scholarly journals Fungal gene expression during ectomycorrhiza formation

1995 ◽  
Vol 73 (S1) ◽  
pp. 541-547 ◽  
Author(s):  
F. Martin ◽  
P. Laurent ◽  
D. de Carvalho ◽  
T. Burgess ◽  
P. Murphy ◽  
...  
Keyword(s):  
Cell Walls ◽  
Molecular Mechanisms ◽  
Sequence Similarity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Pisolithus Tinctorius ◽  
Amino Acid Sequence Similarity ◽  
Cell Fractionation ◽  
Fungal Cell ◽  
Temporal Expressions ◽  
Fungal Genes

Ectomycorrhiza development involves the differentiation of structurally specialized fungal tissues (e.g., mantle and Hartig net) and an interface between symbionts. Polypeptides presenting a preferential, up-, or down-regulated synthesis have been characterized in several developing ectomycorrhizal associations. Their spatial and temporal expressions have been characterized by cell fractionation, two-dimensional polyacrylamide gel electrophoresis, and immunochemical assays in the Eucalyptus spp. – Pisolithus tinctorius mycorrhizas. These studies have emphasized the importance of fungal cell wall polypeptides during the early stages of the ectomycorrhizal interaction. The increased synthesis of 30- to 32-kDa acidic polypeptides, together with the decreased accumulation of a prominent 95-kDa mannoprotein provided evidence for major alterations of Pisolithus tinctorius cell walls during mycorrhiza formation. Differential cDNA library screening and shotgun cDNA sequencing were used to clone symbiosis-regulated fungal genes. Several abundant transcripts showed a significant amino acid sequence similarity to a family of secreted morphogenetic fungal proteins, the so-called hydrophobic. In P. tinctorius, the content of hydrophobin transcripts is high in aerial hyphae and during the ectomycorrhizal sheath formation. Alteration of cell walls and the extracellular matrix is therefore a key event in the ectomycorrhiza development. An understanding of the molecular mechanisms that underlies the temporal and spatial control of genes and proteins involved in the development of the symbiotic interface is now within reach, as more sophisticated techniques of molecular and genetic analysis are applied to the mycorrhizal interactions. Key words: cell walls, ectomycorrhiza, ectomycorrhizins, fungal development, hydrophobins, symbiosis-regulated polypeptides.

scholarly journals A Novel Class of Ectomycorrhiza-Regulated Cell Wall Polypeptides in Pisolithus tinctorius

1999 ◽  
Vol 12 (10) ◽  
pp. 862-871 ◽  
Author(s):  
Pascal Laurent ◽  
Catherine Voiblet ◽  
Denis Tagu ◽  
Dulcinéia de Carvalho ◽  
Uwe Nehls ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Adhesion ◽  
Polyacrylamide Gel Electrophoresis ◽  
State Level ◽  
Root Surface ◽  
Pisolithus Tinctorius ◽  
Surface Proteins ◽  
Ectomycorrhizal Symbiosis ◽  
Fungal Cell ◽  
Fungal Hyphae

Development of the ectomycorrhizal symbiosis leads to the aggregation of fungal hyphae to form the mantle. To identify cell surface proteins involved in this developmental step, changes in the biosynthesis of fungal cell wall proteins were examined in Eucalyptus globulus-Pisolithus tinctorius ectomycorrhizas by two-dimensional polyacrylamide gel electrophoresis. Enhanced synthesis of several immunologically related fungal 31- and 32-kDa polypeptides, so-called symbiosis-regulated acidic polypeptides (SRAPs), was observed. Peptide sequences of SRAP32d were obtained after trypsin digestion. These peptides were found in the predicted sequence of six closely related fungal cDNAs coding for ectomycorrhiza up-regulated transcripts. The PtSRAP32 cDNAs represented about 10% of the differentially expressed cDNAs in ectomycorrhiza and are predicted to encode alanine-rich proteins of 28.2 kDa. There are no sequence homologies between SRAPs and previously identified proteins, but they contain the Arg-Gly-Asp (RGD) motif found in cell-adhesion proteins. SRAPs were observed on the hyphal surface by immunoelectron microscopy. They were also found in the host cell wall when P. tinctorius attached to the root surface. RNA blot analysis showed that the steady-state level of PtSRAP32 transcripts exhibited a drastic up-regulation when fungal hyphae form the mantle. These results suggest that SRAPs may form part of a cell-cell adhesion system needed for aggregation of hyphae in ectomycorrhizas.

scholarly journals Functional and Comparative Bioinformatic Analysis of Expressed Genes from Wheat Spikes Infected with Fusarium graminearum

2002 ◽  
Vol 15 (5) ◽  
pp. 445-455 ◽  
Author(s):  
Warren M. Kruger ◽  
Clara Pritsch ◽  
Shiaoman Chao ◽  
Gary J. Muehlbauer
Keyword(s):  
Cdna Library ◽  
Fusarium Graminearum ◽  
Plant Cell Wall ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Biotic And Abiotic Stress ◽  
Head Blight ◽  
Stress Related Genes ◽  
Fungal Genes ◽  
Sumai 3

Fusarium head blight, caused by the fungus Fusarium graminearum, is a major disease on wheat (Triticum aestivum L.). Expressed sequence tags (ESTs) were used to identify genes expressed during the wheat-F. graminearum interaction. We generated 4,838 ESTs from a cDNA library prepared from spikes of the partially resistant cultivar Sumai 3 infected with F. graminearum. These ESTs were composed of 2,831 singlet (single-copy transcripts) and 715 contigs (multiple-copy transcripts) for a total of 3,546 non-redundant sequences. Four sets of nonredundant sequences were identified. One set contains numerous, common biotic and abiotic stress-related genes. Many of these stress-related genes were represented by multiple ESTs, indicating that they are abundantly expressed. A second set comprised 16 nonredundant sequences from F. graminearum that may be required for pathogenicity. A subset of these fungal genes encodes proteins associated with plant cell wall degradation. A third set of 326 nonredundant sequences had no DNA or amino acid sequence similarity to almost 1 million plant and over 7 million animal sequences in dbEST (as of 22 June 2001). Thus, these 326 nonredundant sequences have only been found in our F. graminearum-infected ‘Sumai 3’ cDNA library. A fourth set of 29 nonredundant sequences was found in our F. graminearum-infected wheat and another plant-pathogen interaction cDNA library. Some of these sequences encode proteins that may act in establishing various plant-fungal interactions.

scholarly journals Cell Wall Chitosaccharides Are Essential Components and Exposed Patterns of the Phytopathogenic Oomycete Aphanomyces euteiches

2008 ◽  
Vol 7 (11) ◽  
pp. 1980-1993 ◽  
Author(s):  
Ilham Badreddine ◽  
Claude Lafitte ◽  
Laurent Heux ◽  
Nicholas Skandalis ◽  
Zacharoula Spanou ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Molecular Mechanisms ◽  
Expressed Sequence Tag ◽  
Pathogenic Fungi ◽  
Aphanomyces Euteiches ◽  
Fungal Cell ◽  
Cdna Sequences ◽  
Essential Components ◽  
Biochemical Analyses

ABSTRACT Chitin is an essential component of fungal cell walls, where it forms a crystalline scaffold, and chitooligosaccharides derived from it are signaling molecules recognized by the hosts of pathogenic fungi. Oomycetes are cellulosic fungus-like microorganisms which most often lack chitin in their cell walls. Here we present the first study of the cell wall of the oomycete Aphanomyces euteiches, a major parasite of legume plants. Biochemical analyses demonstrated the presence of ca. 10% N-acetyl-d-glucosamine (GlcNAc) in the cell wall. Further characterization of the GlcNAc-containing material revealed that it corresponds to noncrystalline chitosaccharides associated with glucans, rather than to chitin per se. Two putative chitin synthase (CHS) genes were identified by data mining of an A. euteiches expressed sequence tag collection and Southern blot analysis, and full-length cDNA sequences of both genes were obtained. Phylogeny analysis indicated that oomycete CHS diversification occurred before the divergence of the major oomycete lineages. Remarkably, lectin labeling showed that the Aphanomyces euteiches chitosaccharides are exposed at the cell wall surface, and study of the effect of the CHS inhibitor nikkomycin Z demonstrated that they are involved in cell wall function. These data open new perspectives for the development of antioomycete drugs and further studies of the molecular mechanisms involved in the recognition of pathogenic oomycetes by the host plants.

scholarly journals Molecular Mechanisms of Chitosan Interactions with Fungi and Plants

2019 ◽  
Vol 20 (2) ◽  
pp. 332 ◽  
Author(s):  
Federico Lopez-Moya ◽  
Marta Suarez-Fernandez ◽  
Luis Lopez-Llorca
Keyword(s):  
Cell Walls ◽  
Fungal Pathogens ◽  
Molecular Mechanisms ◽  
Plant Immunity ◽  
Fungal Colonization ◽  
Fungal Cell ◽  
Physiological Basis ◽  
Mammalian Cell Lines ◽  
Root Interactions ◽  
Plant Chitinases

Chitosan is a versatile compound with multiple biotechnological applications. This polymer inhibits clinically important human fungal pathogens under the same carbon and nitrogen status as in blood. Chitosan permeabilises their high-fluidity plasma membrane and increases production of intracellular oxygen species (ROS). Conversely, chitosan is compatible with mammalian cell lines as well as with biocontrol fungi (BCF). BCF resistant to chitosan have low-fluidity membranes and high glucan/chitin ratios in their cell walls. Recent studies illustrate molecular and physiological basis of chitosan-root interactions. Chitosan induces auxin accumulation in Arabidopsis roots. This polymer causes overexpression of tryptophan-dependent auxin biosynthesis pathway. It also blocks auxin translocation in roots. Chitosan is a plant defense modulator. Endophytes and fungal pathogens evade plant immunity converting chitin into chitosan. LysM effectors shield chitin and protect fungal cell walls from plant chitinases. These enzymes together with fungal chitin deacetylases, chitosanases and effectors play determinant roles during fungal colonization of plants. This review describes chitosan mode of action (cell and gene targets) in fungi and plants. This knowledge will help to develop chitosan for agrobiotechnological and medical applications.

scholarly journals Molecular Characterization, Tissue-Specific Expression, and Regulation of Melanocortin 2 Receptor in Rainbow Trout

Endocrinology ◽  
2008 ◽  
Vol 149 (9) ◽  
pp. 4577-4588 ◽  
Author(s):  
Neelakanteswar Aluru ◽  
Mathilakath M. Vijayan
Keyword(s):  
Rainbow Trout ◽  
Adrenal Cortex ◽  
Molecular Mechanisms ◽  
Sequence Similarity ◽  
Regulatory Protein ◽  
Mrna Abundance ◽  
Amino Acid Sequence Similarity ◽  
Specific Expression ◽  
Tissue Specific ◽  
Specific Distribution

ACTH, the primary secretagogue for corticosteroid biosynthesis, binds to melanocortin 2 receptor (MC2R) and activates the signaling cascade leading to steroid biosynthesis in the adrenal cortex. Whereas MC2R regulation has been studied using mammalian models, little is known about the molecular mechanisms involved in ACTH signaling in nonmammalian vertebrates. A full-length cDNA encoding MC2R was sequenced from rainbow trout (Oncorhynchus mykiss) interrenal tissue (analogous to the adrenal cortex in mammals) and showed about 60 and about 44% amino acid sequence similarity to teleosts and humans, respectively. Phylogenetic analysis confirmed that MC2R from all species clustered together and was distant from other MCRs. Quantitative real-time PCR revealed a marked tissue-specific difference in MC2R mRNA abundance, with the highest levels observed in the interrenal tissue, ovary, and testis. Acute ACTH, but not α-MSH or [Nle4, d-Phe7]-MSH, stimulation resulted in a time- and dose-related elevation in MC2R mRNA abundance in the interrenal tissue. This corresponded with higher steroidogenic acute regulatory protein and cytochrome P450 side-chain cleavage enzyme gene expression as well as elevated cortisol production. An acute stressor transiently elevated plasma ACTH and cortisol levels at 1 h, and this was followed by a significant increase in MC2R mRNA abundance at 4 h after stressor exposure. Taken together, our results demonstrate that ACTH regulation of MC2R is highly conserved in vertebrates, whereas the tissue-specific distribution of this receptor transcript level leads us to propose a role for ACTH signaling in the stressor-mediated suppression of sex steroid levels in fish.

scholarly journals Novel Pathway of Salicylate Degradation by Streptomyces sp. Strain WA46

2004 ◽  
Vol 70 (3) ◽  
pp. 1297-1306 ◽  
Author(s):  
Daisuke Ishiyama ◽  
Dusica Vujaklija ◽  
Julian Davies
Keyword(s):  
Sequence Similarity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Pcr Amplification ◽  
Amino Acid Sequence Similarity ◽  
Chromosomal Dna ◽  
Degenerate Primers ◽  
Putative Gene ◽  
Cell Extracts ◽  
Plasmid Library ◽  
Coa Ligase

ABSTRACT A novel salicylate-degrading Streptomyces sp., strain WA46, was identified by UV fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain WA46 was grown with salicylate. PCR amplification of WA46 DNA with degenerate primers for gentisate 1,2-dioxygenase (GDO) genes produced an amplicon of the expected size. Sequential PCR with nested GDO primers was then used to identify a salicylate degradation gene cluster in a plasmid library of WA46 chromosomal DNA. The nucleotide sequence of a 13.5-kb insert in recombinant plasmid pWD1 (which was sufficient for the complete degradation of salicylate) showed that nine putative open reading frames (ORFs) (sdgABCDEFGHR) were involved. Plasmid pWD1 derivatives disrupted in each putative gene were transformed into Streptomyces lividans TK64. Disruption of either sdgA or sdgC blocked salicylate degradation; constructs lacking sdgD accumulated gentisate. Cell extracts from Escherichia coli DH5α transformants harboring pUC19 that expressed each of the sdg ORFs showed that conversions of salicylate to salicylyl-coenzyme A (CoA) and salicylyl-CoA to gentisyl-CoA required SdgA and SdgC, respectively. SdgA required CoA and ATP as cofactors, while NADH was required for SdgC activity; SdgC was identified as salicylyl-CoA 5-hydroxylase. Gentisyl-CoA underwent spontaneous cleavage to gentisate and CoA. SdgA behaved as a salicylyl-CoA ligase despite showing amino acid sequence similarity to an AMP-ligase. SdgD was identified as a GDO. These results suggest that Streptomyces sp. strain WA46 degrades salicylate by a novel pathway via a CoA derivative. Two-dimensional polyacrylamide gel electrophoresis and reverse transcriptase-PCR studies indicated that salicylate induced expression of the sdg cluster.

Antifungal Proteins from Plant Latex

2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  
Keyword(s):  
Cell Walls ◽  
Defense Mechanisms ◽  
Hydrolytic Enzymes ◽  
Fungal Species ◽  
Biologically Active ◽  
Protein Classification ◽  
Fungal Cell ◽  
Antifungal Proteins ◽  
Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

scholarly journals Plant Morphological, Physiological and Anatomical Adaption to Flooding Stress and the Underlying Molecular Mechanisms

2021 ◽  
Vol 22 (3) ◽  
pp. 1088
Author(s):  
Weitao Jia ◽  
Maohua Ma ◽  
Jilong Chen ◽  
Shengjun Wu
Keyword(s):  
Molecular Mechanisms ◽  
Sequence Similarity ◽  
Survival Strategies ◽  
Ethylene Response Factor ◽  
Flooding Tolerance ◽  
Plant Tolerance ◽  
Flooding Stress ◽  
Crop Varieties ◽  
The Future ◽  
Plant Acclimation

Globally, flooding is a major threat causing substantial yield decline of cereal crops, and is expected to be even more serious in many parts of the world due to climatic anomaly in the future. Understanding the mechanisms of plants coping with unanticipated flooding will be crucial for developing new flooding-tolerance crop varieties. Here we describe survival strategies of plants adaptation to flooding stress at the morphological, physiological and anatomical scale systemically, such as the formation of adventitious roots (ARs), aerenchyma and radial O2 loss (ROL) barriers. Then molecular mechanisms underlying the adaptive strategies are summarized, and more than thirty identified functional genes or proteins associated with flooding-tolerance are searched out and expounded. Moreover, we elaborated the regulatory roles of phytohormones in plant against flooding stress, especially ethylene and its relevant transcription factors from the group VII Ethylene Response Factor (ERF-VII) family. ERF-VIIs of main crops and several reported ERF-VIIs involving plant tolerance to flooding stress were collected and analyzed according to sequence similarity, which can provide references for screening flooding-tolerant genes more precisely. Finally, the potential research directions in the future were summarized and discussed. Through this review, we aim to provide references for the studies of plant acclimation to flooding stress and breeding new flooding-resistant crops in the future.

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