scholarly journals Arabidopsis ERF4 and MYB52 Transcription Factors Play Antagonistic Roles in Regulating Homogalacturonan De-methylesterification in Seed Coat Mucilage

2020 ◽  
Author(s):  
Anming Ding ◽  
Xianfeng Tang ◽  
Linhe Han ◽  
Jianlu Sun ◽  
Angyan Ren ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Seed Coat ◽  
Pectin Methylesterase ◽  
Wild Type ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Transcriptional Complex ◽  
Seed Coat Mucilage ◽  
Seed Mucilage

ABSTRACTThe Arabidopsis (Arabidopsis thaliana) seed coat mucilage is a specialized cell wall with pectin as its major component. Pectin is synthesized in the Golgi apparatus with homogalacturonan fully methylesterified, but it must undergo de-methylesterification by pectin methylesterase (PME) after being secreted into the cell wall. This reaction is critical for pectin maturation, but the mechanisms of its transcriptional regulation remain largely unknown. Here, we show that the Arabidopsis ERF4 transcription factor positively regulates pectin de-methylesterification during seed development and directly suppresses the expression of PME INHIBITOR13 (PMEI13), 14, 15 and SUBTILISIN-LIKE SERINE PROTEASE 1.7 (SBT1.7). The erf4 mutant seeds showed repartitioning of mucilage between soluble and adherent layers as a result of decreased PME activity and increased degree of pectin methylesterification. ERF4 physically associates with and antagonizes MYB52 in activating PMEI6, 14 and SBT1.7 and MYB52 also antagonizes ERF4 activity in the regulation of downstream targets. Gene expression studies revealed that ERF4 and MYB52 have opposite effects on pectin de-methylesterification. Genetic analysis indicated that the erf4-2 myb52 double mutant seeds show mucilage phenotype similar to wild-type. Taken together, this study demonstrates that ERF4 and MYB52 antagonize each other’s activity to maintain the appropriate degree of pectin methylesterification, expanding our understanding of how pectin de-methylesterification is fine-tuned by the ERF4-MYB52 transcriptional complex in the seed mucilage.One-sentence summaryArabidopsis ERF4 and MYB52 transcription factors interact and play antagonistic roles in regulating homogalacturonan de-methylesterification related genes in the seed coat mucilage.

The chinless mutation and neural crest cell interactions in zebrafish jaw development

Development ◽  
1996 ◽  
Vol 122 (5) ◽  
pp. 1417-1426 ◽  
Author(s):  
T.F. Schilling ◽  
C. Walker ◽  
C.B. Kimmel
Keyword(s):  
Neural Crest ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Paraxial Mesoderm ◽  
Wild Type ◽  
Host Genotype ◽  
Pharyngeal Arches ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Cranial Neural Crest Cells

During vertebrate development, neural crest cells are thought to pattern many aspects of head organization, including the segmented skeleton and musculature of the jaw and gills. Here we describe mutations at the gene chinless, chn, that disrupt the skeletal fates of neural crest cells in the head of the zebrafish and their interactions with muscle precursors. chn mutants lack neural-crest-derived cartilage and mesoderm-derived muscles in all seven pharyngeal arches. Fate mapping and gene expression studies demonstrate the presence of both undifferentiated cartilage and muscle precursors in mutants. However, chn blocks differentiation directly in neural crest, and not in mesoderm, as revealed by mosaic analyses. Neural crest cells taken from wild-type donor embryos can form cartilage when transplanted into chn mutant hosts and rescue some of the patterning defects of mutant pharyngeal arches. In these cases, cartilage only forms if neural crest is transplanted at least one hour before its migration, suggesting that interactions occur transiently in early jaw precursors. In contrast, transplanted cells in paraxial mesoderm behave according to the host genotype; mutant cells form jaw muscles in a wild-type environment. These results suggest that chn is required for the development of pharyngeal cartilages from cranial neural crest cells and subsequent crest signals that pattern mesodermally derived myocytes.

scholarly journals Phosphoproteomics of Aspergillus fumigatus Exposed to the Antifungal Drug Caspofungin

mSphere ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Eliciane Cevolani Mattos ◽  
Giuseppe Palmisano ◽  
Gustavo H. Goldman
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Aspergillus Fumigatus ◽  
Protein Kinases ◽  
Pathogenic Fungus ◽  
Fungal Growth ◽  
Wild Type ◽  
Content Type ◽  
Mitogen Activated Protein ◽  
High Concentrations

ABSTRACT Aspergillus fumigatus is an opportunistic and allergenic pathogenic fungus, responsible for fungal infections in humans. A. fumigatus infections are usually treated with polyenes, azoles, or echinocandins. Echinocandins, such as caspofungin, can inhibit the biosynthesis of the β-1,3-glucan polysaccharide, affecting the integrity of the cell wall and leading to fungal death. In some A. fumigatus strains, caspofungin treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Here, we analyze the proteome and phosphoproteome of the A. fumigatus wild-type strain and of mitogen-activated protein kinase (MAPK) mpkA and sakA null mutant strains during CPE (2 μg/ml caspofungin for 1 h). The wild-type proteome showed 75 proteins and 814 phosphopeptides (corresponding to 520 proteins) altered in abundance in response to caspofungin treatment. The ΔmpkA (ΔmpkA caspofungin/wild-type caspofungin) and ΔsakA (ΔsakA caspofungin/wild-type caspofungin) strains displayed 626 proteins and 1,236 phosphopeptides (corresponding to 703 proteins) and 101 proteins and 1,217 phosphopeptides (corresponding to 645 proteins), respectively, altered in abundance. Functional characterization of the phosphopeptides from the wild-type strain exposed to caspofungin showed enrichment for transcription factors, protein kinases, and cytoskeleton proteins. Proteomic analysis of the ΔmpkA and ΔsakA mutants indicated that control of proteins involved in metabolism, such as in production of secondary metabolites, was highly represented in both mutants. Results of functional categorization of phosphopeptides from both mutants were very similar and showed a high number of proteins with decreased phosphorylation of proteins involved in transcriptional control, DNA/RNA binding, cell cycle control, and DNA processing. This report reveals novel transcription factors involved in caspofungin tolerance. IMPORTANCE Aspergillus fumigatus is an opportunistic human-pathogenic fungus causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. Caspofungin is an echinocandin that impacts the construction of the fungal cell wall by inhibiting the biosynthesis of the β-1,3-glucan polysaccharide. Caspofungin is a fungistatic drug and is recommended as a second-line therapy for treatment of aspergillosis. Treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Collaboration between the mitogen-activated protein kinases (MAPK) of the cell wall integrity (MapkA) and high-osmolarity glycerol (SakA) pathways is essential for CPE. Here, we investigate the global proteome and phosphoproteome of A. fumigatus wild-type, ΔmpkA, and ΔsakA strains upon CPE. This study showed intense cross talk between the two MAPKs for the CPE and identified novel protein kinases and transcription factors possibly important for CPE. Increased understanding of how the modulation of protein phosphorylation may affect the fungal growth in the presence of caspofungin represents an important step in the development of new strategies and methods to combat the fungus inside the host.

scholarly journals Identification of MEDIATOR16 as the Arabidopsis COBRA suppressor MONGOOSE1

2015 ◽  
Vol 112 (52) ◽  
pp. 16048-16053 ◽  
Author(s):  
Nadav Sorek ◽  
Heidi Szemenyei ◽  
Hagit Sorek ◽  
Abigail Landers ◽  
Heather Knight ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcriptome Analysis ◽  
Pectin Methylesterase ◽  
Cell Wall Integrity ◽  
Cellulose Biosynthesis ◽  
Wild Type ◽  
Growth Defects ◽  
Genetic Suppressors ◽  
Biosynthesis Inhibitors

We performed a screen for genetic suppressors of cobra, an Arabidopsis mutant with defects in cellulose formation and an increased ratio of unesterified/esterified pectin. We identified a suppressor named mongoose1 (mon1) that suppressed the growth defects of cobra, partially restored cellulose levels, and restored the esterification ratio of pectin to wild-type levels. mon1 was mapped to the MEDIATOR16 (MED16) locus, a tail mediator subunit, also known as SENSITIVE TO FREEZING6 (SFR6). When separated from the cobra mutation, mutations in MED16 caused resistance to cellulose biosynthesis inhibitors, consistent with their ability to suppress the cobra cellulose deficiency. Transcriptome analysis revealed that a number of cell wall genes are misregulated in med16 mutants. Two of these genes encode pectin methylesterase inhibitors, which, when ectopically expressed, partially suppressed the cobra phenotype. This suggests that cellulose biosynthesis can be affected by the esterification levels of pectin, possibly through modifying cell wall integrity or the interaction of pectin and cellulose.

Molecular analysis of the hull-less seed trait in pumpkin: expression profiles of genes related to seed coat development11

2005 ◽  
Vol 15 (3) ◽  
pp. 205-217 ◽  
Author(s):  
Todd N. Bezold ◽  
Dennis Mathews ◽  
J. Brent Loy ◽  
Subhash C. Minocha
Keyword(s):  
Cell Wall ◽  
Seed Coat ◽  
Secondary Cell Wall ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Lignin Biosynthesis ◽  
Molecular Data ◽  
Wild Type ◽  
In The Wild ◽  
Cell Wall Development

We undertook a comparative study of molecular changes during development of seed coats in the wild-type and a recessive hull-less mutant of pumpkin (Cucurbita pepo L.), with the goal of identifying key genes involved in secondary cell wall development in the testa. The mature mutant testa has reduced amounts of cellulose and lignin as compared to the wild type. The expression patterns of several genes involved in secondary cell wall biosynthesis during the development of the testa are described. These genes are: CELLULOSE SYNTHASE, PHENYLALANINE AMMONIA-LYASE, 4-COUMARATE-CoA LIGASE, and CINNAMOYL-CoA REDUCTASE. Additionally, the expression patterns of a few genes that were differentially expressed in the two genotypes during testa development (GLUTATHIONE REDUCTASE, ABSCISIC ACID RESPONSE PROTEIN E, a SERINE-THREONINE KINASE, and a β-UREIDOPROPIONASE) are presented. The results show a coordinated expression of several genes involved in cellulose and lignin biosynthesis, as well as marked differences in the level of their expression between the two genotypes during testa development. There is generally a higher expression of genes involved in cellulose and lignin biosynthesis in the wild-type testa as compared to the mutant. The molecular data presented here are consistent with anatomical and biochemical differences between the wild-type and the mutant testae. An understanding of the genes involved in cell wall development in the testa will facilitate the manipulation of seed coat development in Cucurbita and other species for diverse commercial applications.

scholarly journals Seed coat mucilage cells ofArabidopsis thalianaas a model for plant cell wall research

2010 ◽  
Vol 5 (7) ◽  
pp. 796-801 ◽  
Author(s):  
Andrej A. Arsovski ◽  
George W Haughn ◽  
Tamara L. Western
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Seed Coat ◽  
Plant Cell Wall ◽  
Seed Coat Mucilage

scholarly journals MmpS5-MmpL5 Transporters Provide Mycobacterium smegmatis Resistance to imidazo[1,2-b][1,2,4,5]tetrazines

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 166 ◽  
Author(s):  
Dmitry A. Maslov ◽  
Kirill V. Shur ◽  
Aleksey A. Vatlin ◽  
Valery N. Danilenko
Keyword(s):  
Gene Expression ◽  
Mycobacterium Smegmatis ◽  
Drug Resistant ◽  
Wild Type ◽  
Efflux System ◽  
Mechanisms Of Resistance ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Mutant Genes

The emergence and spread of drug-resistant Mycobacterium tuberculosis strains (including MDR, XDR, and TDR) force scientists worldwide to search for new anti-tuberculosis drugs. We have previously reported a number of imidazo[1,2-b][1,2,4,5]tetrazines – putative inhibitors of mycobacterial eukaryotic-type serine-threonine protein-kinases, active against M. tuberculosis. Whole genomic sequences of spontaneous drug-resistant M. smegmatis mutants revealed four genes possibly involved in imidazo[1,2-b][1,2,4,5]tetrazines resistance; however, the exact mechanism of resistance remain unknown. We used different approaches (construction of targeted mutants, overexpression of the wild-type (w.t.) and mutant genes, and gene-expression studies) to assess the role of the previously identified mutations. We show that mutations in MSMEG_1380 gene lead to overexpression of the mmpS5-mmpL5 operon in M. smegmatis, thus providing resistance to imidazo[1,2-b][1,2,4,5]tetrazines by increased efflux through the MmpS5-MmpL5 system, similarly to the mechanisms of resistance described for M. tuberculosis and M. abscessus. Mycobacterial MmpS5-MmpL5 transporters should be considered as an MDR-efflux system and they should be taken into account at early stages of anti-tuberculosis drug development.

scholarly journals σB Activation under Environmental and Energy Stress Conditions in Listeria monocytogenes

2006 ◽  
Vol 72 (8) ◽  
pp. 5197-5203 ◽  
Author(s):  
Soraya Chaturongakul ◽  
Kathryn J. Boor
Keyword(s):  
Listeria Monocytogenes ◽  
Cumene Hydroperoxide ◽  
Stress Conditions ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Transcript Levels ◽  
Energy Stress ◽  
Expression Studies ◽  
Genes Encoding ◽  
Gene Expression Studies

ABSTRACT To measure σB activation in Listeria monocytogenes under environmental or energy stress conditions, quantitative reverse transcriptase PCR (TaqMan) was used to determine the levels of transcripts for the σB-dependent opuCA and clpC genes in strains having null mutations in genes encoding regulator of sigma B proteins (rsbT and rsbV) and sigma B (sigB) and in the L. monocytogenes wild-type 10403S strain under different stress conditions. The ΔsigB, ΔrsbT, and ΔrsbV strains previously exhibited increased hemolytic activities compared to the hemolytic activity of the wild-type strain; therefore, transcript levels for hly were also determined. RsbT, RsbV, and σB were all required for opuCA expression during growth under carbon-limiting conditions or following exposure to pH 4.5, salt, ethanol, or the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP). Expression of clpC was RsbT, RsbV, and σB dependent in the presence of CCCP but not under the other conditions. hly expression was not RsbT, RsbV, or σB dependent in the presence of either CCCP or salt. opuCA transcript levels did not increase in the presence of rapidly lethal stresses (i.e., pH 2.5 or 13 mM cumene hydroperoxide) despite the enhanced survival of the wild type compared with the survival of the mutant strains under these conditions. These findings highlight the importance of complementing phenotypic characterizations with gene expression studies to identify direct and indirect effects of null mutations in regulatory genes, such as sigB. Overall, our data show that while σB activation occurs through a single pathway under both environmental and energy stress conditions, regulation of expression of some stress response and virulence genes in the σB regulon (e.g., clpC) appears to require networks involving multiple transcriptional regulators.

scholarly journals Norway spruce deploys tissue-specific responses during acclimation to cold

2021 ◽  
Author(s):  
Alexander Vergara ◽  
Julia Haas ◽  
Tuuli Aro ◽  
Paulina Stachula ◽  
Nathaniel Street ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cold Acclimation ◽  
Norway Spruce ◽  
Transcriptional Response ◽  
Early Response ◽  
Response Strategies ◽  
Developmental States ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
Responsive Element

Cold acclimation in plants is a complex phenomenon involving numerous stress-responsive transcriptional and metabolic pathways. Existing gene expression studies have primarily addressed cold acclimation responses in herbaceous plants, and few have focused on perennial evergreens, such as conifers, that survive extremely low temperatures during winter. Relative to Arabidopsis leaves, the main transcriptional response of Norway spruce (Picea abies (L.) H. Karst) needles exposed to cold was delayed, and this delay was associated with slower development of freezing tolerance. Despite this difference in timing, our results indicate that, similar to herbaceous species, Norway spruce principally utilizes early response transcription factors (TFs) of the APETALA 2/ethylene-responsive element binding factor (AP2/ERF) superfamily and NAM (no apical meristem)/ATAF (Arabidopsis Transcription Factors)/CUC (cup shaped cotyledon) (NACs). The needles and root of Norway spruce showed contrasting results, in keeping with their different metabolic and developmental states. Regulatory network analysis identified conserved TFs, including a root-specific bHLH101 homolog, and other members of the same TF family with a pervasive role in cold regulation, such as homologs of ICE1 and AKS3, and also homologs of the NAC (anac47 and anac28) and AP2/ERF superfamilies (DREB2 and ERF3), providing new functional insights into cold stress response strategies in Norway spruce.

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