Transcriptome changes in Hirschfeldia incana in response to lead exposure

Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies

Effects of a Composite Endomycorrhizal Inoculum on Olive Cuttings under the Greenhouse Conditions

This study was carried out in a nursery to evaluate the impact of mycorrhizal fungi on the cutting's root growth, and root colonization of a Moroccan olive variety ‘Picholine Marocaine' under greenhouse conditions during 2 years of cultivation. The results revealed that the inoculation with a composite inoculum of arbuscular mycorrhizal fungi (AMF) stimulated an early root formation and high development of vegetative shoots in inoculated cuttings respectively, 35 days (50 days in the control plots) and 40 days (60 days in the control plots) after their culture. The progressive establishment of mycorrhizal symbiosis in the roots of the inoculated plants showed that the root and vegetative masses were respectively 24 g and 19.5 g two years after inoculation. The average height and the leave's number of the inoculated plants relative to the control were respectively s 42/ 12 cm and 145/12. The newly formed roots were mycorrhizal and present different structures characteristic of AMF: arbuscules, vesicles, hyphae and spores, whose frequency and intensity reached 90% and 75% two years after cuttings cultivation. The arbuscular and vesicular contents and the number of spores were 67%, 96% and 212 spores/ 100 g of soil respectively. The fourteen species of mycorrhizal fungi isolated from the rhizosphere belong to 4 genera (Glomus, Acaulospora, Gigaspora, and Scutellospora) and three families (Glomaceae, Acaulosporaceae and Gigasporacea).The Glomus genus was the most dominant (65%) followed by the Gigaspora genus (22%). Glomus intraradices, Gigaspora sp.2, Glomus versiformes are the most abundant species, their frequency of occurrence are respectively 30%, 21% and 16%

Diversity, phylogeny and distribution of bean rhizobia in salt-affected soils of North-West Morocco

Different molecular methods: BOX-PCR fingerprinting, R-FLP-PCR and sequencing of the 16S rDNA as well as the symbiotic genes nodC and nifH, were used to study the genetic diversity within a collection of nodulating bean rhizobia isolated from five soils of North-West Morocco. BOX fingerprints analysis of 241 isolates revealed 19 different BOX profiles. According to the PFLP-PCR and sequencing of 16S rDNA carried out on 45 representative isolates, 5 genotypes were obtained corresponding to the species Rhizobium etli, R. tropici, R. gallicum, R. leguminosarum and Sinorhizobium meliloti. The most abundant species were R. etli and R. tropici (61% and 24%, respectively). A high intraspecific diversity was observed among the R. etli isolates, while the R. tropici group was homogeneous. Most of the rhizobia studied belong to species known to nodulate common bean, while 2 species were unconventional microsymbionts: R. leguminosarum biovar viciae and S. meliloti. Our results, especially the nodulation promiscuity of common bean and the relation between the predominance of some species of rhizobia in particular soils and the salt content of these soils, indicate that there is a real need for a better understanding of the distribution of common bean rhizobia species in the soils of Morocco before any inoculation attempt

Дводіапазонна силосно-щілинна антена з моделлю еквівалентної схеми для додатків 5G мм-хвиль

У статті розглядається розробка та тонке налаштування MPA (мікросмужкової патч-антени) α - мм-хвиль, що має силосні щілини. Початкові параметри конструкції обчислюються за допомогою встановлених формул, що стосуються конструкції патч-антени. Антена моделюється на підкладці зі специфічними властивостями матеріалу, використовуючи матеріал підкладки Rogers 5058, який характеризується (Ɛr) 2,2 і дотичними втратами 0,0009. Проведено порівняльний аналіз, щоб продемонструвати змодельовану продуктивність представленої силосної антени з використанням HFSS з моделлю її еквівалентної схеми, реалізованою в AWR. Це передбачає ретельне налаштування компонентів для досягнення бажаних характеристик. У статті простежуються еволюційні фази конструкції антени, підкреслюються геометричні модифікації та зміни площини заземлення. Крім того, у ньому докладно розглядаються резонансні частоти антени та пропонується порівняльна оцінка параметра S11 між симуляціями AWR та HFSS, виявляючи сильне узгодження. Запропонована антена має привабливий розмір 14 мм x 12 мм і працює в подвійних робочих діапазонах, що резонують на частотах 28,1 та 37,9 ГГц. Варіації підсилення для різних проектних ітерацій ретельно вивчаються, і, нарешті, досягаються пікові підсилення 5,2 та 6,5 дБі для запропонованої антени на робочих частотах 28 та 37,9 ГГц відповідно разом із діаграмами спрямованості в площинах E та H на різних частотах. Антена підходить для додатків 5G, що підтримують діапазони 28/38 ГГц у міліметровому спектрі.This article explores the development and fine-tuning of α mm-wave MPA (microstrip patch antenna) featuring silo slots. The starting design parameters are computed using established formulas relevant to patch antenna construction. The antenna is simulated on a substrate with specific material properties, utilizing Rogers 5058 substrate material characterized by a (Ɛr) of 2.2 and a tangent-loss of 0.0009. A comparative analysis is conducted to showcase the simulated performance of the presented silo-antenna using HFSS with its equivalent circuit model implemented in AWR. This involves meticulous adjustment of components to achieve the desired characteristics. The article traces the evolutionary phases of the antenna's design, highlighting geometric modifications and alterations to the ground plane. Further, it elaborates on the resonant frequencies of the antenna and offers a comparative assessment of the S11 parameter between AWR and HFSS simulations, revealing strong agreement. The proposed antenna maintains an attractive size of 14 mm x 12 mm and it operates at dual operating bands resonating at 28.1 GHz and 37.9 GHz. Variations in gain for different design iterations are scrutinized and finally the peak gains of 5.2 dBi and 6.5 dBi are attained for the suggested antenna at the operating frequencies of 28 and 37.9 GHz, respectively along with desired radiation patterns in E and H planes at distinct frequencies. The suggested antenna is suitable for 5G applications supporting 28/38 GHz bands in mm-wave spectrum

Chickpea (Cicer arietinum) is nodulated by unexpected wide diversity of Mesorhizobium species in Eastern Algeria

Using a local Algerian cultivar of chickpea, from 9 sites in Eastern Algeria, along a sub-humid to arid gradient, we isolated 60 nodulating isolates, among which 19 were assigned to Mesorhizobium species and 41 to Ensifer meliloti. Trapping revealed great differences among sites for their ability to induce nodules on plant, but no correlation with chemical and physical characterizations of soil samples could be found. Based on 16S rRNA gene sequences, 16S-23S IGS, recA, nodC and nifH sequences, Mesorhizobium isolates were assigned to at least 5 different species, among which one had never been described as nodulating chickpea before. The symbiotic diversity is conversely low, and shared by several species, reflecting horizontal gene transfer. The ability of Mesorhizobium genus to recombine and exchange symbiotic clusters among different species must play a great role in this ability to be associated with chickpea. The question to what extent the symbiotic species would end in this genus is discussed

Role of microorganisms in rehabilitation of mining sites, focus on Sub Saharan African countries

International audienc

In-depth characterization of bacterial and archaeal communities present in the abandoned Kettara pyrrhotite mine tailings (Morocco)

International audienceIn Morocco, pollution caused by closed mines continues to be a serious threat to the environment, like the generation of acid mine drainage. Mine drainage is produced by environmental and microbial oxidation of sulfur minerals originating from mine wastes. The fundamental role of microbial communities is well known, like implication of Fe-oxidizing and to a lesser extent S-oxidizing microorganism in bioleaching. However, the structure of the microbial communities varies a lot from one site to another, like diversity depends on many factors such as mineralogy, concentration of metals and metalloids or pH, etc. In this study, prokaryotic communities in the pyrrhotite-rich tailings of Kettara mine were characterized using the Illumina sequencing. In-depth phylogenetic analysis revealed a total of 12 phyla of bacteria and 1 phyla of Archaea. The majority of sequences belonged to the phylum of Proteobacteria and Firmicutes with a predominance of Bacillus, Pseudomonas or Corynebacterium genera. Many microbial populations are implicated in the iron, sulfur and arsenic cycles, like Acidiferrobacter, Leptospirillum, or Alicyclobacillus in Fe; Acidiferrobacter and Sulfobacillus in S; and Bacillus or Pseudomonas in As. This is one of the first description of prokaryotic communities in pyrrhotite-rich mine tailings using high-throughput sequencing