RESUMO
Two endophytic bacterial strains, designated S1-1-2 T and S1-1-8, were isolated from the leaves of a mangrove plant, Avicennia marina. The isolates were Gram-stain-negative, motile, rod-shaped bacteria with lateral flagella. Growth occurred at 4-41 °C, pH 4.0-11.0, and 0.5-25.0% NaCl. The predominant fatty acids of the novel strains were C18:1 ω6c/ω7c, C19:0 cyclo ω8c, and C16:0. The predominant respiratory quinone was Q-9. The DNA G + C contents of strains S1-1-2 T and S1-1-8 analyzed by genome sequences were 63.8%. Phylogenetic analysis based on 16S rRNA gene sequences obtained using sanger sequencing and whole-genome phylogenetic analysis revealed an affiliation between the two strains and the genus Salinicola in the class Gammaproteobacteria. Detailed genotypic, chemotaxonomic, and phenotypic data support the conclusion that these two strains should be described as a novel species in the genus Salinicola. Here, Salinicola avicenniae sp. nov. (type strain S1-1-2 T = LMG 32655 T = MCCC 1A19027T) is proposed.
Assuntos
Avicennia , Composição de Bases , DNA Bacteriano , Gammaproteobacteria , Filogenia , RNA Ribossômico 16S , Avicennia/microbiologia , RNA Ribossômico 16S/genética , China , DNA Bacteriano/genética , Gammaproteobacteria/classificação , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Ácidos Graxos/análise , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Folhas de Planta/microbiologia , Endófitos/genética , Endófitos/classificação , Endófitos/isolamento & purificaçãoRESUMO
Melanins are heterogenous biopolymers produced by many macro and microorganisms. They enhance the ecological fitness of the producer organisms by improving their virulence and protecting them from radiation, osmotic and heat stresses. Fungi synthesise either DOPA or DHN melanin and deposit them on their cell walls. Some fungal isolates produce water soluble melanin (pyomelanin) which is excerted out of the hyphae into the surrounding environment. Pyomelanin, a polymer of homogentisate, exhibits antimicrobial, UV screening, antioxidative, and anti-inflammatory activities and recent studies also show that pyomelanin could find use in space travel as radiation shield. However, scant literature is available on fungi with ability to produce pyomelanin. We report for the first time that Amorosia littoralis occurs as a root endophyte in mangrove species including Avicennia marina, Bruguiera cylindrica and Bruguiera gymnorhiza and produces pyomelanin. Considering the various technological uses of pyomelanin, this study underscores the need to explore fungi of different habitats to identify hyperproducers and to obtain chemically diverse pyomelanin.
Assuntos
Endófitos , Melaninas , Melaninas/metabolismo , Endófitos/metabolismo , Endófitos/química , Raízes de Plantas/microbiologia , Ascomicetos/química , Ascomicetos/metabolismo , Rhizophoraceae/microbiologia , Avicennia/microbiologiaRESUMO
The scarcity of freshwater resources resulting in a significant yield loss presents a pressing challenge in agriculture. To address this issue, utilizing abundantly available saline water could offer a smart solution. In this study, we demonstrate that the genome sequence rhizosphere bacterium Tritonibacter mobilis AK171, a halophilic marine bacterium recognized for its ability to thrive in saline and waterlogged environments, isolated from mangroves, has the remarkable ability to enable plant growth using saline irrigation. AK171 is characterized as rod-shaped cells, displays agile movement in free-living conditions, and adopts a rosette arrangement in static media. Moreover, The qualitative evaluation of PGP traits showed that AK171 could produce siderophores and IAA but could not solubilize phosphate nor produce hydrolytic enzymes it exhibits a remarkable tolerance to high temperatures and salinity. In this study, we conducted a comprehensive genome sequence analysis of T. mobilis AK171 to unravel the genetic mechanisms underlying its plant growth-promoting abilities in such challenging conditions. Our analysis revealed diverse genes and pathways involved in the bacterium's adaptation to salinity and waterlogging stress. Notably, T. mobilis AK171 exhibited a high level of tolerance to salinity and waterlogging through the activation of stress-responsive genes and the production of specific enzymes and metabolites. Additionally, we identified genes associated with biofilm formation, indicating its potential role in establishing symbiotic relationships with host plants. Furthermore, our analysis unveiled the presence of genes responsible for synthesizing antimicrobial compounds, including tropodithietic acid (TDA), which can effectively control phytopathogens. This genomic insight into T. mobilis AK171 provides valuable information for understanding the molecular basis of plant-microbial interactions in saline and waterlogged environments. It offers potential applications for sustainable agriculture in challenging conditions.
Assuntos
Avicennia , Avicennia/microbiologia , Genoma Bacteriano , Genômica , Rizosfera , Salinidade , Filogenia , Desenvolvimento Vegetal , Sideróforos/metabolismoRESUMO
Mangroves perform a crucial ecological role along the tropical and subtropical coastal intertidal zone where salinity fluctuation occurs frequently. However, the differential responses of mangrove plant at the combined transcriptome and metabolome level to variable salinity are not well documented. In this study, we used Avicennia marina (Forssk.) Vierh., a pioneer species of mangrove wetlands and one of the most salt-tolerant mangroves, to investigate the differential salt tolerance mechanisms under low and high salinity using inductively coupled plasma-mass spectrometry, transcriptomic and metabolomic analysis. The results showed that HAK8 was up-regulated and transported K+ into the roots under low salinity. However, under high salinity, AKT1 and NHX2 were strongly induced, which indicated the transport of K+ and Na+ compartmentalization to maintain ion homeostasis. In addition, A. marina tolerates low salinity by up-regulating ABA signaling pathway and accumulating more mannitol, unsaturated fatty acids, amino acids' and L-ascorbic acid in the roots. Under high salinity, A. marina undergoes a more drastic metabolic network rearrangement in the roots, such as more L-ascorbic acid and oxiglutatione were up-regulated, while carbohydrates, lipids and amino acids were down-regulated in the roots, and, finally, glycolysis and TCA cycle were promoted to provide more energy to improve salt tolerance. Our findings suggest that the major salt tolerance traits in A. marina can be attributed to complex regulatory and signaling mechanisms, and show significant differences between low and high salinity.
Assuntos
Avicennia , Metaboloma , Raízes de Plantas , Salinidade , Tolerância ao Sal , Plantas Tolerantes a Sal , Transcriptoma , Avicennia/genética , Avicennia/fisiologia , Avicennia/metabolismo , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Plantas Tolerantes a Sal/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Tolerância ao Sal/genética , Regulação da Expressão Gênica de PlantasRESUMO
Mangrove habitats support taxonomically diverse benthic communities, yet their effects on microphytobenthos remain understudied. This study investigated the benthic diatom community structure of 17 microtidal mangrove estuaries situated along the east coast of South Africa. High sediment organic content (≤ 18.1 %) and clay fraction (≤ 17.5 %) measured in the Avicennia marina and Rhizophora mucronata habitats favoured diverse communities (H' > 3) and the presence of unique benthic diatom species such as Gyrosigma balticum. The habitat complexity and stabilisation provided by the mangrove forests served as microrefugia for colonisation of benthic diatoms. Taxa displayed a broad range of nutrient tolerance, with some nutrient tolerant species (e.g., Halamphora acutiuscula, Navicula clausii, Navicula gregaria, and Navicula radiosa) dominating the communities in the Mbashe and Mnyameni estuaries. The presence of these nutrient tolerant taxa in relatively pristine systems serves as an early warning for possible anthropogenic nutrient enrichment.
Assuntos
Biodiversidade , Diatomáceas , Estuários , Áreas Alagadas , Rhizophoraceae , Avicennia , África do Sul , Monitoramento Ambiental , Ecossistema , Sedimentos GeológicosRESUMO
As a highly salt-resistant mangrove, Avicennia marina can thrive in the hypersaline water. The leaves of Avicennia marina play a crucial role in salinity stress adaptability by secreting salt. Although the functions of long non-coding RNAs (lncRNAs) in leaves remain unknown, they have emerged as regulators in leaf development, aging and salt response. In this study, we employed transcriptomic data of both short-term and long-term salt treated leaves to identify salt-associated lncRNAs of leaf tissue. As a result, 687 short-term and 797 long-term salt-associated lncRNAs were identified. Notably, both short-term and long-term salt-associated lncRNAs exhibited slightly longer lengths and larger exons, but smaller introns compared with salt-non-associated lncRNAs. Furthermore, salt-associated lncRNAs also displayed higher tissue-specificity than salt-non-associated lncRNAs. Most of the salt-associated lncRNAs were common to short- and long-term salt treatments. And about one fifth of the downregulated salt-associated lncRNAs identified both in two terms were leaf tissue-specific lncRNAs. Besides, these leaf-specific lncRNAs were found to be involved in the oxidation-reduction and photosynthesis processes, as well as several metabolic processes, suggesting the noticeable functions of salt-associated lncRNAs in regulating salt responses of Avicennia marina leaves.
Assuntos
Avicennia , Folhas de Planta , RNA Longo não Codificante , RNA de Plantas , Avicennia/genética , Avicennia/fisiologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Folhas de Planta/genética , RNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Transcriptoma , Perfilação da Expressão GênicaRESUMO
Avicennia marina (Forssk.) Vierh. is a highly salt-tolerant mangrove, and its fruit has been traditionally used for treating constipation and dysentery. In this study, a pectin (AMFPs-0-1) was extracted and isolated from this fruit for the first time, its structure was analyzed, and the effects on the human gut microbiota were investigated. The results indicated that AMFPs-0-1 with a molecular weight of 798 kDa had a backbone consisting of alternating â2)-α-L-Rhap-(1â and â4)-α-D-GalpA-(1â residues and side chains composed of â3-α-L-Araf-(1â-linked arabinan with a terminal ß-L-Araf, â5-α-L-Araf-(1â-linked arabinan, and â4)-ß-D-Galp-(1â-linked galactan that linked to the C-4 positions of all α-L-Rhap residues in the backbone. It belongs to a type I rhamnogalacturonan (RG-I) pectin but has no arabinogalactosyl chains. AMFPs-0-1 could be consumed by human gut microbiota and increase the abundance of some beneficial bacteria, such as Bifidobacterium, Mitsuokella, and Megasphaera, which could help fight digestive disorders. These findings provide a structural basis for the potential application of A. marina fruit RG-I pectic polysaccharides in improving human intestinal health.
Assuntos
Avicennia , Fermentação , Frutas , Microbioma Gastrointestinal , Pectinas , Prebióticos , Pectinas/química , Frutas/química , Avicennia/química , Avicennia/microbiologia , Humanos , Microbioma Gastrointestinal/efeitos dos fármacos , Peso MolecularRESUMO
The field of bio-fabricated noble metallic nanoparticles (NPs) has gained significant attention in applied research due to their eco-friendly and biocompatible nature. This study focuses on employing a green synthesis method to produce silver and gold nanoparticles (bio-fabricated) using a Mangrove plant extract and assessing their insecticidal and growth-inhibitory effects for environmentally friendly pest control. The resulting NPs underwent comprehensive characterization through various spectroscopy techniques. The morphology of both silver and gold mediated nanoparticles of Avicennia marina leaf extract displayed a spherical shape, with average sizes measuring around 70-80 nm and 95-100 nm, respectively. Regarding cytotoxicity, the inhibitory effects of silver nanoparticles were less than that observed by the extract alone while gold nanoparticles showed stronger cell growth inhibitory effects on splenic cells. The hepatic toxicity of silver and gold nanoparticles showed significant toxic effects as compared to A. marina extract alone. Notably, as prepared silver nanoparticles exhibited substantial larvicidal toxicity as compared to gold nanoparticles, when tested against fourth instar Culex pipiens larvae. These biocompatible silver and gold nanoparticles prepared from A. marina leaf extract hold promise for future applications as larvicides to effectively control mosquito species.
Assuntos
Avicennia , Culex , Ouro , Inseticidas , Larva , Nanopartículas Metálicas , Extratos Vegetais , Folhas de Planta , Prata , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Ouro/química , Ouro/toxicidade , Ouro/farmacologia , Prata/química , Prata/toxicidade , Prata/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Folhas de Planta/química , Animais , Inseticidas/síntese química , Inseticidas/farmacologia , Inseticidas/química , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Culex/efeitos dos fármacos , Culex/crescimento & desenvolvimento , Química Verde/métodos , Camundongos , Sobrevivência Celular/efeitos dos fármacos , Tamanho da PartículaRESUMO
Mangroves buffer metals transfer to coastal areas though strong accumulation in sediments making necessary to investigate metals' bioavailability to plants at the rhizosphere. This work evaluates the effect of mangrove root activity, through iron plaque formation, on the mobility of iron and copper its influence on metals' uptake, and translocation through simultaneous histochemical analysis. The Fe2+ and Fe3+ contents in porewaters ranged from 0.02 to 0.11 µM and 1.0 to 18.3 µg.l-1, respectively, whereas Cu concentrations were below the method's detection limit (<0.1 µM). In sediments, metal concentrations ranged from 12,800 to 39,500 µg.g-1 for total Fe and from 10 to 24 µg.g-1 for Cu. In iron plaques, Cu concentrations ranged from 1.0 to 160 µg.g-1, and from 19.4 to 316 µg.g-1 in roots. Fe concentrations were between 605 to 36,000 µg.g-1 in the iron plaques and from 2,100 to 62,400 µg.g-1 in roots. Histochemical characterization showed Fe3+ predominance at the tip of roots and Fe2+ in more internal tissues. A. schaueriana showed significant amounts of Fe in pneumatophores and evident translocation of this metal to leaves and excretion through salt glands. Iron plaques formation was essential to the Fe and Cu regulation and translocation in tissues of mangrove plants.
Assuntos
Avicennia , Cobre , Ferro , Raízes de Plantas , Rhizophoraceae , Rhizophoraceae/química , Ferro/análise , Ferro/metabolismo , Brasil , Cobre/análise , Avicennia/química , Raízes de Plantas/química , Sedimentos Geológicos/química , Sedimentos Geológicos/análise , Disponibilidade Biológica , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodosRESUMO
Around one-third of the world's most carbon-rich ecosystems, mangrove forests, have already been destroyed in Thailand owing to coastal development and aquaculture. Improving these degraded areas through mangrove plantations can restore various coastal ecosystem services, including CO2 absorption and protection against wave action. This study examines the biomass of three coastal mangrove plantations (Avicennia alba) of different ages in Samut Prakarn province, Central Thailand. Our aim was to understand the forest biomass recovery during the early stages of development, particularly fine root biomass expansion. In the chronosequence of the mangrove plantations, woody biomass increased by 40% over four years from 79.7 ± 11.2 Mg C ha-1 to 111.7 ± 12.3 Mg C ha-1. Fine root biomass up to a depth of 100 cm was 4.47 ± 0.33 Mg C ha-1, 4.24 ± 0.63 Mg C ha-1, and 6.92 ± 0.32 Mg C ha-1 at 10, 12, and 14 year-old sites, respectively. Remarkably, the fine root biomass of 14-year-old site was significantly higher than those of the younger sites due to increase of the biomass at 15-30 cm and 30-50 cm depths. Our findings reveal that the biomass recovery in developing mangrove plantations exhibit rapid expansion of fine roots in deeper soil layers.
Assuntos
Biomassa , Raízes de Plantas , Áreas Alagadas , Tailândia , Raízes de Plantas/crescimento & desenvolvimento , Avicennia/crescimento & desenvolvimento , Ecossistema , Conservação dos Recursos Naturais/métodos , Carbono/análise , Carbono/metabolismoRESUMO
Mangroves is an ecosystem which plays an economical role in Gabon for its watercourses where are used for fishing and marine traffic or as little bin for garbage and waste water disposal. These bad practices destroy that fragile ecosystem, perturbing like this carbon sequestration and biodiversity protection. Hence, the impact of the anthropogenic pollution stress of fishing engine oils so called hydrocarbons pollution on the chemical, microstructure and natural durability of Avicennia. germinans (L.)L. from Ambowé mangrove of the Estuary region of Gabon was studied. The results were compared with samples from Oveng and Mamboumba, two unpolluted sites of Libreville. Dichloromethane and hexane soluble extractives content decreased significantly (p < 0.05) in the polluted heartwoods, 5 ± 0,007 % et 2.11 ± 0,2 %, respectively. Confocal microscopy revealed for the first time the occurrence of rays and vessels opening in the polluted heartwood which could explain the loss of some extractives. That loss of extractives was supported by UV where a dramatic decrease of extractives was observed in the heartwood exposed to pollutants while no changes occurred in lignin. These changes on extractives content and wood microstructures would explain the high mass loss of the polluted heartwood exposed to Trametes versicolor (35.69 ± 6.27 %) and Rhodonia placenta (11.65 ± 6.62 %), these rot fungi provoked only mass losses <10 and 5 %, respectively for the unpolluted heartwoods.
Assuntos
Avicennia , Estuários , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Gabão , Hidrocarbonetos/análise , Áreas Alagadas , Monitoramento Ambiental , ÁrvoresRESUMO
Salinity stress is a critical challenge in crop production and requires innovative strategies to enhance the salt tolerance of plants. Insights from mangrove species, which are renowned for their adaptability to high-salinity environments, provides valuable genetic targets and resources for improving crops. A significant hurdle in salinity stress is the excessive uptake of sodium ions (Na+) by plant roots, causing disruptions in cellular balance, nutrient deficiencies, and hampered growth. Specific ion transporters and channels play crucial roles in maintaining a low Na+/K+ ratio in root cells which is pivotal for salt tolerance. The family of high-affinity potassium transporters, recently characterized in Avicennia officinalis, contributes to K+ homeostasis in transgenic Arabidopsis plants even under high-salt conditions. The salt overly sensitive pathway and genes related to vacuolar-type H+-ATPases hold promise for expelling cytosolic Na+ and sequestering Na+ in transgenic plants, respectively. Aquaporins contribute to mangroves' adaptation to saline environments by regulating water uptake, transpiration, and osmotic balance. Antioxidant enzymes mitigate oxidative damage, whereas genes regulating osmolytes, such as glycine betaine and proline, provide osmoprotection. Mangroves exhibit increased expression of stress-responsive transcription factors such as MYB, NAC, and CBFs under high salinity. Moreover, genes involved in various metabolic pathways, including jasmonate synthesis, triterpenoid production, and protein stability under salt stress, have been identified. This review highlights the potential of mangrove genes to enhance salt tolerance of crops. Further research is imperative to fully comprehend and apply these genes to crop breeding to improve salinity resilience.
Assuntos
Avicennia , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas , Tolerância ao Sal , Tolerância ao Sal/genética , Avicennia/genética , Avicennia/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Salinidade , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sódio/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismoRESUMO
Avicennia marina, known for its remarkable adaptability to the challenging coastal environment, including high salinity, tide, and anaerobic soils, holds pivotal functions in safeguarding the coastal ecosystem. Long non-coding RNAs (lncRNAs) have emerged as significant players in various natural processes of plants such as development. However, lncRNAs in A. marina remain largely unknown and uncharacterized. Here, we employed the transcriptome datasets from multiple tissues, such as root, leaf, and seed, to detect and characterize the lncRNAs of A. marina. Analyzing synthetically, we finally identified 6333 lncRNAs in the A. marina. These lncRNAs exhibited distinct features compared to messenger RNAs, including larger exons, lower guanine-cytosine contents, lower expression levels, and higher tissue specificities. Moreover, we identified thousands of tissue-specific lncRNAs across the examined tissues and further found that these tissue-specific lncRNAs were significantly enriched in biological processes related to the major functions of their corresponding tissues. For instance, leaf-specific lncRNAs showed prominent enrichment in photosynthesis, oxidation-reduction processes, and light harvesting. By providing a comprehensive dataset and functional annotations for A. marina lncRNAs, this study offers a valuable overview of lncRNAs in A. marina and lays the fundamental foundation for further functional exploring of them.
Assuntos
Avicennia , RNA Longo não Codificante , RNA Longo não Codificante/genética , Avicennia/genética , RNA de Plantas/genética , Genoma de Planta , Transcriptoma , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Perfilação da Expressão GênicaRESUMO
Mangroves are nature-based solutions for coastal protection however their ability to attenuate waves and stabilise and accrete sediment varies with their species-specific architecture and frontal area. Hydrodynamic models are typically used to predict and assess the protection afforded by mangroves, but without species or genus distribution information, the results can be significantly different from reality. Data on the frontal genus of mangroves exposed to waves and tides can provide information that can be used in hydrodynamic models to more accurately forecast the protection benefit provided by mangroves. Globally, frontal species were identified from existing mangrove zonation diagrams to create a global mangrove genus distribution map. This dataset aims to improve the accuracy of hydrodynamic models. Data may be of interest to researchers in coastal engineering, marine science, wetland ecology and blue carbon.
Assuntos
Avicennia , Ecologia , Rhizophoraceae , Áreas Alagadas , Carbono , Ecossistema , Previsões , Especificidade da EspécieRESUMO
Mangroves are of important economic and environmental value and research suggests that their carbon sequestration and climate change mitigation potential is significantly larger than other forests. However, increasing salinity and heavy metal pollution significantly affect mangrove ecosystem function and productivity. This study investigates the tolerance mechanisms of rhizobacteria in the rhizosphere of Avicennia marina under salinity and copper (Cu) stress during a 4-y stress period. The results exhibited significant differences in antioxidant levels, transcripts, and secondary metabolites. Under salt stress, the differentially expressed metabolites consisted of 30% organic acids, 26.78% nucleotides, 16.67% organic heterocyclic compounds, and 10% organic oxides as opposed to 27.27% organic acids, 24.24% nucleotides, 15.15% organic heterocyclic compounds, and 12.12% phenyl propane and polyketides under Cu stress. This resulted in differential regulation of metabolic pathways, with phenylpropanoid biosynthesis being unique to Cu stress and alanine/aspartate/glutamate metabolism and α-linolenic acid metabolism being unique to salt stress. The regulation of metabolic pathways enhanced antioxidant defenses, nutrient recycling, accumulation of osmoprotectants, stability of plasma membrane, and chelation of Cu, thereby improving the stress tolerance of rhizobacteria and A. marina. Even though the abundance and community structure of rhizobacteria were significantly changed, all the samples were dominated by Proteobacteria, Chloroflexi, Actinobacteriota, and Firmicutes. Since the response mechanisms were unbalanced between treatments, this led to differential growth trends for A. marina. Our study provides valuable inside on variations in diversity and composition of bacterial community structure from mangrove rhizosphere subjected to long-term salt and Cu stress. It also clarifies rhizobacterial adaptive mechanisms to these stresses and how they are important for mitigating abiotic stress and promoting plant growth. Therefore, this study can serve as a reference for future research aimed at developing long-term management practices for mangrove forests.
Assuntos
Avicennia , Compostos Heterocíclicos , Cobre/toxicidade , Cobre/metabolismo , Ecossistema , Avicennia/metabolismo , Solo , Antioxidantes/metabolismo , Multiômica , Estresse Salino , Nucleotídeos/metabolismo , Compostos Heterocíclicos/metabolismoRESUMO
The mangrove ecosystem plays a crucial role in preserving the biodiversity of plants, animals, and microorganisms that are essential for materials cycles. However, the exploration of endophytic fungi isolated from mangroves, particulary in Santa Catarina (SC, Brazil), remains limited. Therefore, the purpose of this study was to assess the biodiversity of endophytic fungi found in Avicennia schaueriana, Laguncularia racemosa, Rhizophora mangle, and Spartina alterniflora from two mangroves on the Island of Santa Catarina: one impacted by anthropic action (Itacorubi mangrove) and the other environmentally preserved (Ratones mangrove). Samplings were carried out between January 2020 and May 2021. Fungi were isolated from leaves, stems, and roots, identified, and clustered into groups through morphological characteristics. Further, a representative strain of each group was identified through ITS1 sequencing. A total of 373 isolates were obtained from plant tissues, of which 96 and 277 isolates were obtained from Itacorubi and Ratones mangroves, respectively. Molecular identification showed that the endophytic fungal community comprised at least 19 genera. The data on fungal community diversity revealed comparable diversity indices for genera in both mangroves. However, we observed differences in the total frequency of fungal genera between impacted (27.38%) and non-impacted (72.62%) mangroves. These findings suggest that anthropic activities in and around the Santa Catarina mangroves have had negative impact on the frequency of endophytic fungi. This emphasizes the reinforcing the significance of preserving these environments to ensure the maintenance of fungal community diversity.
Assuntos
Biodiversidade , Endófitos , Fungos , Filogenia , Rhizophoraceae , Áreas Alagadas , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/genética , Brasil , Fungos/classificação , Fungos/isolamento & purificação , Fungos/genética , Rhizophoraceae/microbiologia , Avicennia/microbiologia , Ilhas , Raízes de Plantas/microbiologia , Micobioma , Folhas de Planta/microbiologiaRESUMO
Avicennia marina is a salt-tolerance plant with high antioxidant and antibacterial potential. In the present work, a gene encoding MnSOD from Avicennia marina (AmSOD2) was cloned in the expression vectors pET28a. The resulting constructs were transformed into Escherichia coli strains Rosetta (DE3). Following the induction with Isopropyl ß-D-1-thiogalactopyranoside, the protein His-AmSOD2 was expressed but dominantly found in the insoluble fraction of strain R-AmSOD2. Due to detection of mitochondrial transit peptide in the amino acid sequence of AmSOD2, the transit peptide was removed and AmSOD2 without transit peptide (tAmSOD2) was expressed in E. coli and dominantly found in the soluble fraction. The enzyme His-tAmSOD2 exhibited a molecular mass of 116 kDa in native condition. Nevertheless, in reducing conditions the molecular mass is 28 kDa indicating the enzyme His-tAmSOD2 is a tetramer protein. As shown by ICP analysis there is one mole Mn2+ in each monomer. The Pure His-tAmSOD2 was highly active in vitro, however the activity was almost three-fold lower than His-AmSOD1. Whereas the high stability of the recombinant His-AmSOD1was previously shown after incubation in a broad range pH and high temperature, His-tAmSOD2 was stable up to 50 °C and pH 6 for 1 h. The gene expression analysis showed that the gene encoding AmSOD2 is expressed in root, shoot and leaves of A. marina. In addition, the results show that the expression in the leaves was enhanced after treatment of plant with NaCl, H2O2, Cd2+ and Ni2+ indicating the important role of MnSOD in the resistant mechanism of mangroves.
Assuntos
Avicennia , Metais Pesados , Avicennia/genética , Avicennia/metabolismo , Peróxido de Hidrogênio/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Metais Pesados/análise , Superóxido Dismutase/metabolismo , Peptídeos/metabolismoRESUMO
Biological systems occurring in ecologically heterogeneous and spatially discontinuous habitats provide an ideal opportunity to investigate the relative roles of neutral and selective factors in driving lineage diversification. The grey mangroves (Avicennia marina) of Arabia occur at the northern edge of the species' range and are subject to variable, often extreme, environmental conditions, as well as historic large fluctuations in habitat availability and connectivity resulting from Quaternary glacial cycles. Here, we analyse fully sequenced genomes sampled from 19 locations across the Red Sea, the Arabian Sea and the Persian/Arabian Gulf (PAG) to reconstruct the evolutionary history of the species in the region and to identify adaptive mechanisms of lineage diversification. Population structure and phylogenetic analyses revealed marked genetic structure correlating with geographic distance and highly supported clades among and within the seas surrounding the Arabian Peninsula. Demographic modelling showed times of divergence consistent with recent periods of geographic isolation and low marine connectivity during glaciations, suggesting the presence of (cryptic) glacial refugia in the Red Sea and the PAG. Significant migration was detected within the Red Sea and the PAG, and across the Strait of Hormuz to the Arabian Sea, suggesting gene flow upon secondary contact among populations. Genetic-environment association analyses revealed high levels of adaptive divergence and detected signs of multi-loci local adaptation driven by temperature extremes and hypersalinity. These results support a process of rapid diversification resulting from the combined effects of historical factors and ecological selection and reveal mangrove peripheral environments as relevant drivers of lineage diversity.
Assuntos
Avicennia , Filogenia , Avicennia/genética , Arábia , Ecossistema , Oceano ÍndicoRESUMO
Coastal wetlands such as mangrove forests are breeding grounds for nuisance-causing insects. Rotational Impoundment Management (RIM) for mosquito control involves annual summer inundation of impounded mangrove forests with estuarine water during the summer half year. However, in addition to controlling mosquitos, RIM may change biogeochemical pathways. This study set out to investigate how RIM quantitatively affects physicochemical soil characteristics and potential nitrifying and denitrifying activities (PNA and PDA), which are key in the global nitrogen cycle. Before and after the implementation of RIM, soil samples were collected annually in habitats differing in size and abundance of black mangroves (Avicennia germinans) in an impoundment with RIM and in an adjacent impoundment with a more open connection to the lagoon. Compared to the non-managed impoundment, soil moisture content, total nitrogen and PDA increased, while salinity decreased after the start of annual summer flooding, but only in the dwarf habitat. In the sparse and dense habitats, total nitrogen and PDA increased independently of summer flooding, whereas soil moisture content and salinity were not affected by RIM. Labile organic nitrogen increased only in the RIM impoundment, irrespective of the habitat type. PNA was generally not affected with time, except in the dwarf habitat in the absence of intentional summer flooding where it increased. Changes in the non-managed impoundment adjacent to the RIM impoundment demonstrate the importance of groundwater exchange in linked ecosystems. The consequences of interventions in the management of mangrove impoundments and adjacent forests for the nitrogen budget are discussed.
Assuntos
Avicennia , Áreas Alagadas , Ecossistema , Controle de Mosquitos , Nitrogênio/análise , Melhoramento Vegetal , Florestas , Solo/químicaRESUMO
Mangrove is one of the most productive and sensitive ecosystems in the world. Due to the complexity and specificity of mangrove habitat, the development of mangrove is regulated by several factors. Species distribution models (SDMs) are effective tools to identify the potential habitats for establishing and regenerating the ecosystem. Such models usually include exclusively environmental factors. Nevertheless, recent studies have challenged this notion and highlight the importance of including biotic interactions. Both factors are necessary for a mechanistic understanding of the mangrove distribution in order to promote the protection and restoration of mangroves. Thus, we present a novel approach of combining environmental factors and interactions with salt marsh for projecting mangrove distributions at the global level and within latitudinal zones. To test the salt marsh interaction, we fit the MaxEnt model with two predicting sets: (1) environments only and (2) environments + salt marsh interaction index (SII). We found that both sets of models had good predictive ability, although the SII improved model performance slightly. Potential distribution areas of mangrove decrease with latitudes, and are controlled by biotic and abiotic factors. Temperature, precipitation and wind speed are generally critical at both global scale and ecotones along latitudes. SII is important on global scale, with a contribution of 5.9%, ranking 6th, and is particularly critical in the 10-30°S and 20-30°N zone. Interactions with salt marsh, including facilitation and competition, are shown to affect the distribution of mangroves at the zone of coastal ecotone, especially in the latitudinal range from 10° - 30°. The contribution of SII to mangrove distribution increases with latitudes due to the difference in the adaptive capacity of salt marsh plants and mangroves to environments. Totally, this study identified and quantified the effects of salt marsh on mangrove distribution by establishing the SII. The results not only facilitate to establish a more accurate mangrove distribution map, but also improve the efficiency of mangrove restoration by considering the salt marsh interaction in the mangrove management projects. In addition, the method of incorporating biotic interaction into SDMs through establish the biotic interaction index has contributed to the development of SDMs.