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This study investigates the impact of carbohydrate accumulation in mangrove and halophytic plants on their response to abiotic stress. Using soil analysis and FT-IR spectroscopy, key species (Sueda nudiflora, Aeluropus lagopoides, Avicennia marina) were examined for seasonal changes in sugar content (reducing sugars, total soluble sugars, starch). The elevated carbohydrate levels may serve as an indication of the plant's ability to adapt to different environmental conditions throughout the year. This accumulation enables plants to adapt to variations in their environment, assuring their survival and functionality during periods of environmental fluctuation. Halophytic plants' sugar content peaked during the monsoon, suggesting biotic adaptations. The mangrove Avicennia marina had year-round sugar levels. PCA and Hierarchical Cluster Analysis revealed sugar accumulation trends across species and seasons. Partial Least Squares (PLS) analysis revealed correlations between soil characteristics and sugar content, suggesting plant-microbe interactions. K-means clustering and correlation analysis of FT-IR data revealed sugar composition and resource allocation trade-offs. These findings shed light on the role of carbohydrate metabolism in enabling coastal plants to endure stress. Gaining insight into these mechanisms can enhance sustainable agriculture in challenging environments and shed light on plant adaptations to evolving environmental conditions, especially biotic interactions. [ABSTRACT FROM AUTHOR]

Abiotic stresses encompass different environmental stimuli and constantly affect plant sustainability throughout their lifetime. Plants have developed several complex mechanisms to respond against these abiotic stresses. Studies have shown that microRNAs (miRNAs) effectively reduce stress‐responsive genes that significantly help plants tolerate abiotic stresses such as drought, salinity, temperature, and heavy metals. The regulation of such genes by miRNAs not only aids in plant growth and development but also controls physiological processes such as identifying floral organs, leaf morphogenesis, and root development. As per the information, miRNA plays an important role in stress regulation and regulates homeostasis in mangrove plants such as Rhizophore apiculata. Several modern technologies and approaches have been developed to determine these stress response miRNAs. The targeted genes of miRNAs are transcription factors that further control a set of down and upstream genes to affect physiological response. This paper explores the miRNAs found in a mangrove plant Avicennia marina. The plant contains many miRNAs and knowledge of miRNAs – their development, roles, functions, and target genes under abiotic stress conditions. [ABSTRACT FROM AUTHOR]

Abstract This study investigates the impact of carbohydrate accumulation in mangrove and halophytic plants on their response to abiotic stress. Using soil analysis and FT-IR spectroscopy, key species (Sueda nudiflora, Aeluropus lagopoides, Avicennia marina) were examined for seasonal changes in sugar content (reducing sugars, total soluble sugars, starch). The elevated carbohydrate levels may serve as an indication of the plant’s ability to adapt to different environmental conditions throughout the year. This accumulation enables plants to adapt to variations in their environment, assuring their survival and functionality during periods of environmental fluctuation. Halophytic plants’ sugar content peaked during the monsoon, suggesting biotic adaptations. The mangrove Avicennia marina had year-round sugar levels. PCA and Hierarchical Cluster Analysis revealed sugar accumulation trends across species and seasons. Partial Least Squares (PLS) analysis revealed correlations between soil characteristics and sugar content, suggesting plant-microbe interactions. K-means clustering and correlation analysis of FT-IR data revealed sugar composition and resource allocation trade-offs. These findings shed light on the role of carbohydrate metabolism in enabling coastal plants to endure stress. Gaining insight into these mechanisms can enhance sustainable agriculture in challenging environments and shed light on plant adaptations to evolving environmental conditions, especially biotic interactions.

This study comprehensively examined the Avicennia marina plant, a key species along the Red Sea coast of the Saudi Arabian Kingdom, focusing on its microbial, biochemical, and ecological aspects. Specimens, including leaves, seeds, and seedlings of Avicennia marina plant, were collected during the summer of 2021 from two distinct mangrove-abundant regions in Yanbu Governorate, Kingdom of Saudi Arabia. Analysis of the plant revealed significant heavy metal concentrations in its sediment, leaves, and seeds, with the sediment from region 1 recording metals such as Cr (40.202 ppm) and Se (30.522 ppm). Additionally, the plant’s extracts exhibited notable antimicrobial properties, inhibiting growth of several pathogenic bacteria, with ethyl acetate extracts from leaves being especially potent against strains like P. aeruginosa and S. aureus. Moreover, from the leaves collected in the Yanbu region, 10 unique endophytic bacterial species were identified. Utilizing genomic analysis tools, two of these bacteria were closely characterized, revealing more than 99% similarity to known bacterial species; Mixta and Cytobacillus species, emphasizing the microbial diversity within the mangrove leaves. In sum, Avicennia marina emerges as ecologically significant, with potential implications for bio-remediation and antimicrobial applications, and as a reservoir of diverse microbial species. With mounting global challenges, such as climate change, understanding these microbial-plant interactions is pivotal for both conservation and biotechnological pursuits in the future.

Abstract 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.

Background and aims: Mangrove species respond to variation in soil bulk density (BD). However, very little is known about the regulatory mechanisms that trigger these responses. Methods: Endogenous concentrations of different phytohormones were measured in the roots of two mangrove species (Avicennia marina and Rhizophora stylosa) grown in low and high BD soils. The potential involvement of ethylene in regulating plant growth responses was tested by applying the ethylene biosynthesis inhibitors cobalt chloride (CoCl2) and aminoisobutyric acid (AIB). Results: The two mangrove species responded differently to variation in soil BD. High BD decreased root growth of R. stylosa, but not A. marina. Soil BD had no effect on root phytohormone levels in R. stylosa, but loose soils increased 1-aminocyclopropane-1-carboxylic acid whilst decreasing salicylic acid and gibberellin in A. marina. Applying ethylene inhibitors enhanced R. stylosa root growth, while increasing indole-3-acetic acid but decreasing isopentenyl adenine levels. In contrast, AIB inhibited A. marina root growth, while increasing trans-zeatin levels. Ethylene inhibitors affected salicylic acid levels in both species. Conclusion: Salicylic acid is central to root growth responses to variation in BD in A. marina. Conversely, the interaction of ethylene and gibberellin drives responses in R. stylosa. Hormonal interactions involving ethylene potentially reflect the adaptations of the two species to differing conditions within the intertidal zone, with A. marina behaving like an aquatic species and R. stylosa behaving like a terrestrial species. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study comprehensively examined the Avicennia marina plant, a key species along the Red Sea coast of the Saudi Arabian Kingdom, focusing on its microbial, biochemical, and ecological aspects. Specimens, including leaves, seeds, and seedlings of Avicennia marina plant, were collected during the summer of 2021 from two distinct mangrove-abundant regions in Yanbu Governorate, Kingdom of Saudi Arabia. Analysis of the plant revealed significant heavy metal concentrations in its sediment, leaves, and seeds, with the sediment from region 1 recording metals such as Cr (40.202 ppm) and Se (30.522 ppm). Additionally, the plant's extracts exhibited notable antimicrobial properties, inhibiting growth of several pathogenic bacteria, with ethyl acetate extracts from leaves being especially potent against strains like P. aeruginosa and S. aureus. Moreover, from the leaves collected in the Yanbu region, 10 unique endophytic bacterial species were identified. Utilizing genomic analysis tools, two of these bacteria were closely characterized, revealing more than 99% similarity to known bacterial species; Mixta and Cytobacillus species, emphasizing the microbial diversity within the mangrove leaves. In sum, Avicennia marina emerges as ecologically significant, with potential implications for bio-remediation and antimicrobial applications, and as a reservoir of diverse microbial species. With mounting global challenges, such as climate change, understanding these microbial-plant interactions is pivotal for both conservation and biotechnological pursuits in the future. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Marine & Coastal Science is the property of Universitas Airlangga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to determine the effect of giving Avicennia marina mangrove leaf solution on artificial feed to increase the immune response and growth of vannamei shrimp. The parameters observed in this study were the enhancement of PA value (Phagocytosis Activity), ADG (Average Daily Growth), FCR (Feed Conversion Ratio), and EPP (Efficiency of Feed Utilization). The vannamei shrimp used was PL-20 fry with a weight of 1,09 - 1,13 g·head-1 and density 1 shrimp L-1. The method used in this study was experimental in the laboratory, with a completely randomized design (CRD) with 4 treatments and 3 replications. This research was conducted by adding A. marina mangrove leaf solution to the feed, with treatments of A (control), B (125 ‰), C (175 ‰), and D (225 ‰). The addition of Avicennia marina leaf solution to the feed significantly affected the increase of phagocytosis activity and growth of the shrimp with an F count of 30,773, which was higher than the F table of 4,06. Moreover, the best dose obtained in treatment D which increased PA was 61,9%, ADG was 0,22 g·day-1, FCR was 1,29, and EPP was 79,04%. [ABSTRACT FROM AUTHOR]

Reef, R. and Gordon, C., 2024. Allometric equations for aboveground biomass estimation of temperate mangroves using uncrewed aerial vehicles. Journal of Coastal Research, 40(3), 474–484. Charlotte (North Carolina), ISSN 0749-0208. Temperate mangrove ecosystems face different stresses compared with their tropical counterparts, resulting in reduced extent, biodiversity, and productivity. Temperate mangroves represent less than 2% of global mangrove cover and are thus less studied, but where they occur, they provide distinct ecosystem services and are expanding. Avicennia marina subsp. australasica is the sole mangrove species found in Victoria, Australia, where mangroves reach their highest latitudinal limit globally. Estimating aboveground biomass (AGB) in temperate mangroves poses challenges because of their morphological differences from tropical forests. This study used uncrewed aerial vehicle (UAV)–derived measurements and ground inventory data to develop allometric equations for A. marina at its latitudinal limit. A hybrid allometric equation, incorporating both field- and UAV-derived metrics, provided the most accurate prediction of AGB (coefficient of determination [R2] = 0.93). An allometric equation using solely UAV-derived inputs (canopy area and canopy height) had high-fidelity prediction capacity (R2 = 0.85), although it overestimated AGB by 11%. A significant finding was the simplification of scaling from individual tree AGB to landscape-scale AGB by eliminating the need to segment individual tree canopies. Landscape-scale AGB estimates showed a stable underestimation of approximately 30%, which could be improved by segmenting the area into zones of similar height. AGB of mangroves in Western Port was estimated at 48 t ha–1, which is within the range measured for temperate mangroves around the world. The biomass density in this temperate region is significantly lower (40%) than the continental average. [ABSTRACT FROM AUTHOR]

Mangrove-associated endophytic fungi are producers of secondary metabolites in unique and diverse structures with interesting biological activities such as antiviral, antifungal, antibacterial, anti-inflammatory, and cytotoxic agents. Endophytes play an important role in the physiological activities of the host plants, influencing the improvement of resistance to stress, insects, nematodes, and diseases. In this study, arohynapene A, a polyketide compound, was successfully isolated from the mangrove-derived fungus Penicillium steckii JB-NW-2-1 obtained from mangrove plant Avicennia marina (Forssk) Vierh. The structure was determined by a spectroscopic method including IR, MS, 1D-, and 2D-NMR techniques. This compound was evaluated for cytotoxic activities using resazurin assay against four cancer cells, HeLa cervical, MCF-7 breast cancer, B16-F10 melanoma, and A549 lung adenocarcinoma. The results showed no significant activities against all cancer cells tested (IC50 > 500 µM).

Mangroves are unique ecosystems. As they are present in a transition zone, they harbour a variety of organisms, which include microorganisms, aquatic as well as terrestrial organisms. Being present in an ever-changing and adverse environment, mangroves have developed several adaptations that make them unique. These unique features have been exploited for the isolation of various useful compounds from mangroves. The organisms associated with the mangrove ecosystem will also be well equipped to survive such extreme conditions. Microorganisms such as bacteria, fungi, actinomycetes, algae etc, survive in this changing environment, and they might be producing certain metabolites as a part of their survival mechanism, which can be exploited for the production of various compounds that are useful to mankind. Mangrove microorganisms can be used as an important source of food, medicines, enzymes, antimicrobials etc. [ABSTRACT FROM AUTHOR]

The search for ecofriendly products to reduce crop dependence on synthetic chemical fertilizers presents a new challenge. The present study aims to isolate and select efficient native PGPB that can reduce reliance on synthetic NPK fertilizers. A total of 41 bacteria were isolated from the sediment and roots of mangrove trees (Avicennia marina) and assessed for their PGP traits under in vitro conditions. Of them, only two compatible strains of Bacillus species were selected to be used individually and in a mix to promote tomato seedling growth. The efficiency of three inoculants applied to the soil was assessed in a pot experiment at varying rates of synthetic NPK fertilization (0, 50, and 100% NPK). The experiment was set up in a completely randomized design with three replications. Results showed that the different inoculants significantly increased almost all the studied parameters. However, their effectiveness is strongly linked to the applied rate of synthetic fertilization. Applying bacterial inoculant with only 50% NPK significantly increased the plant height (44-51%), digital biomass (60-86%), leaf area (77-87%), greenness average (29-36%), normalized difference vegetation index (29%), shoot dry weight (82-92%) and root dry weight (160-205%) compared to control plants. Concerning the photosynthetic activity, this treatment showed a positive impact on the concentrations of chlorophyll a (25-31%), chlorophyll b (34-39%), and carotenoid (45-49%). Interestingly, these increases ensured the highest values significantly similar to or higher than those of control plants given 100% NPK. Furthermore, the highest accumulation of N, P, K, Cu, Fe, Zn, and Ca in tomato shoots was recorded in plants inoculated with the bacterial mix at 50% NPK. It was proven for the first time that the native PGP bacteria derived from mangrove plant species A. marina positively affects the quality of tomato seedlings while reducing 50% NPK. [ABSTRACT FROM AUTHOR]

A novel fungus species, Nemania hydei, isolated from Avicennia marina in Pranburi District, Prachuap Khiri Khan, Thailand is described. The samples were collected from mangrove habitats, and the fungus was isolated and characterised. Nemania species produce carbonaceous, superficial stromata that are multi-peritheciate with papillate ostioles. They are frequently isolated from decomposing angiospermous wood and are primarily considered saprophytic, although some are endophytic, while a few are pathogenic. DNA extraction was performed on pure cultures, and the ITS, LSU, RPB-2, and TUB sequence data were amplified. Molecular phylogenetic investigation revealed that the isolate formed a distinct and well-supported clade with Nemania viridis as a sister taxon. Morphological observations further demonstrated unique characteristics that distinguish N. hydei from its closest taxonomic relative. Primarily, they differ in the shape and size of ascospores, asci, and the characteristic reaction of the apical ring. Despite the existence of over 70 known species within the genus Nemania, only four species have been previously documented from mangrove ecosystems. The discovery of N. hydei contributes to knowledge of species from mangroves, expanding our understanding of the diversity within Nemania in marine habitats. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Limited knowledge exists regarding the diversity of mangrove plant-associated Pseudarthrobacter species. This study presents the first draft genome and phylogenetic analysis of a Pseudarthrobacter oxydans NCCP-2145, isolated from the rhizospheric soil of Aviciana marina, a native mangrove plant found in Miani Hor, Lasbela-Baluchistan, Pakistan. Results: The genome of P. oxydans NCCP-2145 comprises 4,495,869 base pairs, with a G+C content of 65.9% and 4,207 coding sequences. Genome annotation revealed the presence of multiple biosynthesis pathways. The analysis also identified genes responsible for plant growth-promoting traits, such as the synthesis of indole acetic acid, nitrogen fixation, and phosphorus solubilization. Experimental evaluations confirmed strain NCCP-2145 positive reactions for phosphorus solubilization, indole-3-acetic acid production, and ammonia production. Furthermore, strain NCCP-2145 exhibited tolerance to heavy metals (nickel, copper, and cadmium) and salinity levels up to 10% NaCl. Antibiotic susceptibility testing indicated resistance only to ceftazidime and the combination of amoxicillin/clavulanic acid. For phylogenomic analysis, strain NCCP-2145 was analyzed and compared to the closely related validly published type species P. oxydans DSM 20119T, revealing a similarity score of 98.64% based on 16S rRNA gene sequences and 89.1% based on DNA-DNA hybridization, confirming its classification as a member of species, P. oxydans. Conclusions: This study significantly contributes to our understanding of the genomic characteristics, functional capabilities, and potential plant growth-promoting attributes of P. oxydans NCCP-2145. Future research should focus on unraveling the precise mechanisms underlying its plant growth-promoting abilities and exploring practical applications in sustainable agriculture and environmental restoration.How to cite: Bushra R, Uzair B, Ali A, et al. Draft genome sequence of a halotolerant plant growth-promoting bacterium Pseudarthrobacter oxydans NCCP-2145 isolated from rhizospheric soil of mangrove plant Avicennia marina. Electron J Biotechnol 2023;66. https://doi.org/10.1016/j.ejbt.2023.08.003.

Copyright of Mesopotamian Journal of Marine Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Main conclusion: Transcriptional and metabolic regulation of lignin biosynthesis and lignification plays crucial roles in Avicennia marina pneumatophore development, facilitating its adaptation to coastal habitats. Avicennia marina is a pioneer mangrove species in coastal wetland. To cope with the periodic intertidal flooding and hypoxia environment, this species has developed a complex and extensive root system, with its most unique feature being a pneumatophore with a distinct above- and below-ground morphology and vascular structure. However, the characteristics of pneumatophore lignification remain unknown. Studies comparing the anatomy among above-ground pneumatophore, below-ground pneumatophore, and feeding root have suggested that vascular structure development in the pneumatophore is more like the development of a stem than of a root. Metabolome and transcriptome analysis illustrated that the accumulation of syringyl (S) and guaiacyl (G) units in the pneumatophore plays a critical role in lignification of the stem-like structure. Fourteen differentially accumulated metabolites (DAMs) and 10 differentially expressed genes involved in the lignin biosynthesis pathway were targeted. To identify genes significantly associated with lignification, we analyzed the correlation between 14 genes and 8 metabolites and further built a co-expression network between 10 transcription factors (TFs), including 5 for each of MYB and NAC, and 23 enzyme-coding genes involved in lignin biosynthesis. 4-Coumarate-CoA ligase, shikimate/quinate hydroxycinnamoyl transferase, cinnamyl alcohol dehydrogenase, caffeic acid 3-O-methyltransferase, phenylalanine ammonia-lyase, and peroxidase were identified to be strongly correlated with these TFs. Finally, we examined 9 key candidate genes through quantitative real-time PCR to validate the reliability of transcriptome data. Together, our metabolome and transcriptome findings reveal that lignin biosynthesis and lignification regulate pneumatophore development in the mangrove species A. marina and facilitate its adaptation to coastal habitats. [ABSTRACT FROM AUTHOR]

Iron (Fe) supply is one of the key factors in alleviating cadmium (Cd) stress in different plants, including mangroves. However, the effects and mechanisms of Fe in mediating the mangrove response to Cd stress still need to elaborate on the level of plant physiology and metabolism. Herein a 40-day hydroponic study was conducted to evaluate the mediating effect of Fe on Cd tolerance of Avicennia marina (Forssk.) Vierh. Results showed that the Fe supply directly improved the activity of ferric chelate reductase (FCR), increased Fe concentration in tissues, enhanced its competitiveness with Cd, and improved Fe bioavailability, thereby reducing the uptake of Cd by plants. Simultaneously, moderate Fe enhanced the photosynthesis and increased concentrations of total phenolics and tannins in both roots and leaves that play a critical role in chelating and immobilizing Cd, thus restricting the Cd translocation from roots to aboveground tissues. Additionally, the application of Fe significantly upregulated the activity of antioxidant enzymes, including POD and PPO and hence scavenging the reactive oxygen species caused by Cd stress. In conclusion, moderate Fe application improved the growth of A. marina and enhanced its tolerance to Cd at physiological and metabolic levels. Therefore, improving Fe bioavailability will reduce the mangrove degradation caused by Cd contamination, and also this may be a potential way to restore contaminated mangrove ecosystems. Protecting and restoring mangroves is not only essential for preserving biodiversity and supporting coastal ecosystems but also crucial for maintaining their role as crucial carbon sinks (i.e., mangrove blue carbon) combating global warming and climate change. [ABSTRACT FROM AUTHOR]

Although many novel marine fungi have been described from Indian mangroves, a significant number of mangroves in India have not been thoroughly investigated for marine fungi. This study highlights the diversity of marine fungi inhabiting dead and decaying wood of Avicennia marina and Rhizophora mucronata, collected from Thengaithittu and Veerampattinam mangroves of Pondicherry, Puducherry State, India. Through microscopic examination, a total of 52 species (in 48 genera) of marine fungi were identified, with 50 species (in 46 genera) belonging to the Ascomycota and 2 species (in 2 genera) belonging to the Basidiomycota. Previous studies recorded 69 marine fungi from Ariyankuppam and Mahé mangroves of Puducherry, and this study contributes 22 new records of marine fungi to this region. In this study, the phylogenetic placement of Rhizophila marina was determined, and this fungus was found to belong to the family Diatrypaceae. [ABSTRACT FROM AUTHOR]

The salinity of the soil exerts an adverse effect on plant development and yield. However, amid saline stress, certain halophilic bacteria enhance the growth of plants. In this investigation, the mangrove halophyte Avicennia marina's (A. marina) rhizosphere soil was used as the source for the isolation of halophilic bacteria. The isolates' growth capacity at different pH, salinity, temperature, and polyethylene glycol (PEG) was assessed, and it was found that 56% showed growth in media supplemented with 2–7.5% NaCl; 50% showed efficient growth at pH 6–8, 62% grow optimally at temperature 25–35 °C, and about 88% showed growth in media with 5% PEG. The isolates possess growth-promoting traits evidenced by nitrogen fixation (18%), ammonia production (31%), phosphate solubilization (88%), zinc solubilization (44%), and indole acetic acid (IAA) (88%) production. The isolates can produce extracellular enzymes, viz., protease (88%), amylase (62%), cellulase (56%), and lipase (31%). The bacterial isolate S1B1 that displayed maximum plant growth-promoting traits was selected as the potent and subjected to plant growth promotion studies. The potent isolate S1B1 enhances Solanum lycopersicum's germination under different salinity compared to untreated seeds with germination of 64% at the maximum concentration of 2% NaCl. The potential halophilic plant growth-promoting rhizobacteria (PGPR) isolate was determined as Rossellomorea aquimaris (R. aquimaris) by 16s rRNA analysis. The results demonstrated that R. aquimaris recovered from the rhizosphere of halophyte A. marina found possible applications for enhancing plant development and productivity in salinity-affected soils. [ABSTRACT FROM AUTHOR]

Due to the gravity of arsenic contamination and its potentially detrimental effects on public health, extensive endeavors have been undertaken to treat water sources harboring these hazardous pollutants. This study focuses on investigating the kinetics and equilibrium of biosorption of arsenic (III) and As(V) from aqueous solutions using mangrove leaf biomass (Avicennia marina). Optimal biosorption conditions were determined by considering the optimum pH, initial concentration of adsorbate, contact time, and adsorbent dose. Adsorption models like Langmuir's and Freundlich's were employed to describe the adsorption and determine the corresponding constants of the isotherm. The isothermal data for biosorption demonstrated acceptable compatibility for the Langmuir and Freundlich isothermal models. The maximum adsorption capacity of As(III) and As(IV) onto mangrove leaf biomass (Avicennia marina) was found to be 90.9 and 76.9 mg/g for As (III) and As (V), respectively. Moreover, the correlation between the kinetic experimental data and the second-order kinetic model was significant, indicating its suitability in describing adsorption. [ABSTRACT FROM AUTHOR]

Background: Limited knowledge exists regarding the diversity of mangrove plant-associated Pseudarthrobacter species. This study presents the first draft genome and phylogenetic analysis of a Pseudarthrobacter oxydans NCCP-2145, isolated from the rhizospheric soil of Aviciana marina, a native mangrove plant found in Miani Hor, Lasbela-Baluchistan, Pakistan. Results: The genome of P. oxydans NCCP-2145 comprises 4,495,869 base pairs, with a G+C content of 65.9% and 4,207 coding sequences. Genome annotation revealed the presence of multiple biosynthesis pathways. The analysis also identified genes responsible for plant growth-promoting traits, such as the synthesis of indole acetic acid, nitrogen fixation, and phosphorus solubilization. Experimental evaluations confirmed strain NCCP-2145 positive reactions for phosphorus solubilization, indole-3-acetic acid production, and ammonia production. Furthermore, strain NCCP-2145 exhibited tolerance to heavy metals (nickel, copper, and cadmium) and salinity levels up to 10% NaCl. Antibiotic susceptibility testing indicated resistance only to ceftazidime and the combination of amoxicillin/clavulanic acid. For phylogenomic analysis, strain NCCP-2145 was analyzed and compared to the closely related validly published type species P. oxydans DSM 20119T, revealing a similarity score of 98.64% based on 16S rRNA gene sequences and 89.1% based on DNA-DNA hybridization, confirming its classification as a member of species, P. oxydans. Conclusions: This study significantly contributes to our understanding of the genomic characteristics, functional capabilities, and potential plant growth-promoting attributes of P. oxydans NCCP-2145. Future research should focus on unraveling the precise mechanisms underlying its plant growthpromoting abilities and exploring practical applications in sustainable agriculture and environmental restoration. [ABSTRACT FROM AUTHOR]

The grey mangrove, Avicennia marina, grows in coastal zones in which salinity is frequently associated with iron deficiency. Its response to these combined stresses has not yet explored. The current study aims to assess the physiological and biochemical effects of iron deficiency (ID), salt stress (SS) and their combination (ID + SS) on A. marina seedlings. Iron deficiency reduced growth at non-saline treated plants by 27% while its deleterious effect was mitigated by the supply of 600 mM NaCl, mainly through the increase of photosynthetic pigment contents, iron accumulation in leaves, and intrinsic water use efficiency (iWUE), and the maintain of iron use efficiency (FeUE). Iron deficiency restricted iron accumulation in leaves (31%), iron absorption efficiency (FeAE) (38%), photosynthetic activity and pigment contents, and enhanced FeUE (48%) at saline treated plants. Otherwise, salinity enhanced growth (47%), root volume (20%), Fe accumulation in leaves (8%), and pigment contents at Fe-deficient plants. However, it reduced their FeAE (18%), transpiration rate (77%) and stomatal conductance (86%). Equally, it increased Na and Cl accumulation, the net photosynthetic assimilation rate and iWUE at Fe-deficient. Interestingly, the combined stresses had no additive effects and stressed plants (ID +SS) had comparable biomass to that of the control. [ABSTRACT FROM AUTHOR]

The search for ecofriendly products to reduce crop dependence on synthetic chemical fertilizers presents a new challenge. The present study aims to isolate and select efficient native PGPB that can reduce reliance on synthetic NPK fertilizers. A total of 41 bacteria were isolated from the sediment and roots of mangrove trees (Avicennia marina) and assessed for their PGP traits under in vitro conditions. Of them, only two compatible strains of Bacillus species were selected to be used individually and in a mix to promote tomato seedling growth. The efficiency of three inoculants applied to the soil was assessed in a pot experiment at varying rates of synthetic NPK fertilization (0, 50, and 100% NPK). The experiment was set up in a completely randomized design with three replications. Results showed that the different inoculants significantly increased almost all the studied parameters. However, their effectiveness is strongly linked to the applied rate of synthetic fertilization. Applying bacterial inoculant with only 50% NPK significantly increased the plant height (44-51%), digital biomass (60-86%), leaf area (77-87%), greenness average (29-36%), normalized difference vegetation index (29%), shoot dry weight (82-92%) and root dry weight (160-205%) compared to control plants. Concerning the photosynthetic activity, this treatment showed a positive impact on the concentrations of chlorophyll a (25-31%), chlorophyll b (34-39%), and carotenoid (45-49%). Interestingly, these increases ensured the highest values significantly similar to or higher than those of control plants given 100% NPK. Furthermore, the highest accumulation of N, P, K, Cu, Fe, Zn, and Ca in tomato shoots was recorded in plants inoculated with the bacterial mix at 50% NPK. It was proven for the first time that the native PGP bacteria derived from mangrove plant species A. marina positively affects the quality of tomato seedlings while reducing 50% NPK.

Abstract Mangrove forests grow in coastal areas, lagoons, estuaries, and deltas and form the main vegetation in tidal and saline wetlands. Due to the mankind activities and also changes in climate, these forests face degradations and probably extinction in some areas. Avicennia marina is one of the most distributed mangrove species throughout the world. The populations of A. marina occur in a limited region in southern parts of Iran. Very few genetic and spatial analyses are available on these plants from our country. Therefore, the present study was planned to provide detailed information on Avicennia marina populations with regard to genetic diversity, gene flow versus genetic isolation, effects of spatial variables on connectivity and structuring the genetic content of trees populations and also identifying adaptive genetic regions in respond too spatial variables. We used SCoT molecular markers for genetic analyses and utilized different computational approaches for population genetics and landscapes analyses. The results of present study showed a low to moderate genetic diversity in the studied populations and presence of significant Fst values among them. Genetic fragmentation was also observed within each province studied. A limited gene flow was noticed among neighboring populations within a particular province. One population was almost completely isolated from the gene flow with other populations and had peculiar genetic content.Spatial PCA analysis revealed both significant global and local genetic structuring in the studied populations. Spatial variables like humidity, longitude and altitude were the most important spatial features affecting genetic structure in these populations.

The Iranian southern intertidal ecosystems are colonized by mangrove forests (mostly Avicennia marina) and presented a notable mangrove area expansion over the past decades. To discover its spatio-temporal dependencies, five mangrove forests were studied along a coastline of more than 1,200 km. Cloud-free Landsat images were processed using a temporal median filter to produce one representative Landsat image for each year from 1988 to 2020. The images were categorized into mangrove and non-mangrove classes using an object-based algorithm and visual post-classification. A consistent mangrove area expansion was observed across all regions, which regressed linearly against time with an adjusted R2 range of 0.914–0.955 (p < 0.01). The expansions were also found to be highly significantly similar (0.182 < p < 0.822) using the t-test applied on the slope of region-specific regression models. Three spatial metrics of infilling, edge-expansion, and outlying were developed to investigate the spatial pattern of expansions. Results showed the dominance of the edge-expansion pattern across all regions (53–78% of the expansions), which was attributed to the better establishment of propagules near and under the canopy of parent trees. The outlying pattern (11–22%) was related to mangrove colonization along the inland creeks. HIGHLIGHTS The Iranian southern intertidal ecosystems are colonized by mangrove forests.; Results exhibited a spatio-temporal harmony in the expansion of mangrove forests.; Edge-expansion was found to be the dominant type in all regions.; Future studies should categorize these expansion patterns into landward and seaward groups.;

Given the pressure of population growth, economic difficulties, and climate change, the mangrove forests of Iran need a management plan based on forest protection, reforestation, and afforestation. In this study, the sustainability of mangrove forests in coastal areas of the Bushehr Province in the north of the Persian Gulf was evaluated using two criteria including “extent of forest resources” and “forest health and vitality” from 1993 to 2009. Indicators of area changes, density changes or survival rate, natural regeneration establishment, and height growth were measured as part of the assessment method. Google Earth images were visually interpreted, and a random sample technique was used. A total of 70 circular samples of 100 m2 were chosen. The results showed that Avicennia marina was planted in 7 sites in Kangan and Dayyer townships on the coasts of the Bushehr Province. Out of 370 ha of the plantation, only 42.4 ha remained, showing an area reduction of 88.5% and an average survival rate of 48.5%. Forest planted density averaged 6635 seedlings per hectare which has decreased by 69.5% (i.e. 4611 seedlings/ha). The decreased area in the Khan site was 91% and in the Basatin site was 52.5%. It is necessary to take into account management measures to improve the status of forest sustainability indicators on the coasts of the Bushehr Province, especially in the process of site selection, to improve the success rate of reforestation and afforestation plans.

Mangroves are the most diverse and productive ecosystem that is enriched with various classes of phytochemicals having potential medicinal applications. Here we have studied the bioactive potential and the presence of secondary metabolites in Avicennia marina, one of the dominant species in the Indian Sundarbans mangrove habitat. The bioactive potential study of A. marina was carried out in terms of the determination of total phenolic content, total flavonoid content and reactive oxygen species scavenging potential. The methanolic and ethyl acetate extracts were subjected to Fourier transform infrared spectroscopy (FTIR) for functional group identification. Further, detailed phytochemical profiling has been carried out by liquid chromatography-mass spectrometry (LC-MS). The Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) values for the methanolic extract of A. marina leaves were 148.0 mg GAE g−1 dry extract and 251.9 mg CE g−1 dry extract which was higher than ethyl acetate extracts. The free radical scavenging potential showed that methanolic extract of A. marina leaves can scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical up to 96.0 % and ethyl acetate extract can scavenge up to 73.7 % at 250 µg mL−1. LC-MS metabolic profile revealed the presence of different classes of secondary metabolites like fatty acids, flavonoids, plant hormones, etc., in methanolic extract. The presence of different classes of phytochemicals in the methanolic extract proves its potential as a source of plant-derived medicinal compounds.

Mangrove forests grow in coastal areas, lagoons, estuaries, and deltas and form the main vegetation in tidal and saline wetlands. Due to the mankind activities and also changes in climate, these forests face degradations and probably extinction in some areas. Avicennia marina is one of the most distributed mangrove species throughout the world. The populations of A. marina occur in a limited region in southern parts of Iran. Very few genetic and spatial analyses are available on these plants from our country. Therefore, the present study was planned to provide detailed information on Avicennia marina populations with regard to genetic diversity, gene flow versus genetic isolation, effects of spatial variables on connectivity and structuring the genetic content of trees populations and also identifying adaptive genetic regions in respond too spatial variables. We used SCoT molecular markers for genetic analyses and utilized different computational approaches for population genetics and landscapes analyses. The results of present study showed a low to moderate genetic diversity in the studied populations and presence of significant Fst values among them. Genetic fragmentation was also observed within each province studied. A limited gene flow was noticed among neighboring populations within a particular province. One population was almost completely isolated from the gene flow with other populations and had peculiar genetic content.Spatial PCA analysis revealed both significant global and local genetic structuring in the studied populations. Spatial variables like humidity, longitude and altitude were the most important spatial features affecting genetic structure in these populations. [ABSTRACT FROM AUTHOR]

Located in coastal areas, mangrove forests endure harsh conditions of pollution caused by oil pollutants and heavy metals. In this research, the accumulation of heavy metals lead, zinc, nickel, cadmium, and copper in sediments, leaves, and roots of mangrove plants (Avicennia marina) in the Asalouyeh area was investigated. Also, translocation factor (TF) and bioconcentration factor (BCF) were assessed to investigate the ability of mangroves to absorb heavy metals from the growth medium. In order to investigate the role of mangrove plants in the accumulation of heavy metals, leaves, roots, and sediments were randomly sampled from different areas in May 2021. The results showed that the average concentration of lead in the sediments of the different studied areas is between 26 and 91, in the roots 5 to 23 and in the leaves 3 to 9 µg/g, the concentration of the zinc is 117 to 212 µg/g, 65 to 191 and 19 to 27 µg/g, the concentration of the nickel 43 to 78 µg/g, 21 to 62 and 15 to 41 µg/g, cadmium concentration 1.5 to 2.5 µg/g, 1.4 to 2.2 µg/g and 0.8 to 1.05 µg/g and copper concentration 116 to 36 µg/g, 36 to 63 µg/g and 6 to 13 µg/g, respectively. Also, a positive and significant correlation was obtained between the concentration of metals in sediments and plant tissues. TF and BCF in mangrove plants for all metals were less than 1, which indicates that mangrove plant cannot hyperaccumulate heavy metals cadmium, copper, lead, nickel, and zinc. However, it can remove heavy metals from polluted sediments. [ABSTRACT FROM AUTHOR]

In the present study, the accumulation of heavy metals in sediments in two healthy and damaged sediments of Avicennia marina in Nai Band National Park, on the southern coast of Iran, was compared. Samples of water, sediment, and plant materials were collected in healthy and damaged masses. The concentration of heavy metals (Pb, Cd, Ni, and Zn) in the leaves and roots of mangroves, sediments, and seawater was measured by inductively coupled plasma optical emission spectrometry (ICP-OES, 730 ES, US). The percentage of organic matter was measured using the titration method. Sediment and water acidity were measured with an ATC model pH meter with an accuracy of 0.01%. The electrical conductivity of soil and water was measured with the Hana model HI98331 soil salinity meter. Triplicate samples were analyzed. The ANOVA statistical analysis and Duncan test were used. The results showed that the concentration of heavy metals in the damaged mass was significantly higher than in the healthy mass. The pollution index also showed that the sediment of the damaged mass has higher contamination of heavy metals, especially Cd. The result of the ANOVA test showed that there is no significant difference between the leaf morphological traits in the two healthy and damaged stands, except that the basal angle (BA) in the leaves of the healthy stands is higher than that of the damaged stands (BA of 76.5 and 0.73.1, respectively). Trees in a healthy mass have a higher heavy metal transition factor due to their health and more photosynthesis and better absorption, especially the transition factor of Ni and Cd metal in healthy mass is higher than in damaged mass (of 0.083 and 0.289, respectively). The accumulation pattern of elements in sediments is Cd (34.5 ± 17.39) > Pb (14.12 ± 10.29) > Zn (12. 5 ± 5.16) > Ni (1.967 ± 1.26). The pattern of the transition factor in healthy mass is Ni (0.743 ± 0.159) > Cd (0.529 ± 0.199) > Pb (0.178 ± 0.112) > Zn (1.39 ± 0.624), and damaged mass is Zn (1.35 ± 0.211) > Cd (0.289 ± 0.052) > Pb (0.165 ± 0.084) and Ni (0.083 ± 0.007). Correlation between morphological traits and pollution index and transition factor showed that leaves of trees with larger areas and tip angles can absorb more Pb. The smaller the angle of the tip and the basal of the trees, the higher the amount of Zn in them. Trees with narrower leaves and more tip angles have more heavy metal contamination. The correlation between the translocation factor and the structure of the A. marina showed that there is a correlation between the Ni and the Zn transition factor. Also, there is a significant negative relationship between the Cd transition factor and the drying of trees, which shows that the higher the value of the Cd transition factor, the more drying the trees. This study showed the importance of the mangrove plant, which acts as a more efficient pollution barrier than the healthy one in the change of soil quality and the accumulation of heavy metals in the damaged mass. [ABSTRACT FROM AUTHOR]

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Litterfall production, decomposition and the release of chemical components were estimated in two Avicennia marina mangrove systems on the Red Sea coast, a northern site in Yanbu and a southern site in Shuaiba regions. Over a period of 2 years, monthly litterfall and litter standing stock production were estimated using litter traps and ground plots, respectively. The decomposition of leaf litter was assessed over a period of 256 days using litterbags, the changes in the chemical composition (carbon and nitrogen) and their ratios, and the chemical compound concentrations (leachable carbohydrates, cellulose, hemicelluloses and lignin) were estimated at each decomposition stage. The annual litterfall rates did not differ significantly between sites. In Shuaiba, monthly litterfall ranged from 87.7 kg ha-1 to 543.1 kg ha-1 with an annual litterfall rate of 3.68 t ha-1 y-1 while in Yanbu, the monthly litterfall ranged from 142 kg ha-1 to 539.5 kg ha-1 with an annual litterfall rate of 3.51 t ha-1. Monthly standing stock litter was significantly lower than monthly litterfall in both sites (p <0.05) indicating litter removal from the forest floor, however, the removed litter is retained within the mangrove system rather than exported owing to low tidal ranges. The litterfall lost 41% of its mass in the first 64 days with no significant differences in final mass loss between Shuaiba and Yanbu sites (p >0.05) and with a half-life value of approximately 90 days. The N concentration in the decomposing leaves was 40% lower than those of fresh leaves. In addition, the lignin concentration in litter increased over time and was negatively correlated to mass loss. These findings indicate low litter production and litter quality compared to systems in other parts of the world. Moreover, it indicates the accumulation and conservation mechanism of mangrove ecosystems in the extreme Red Sea environment. [ABSTRACT FROM AUTHOR]

Developing new antibiotics is a critical area of research that grows as a result of the increasing problem of antibiotic resistance. Scientists search for new antibiotics by screening natural sources such as soil, plants, and marine environments. One of the iconic plants in the marine environment is the mangrove, which is a source of honeybee propolis. Propolis collected from the grey mangrove Avicennia marina on Tarout Island, the Eastern Province of Saudi Arabia, was used to evaluate antibacterial activities against three pathogenic bacteria: gram-negative Enterobacter cloacae (RCMB 001(1) ATCC® 23355TM), gram-positive methicillin-resistant Staphylococcus aureus (clinical isolate), and Streptococcus mutans Clark (RCMB 017(1) ATCC® 25175TM). The results indicate the effectiveness of the methanolic extract of such propolis. The chemical composition of this extract was analyzed using LC-MS, and four compounds were identified (alginic acid, carrageenan, fucoxanthin, cycloeudesmol). Their modes of action were evaluated against bacterial cell walls. Bacterial transpeptidase and transglycosylase on the surface are basic for cell divider amalgamation, and numerous antimicrobials have been created to target these compounds. Molecular docking was employed to predict the interactions of four compounds and S. aureus to predict interaction. Alginic acid was found to be the best interaction with a score of −7.44 Kcal/mol with distance ranges between 2.86 and 3.64 and RMSD refined below 2 Å. Carrageenan with −6.64 Kcal/mol and a distance of 3.05 and 2.87 came second. Then, fucoxanthin with −6.57 Kcal/mol and a distance of 1.4. Finally, cycloeudesmol with a score of −4.6 Kcal/mol and a distance of 2.87 showed the least activity. The first three compounds interacted effectively and could form very promising chemicals that could be used one day against pathogenic bacteria in the future. [ABSTRACT FROM AUTHOR]

Mangrove is one of the most precious ecosystems with the greatest losses due to climate change, human activities, and pollution. The objective of this study is to assess the accumulation and distribution of some trace metals (Cu, Cd, Ni, Pb, and Zn) in sediments and Avicennia marina roots and leaves and to discuss the antioxidant potential of A. marina under metallic pollution stress. Sediments, leaf, and root samples of A. marina were collected from five sites along the Red Sea Coast of Egypt. Several ecological pollution indices, including the geo accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), bioconcentration factor (BCF), and translocation factor (TF), were used to assess the pollution load. Cu, Cd, Ni, Pb, and Zn average concentrations in sediments were 167.4, 0.75, 110.65, 39.79, and 220 μg g−1, respectively, and the average values of these metals in A. marina roots were 44.9, 0.5, 87.96, 39.02, and 54.68 μg g−1, respectively, while in leaves their concentration were 50.46, 0.5572, 88.24, 40.08, and 56.08 μg g−1, respectively. The values of the Igeo, CF, and PLI index indicated that location 1 and 5 are moderate-to-heavily contaminated sites. On the other hand, leaves and roots of A. marina grown in polluted locations 1 and 5 showed high accumulation of malondialdehyde (MDA), low chlorophyll a and chlorophyll b contents concomitant with a decrease in total soluble sugars. High total antioxidant capacity was associated with a significant increase in activity levels of antioxidant enzymes (Catalase, Polyphenol oxidase, Polyphenol peroxidase, and Ascorbic acid oxidase), accumulation of secondary metabolites (total phenols, flavonoids, and tannins), and proline and carotenoids content increase. Overall, the present study suggests that the mangrove habitat of the Egyptian Red Sea coast is under the stress of anthropogenic activities, which necessitates a conservation plan to avoid further contamination and protect the unique biota of this distinctive habitat. [ABSTRACT FROM AUTHOR]

Multidrug and Toxic Compound Extrusion (MATE) proteins are essential transporters that extrude metabolites and participate in plant development and cellular detoxification. MATE transporters, which play crucial roles in the survival of mangrove plants under highly challenged environments, by specialized salt extrusion mechanisms, are mined from their genomes and reported here for the first time. Through homology search and domain prediction in the genome assemblies of Avicennia marina, Bruguiera sexangula, Ceriops zippeliana, Kandelia obovata, Rhizophora apiculata and Ceriops tagal, 74, 68, 66, 66, 63 and 64 MATE proteins, respectively were identified. The phylogenetic analysis divided the identified proteins into five major clusters and following the clustering pattern of the functionally characterized proteins, functions of the transporters in each cluster were predicted. Amino acid sequences, exon-intron structure, motif details and subcellular localization pattern for all the 401 proteins are described. The custom designed repeat masking libraries generated for each of these genomes, which will be of extensive use for the researchers worldwide, are also provided in this paper. This is the first study on the MATE genes in mangroves and the results provide comprehensive information on the molecular mechanisms enabling the survival of mangroves under hostile conditions. [ABSTRACT FROM AUTHOR]

Host defense peptides (HDPs) are components of plant defensive barriers that resist microbial infection. Members of the Snakin/GASA protein family in plants have functions of regulating plant growth, defense, and bacteriostasis. Most mangrove plants grow in coastal zones. In order to survive in harsh environments, mangrove plants have evolved complex adaptations against microbes. In this study, Snakin/GASA family members were identified and analyzed in the genomes of three mangrove species. Twenty-seven, thirteen, and nine candidate Snakin/GASA family members were found in Avicennia marina, Kandelia obovata, and Aegiceras corniculatum, respectively. These Snakin/GASA family members were identified and categorized into three subfamilies via phylogenetic analysis. The genes coding for the Snakin/GASA family members were unevenly distributed on chromosomes. Collinearity and conservative motif analyses showed that the Snakin/GASA family members in K. obovata and A. corniculatum underwent multiple gene duplication events. Snakin/GASA family member expression in normal leaves and leaves infected with pathogenic microorganisms of the three mangrove species was verified using real-time quantitative polymerase chain reaction. The expression of KoGASA3 and 4, AcGASA5 and 10, and AmGASA1, 4, 5, 15, 18, and 23 increased after microbial infection. This study provides a research basis for the verification of HDPs from mangrove plants and suggests directions for the development and utilization of marine biological antimicrobial peptides. [ABSTRACT FROM AUTHOR]

The present work aims to study the phytochemistry and anti-biofouling potential of the mangrove strands of the Avicennia marina. Bioassay-guided active spot purification and GC-MS analysis revealed the existence of two key compounds (> 65%) responsible for the promising anti-biofouling activity. To investigate the phytochemicals, present in the aerial part of the A. marina through GCMS and FTIR. In-silico anti-biofouling property of the selected compounds of A.marina. The approach used by the United States Environmental Protection Agency USEPA, (BIOWINTM, a biodegradation probability programme) used to estimate the detected lead compounds suggests that they are naturally biodegradable. [ABSTRACT FROM AUTHOR]

NAC (NAM, ATAF1/2, CUC2) transcription factors (TFs) constitute a plant-specific gene family. It is reported that NAC TFs play important roles in plant growth and developmental processes and in response to biotic/abiotic stresses. Nevertheless, little information is known about the functional and evolutionary characteristics of NAC TFs in mangrove plants, a group of species adapting coastal intertidal habitats. Thus, we conducted a comprehensive investigation for NAC TFs in Avicennia marina, one pioneer species of mangrove plants. We totally identified 142 NAC TFs from the genome of A. marina. Combined with NAC proteins having been functionally characterized in other organisms, we built a phylogenetic tree to infer the function of NAC TFs in A. marina. Gene structure and motif sequence analyses suggest the sequence conservation and transcription regulatory regions-mediated functional diversity. Whole-genome duplication serves as the driver force to the evolution of NAC gene family. Moreover, two pairs of NAC genes were identified as positively selected genes of which AmNAC010/040 may be imposed on less constraint toward neofunctionalization. Quite a few stress/hormone-related responsive elements were found in promoter regions indicating potential response to various external factors. Transcriptome data revealed some NAC TFs were involved in pneumatophore and leaf salt gland development and response to salt, flooding and Cd stresses. Gene co-expression analysis found a few NAC TFs participates in the special biological processes concerned with adaptation to intertidal environment. In summary, this study provides detailed functional and evolutionary information about NAC gene family in mangrove plant A. marina and new perspective for adaptation to intertidal habitats. Key message: This study provides comprehensive functional and evolutionary information for NAC transcription factor in the genome of mangrove plants Avicennia marina and new perspectives from the regulatory mechanisms for adaptation to intertidal habitats. [ABSTRACT FROM AUTHOR]

Every ecosystem supports the living organisms by providing direct and indirect benefits and services. Among these areas, mangrove forests are one of the most fertile ecosystems in the intertidal zones. These natural forests are one of the coastal ecosystems that not only provide a source of food for humans and animals, but also play a major role in protecting and stabilizing coastlines and controlling climate. Mangroves are a breeding ground and a safe habitat for a variety of marine vertebrates and invertebrates. This study explains the experienced methods of propagation and foresting of Avicenna marina species. For the first time in the Persian Gulf, we reported a 5-year evaluation of reforestation method of grey mangrove. Reforestation in the highest latitude of natural forests in the Persian Gulf did not have any side effects on growing of Grey mangrove in the selected sites. As a result, increasing the area of Grey mangrove forests in the Persian Gulf improves the ecosystems of the tidal area. Increasing the chances of fishing and improving the economic conditions of the local communities around this bay will be some of the results of mangrove forestation. Furthermore, this is the first report of a simple method to train all the steps of grey mangrove reforestation. [ABSTRACT FROM AUTHOR]

This study evaluated the freshwater use of two mangrove species (R. mucronate: Rhizophora mucronata and A. marina: Avicennia marina) growing in a coastal area of Djibouti City and on Moucha Island in Djibouti. We accomplished this by comparing hydrogen and oxygen stable isotope ratios (δ2H and δ18O) in the body water with those of creek water, soil water, groundwater, and rainwater samples. Line-conditioned excess (lc-excess) was calculated for the δ2H and δ18O values of the groundwater and rainwater samples. Although two regression lines were drawn using the δ2H and δ18O values of the plant body water as well as the environmental water, no significant differences were found, suggesting that the effects of isotope fractionation due to evaporation in all the samples were almost similar. Comparison of lc-excess and δ18O suggested that the body water from the two mangrove species growing on Moucha Is. were strongly influenced by seawater, but contained some freshwater sources other than the seawater, the soil water, and the creek water. It was also found that Avicennia marina growing in the coastal area was strongly influenced by groundwater. The origin of the freshwater absorbed by the mangroves on the island was not clear, but it could be groundwater recharged in a faraway place. [ABSTRACT FROM AUTHOR]