Resposta ao Choque Frio , Dieta , Regulação da Expressão Gênica de Plantas/fisiologia , Herbivoria/fisiologia , Larva , Mariposas/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Transcriptoma
3.
BMC Plant Biol ; 19(1): 337, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375064

RESUMO

BACKGROUND: Cymbidium goeringii belongs to the Orchidaceae, which is one of the most abundant angiosperm families. Cymbidium goeringii consist with high economic value and characteristics include fragrance and multiple flower colors. Floral scent is one of the important strategies for ensuring fertilization. However, limited genetic data is available in this non-model plant, and little known about the molecular mechanism responsible for floral scent in this orchid. Transcriptome and expression profiling data are needed to identify genes and better understand the biological mechanisms of floral scents in this species. Present transcriptomic data provides basic information on the genes and enzymes related to and pathways involved in flower secondary metabolism in this plant. RESULTS: In this study, RNA sequencing analyses were performed to identify changes in gene expression and biological pathways related scent metabolism. Three cDNA libraries were obtained from three developmental floral stages: closed bud, half flowering stage and full flowering stage. Using Illumina technique 159,616,374 clean reads were obtained and were assembled into 85,868 final unigenes (average length 1194 nt), 33.85% of which were annotated in the NCBI non redundant protein database. Among this unigenes 36,082 were assigned to gene ontology and 23,164 were combined with COG groups. Total 33,417 unigenes were assigned in 127 pathways according to the Kyoto Encyclopedia of Genes and Genomes pathway database. According these transcriptomic data we identified number of candidates genes which differentially expressed in different developmental stages of flower related to fragrance biosynthesis. In q-RT-PCR most of the fragrance related genes highly expressed in half flowering stage. CONCLUSIONS: RNA-seq and DEG data provided comprehensive gene expression information at the transcriptional level that could be facilitate the molecular mechanisms of floral biosynthesis pathways in three developmental phase's flowers in Cymbidium goeringii, moreover providing useful information for further analysis on C. goeringii, and other plants of genus Cymbidium.


Assuntos
Flores/metabolismo , Genes de Plantas/genética , Odorantes , Orchidaceae/genética , Acetatos/metabolismo , Ciclopentanos/metabolismo , Farneseno Álcool/metabolismo , Flores/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Orchidaceae/metabolismo , Oxilipinas/metabolismo , Filogenia , Análise de Sequência de RNA , Sesquiterpenos/metabolismo , Terpenos/metabolismo
4.
Dokl Biochem Biophys ; 486(1): 163-167, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31367812

RESUMO

The treatment of Arabidopsis thaliana plants with exogenous cytokinin (CK) followed by heat shock (HS) activated the expression of the genes for the plastid transcription machinery but adversely affected the plant viability. Abscisic acid (ABA), conversely, promoted maintaining the resistance to HS and had differentially affected different components of the plastid transcriptional complex. This hormone suppressed the accumulation of transcripts of PEP genes and the genes encoding PAP proteins, which are involved in DNA-RNA metabolism. However, it had no effect or activated the expression of NEP genes and PAP genes, which are involved in the redox regulation, as well as the genes encoding the stress-inducible trans-factor (SIG5) and the plastid transcription Ser/Thr protein kinase (cpCK2). Thus, for the adaptation of plants to elevated temperatures, both increase and decrease in the expression of the genes for the plastid transcriptional machinery with the involvement of various regulatory systems, including phytohormones, are equally significant.


Assuntos
Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Citocininas/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Resposta ao Choque Térmico/genética , Plastídeos/genética , Transcrição Genética/efeitos dos fármacos , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/fisiologia , Resposta ao Choque Térmico/efeitos dos fármacos , Plastídeos/efeitos dos fármacos
5.
Pestic Biochem Physiol ; 159: 1-8, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400771

RESUMO

We examined the molecular regulation of porphyrin biosynthesis and protective responses in transgenic rice (Oryza sativa) expressing Bradyrhizobium japonicum Fe-chelatase (BjFeCh) after treatment with acifluorfen (AF). During the photodynamic stress imposed by AF, transcript levels of BjFeCh in transgenic plants increased greatly; moreover, transcript levels of OsFeCh2 remained almost constant, whereas in wild type (WT) plants they were considerably down-regulated. In the heme branch, transgenic plants exhibited greater levels of OsFC and HO transcripts than WT plants in the untreated stems as well as in the AF-treated leaves and stems. Both WT and transgenic plants treated with AF substantially decreased transcript levels for all the genes in the chlorophyll branch, with less decline in transgenic plants. After AF treatment, ascorbate (Asc) content and the redox Asc state greatly decreased in leaves of WT plants; however, in transgenic plants both parameters remained constant in leaves and the Asc redox state increased by 20% in stems. In response to AF, the leaves of WT plants greatly up-regulated CatA, CatB, and GST compared to those of transgenic plants, whereas, in the stems, transgenic plants showed higher levels of CatA, CatC, APXb, BCH, and VDE. Photochemical quenching, qP, was considerably dropped by 31% and 18% in WT and transgenic plants, respectively in response to AF, whereas non-radiative energy dissipation through non-photochemical quenching increased by 77% and 38% in WT and transgenic plants, respectively. Transgenic plants treated with AF exhibited higher transcript levels of nucleus-encoded photosynthetic genes, Lhcb1 and Lhcb6, as well as levels of Lhcb6 protein compared to those of WT plants. Our study demonstrates that expression of BjFeCh in transgenic plants influences not only the regulation of porphyrin biosynthesis through maintaining higher levels of gene expression in the heme branch, but also the Asc redox function during photodynamic stress caused by AF.


Assuntos
Proteínas de Bactérias/metabolismo , Bradyrhizobium/enzimologia , Ferroquelatase/metabolismo , Nitrobenzoatos/farmacologia , Oryza/metabolismo , Porfirinas/biossíntese , Proteínas de Bactérias/genética , Ferroquelatase/genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Plantas Geneticamente Modificadas
6.
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
7.
BMC Plant Biol ; 19(1): 367, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429697

RESUMO

BACKGROUND: Adaptation to abiotic stresses is crucial for the survival of perennial plants in a natural environment. However, very little is known about the underlying mechanisms. Here, we adopted a liquid culture system to investigate plant adaptation to repeated salt stress in Populus trees. RESULTS: We first evaluated phenotypic responses and found that plants exhibit better stress tolerance after pre-treatment of salt stress. Time-course RNA sequencing (RNA-seq) was then performed to profile changes in gene expression over 12 h of salt treatments. Analysis of differentially expressed genes (DEGs) indicated that significant transcriptional reprogramming and adaptation to repeated salt treatment occurred. Clustering analysis identified two modules of co-expressed genes that were potentially critical for repeated salt stress adaptation, and one key module for salt stress response in general. Gene Ontology (GO) enrichment analysis identified pathways including hormone signaling, cell wall biosynthesis and modification, negative regulation of growth, and epigenetic regulation to be highly enriched in these gene modules. CONCLUSIONS: This study illustrates phenotypic and transcriptional adaptation of Populus trees to salt stress, revealing novel gene modules which are potentially critical for responding and adapting to salt stress.


Assuntos
Adaptação Fisiológica/genética , Regulação da Expressão Gênica de Plantas , Populus/genética , Estresse Salino/genética , Transcrição Genética , Ontologia Genética , Redes Reguladoras de Genes , Genoma de Planta , Fenótipo , Populus/fisiologia , RNA de Plantas , Análise de Sequência de RNA , Transcriptoma , Árvores/genética , Árvores/fisiologia
8.
BMC Plant Biol ; 19(1): 300, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31288738

RESUMO

BACKGROUND: Salinity is a major abiotic stress that limits the growth, productivity, and geographical distribution of plants. A comparative proteomics and gene expression analysis was performed to better understand salinity tolerance mechanisms in chickpea. RESULTS: Ten days of NaCl treatments resulted in the differential expression of 364 reproducible spots in seedlings of two contrasting chickpea genotypes, Flip 97-43c (salt tolerant, T1) and Flip 97-196c (salt susceptible, S1). Notably, after 3 days of salinity, 80% of the identified proteins in T1 were upregulated, while only 41% in S2 had higher expression than the controls. The proteins were classified into eight functional categories, and three groups of co-expression profile. The second co-expressed group of proteins had higher and/or stable expression in T1, relative to S2, suggesting coordinated regulation and the importance of some processes involved in salinity acclimation. This group was mainly enriched in proteins associated with photosynthesis (39%; viz. chlorophyll a-b binding protein, oxygen-evolving enhancer protein, ATP synthase, RuBisCO subunits, carbonic anhydrase, and fructose-bisphosphate aldolase), stress responsiveness (21%; viz. heat shock 70 kDa protein, 20 kDa chaperonin, LEA-2 and ascorbate peroxidase), and protein synthesis and degradation (14%; viz. zinc metalloprotease FTSH 2 and elongation factor Tu). Thus, the levels and/or early and late responses in the activation of targeted proteins explained the variation in salinity tolerance between genotypes. Furthermore, T1 recorded more correlations between the targeted transcripts and their corresponding protein expression profiles than S2. CONCLUSIONS: This study provides insight into the proteomic basis of a salt-tolerance mechanism in chickpea, and offers unexpected and poorly understood molecular resources as reliable starting points for further dissection.


Assuntos
Cicer/fisiologia , Proteínas de Plantas/metabolismo , Proteômica , Cicer/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Fotossíntese , Proteínas de Plantas/genética , Salinidade , Tolerância ao Sal , Plântula/genética , Plântula/fisiologia , Estresse Fisiológico
9.
BMC Plant Biol ; 19(1): 301, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291885

RESUMO

BACKGROUND: Nothapodytes nimmoniana, a plant of pivotal medicinal significance is a source of potent anticancer monoterpene indole alkaloid (MIA) camptothecin (CPT). This compound owes its potency due to topoisomerase-I inhibitory activity. However, biosynthetic and regulatory aspects of CPT biosynthesis so far remain elusive. Production of CPT is also constrained due to unavailability of suitable in vitro experimental system. Contextually, there are two routes for the biosynthesis of MIAs: the mevalonate (MVA) pathway operating in cytosol and the methylerythritol phosphate (MEP) pathway in the plastids. Determination of relative precursor flux through either of these pathways may provide a new vista for manipulating the enhanced CPT production. RESULTS: In present study, specific enzyme inhibitors of MVA (lovastatin) and MEP pathways (fosmidomycin) were used to perturb the metabolic flux in N. nimmoniana. Interaction of both these pathways was investigated at transcriptional level by using qRT-PCR and at metabolite level by evaluating secologanin, tryptamine and CPT contents. In fosmidomycin treated plants, highly significant reduction was observed in both secologanin and CPT accumulation in the range 40-57% and 64-71.5% respectively, while 4.61-7.69% increase was observed in tryptamine content as compared to control. Lovastatin treatment showed reduction in CPT (7-11%) and secologanin (7.5%) accumulation while tryptamine registered slight increase (3.84%) in comparison to control. These inhibitor mediated changes were reflected at transcriptional level via altering expression levels of deoxy-xylulose-5-phosphate reductoisomerase (DXR) and hydroxymethylglutaryl-CoA reductase (HMG). Further, mRNA expression of four more genes downstream to DXR and HMG of MEP and MVA pathways respectively were also investigated. Expression analysis also included secologanin synthase (SLS) and strictosidine synthase (STR) of seco-iridoid pathway. Present investigation also entailed development of an efficient in vitro multiplication system as a precursor to pathway flux studies. Further, a robust Agrobacterium-mediated transformed hairy root protocol was also developed for its amenability for up-scaling as a future prospect. CONCLUSIONS: Metabolic and transcriptional changes reveal differential efficacy of cytosolic and plastidial inhibitors in context to pathway flux perturbations on seco-iridoid end-product camptothecin. MEP pathway plausibly is the major precursor contributor towards CPT production. These empirical findings allude towards developing suitable biotechnological interventions for enhanced CPT production.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Camptotecina/biossíntese , Magnoliopsida/genética , Vias Biossintéticas , Regulação da Expressão Gênica de Plantas , Magnoliopsida/metabolismo , Plantas Medicinais
10.
BMC Plant Biol ; 19(1): 309, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299898

RESUMO

BACKGROUND: Ethylene promotes fruit ripening whereas 1-methylcyclopropene (1-MCP), a non-toxic antagonist of ethylene, delays fruit ripening via the inhibition of ethylene receptor. However, unsuitable 1-MCP treatment can cause fruit ripening disorders. RESULTS: In this study, we show that short-term 1-MCP treatment (400 nL•L- 1, 2 h) significantly delays papaya fruit ripening with normal ripening characteristics. However, long-term 1-MCP treatment (400 nL•L- 1, 16 h) causes a "rubbery" texture of fruit. The comparative transcriptome analysis showed that a total of 5529 genes were differently expressed during fruit ripening compared to freshly harvested fruits. Comprehensive functional enrichment analysis showed that the metabolic pathways of carbon metabolism, plant hormone signal transduction, biosynthesis of amino acids, and starch and sucrose metabolism are involved in fruit ripening. 1-MCP treatment significantly affected fruit transcript levels. A total of 3595 and 5998 differently expressed genes (DEGs) were identified between short-term 1-MCP, long-term 1-MCP treatment and the control, respectively. DEGs are mostly enriched in the similar pathway involved in fruit ripening. A large number of DEGs were also identified between long-term and short-term 1-MCP treatment, with most of the DEGs being enriched in carbon metabolism, starch and sucrose metabolism, plant hormone signal transduction, and biosynthesis of amino acids. The 1-MCP treatments accelerated the lignin accumulation and delayed cellulose degradation during fruit ripening. Considering the rubbery phenotype, we inferred that the cell wall metabolism and hormone signal pathways are closely related to papaya fruit ripening disorder. The RNA-Seq output was confirmed using RT-qPCR by 28 selected genes that were involved in cell wall metabolism and hormone signal pathways. CONCLUSIONS: These results showed that long-term 1-MCP treatment severely inhibited ethylene signaling and the cell wall metabolism pathways, which may result in the failure of cell wall degradation and fruit softening. Our results reveal multiple ripening-associated events during papaya fruit ripening and provide a foundation for understanding the molecular mechanisms underlying 1-MCP treatment on fruit ripening and the regulatory networks.


Assuntos
Carica/genética , Ciclopropanos/farmacologia , Etilenos/antagonistas & inibidores , Reguladores de Crescimento de Planta/antagonistas & inibidores , Proteínas de Plantas/metabolismo , Transcriptoma , Carica/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética
11.
BMC Plant Biol ; 19(1): 287, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262258

RESUMO

BACKGROUND: The majority of apricot (Prunus armeniaca L.) cultivars display orange or yellow background skin, whereas some cultivars are particularly preferred by consumers because of their red blushed skin on the background. RESULTS: In this study, two blushed ('Jianali' and 'Hongyu') and two nonblushed ('Baixing' and 'Luntaixiaobaixing') cultivars were used to investigate the formation mechanism of blushed skin in apricots. High-performance liquid chromatography (HPLC) analysis showed that the blushed cultivars accumulated higher cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and peonidin-3-O-rutinoside levels during fruit ripening than the nonblushed cultivars. Based on coexpression network analysis (WGCNA), a putative anthocyanin-related R2R3-MYB, PaMYB10, and seven structural genes were identified from transcriptome data. The phylogenetic analysis indicated that PaMYB10 clustered in the anthocyanin-related MYB clade. Sequence alignments revealed that PaMYB10 contained a bHLH-interaction motif ([DE]Lx2[RK]x3Lx6Lx3R) and an ANDV motif. Subcellular localization analysis showed that PaMYB10 was a nuclear protein. Real-time qRT-PCR analysis demonstrated that the transcript levels of PaMYB10 and seven genes responsible for anthocyanin synthesis were significantly higher in blushed than in nonblushed apricots, which was consistent with the accumulation of anthocyanin. In addition, bagging significantly inhibited the transcript levels of PaMYB10 and the structural genes in 'Jianali' and blocked the red coloration and anthocyanin accumulation. Transient PaMYB10 overexpression in 'Luntaixiaobaixing' fruits resulted in the red blushed skin at the maturation stage. CONCLUSIONS: Taken together, these data reveal that three anthocyanins are responsible for the blushed skin of apricots, identify PaMYB10 as a positive regulator of anthocyanin biosynthesis in apricots, and demonstrate that blush formation depends on light.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Pigmentos Biológicos/biossíntese , Proteínas de Plantas/genética , Prunus armeniaca/fisiologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Antocianinas/genética , Cromatografia Líquida de Alta Pressão , Cor , Frutas/genética , Frutas/fisiologia , Glucosídeos/biossíntese , Glucosídeos/genética , Filogenia , Pigmentos Biológicos/genética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Prunus armeniaca/genética , Alinhamento de Sequência , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
12.
Gene ; 714: 143985, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31330236

RESUMO

In all eukaryotes, the response to heat stress (HS) is dependent on the activity of HS transcription factors (Hsfs). Plants contain a large number of Hsfs, however, only members of the HsfA1 subfamily are considered as master regulators of stress response and thermotolerance. In Solanum lycopersicum, among the four HsfA1 members, only HsfA1a has been proposed to possess a master regulator function. We performed a comparative analysis of HsfA1a, HsfA1b, HsfA1c and HsfA1e at different levels of regulation and function. HsfA1a is constitutively expressed under control and stress conditions, while the other members are induced in specific tissues and stages of HS response. Despite that all members are localized in the nucleus when expressed in protoplasts, only HsfA1a shows a wide range of basal activity on several HS-induced genes. In contrast, HsfA1b, HsfA1c, and HsfA1e show only high activity for specific subsets of genes. Domain swapping mutants between HsfA1a and HsfA1c revealed that the variation in that transcriptional transactivation activity is due to differences in the DNA binding domain (DBD). Specifically, we identified a conserved arginine (R107) residue in the turn of ß3 and ß4 sheet in the C-terminus of the DBD of HsfA1a that is highly conserved in plant HsfA1 proteins, but is replaced by leucine and cysteine in tomato HsfA1c and HsfA1e, respectively. Although not directly involved in DNA interaction, R107 contributes to DNA binding and consequently the activity of HsfA1a. Thus, we demonstrate that this variation in DBD in part explains the functional diversification of tomato HsfA1 members.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Fatores de Transcrição de Choque Térmico/genética , Lycopersicon esculentum/genética , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/genética , Temperatura Alta , Domínios Proteicos/genética , Protoplastos/fisiologia , Temperatura Ambiente , Termotolerância/genética , Transcrição Genética/genética , Ativação Transcricional/genética
13.
Gene ; 714: 144004, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31351124

RESUMO

Calreticulin (CRT) is calcium binding protein of endoplasmic reticulum (ER) which performs plethora of functions besides it's role as molecular chaperone. Among the three different isoforms of this protein, CRT3 is most closely related to primitive CRT gene of higher plants. Based on their distinct structural and functional organisation, the plant CRTs have been known to contain three different domains: N, P and the C domain. The domain organisation and various biochemical characterstics of plant and animal CRTs are common with the exception of some differences. In plant calreticulin, the important N-glycosylation site(s) are replaced by the glycan chain(s) and several consensus sequences for in vitro phosphorylation by protein kinase CK2 (casein kinase-2), are also present unlike the animal calreticulin. Biotic and abiotic stresses play a significant role in bringing down the crop production. The role of various phytohormones in defense against fungal pathogens is well documented. CRT3 has been reported to play important role in protecting the plants against fungal and bacterial pathogens and in maintaining plant innate immunity. There is remarkable crosstalk between CRT mediated signalling and biotic, abiotic stress, and phytohormone mediated signalling pathways The role of CRT mediated pathway in mitigating biotic and abiotic stress can be further explored in plants so as to strategically modify it for development of stress tolerant plants.


Assuntos
Proteínas de Arabidopsis/genética , Calreticulina/genética , Transdução de Sinais/genética , Estresse Fisiológico/genética , Animais , Regulação da Expressão Gênica de Plantas/genética , Imunidade Vegetal/genética , Isoformas de Proteínas/genética
14.
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
15.
Plant Sci ; 286: 78-88, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300145

RESUMO

Chloroplastic Cpn60 proteins are type I chaperonins comprising of Cpn60α and Cpn60ß subunits. Arabidopsis genome contains six entries in Cpn60 family, out of which two are for Cpn60α subunit and four for Cpn60ß subunit. We noted that the cpn60ß4 knockout mutant plants (T-DNA insertion salk_064887 line) differed from the wild type Col-0 plants in the developmental programming. cpn60ß4 mutant plants showed early seed germination. Radical emergence, hypocotyl emergence and cotyledons opening were faster in cpn60ß4 mutant plants than WT. Importantly, cpn60ß4 mutant plants showed early-flowering phenotype. The number of flowers and siliques as well as weight of the seeds were higher in cpn60ß4 mutant plants as compared to Col-0 plants. These effects were reverted to wild type like growth and developmental patterns when genomic fragment of Arabidopsis encompassing Cpn60ß4 gene was complemented in the mutant background. The overexpression of Cpn60ß4 gene using CaMV35 promoter in wild type background (OE-Cpn60ß4) delayed the floral transition as against wild type plants. The plastid division were affected in cpn60ß4 mutant plants compared to Col-0. The results of this study suggest that Cpn60ß4 plays important role(s) in chloroplast development and is a key factor in plant growth, development and flowering in Arabidopsis.


Assuntos
Arabidopsis/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Flores/genética , Regulação da Expressão Gênica no Desenvolvimento , Reprodução
16.
Plant Sci ; 286: 98-107, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300147

RESUMO

Flax seeds have a high oil content and are rich in unsaturated fatty acids, which have advantageous effects in preventing chronic diseases, such as cardiovascular diseases. At present, flax seeds are mainly developed for oil. Therefore, it is of practical significance to identify the candidate genes of fatty acid metabolism in flax seeds for breeding flax seeds with high oil content. In the present study, a natural population of flax containing 224 samples planted in 3 different environments was studied. The genome-wide association analysis (GWAS) of seed fatty acid content was conducted based on specific length amplified fragment sequencing (SLAF-seq) data. Transcriptome sequencing (RNA-seq) of samples from 3 different periods (14 d, 21 d and 28 d after anthesis) during seed development of the low oil variety Shuangya 4 and the high oil variety NEW was performed. The candidate genes for seed fatty acid metabolism were identified by combined analysis of these 2 methods. GWAS detected 16 SNP loci significantly associated with seed fatty acid content, and RNA-seq analysis identified 11,802 differentially expressed genes between high and low oil samples. Pathway enrichment analysis revealed that some differentially expressed genes were classified into fatty acid-related pathways. After comparison of these differentially expressed genes with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, 20 genes homologous to other species were obtained. After analysis, 10 candidate genes were screened by GWAS and RNA-seq screening. Of these 10 genes, qRT-PCR assays using flax seeds in 5 different developmental stages showed that the expression levels of 6 candidate genes were significantly correlated with 5 fatty acid contents in seeds of the high oil variety NEW. Through metabolic pathway analysis found that 6 genes were involved in important fatty acid metabolic pathways, and some of them also have upstream and downstream regulation relations. The present study combined GWAS and RNA-seq methods to identify candidate genes for fatty acid metabolism in flax seeds, which provided reference for screening of candidate genes with complex traits.


Assuntos
Ácidos Graxos/metabolismo , Linho/genética , Genes de Plantas , Estudo de Associação Genômica Ampla , Transcriptoma , Linho/metabolismo , Regulação da Expressão Gênica de Plantas , Sementes/metabolismo , Análise de Sequência de RNA
17.
BMC Plant Biol ; 19(1): 312, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307379

RESUMO

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


Assuntos
Fibra de Algodão , Genes de Plantas , Gossypium/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Gossypium/crescimento & desenvolvimento , Proteínas de Homeodomínio/genética , Filogenia , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética
18.
BMC Plant Biol ; 19(1): 317, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307384

RESUMO

BACKGROUND: Anthocyanins, which are colored pigments, have long been used as food and pharmaceutical ingredients due to their potential health benefits, but the intermediate signals through which environmental or developmental cues regulate anthocyanin biosynthesis remains poorly understood. Fleshy fruits have become a good system for studying the regulation of anthocyanin biosynthesis, and exploring the mechanism underlying pigment metabolism is valuable for controlling fruit ripening. RESULTS: The present study revealed that ABA accumulated during Lycium fruit ripening, and this accumulation was positively correlated with the anthocyanin contents and the LbNCED1 transcript levels. The application of exogenous ABA and of the ABA biosynthesis inhibitor fluridon increased and decreased the content of anthocyanins in Lycium fruit, respectively. This is the first report to show that ABA promotes the accumulation of anthocyanins in Lycium fruits. The variations in the anthocyanin content were consistent with the variations in the expression of the genes encoding the MYB-bHLH-WD40 transcription factor complex or anthocyanin biosynthesis-related enzymes. Virus-induced LbNCED1 gene silencing significantly slowed fruit coloration and decreased both anthocyanin and ABA accumulation during Lycium fruit ripening. An qRT-PCR analysis showed that LbNCED1 gene silencing clearly reduced the transcript levels of both structural and regulatory genes in the flavonoid biosynthetic pathway. CONCLUSIONS: Based on the results, a model of ABA-mediated development-dependent anthocyanin biosynthesis and fruit coloration during Lycium fruit maturation was proposed. In this model, the developmental cues transcriptionally activates LbNCED1 and thus enhances accumulation of the phytohormone ABA, and the accumulated ABA stimulates transcription of the MYB-bHLH-WD40 transcription factor complex to upregulate the expression of structural genes in the flavonoid biosynthetic pathway and thereby promoting anthocyanin production and fruit coloration. Our results provide a valuable strategy that could be used in practice to regulate the ripening and quality of fresh fruit in medicinal and edible plants by modifying the phytohormone ABA.


Assuntos
Ácido Abscísico/metabolismo , Antocianinas/biossíntese , Frutas/metabolismo , Lycium/metabolismo , Pigmentação , Reguladores de Crescimento de Planta/metabolismo , Dioxigenases/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , Lycium/genética , Lycium/crescimento & desenvolvimento , Proteínas de Plantas/genética , Transdução de Sinais
19.
Bioresour Technol ; 289: 121720, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271916

RESUMO

Haematococcus pluvialis is a main biological resource for the antioxidant astaxanthin production, however, potential modulators and molecular mechanisms underpinning astaxanthin accumulation remain largely obscured. We discovered that provision of ethanol (0.4%) significantly triggered the cellular astaxanthin content up to 3.85% on the 4th day of treatment. Amongst, 95% of the accumulated astaxanthin was esterified, particularly enriched with monoesters. Ultrastructural analysis revealed that ethanol altered cell wall structure and physiological properties. Antioxidant analyses revealed that astaxanthin accumulation offset the ethanol induced oxidative stress. Ethanol treatment reduced carbohydrates while increased lipids and jasmonic acid production. Transcriptomic analysis uncovered that ethanol orchestrated the expression of crucial genes involved in carotenogenesis, e.g. PSY, BKT and CRTR-b were significantly upregulated. Moreover, methyl jasmonic acid synthesis was induced and played a major role in regulating the carotenogenic genes. The findings uncovered the novel viewpoint in the intricate transcriptional regulatory mechanisms of astaxanthin biosynthesis.


Assuntos
Clorofíceas/metabolismo , Ciclopentanos/metabolismo , Etanol/farmacologia , Oxilipinas/metabolismo , Clorofíceas/efeitos dos fármacos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Xantofilas/biossíntese
20.
J Agric Food Chem ; 67(30): 8319-8331, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31287308

RESUMO

The layer of cuticular wax covering fruits plays important roles in protecting against disease, preventing non-stomatal water loss, and extending shelf life. However, the molecular basis of cuticular wax biosynthesis in pear (Pyrus) fruits remains elusive. Our study thoroughly investigates cuticular wax biosynthesis during pear fruit development from morphologic, transcriptomic, and gas chromatography-mass spectrometry metabolomic perspectives. Our results showed that cuticular wax concentrations increased during the early stage [20-80 days after full bloom (DAFB)] from 0.64 mg/cm2 (50 DAFB) to 1.75 mg/cm2 (80 DAFB) and then slightly decreased to 1.22 mg/cm2 during the fruit ripening period (80-140 DAFB). Scanning electron microscopy imaging indicated that wax plate crystals increased and wax structures varied during the pear fruit development. The combined transcriptomic and metabolomic profiling analysis revealed 27 genes, including 12 genes encoding transcription factors and a new structural gene (Pbr028523) encoding ß-amyrin synthase, participating in the biosynthesis, transport, and regulation of cuticular wax according to their expression patterns in pear fruit. The quantitative real-time polymerase chain reaction experiments of 18 differentially expressed genes were performed and confirmed the accuracy of the RNA-Seq-derived transcript expression. A model of VLCFAs and cuticular wax synthesis and transport in pear fruit is proposed, providing a mechanistic framework for understanding cuticular wax biosynthesis in pear fruit. These results and data sets provide a foundation for the molecular events related to cuticular wax in 'Yuluxiang' pear fruit and may also help guide the functional analyses of candidate genes important for improving the cuticular wax of pear fruit in the future.


Assuntos
Epiderme/metabolismo , Frutas/crescimento & desenvolvimento , Pyrus/genética , Ceras/metabolismo , Epiderme/química , Frutas/química , Frutas/genética , Frutas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica de Plantas , Metabolômica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pyrus/química , Pyrus/crescimento & desenvolvimento , Pyrus/metabolismo , Transcriptoma
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