Title, Biologia marinha. Authors, RENATO CRESPO PEREIRA, ABILIO SOARES- GOMES. Publisher, Interciência, ISBN, , Renato Crespo Pereira is the author of Biologia Marinha ( avg rating, 0 ratings , 0 reviews). [X] Livro Biologia Marinha – 2ª Ed. Pereira, Renato Crespo, Soares-gomes, Abílio pdf. Are you a Read PDF Biologia Marinha – 2ª Ed. Online book lover??? we.
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Numbers of genes shared among control samples left, 7 samples and samples of Laurencia dendroidea inoculated with Vibrio madracius right, 8 samples. Numbers of replicates were as follows: Genes differentially expressed in Laurencia dendroidea 24, 48, and 72 h after inoculation with Vibrio madracius. The ability to recognize and respond to the presence xrespo microbes is an essential strategy for seaweeds to survive in the marine environment, but understanding of molecular seaweed-microbe interactions is limited.
Laurencia dendroidea clones were inoculated with the marine bacterium Vibrio madracius. The seaweed RNA was sequenced, providing an unprecedentedly high coverage of the transcriptome of Laurenciaand the gene expression levels were compared between control and inoculated samples after renatp, 48, and 72 h. Transcriptomic changes in L. Genes coding mwrinha defense-related transcription activators, reactive oxygen species metabolism, terpene biosynthesis, and energy conversion pathways were upregulated in inoculated samples of L.
This report contributes significantly to the current knowledge about the bio,ogia mechanisms involved in the highly dynamic seaweed-bacterium interactions. In this context, the ability of seaweeds to recognize microbes and, when necessary, activate defense mechanisms is essential for their survival.
However, studies dedicated to understanding the molecular components of the immune response in seaweeds are rare and restricted to indirect stimulus.
This work provides an unprecedentedly large-scale evaluation of the transcriptional changes involved in microbe recognition, cellular signaling, and defense in the red seaweed Laurencia dendroidea in response to the marine bacterium Vibrio madracius.
By expanding knowledge about seaweed-bacterium interactions and about the integrated defensive system in seaweeds, this work offers the basis for the development biklogia tools to increase the resistance of cultured seaweeds to bacterial infections. Seaweeds are extremely susceptible to microbial colonization due to the release of large amounts of carbon compounds that act as chemical attractants and nutrient sources for bacteria 1.
The microbial community associated with seaweeds tends to be species specific and different from that renago with seawater 2. The microbiome associated with healthy individuals of the red seaweed Laurencia dendroidea can fix nitrogen and provide relevant amino acids and vitamins to the seaweed 3. The tight association between seaweeds and their epiphytic microbes led to the establishment of a holobiont marinnha that is analogous to that corresponding to the well-described microbe-coral relationship 4.
However, potential pathogens were also previously detected on seaweed renwto and include microorganisms capable of degrading cell wall polysaccharides 5— 7. Diseases can significantly impact host biologiaa by promoting a decrease of individual fitness and negatively affecting the ability of seaweeds to defend against herbivores 8.
Besides, the occurrence of disease outbreaks in valuable reared seaweeds, such as Porphyra nori cultures, causes significant economic losses due to biologka reduction of annual production 9.
Overall, MAMPs include conserved molecules that are characteristic of microbes but are absent in hosts, e.
Following the recognition of microbes, evidence has emerged for the occurrence and significant role of innate immunity processes as the first line of defense in seaweeds, similarly to that observed in vascular plants and metazoans 10— 13including transient production of reactive oxygen species ROS 14— Besides being directly toxic to microbes 17ROS participate in intracellular signaling mechanisms leading to the activation of other defense responses 18such as the expression of genes related to the biosynthesis of secondary crepso Despite being part of the defensive strategy of seaweeds against fouling 20the cresp of ROS can damage the seaweed cell structures, so the oxidative burst must be tightly regulated through the activation of antioxidant enzymes Molecular studies in seaweeds have had mixed results regarding the potential costs involved in defense.
For example, an increase in the expression of genes involved in cellular energy was detected through s uppression s ubtractive h ybridization SSH biokogia the exposure of Laminaria digitata to oligoguluronates In contrast, the downregulation of genes involved in energy conversion was detected, through a microarray, after the exposure of Chondrus crispus to methyl jasmonate The conflicting results could be attributed to intrinsic biological differences between the two species or to the relatively small number of sequences analyzed.
Laurencia is a red seaweed genus widely distributed around the world, recognized for the biosynthesis of diverse halogenated secondary metabolites, especially terpenes, with relevant ecological 2324 and pharmacological 25— 29 activities. Some of these halogenated compounds are able to prevent the growth of marine bacteria 30— Creslo, disease symptoms were not observed in natural populations of L.
The halogenated metabolites in L. The compartmentation of secondary metabolites in vacuoles, possibly to avoid autotoxicity, was previously observed in plants and other seaweeds 36 However, the genes involved in this cellular process are still largely unknown. Although a large array of genes responsible for the perejra of terpenes was recently characterized in L. Vibrio is a genus of Gram-negative bacteria associated with ice-ice disease in several red seaweeds, such as Kappaphycus alvarezii and Eucheuma denticulatum 5and also with hole-rotten disease in the brown seaweed Laminaria japonica Vibrio madracius is phylogenetically close to the V.
Oxidative stress resistance proteins are necessary in the pathogenic marine Vibrio species for the progression of virulence Current knowledge about seaweed-microbe interactions at the molecular level is limited, because studies evaluating seaweed resistance to pathogens have been based on the use of indirect stimulus through the application of MAMPs 16PIMPS 15194546and signaling molecules e.
Recently, an initial mafinha to understand the global effects of microbes on a seaweed transcriptome was indirectly made using an agarolytic enzyme Nonetheless, the direct effects of microorganisms on seaweed gene expression have rarely been evaluated and have relied on real-time PCR techniques, monitoring a limited number of genes 49 Our aim was to identify the major transcriptional responses of L.
The transcriptome sequencing of L. A total of We detected in both the control uninoculated samples and the samples of L. Characteristics of the cDNA sequences from Laurencia dendroidea after preprocessing and assembly a. The number of differentially expressed genes in the seaweed L.
The concentration of V. Plating the seaweed tissue homogenate on thiosulfate-citrate-bile salts-sucrose TCBS media did not result in bacterial growth, suggesting that this reduction was not due to bacterial attachment to L.
Concentration of Vibrio madracius in the culture medium in the presence 2 replicates [T1 and T2] and absence 2 replicates [CV1 and CV2] of Laurencia dendroidea. The comparative analysis of control and inoculated specimens of L.
Most of the genes differentially expressed were upregulated in the inoculated samples of L. Both annotated and nonannotated genes are represented. The analysis was based on the following numbers of replicates: S3which included Rho-related protein rac1 Fig. Several genes related to the biosynthesis of terpenes were also upregulated in L. Genes related to the biosynthesis of terpenes characterized for the first time in Laurencia dendroidea with their EC number, Blast E value, identity, and similarity and the metabolic pathway in which they participate.
Functional categories associated with energy conversion, such as the glycolytic process, including glucosephosphate isomerase G6PIfructose-bisphosphate aldolase FBAglyceraldehydephosphate dehydrogenase GAPDHand phosphopyruvate hydratase PPHwere overrepresented in the transcriptome of L.
Further, genes related to the tricarboxylic acid cycle and oxidative phosphorylation, e. Because this reduction could not be attributed to biofilm formation, we hypothesized that it should have been due to responses of or defense strategies activated in L. Pattern recognition receptors are largely unknown in seaweeds.
A recent study demonstrated the occurrence of genes coding for LRR kinases in the brown seaweed Ectocarpus siliculosus that, due to their molecular structure, were considered to represent candidate pathogen receptors Here, we detected, in both control and inoculated samples, the expression of genes coding for LRR-RLKs, representing a major class of receptors involved in microbe detection in plants through the recognition of MAMPs 54suggesting that these genes are constitutively expressed in the red seaweed L.
Because ROS can react with essential host molecules, the activity of antioxidant enzymes is important to limit the oxidative burst. Signaling cascades that modulate the innate immune response have been well described in plants but are still unknown in seaweeds.
Despite indirect evidence for the occurrence of mitogen-activated protein kinase MAPK cascades in seaweeds 49the involvement of this pathway in the response to bacteria was not previously investigated.
Here, we detected the upregulation in L. The MAPK cascade transduces extracellular stimuli into intracellular responses during plant defense against pathogens and can induce the expression of defense-related genes through the phosphorylation of transcription factors, such as ERF Further, we observed the upregulation of L.
The Rac1 homolog of rice is a regulator of ROS production and induces the expression of defense-related genes promoting resistance against pathogenic bacteria Genes involved in PI signaling were also upregulated in L. Another gene coding for a protein kinase upregulated in L. Further, a relevant role was attributed to Snf1-related protein kinases as global regulators of gene expression, inducing catabolic pathways that provide alternative sources of energy and controlling genes that encode signal transduction components and transcription regulators Our work suggests that well-known mechanisms acting on the plant innate immunity response are also present in seaweeds Fig.
Molecular Mechanisms for Microbe Recognition and Defense by the Red Seaweed Laurencia dendroidea
Hypothetical model representing bacterium recognition through microbe-associated molecular pattern [MAMP] and some relevant metabolic processes overrepresented in the transcriptomic profile of Laurencia dendroidea in response to Vibrio madracius.
Note that the figure is not drawn to scale. Another important transcriptional regulatory element upregulated in L. There is evidence that JA, or a structurally similar compound sis also involved in defense signals in macroalgae, as this substance induced the expression of stress-related genes in C.
Isolated and synergistic effects of chemical and structural defenses of two spec
Although the role of ET signaling in seaweeds was not demonstrated, the ability to synthesize and respond to this plant hormone was previously detected in Enteromorpha intestinalis 73 and Pterocladiella capillacea The present report contributes to evidence indicating the presence of a mechanism in seaweeds similar to plant hormone-regulated defense against microbes.
Diverse evidence suggests that fighting against microbes is energetically demanding in vascular plants By using high-throughput transcriptome sequencing, we verified the transient upregulation, in response to V. The expression level of several genes involved in the biosynthesis of terpenes in L. Terpenoid compounds are recognized as important secondary metabolites acting to defend Laurencia species against bacterial colonization Moreover, the upregulation of genes involved in monoterpene biosynthesis was detected in L.
Genes relevant for vesicle trafficking—including those coding for Rab, billogia participates in intracellular membrane trafficking by regulating the movement of vesicles along cytoskeletal filaments 79 ; actin, which composes the structure of the connections linking the CC to the cell periphery in L. These findings may corroborate the occurrence of increased vesicle transport in Laurencia as a response to microbes The present report shows that even though V.
It is also necessary to determine if the measured differences represented a generic response of Laurencia to bacteria or a response to a specific potential pathogen. The response of L. The upregulation of genes coding for NADPH oxidase and antioxidant enzymes suggests the occurrence of an oxidative burst. Intracellular marinhaa mediated by a MAPK cascade, small GTPases, phosphatidylinositol, and calcium calmodulin-dependent protein kinases was observed as a seaweed response to bacteria.
Further, the upregulation of genes related to the biosynthesis of terpenes, along with the overexpression of genes involved in vesicular transport, suggests increased release of terpenes by L.
Finally, we verified the upregulation of genes associated with energy metabolism, indicating that the defense mechanisms in Mairnha. The upregulation of the genes involved in ROS production and in the biosynthesis of terpenes reveals a previously unknown integrated defensive system in ceespo.
The present study provided novel insights into the complexity of seaweed-microbe interactions and the defensive strategies of L.
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Laurencia dendroidea Hudson J. The unialgal culture of this seaweed was established through successive excision of the apices. Clones were used to prevent intraspecific variations in transcriptomic profiles from masking the effect of bacterial inoculation.