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Farid Menaa P. A. U. I. Wijesinghe Gobika Thiripuranathar Bushra Uzair Haroon Iqbal Barkat Ali Khan Bouzid Menaa 《Marine drugs》2020,18(12)
Seaweeds are broadly distributed and represent an important source of secondary metabolites (e.g., halogenated compounds, polyphenols) eliciting various pharmacological activities and playing a relevant ecological role in the anti-epibiosis. Importantly, host (as known as basibiont such as algae)–microbe (as known as epibiont such as bacteria) interaction (as known as halobiont) is a driving force for coevolution in the marine environment. Nevertheless, halobionts may be fundamental (harmless) or detrimental (harmful) to the functioning of the host. In addition to biotic factors, abiotic factors (e.g., pH, salinity, temperature, nutrients) regulate halobionts. Spatiotemporal and functional exploration of such dynamic interactions appear crucial. Indeed, environmental stress in a constantly changing ocean may disturb complex mutualistic relations, through mechanisms involving host chemical defense strategies (e.g., secretion of secondary metabolites and antifouling chemicals by quorum sensing). It is worth mentioning that many of bioactive compounds, such as terpenoids, previously attributed to macroalgae are in fact produced or metabolized by their associated microorganisms (e.g., bacteria, fungi, viruses, parasites). Eventually, recent metagenomics analyses suggest that microbes may have acquired seaweed associated genes because of increased seaweed in diets. This article retrospectively reviews pertinent studies on the spatiotemporal and functional seaweed-associated microbiota interactions which can lead to the production of bioactive compounds with high antifouling, theranostic, and biotechnological potential. 相似文献
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Determination of Ploidy Level and Nuclear DNA Content in Tunisian Populations of Atriplex halimus L.
Kheiria Hcini David J. Walker Sadok Bouzid Elena González Nora Frayssinet Enrique Correal 《Genetic Resources and Crop Evolution》2006,53(1):1-5
Atriplex halimus L. (Chenopodiaceae) (Saltbush) is a perennial species used as a fodder shrub for livestock in arid and semi-arid areas, particularly
in North Africa. The aim of this work was to determine whether differences in ploidy level and/or nuclear DNA content exist
among populations from widely-separated sites in Tunisia. We determined nuclear DNA content and chromosome numbers for populations
of A. halimus from seven different locations (Gabes, Medenine, Tataouine, Monastir, Tunis, Sidi Bouzid, Kairouan). The chromosome counts
showed that all the Tunisian populations, plus a population from Eraclea (Italy), were tetraploid (2n = 4x = 36) whereas a population from Cala Tarida (Spain) was diploid (2n = 2x = 18). With respect to nuclear DNA, the 2C DNA content of population Cala Tarida was estimated to be 2.41 pg. There was no
significant difference among the tetraploid populations (or among plants within populations), whose 2C DNA content ranged
from 4.92 to 4.97 pg. 相似文献
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Artemisia herba–alba Asso (known in Arabic as Shih) is an evergreen aromatic shrub endemic in North African rangelands with high pastoral and medicinal relevance. The present work was designed to determine the effect of four soluble salts (NaCl, Na2SO4, MgCl2, and CaCl2) on germination of A. herba–alba seeds. Four concentrations (0, 50, 10, and 150 mM) of each salt were used to test the influence of salinities on germination percentage (GP), rate of germination (RG), and germination tolerance index (GTI %). The experiment was conducted in a controlled incubator with a 12h–photoperiod under 15°C dark/25°C light. The results showed that both GP and (RG) decreased significantly with salinity, and the highest GP was observed in the distilled water control (~ 80%). The germination tolerance index (GTI %) revealed that A. herba–alba seeds were more tolerant to CaCl2 than other soluble salts. Comparatively, at high salt concentrations, MgCl2 and Na2SO4 were generally the most toxic salts followed by NaCl and CaCl2. The germination of A. herba–alba over a wide range of soluble salts suggests that this species can establish in salt-degraded soils. Therefore, this species appears a promising candidate for the rehabilitation of rangeland with saline soils. 相似文献
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In order to improve somatic embryogenesis production in date palm Phoenix dactilyfera L. cv. Deglet Nour (DN), a comparative study between somatic (SE) and zygotic (ZE) embryos developments was carried out. The data showed that ZE maturation occurred from 10 to 19 weeks after pollination (WAP). During this period, the fresh weight (FW) and the dry weight (DW) of ZE increased progressively to reach a maximum level at 19 WAP. SE development occurred in three distinct stages. The DW remained constant during the two first stages, and declined slightly during the third and final stage. Embryo protein analysis revealed significant differences between ZE and SE. The ZE total protein level was initially low and increased to the maximum at mature stage. However, no significant change in total protein was detected during SE development. SDS-PAGE analysis showed a poor protein profile for SE, compared to that of ZE. In the latter, a 22 kDa protein was identified by N-terminal sequencing as a glutelin. This protein was accumulated rapidly during early development and remained at a relatively constant level during ZE development, and then declined progressively 12 days after embryo germination (DG). This protein seems to be absent in SE. 相似文献
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Experiments on larvicide and ovicide activity of 13 insecticides in semi‐natural conditions showed a medium to low efficacy of bio‐insecticides on all instars of Tuta absoluta (Meyrick) except for Bacillus thuringiensis Berliner var. kurstaki which was distinguished by an average mortality of 72.5%. Spinosad and Spinetoram based insecticides showed high efficiency in controlling all instars of larvae with respectively an average mortality of 66.5% and 85.6%. However, this study revealed a unique ovicide effect of azadirachtin‐neem oil based insecticide with 43.8% egg mortality. 相似文献
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Calcium (Ca) has an important role in plant physiology, including involvement in the responses to salt stress, and controls numerous processes. To overcome the negative impact of high salinity, the addition of supplemental Ca to the growth medium as an ameliorative agent could be necessary. Atriplex halimus subsp. schweinfurthii and Atriplex canescens subsp. linearis were grown in hydroponic conditions to investigate the effectiveness of supplementary calcium chloride (CaCl2) applied into nutrient solution on plants grown at high (400 mM) sodium chloride (NaCl) concentration. Treatments were: 1) nutrient solution alone [control (C)]; 2) nutrient solution plus 400 mM sodium chloride (NaCl); and 3) nutrient solution and 400 mM NaCl plus supplementary 40 mM CaCl2 supplied in nutrient solution (NaCl + CaCl2). The experiment was set up as a completely randomized design, consisting of two species (A. halimus and A. canescens), three treatments (control, NaCl, and NaCl + CaCl2), and five replicates. Dry weight and chlorophyll content of plants grown at high NaCl were lower than those at normal nutrient solution. Supplementary CaCl2 ameliorated the negative effects of salinity on plant growth in both species. Root hydraulic conductivity (L 0) decreased with elevated NaCl and increased with supplementary CaCl2 compared to the stressed plants. Membrane permeability increased with high NaCl application and these increases in root membrane permeability decreased with supplementary CaCl2 compared to the NaCl treatment. Sodium (Na) concentration in plant tissues increased in both species in high NaCl level. Application of supplementary CaCl2 lowered Na concentration. Concentrations of calcium (Ca) and potassium (K) were at deficient ranges in the plants grown at high NaCl levels and these deficiencies were corrected by supplementary CaCl2. 相似文献
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Samira ChekaliSamia Gargouri Timothy Paulitz Julie M. NicolMohsen Rezgui Bouzid Nasraoui 《Crop Protection》2011,30(6):718-725
The effects of water stress on Fusarium foot and root rot in durum wheat were investigated in growth chamber, greenhouse and field tests in Tunisia. In the seedling stage, emergence of six durum wheat cultivars in the growth chamber was significantly reduced by inoculation with Fusarium culmorum and water stress (P<0.0001), with more disease under drier conditions. Additionally, the tiller number per mature plant, the 1000 grain weight and disease severity in mature stage were reduced by inoculation in greenhouse studies. In a field test, inoculation with F. culmorum significantly reduced the yield (P<0.001), by more than 17% for Om Rabiaa and 38% for Karim, the two cultivars tested. Yield was also significantly affected by precipitation and irrigation levels. The severity of the disease, estimated by the percentage of white heads, was separately affected by the cultivar (P<0.001) and inoculation (P = 0.0004). Percentage of white heads was 1.5 and 2 × higher in inoculated plants than non-inoculated for Om Rabiaa and Karim cultivars, respectively. Disease severity was highest in treatments with the greatest water stress. This is the first detailed study of water stress and F. culmorum on durum wheat in Tunisia, and indicates that cultivar resistance and irrigation management may be important in the management of Fusarium foot rot. 相似文献
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Thabèt Yangui Ali Rhouma Kamel Gargouri Mohamed Ali Triki Jalel Bouzid 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(4):495-504
Olive mill waste water (OMW) and some of its indigenous bacterial strains were tested in vitro and in planta for their efficacy against crown gall disease caused by Agrobacterium tumefaciens. OMW and polyphenols displayed a high level of antibacterial activity, however the volatile fraction was less efficient as
only a bacteriostatic effect was observed. In pot experiments, the percentage of bitter almond rootstock showing symptoms
of crown gall was significantly reduced with the dosage rate of OMW 1% as compared to the control (highly natural infected
soil treated with water). Five indigenous bacterial strains isolated from OMW exhibited an antagonistic effect against the
bacterium. Based on the gene 16S rRNA sequence analysis, one isolate showed 99.2% similarity to known sequences of Bacillus subtilis, one isolate demonstrated high percentage similarities (99.3%) to the genera Bacillus pumilis, and two isolates were associated with Stenotrophomonas maltophilia and Pseudomonas putida 100% and 99.6% similarities respectively. Among these bacteria, the strain B1 proved efficient against the soil borne pathogen
in vitro and pot experiments. Our study in controlled conditions suggested that the addition of OMW to soil exerts significant disease
suppressiveness against A. tumefaciens.
Thabet Yangui and Ali Rhouma contributed equally to this work and are regarded as joint first authors. 相似文献
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