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Although the T helper 2 (Th2) subset is a critical player in the humoral immune response to extracellular parasites and suppression of Th1-mediated inflammation, Th2 cells have been implicated in allergic inflammatory diseases such as asthma, allergic rhinitis, and atopic dermatitis. GATA binding protein 3 (GATA3) is a primary transcription factor that mediates Th2 differentiation and secretion of Th2 cytokines, including IL-4, IL-5, and IL-13. Here, a nucleus-deliverable form of GATA3-transcription modulation domain (TMD) (ndG3-TMD) was generated using Hph-1 human protein transduction domain (PTD) to modulate the transcriptional function of endogenous GATA3 without genetic manipulation. ndG3-TMD was shown to be efficiently delivered into the cell nucleus quickly without affecting cell viability or intracellular signaling events for T cell activation. ndG3-TMD exhibited a specific inhibitory function for the endogenous GATA3-mediated transcription, such as Th2 cell differentiation and Th2-type cytokine production. Intranasal administration of ndG3-TMD significantly alleviated airway hyperresponsiveness, infiltration of immune cells, and serum IgE level in an OVA-induced mouse model of asthma. Also, Th2 cytokine secretion by the splenocytes isolated from the ndG3-TMD-treated mice substantially decreased. Our results suggest that ndG3-TMD can be a new therapeutic reagent to suppress Th2-mediated allergic diseases through intranasal delivery.
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Asma , Fator de Transcrição GATA3 , Hipersensibilidade Respiratória , Animais , Humanos , Camundongos , Administração Intranasal , Asma/terapia , Núcleo Celular/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Fator de Transcrição GATA3/administração & dosagem , Fator de Transcrição GATA3/química , Camundongos Endogâmicos BALB C , Ovalbumina , Hipersensibilidade Respiratória/terapia , Células Th2RESUMO
The calmodulin-binding transcription activators (CAMTAs) mediate transcriptional regulation of development, growth, and responses to various environmental stresses in plants. To understand the biological roles of soybean CAMTA (GmCAMTA) family members in response to abiotic stresses, we characterized expression patterns of 15 GmCAMTA genes in response to various abiotic stresses. The GmCAMTA genes exhibited distinct circadian regulation expression patterns and were differently expressed in response to salt, drought, and cold stresses. Interestingly, the expression levels of GmCAMTA2, GmCAMTA8, and GmCAMTA12 were higher in stem tissue than in other soybean tissues. To determine the roles of GmCAMTAs in the regulation of developmental processes and stress responses, we isolated GmCAMTA2 and GmCAMTA8 cDNAs from soybean and generated Arabidopsis overexpressing transgenic plants. The GmCAMTA2-OX and GmCAMTA8-OX plants showed hypersensitivity to drought stress. The water in the leaves of GmCAMTA2-OX and GmCAMTA8-OX plants was lost faster than that in wild-type (WT) plants under drought-stress conditions. In addition, stress-responsive genes were down-regulated in the GmCAMTA2-OX and GmCAMTA8-OX plants under drought stress conditions compared to WT plants. Our results suggest that GmCAMTA2 and GmCAMTA8 genes are regulated by circadian rhythms and function as negative regulators in development and drought stress responses.
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Arabidopsis , Glycine max , Glycine max/metabolismo , Calmodulina/metabolismo , Secas , Fatores de Transcrição/metabolismo , Estresse Fisiológico/genética , Arabidopsis/metabolismo , Resposta ao Choque Frio/genética , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Although recent studies suggest that the plant cytoskeleton is associated with plant stress responses, such as salt, cold, and drought, the molecular mechanism underlying microtubule function in plant salt stress response remains unclear. We performed a comparative proteomic analysis between control suspension-cultured cells (A0) and salt-adapted cells (A120) established from Arabidopsis root callus to investigate plant adaptation mechanisms to long-term salt stress. We identified 50 differentially expressed proteins (45 up- and 5 down-regulated proteins) in A120 cells compared with A0 cells. Gene ontology enrichment and protein network analyses indicated that differentially expressed proteins in A120 cells were strongly associated with cell structure-associated clusters, including cytoskeleton and cell wall biogenesis. Gene expression analysis revealed that expressions of cytoskeleton-related genes, such as FBA8, TUB3, TUB4, TUB7, TUB9, and ACT7, and a cell wall biogenesis-related gene, CCoAOMT1, were induced in salt-adapted A120 cells. Moreover, the loss-of-function mutant of Arabidopsis TUB9 gene, tub9, showed a hypersensitive phenotype to salt stress. Consistent overexpression of Arabidopsis TUB9 gene in rice transgenic plants enhanced tolerance to salt stress. Our results suggest that microtubules play crucial roles in plant adaptation and tolerance to salt stress. The modulation of microtubule-related gene expression can be an effective strategy for developing salt-tolerant crops.
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Proteínas de Arabidopsis/fisiologia , Arabidopsis , Microtúbulos/fisiologia , Oryza , Tolerância ao Sal , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , Oryza/fisiologia , Plantas Geneticamente Modificadas/fisiologiaRESUMO
Global warming has an impact on crop growth and development. Flowering time is particularly sensitive to environmental factors such as day length and temperature. In this study, we investigated the effects of global warming on flowering using an open-top Climatron chamber, which has a higher temperature and CO2 concentration than in the field. Two different soybean cultivars, Williams 82 and IT153414, which exhibited different flowering times, were promoted flowering in the open-top Climatron chamber than in the field. We more specifically examined the expression patterns of soybean flowering genes on the molecular level under high-temperature conditions. The elevated temperature induced the expression of soybean floral activators, GmFT2a and GmFT5a as well as a set of GmCOL genes. In contrast, it suppressed floral repressors, E1 and E2 homologs. Moreover, high-temperature conditions affected the expression of these flowering genes in a day length-independent manner. Taken together, our data suggest that soybean plants properly respond and adapt to changing environments by modulating the expression of a set of flowering genes in the photoperiod pathway for the successful production of seeds and offspring.
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Perfilação da Expressão Gênica/métodos , Glycine max/crescimento & desenvolvimento , Proteínas de Plantas/genética , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Aquecimento Global , Temperatura Alta , Fotoperíodo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glycine max/genética , Estresse FisiológicoRESUMO
Sessile plants reprogram their metabolic and developmental processes during adaptation to prolonged environmental stresses. To understand the molecular mechanisms underlying adaptation of plant cells to saline stress, we established callus suspension cell cultures from Arabidopsis roots adapted to high salt for an extended period of time. Adapted cells exhibit enhanced salt tolerance compared with control cells. Moreover, acquired salt tolerance is maintained even after the stress is relieved, indicating the existence of a memory of acquired salt tolerance during mitotic cell divisions, known as mitotic stress memory. Metabolite profiling using 1H-nuclear magnetic resonance (NMR) spectroscopy revealed metabolic discrimination between control, salt-adapted and stress-memory cells. Compared with control cells, salt-adapted cells accumulated higher levels of sugars, amino acids and intermediary metabolites in the shikimate pathway, such as coniferin. Moreover, adapted cells acquired thicker cell walls with higher lignin contents, suggesting the importance of adjustments of physical properties during adaptation to elevated saline conditions. When stress-memory cells were reverted to normal growth conditions, the levels of metabolites again readjusted. Whereas most of the metabolic changes reverted to levels intermediate between salt-adapted and control cells, the amounts of sugars, alanine, γ-aminobutyric acid and acetate further increased in stress-memory cells, supporting a view of their roles in mitotic stress memory. Our results provide insights into the metabolic adjustment of plant root cells during adaptation to saline conditions as well as pointing to the function of mitotic memory in acquired salt tolerance.
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Arabidopsis/metabolismo , Metabolômica/métodos , Arabidopsis/genética , Mitose/genética , Mitose/fisiologia , Estresse Salino/genética , Estresse Salino/fisiologia , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologiaRESUMO
Sulfated steroids can act as a latent form of active free steroids, coexisting with them in biological specimens. To evaluate the metabolic significance of free and sulfated steroid species, a simultaneous analysis of eight free steroids [cholesterol, pregnenolone, 17α-hydroxypregnenolone, progesterone, 17α-hydroxyprogesterone, dehydroepiandrosterone (DHEA), testosterone, and 17ß-estradiol] and four biologically relevant sulfated steroids was developed and validated, using selected-ion and multiple-reaction monitoring modes coupled to polarity-switching liquid chromatography/mass spectrometry (LC/MS). All steroids were separated on a reversed-phase phenyl column (50 mm × 2 mm, 3 µm) at a flow rate of 0.5 mL/min. The limits of quantification ranged from 0.1 to 50 ng/mL at extraction recoveries of 94.1-105.5%, while the precision and accuracy were 2.5-9.3% and 92.4-105.9%, respectively. Quantitative results obtained for samples from obese girls showed that the serum levels of DHEA sulfate were significantly increased (P = 0.004), along with the metabolic ratio representing DHEA sulfotransferase (P < 0.02). The developed novel LC/MS method can quantitatively profile both free and sulfated steroids in a single analytical run.
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Bud sports in fruit crops often result in new cultivars with unique traits, such as distinct fruit size and color, compared to their parent plants. This study investigates the phenotypic differences and gene expression patterns in Tonewase and Ohtanenashi persimmon bud sports compared to those in their parent, Hiratanenashi, based on RNA-seq data. Tonewase is characterized by early maturation, whereas Ohtanenashi is noted for its larger fruit size. Despite the importance of these traits in determining fruit quality, their molecular bases in persimmons have been understudied. We compared transcriptome-level differences during fruit development between the bud sport samples and their original cultivar. Comprehensive transcriptome analyses identified 15,814 differentially expressed genes and 26 modules via weighted gene co-expression network analysis. Certain modules exhibited unique expression patterns specific to the different cultivars during fruit development, likely contributing to the phenotypic differences observed. Specifically, M11, M16, M22, and M23 were uniquely expressed in Tonewase, whereas M13 and M24 showed distinct patterns in Ohtanenashi. By focusing on genes with distinct expression profiles, we aimed to uncover the genetic basis of cultivar-specific traits. Our findings suggest that changes in the expression of genes associated with ethylene and cell wall pathways may drive Tonewase's earlier maturation, whereas genes related to the cell cycle within the M24 module appear crucial for Ohtanenashi's larger fruit size. Additionally, ethylene and transcription factor genes within this module may contribute to the increased fruit size observed. This study elucidates the differences in transcriptomic changes during fruit development between the two bud sport samples and their original cultivar, enhancing our understanding of the genetic determinants influencing fruit size and maturation.
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Cannabis sativa L. is an industrially valuable plant known for its cannabinoids, such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), renowned for its therapeutic and psychoactive properties. Despite its significance, the cannabis industry has encountered difficulties in guaranteeing consistent product quality throughout the drying process. Hyperspectral imaging (HSI), combined with advanced machine learning technology, has been used to predict phytochemicals that presents a promising solution for maintaining cannabis quality control. We examined the dynamic changes in cannabinoid compositions under diverse drying conditions and developed a non-destructive method to appraise the quality of cannabis flowers using HSI and machine learning. Even when the relative weight and water content remained constant throughout the drying process, drying conditions significantly influenced the levels of CBD, THC, and their precursors. These results emphasize the importance of determining the exact drying endpoint. To develop HSI-based models for predicting cannabis quality indicators, including dryness, precursor conversion of CBD and THC, and CBD : THC ratio, we employed various spectral preprocessing methods and machine learning algorithms, including logistic regression (LR), support vector machine (SVM), k-nearest neighbor (KNN), random forest (RF), and Gaussian naïve Bayes (GNB). The LR model demonstrated the highest accuracy at 94.7-99.7% when used in conjunction with spectral pre-processing techniques such as multiplicative scatter correction (MSC) or Savitzky-Golay filter. We propose that the HSI-based model holds the potential to serve as a valuable tool for monitoring cannabinoid composition and determining optimal drying endpoint. This tool offers the means to achieve uniform cannabis quality and optimize the drying process in the industry.
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Rotundifuran (RF), a potent anti-inflammatory and anti-cancer compound, is a natural compound predominantly present in Vitex Rotundifolia. Herein, we investigated the effects of RF on the growth of lung cancer cells. Our findings suggested that RF inhibits cell growth, highlighting its potential as a therapeutic agent for cancer treatment. Interestingly, we observed that cell growth inhibition was not due to apoptosis, as caspases were not activated and DNA fragmentation did not occur. Furthermore, we found that intracellular vacuoles and autophagy were induced, but RF-induced cell death was not affected when autophagy was inhibited. This prompted us to investigate other possible mechanisms underlying cell growth inhibition. Through a cDNA chip analysis, we confirmed changes in the expression of ferroptosis-related genes and observed lipid peroxidation. We further examined the effect of ferroptosis inhibitors and found that they alleviated cell growth inhibition induced by RF. We also observed the involvement of calcium signaling, ROS accumulation, and JNK signaling in the induction of ferroptosis. Our findings suggested that RF is a potent anti-cancer drug and further studies are needed to validate its clinal use.
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Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver diseases and encompasses non-alcoholic steatosis, steatohepatitis, and fibrosis. Sanguisorba officinalis L. (SO) roots have traditionally been used for their antioxidant properties and have beneficial effects on metabolic disorders, including diabetes and obesity. However, its effects on hepatic steatosis and fibrosis remain unclear. In this study, we explored the effects of a 95% ethanolic SO extract (SOEE) on NAFLD and fibrosis in vivo and in vitro. The SOEE was orally administered to C57BL/6J mice fed a choline-deficient, L-amino-acid-defined, high-fat diet for 10 weeks. The SOEE inhibited hepatic steatosis by modulating hepatic malondialdehyde levels and the expression of oxidative stress-associated genes, regulating fatty-acid-oxidation-related genes, and inhibiting the expression of genes that are responsible for fibrosis. The SOEE suppressed the deposition of extracellular matrix hydroxyproline and mRNA expression of fibrosis-associated genes. The SOEE decreased the expression of fibrosis-related genes in vitro by inhibiting SMAD2/3 phosphorylation. Furthermore, the SOEE restored the gut microbial diversity and modulated specific bacterial genera associated with NAFLD and fibrosis. This study suggests that SOEE might be the potential candidate for inhibiting hepatic steatosis and fibrosis by modulating oxidative stress, fatty acid oxidation, and gut microbiota composition.
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Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Sanguisorba , Animais , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/etiologia , Estresse Oxidativo , Fibrose , Cirrose Hepática/tratamento farmacológico , Ácidos GraxosRESUMO
[This corrects the article DOI: 10.3389/fimmu.2022.1054472.].
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Regulatory T cells (Treg) are CD4+ T cells with immune-suppressive function, which is defined by Foxp3 expression. However, the molecular determinants defining the suppressive population of T cells have yet to be discovered. Here we report that the cell surface protein Lrig1 is enriched in suppressive T cells and controls their suppressive behaviors. Within CD4+ T cells, Treg cells express the highest levels of Lrig1, and the expression level is further increasing with activation. The Lrig1+ subpopulation from T helper (Th) 17 cells showed higher suppressive activity than the Lrig1- subpopulation. Lrig1-deficiency impairs the suppressive function of Treg cells, while Lrig1-deficient naïve T cells normally differentiate into other T cell subsets. Adoptive transfer of CD4+Lrig1+ T cells alleviates autoimmune symptoms in colitis and lupus nephritis mouse models. A monoclonal anti-Lrig1 antibody significantly improves the symptoms of experimental autoimmune encephalomyelitis. In conclusion, Lrig1 is an important regulator of suppressive T cell function and an exploitable target for treating autoimmune conditions.
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Autoimunidade , Colite , Animais , Camundongos , Linfócitos T CD4-Positivos , Linfócitos T Reguladores , Transferência Adotiva , Fatores de Transcrição , Fatores de Transcrição Forkhead/genéticaRESUMO
Th17 cells are implicated in the pathogenesis of several autoimmune diseases. During the inflammation, Th17 cells exposed to IL-12 can shift towards the Th1 phenotype. These shifted cells are defined as 'non-classic Th1 cells'. Th17-derived non-classic Th1 cells play a critical role in late-onset chronic inflammatory diseases and are more pathogenic than the unshifted Th17 cells. Eomes is a transcription factor highly expressed in non-classic Th1 cells. To study the functional role of Eomes without genetic alteration, novel recombinant protein, ntEomes-TMD, was generated by fusing TMD of Eomes and Hph-1-PTD that facilitate intracellular delivery of its cargo molecule. ntEomes-TMD was delivered into the nucleus of the cells without influencing the T cell activation and cytotoxicity. ntEomes-TMD specifically inhibited the Eomes- and ROR-γt-mediated transcription and suppressed the Th1 and Th17 differentiation. Interestingly, ntEomes-TMD blocked the generation of non-classic Th1 cells from Th17 cells, leading to the inhibition of IFN-γ and GM-CSF secretion. In EAE, ntEomes-TMD alleviated the symptoms of EAE, and the combination treatment using ntEomes-TMD and anti-IL-17 mAb together showed better therapeutic efficacy than anti-IL-17 mAb treatment. The results suggest that ntEomes-TMD can be a new therapeutic reagent for treating chronic inflammatory diseases associated with non-classic Th1 cells.
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Encefalomielite Autoimune Experimental , Células Th17 , Animais , Diferenciação Celular , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/metabolismo , Inflamação , Células Th1/metabolismo , Células Th1/patologia , Células Th17/metabolismo , Células Th17/patologiaRESUMO
Qigong and Tai chi are traditional methods of physical and mental training and exercises in East Asia. Their health-promoting effects against various diseases have been studied for a long time, and they have been the subject of many clinical trials and systematic reviews (SRs). The present study aimed to comprehensively evaluate all published SRs on Qigong and Tai chi and to summarize the supporting evidence. The following databases were searched: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Research Information Sharing Service, and Korean Studies Information Service System. The selection and extraction processes were performed by two independent reviewers, and a qualitative synthesis was conducted. There were 58 SRs of randomized controlled trials on Qigong and Tai chi. There have been many studies on patients with cardiovascular diseases and different cancers, and a number of other studies in which mobility, quality of life, blood lipids, and blood pressure were outcome measurements. Thus, Qigong and Tai chi for various diseases and medical conditions have been accumulated. Based on current evidence, the number of publications of Qigong and Tai chi-related articles showed an increasing trend, and most of them were performed in China. Qigong and Tai chi have shown beneficial effects in different age groups and health conditions, including decreasing blood lipid level, reducing blood pressure, facilitating mobility, preventing falls, and improving overall quality of life.
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Qigong , Tai Chi Chuan , Humanos , Pressão Sanguínea , Qigong/métodos , Qualidade de Vida , Revisões Sistemáticas como Assunto , Tai Chi Chuan/métodosRESUMO
T helper 1 cells (Th1 cells) and T helper 17 cells (Th17 cells) play pivotal roles in the pathogenesis of various autoimmune diseases, including psoriasis and inflammatory bowel disease (IBD). Signal transducer and activator of transcription 1 (STAT1) regulates the Th1 and Th17 cell lineage commitment at an early stage and maintains their immunological functions in vitro and in vivo. The previous strategies to block STAT1 functions to treat autoimmune diseases inhibit Th1 cell activity but simultaneously cause hyper-activation of Th17 cells. Herein, to modulate the functions of pathogenic Th1 and Th17 cells without genetic modification in normal physiological conditions, we generated the nucleus-deliverable form of the transcription modulation domain of STAT1 (ndSTAT1-TMD), which can be transduced into the nucleus of the target cells in a dose- and time-dependent manner without affecting the cell viability and T cell activation signaling events. ndSTAT1-TMD significantly blocked the differentiation of naïve CD4+ T cells into Th1 or Th17 cells via competitive inhibition of endogenous STAT1-mediated transcription, which did not influence Th2 and Treg cell differentiation. When the gene expression profile of Th1 or Th17 cells after ndSTAT1-TMD treatment was analyzed by mRNA sequencing, the expression of the genes involved in the differentiation capacity and the immunological functions of Th1 or Th17 cells were substantially reduced. The therapeutic potential of ndSTAT1-TMD was tested in the animal model of psoriasis and colitis, whose pathogenesis is mainly contributed by Th1 or/and Th17 cells. The symptoms and progression of psoriasis and colitis were significantly alleviated by ndSTAT1-TMD treatment, comparable to anti-IL-17A antibody treatment. In conclusion, our study demonstrates that ndSTAT1-TMD can be a new therapeutic reagent for Th1/17 cell-mediated autoimmune diseases by modulating the functions of pathogenic Th1 and Th17 cells together.
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Doenças Autoimunes , Colite , Psoríase , Animais , Células Th17 , Células Th1 , Colite/patologia , Psoríase/patologiaRESUMO
It is very important to understand the residual performance of a structure for repair, retrofit, and reuse of a building after a fire. In this study, an experiment is conducted on the residual performance of real-scale siliceous aggregates-based reinforced concrete (RC) wall-slab connection (WSC) after the fire, using the simple calculation method (SCM) of standards (Eurocode, ACI, and NIST) for comparison and analysis. A description of the WSC specimen and detailed methods for the experiment are introduced. The fire test is conducted according to the fire scenario by dividing it into one-sided and two-sided heating based on the wall. In the post-fire residual performance test, the load-displacement and moment-deflection angle relationship according to the fire time are derived and discussed. In addition, the residual mechanical properties after the fire are derived for the 35 MPa siliceous concrete used in the wall-slab specimen. The load and moment, derived using SCM, are compared with the experimental results. Our results show that the one-sided heating test result is close to that of Eurocode's SCM, and the two-sided heating test result is close to that of ACI (NIST)'s SCM. This study provides a database on the residual strength through a real-scale fire test and standard comparison.
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OBJECTIVE: To compare shear-wave velocities (SWVs) with shear-wave elastography of various peripheral lymph nodes (LNs). ANIMALS: 11 healthy Beagles. PROCEDURES: For each dog, bilateral mandibular, medial retropharyngeal, superficial cervical, axillary, superficial inguinal, and popliteal LNs were evaluated with shear-wave elastography in sagittal and transverse scanning planes. Depth of each lymph node was recorded, and intra- and interobserver reliability was determined. RESULTS: SWVs for all LNs were significantly higher in the sagittal scanning plane, compared with those in the transverse scanning plane. The SWV of the most superficial LN, the mandibular LN, was significantly higher, compared with that for the other LNs, except for the medial retropharyngeal LN. The SWV of the deepest LN, the medial retropharyngeal LN, was as high as that for the mandibular LN. Intra- and interobserver reliability was excellent. CONCLUSIONS AND CLINICAL RELEVANCE: SWVs for normal peripheral LNs of Beagles may serve as a reference to compare with those for other breeds and diseased LNs. Scanning plane, LN depth, and interfering tissues between the LN and the transducer may affect SWV. Shear-wave elastography may not be operator dependent.
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The proper timing of flowering in response to environmental changes is critical for ensuring crop yields. FLOWERING LOCUS T (FT) homologs of the phosphatidylethanolamine-binding protein family play important roles as floral integrators in many crops. In soybean, we identified 17 genes of this family, and characterized biological functions in flowering for ten FT homologs. Overexpression of GmFT homologs in Arabidopsis revealed that a set of GmFT homologs, including GmFT2a/2b, GmFT3a/3b, and GmFT5a/5b, promoted flowering similar to FT; in contrast, GmFT1a/1b, GmFT4, and GmFT6 delayed flowering. Consistently, expressions of GmFT2a, GmFT2b, and GmFT5a were induced in soybean leaves in response to floral inductive short days, whereas expressions of GmFT1a and GmFT4 were induced in response to long days. Exon swapping analysis between floral activator GmFT2a and floral repressor GmFT4 revealed that the segment B region in the fourth exon is critical for their antagonistic functions. Finally, expression analysis of GmFT2a, GmFT5a, and GmFT4 in soybean accessions exhibiting various flowering times indicated that the mRNA levels of GmFT2a and GmFT5a were higher in early flowering accessions than in late-flowering accessions, while GmFT4 showed the opposite pattern. Moreover, the relative mRNA levels between GmFT2a/GmFT5a and GmFT4 was important in determining day length-dependent flowering in soybean accessions. Taken together, our results suggest that the functions of GmFT homologs have diversified into floral activators and floral repressors during soybean evolution, and the timing of flowering in response to changing day length is determined by modulating the activities of antagonistic GmFT homologs.
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Plants possess adaptive reprogramed modules to prolonged environmental stresses, including adjustment of metabolism and gene expression for physiological and morphological adaptation. CCoAOMT1 encodes a caffeoyl CoA O-methyltransferase and is known to play an important role in adaptation of Arabidopsis plants to prolonged saline stress. In this study, we showed that the CCoAOMT1 gene plays a role in drought stress response. Transcript of CCoAOMT1 was induced by salt, dehydration (drought), and methyl viologen (MV), and loss of function mutants of CCoAOMT1, ccoaomt1-1, and ccoaomt1-2 exhibit hypersensitive phenotypes to drought and MV stresses. The ccoaomt1 mutants accumulated higher level of H2O2 in the leaves and expressed lower levels of drought-responsive genes including RD29B, RD20, RD29A, and ERD1, as well as ABA3 3 and NCED3 encoding ABA biosynthesis enzymes during drought stress compared to wild-type plants. A seed germination assay of ccoaomt1 mutants in the presence of ABA also revealed that CCoAOMT1 functions in ABA response. Our data suggests that CCoAOMT1 plays a positive role in response to drought stress response by regulating H2O2 accumulation and ABA signaling.
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Salinity is a major abiotic stressor that limits the growth, development, and reproduction of plants. Our previous metabolic analysis of high salt-adapted callus suspension cell cultures from Arabidopsis roots indicated that physical reinforcement of the cell wall is an important step in adaptation to saline conditions. Compared to normal cells, salt-adapted cells exhibit an increased lignin content and thickened cell wall. In this study, we investigated not only the lignin biosynthesis gene expression patterns in salt-adapted cells, but also the effects of a loss-of-function of CCoAOMT1, which plays a critical role in the lignin biosynthesis pathway, on plant responses to high-salt stress. Quantitative real-time PCR analysis revealed higher mRNA levels of genes involved in lignin biosynthesis, including CCoAOMT1, 4CL1, 4CL2, COMT, PAL1, PAL2, and AtPrx52, in salt-adapted cells relative to normal cells, which suggests activation of the lignin biosynthesis pathway in salt-adapted cells. Moreover, plants harboring the CCoAOMT1 mutants, ccoaomt1-1 and ccoaomt1-2, were phenotypically hypersensitive to salt stress. Our study has provided molecular and genetic evidence indicating the importance of enhanced lignin accumulation in the plant cell wall during the responses to salt stress.