Contributions of <Emphasis Type="Italic">TaSUTs</Emphasis> to grain weight in wheat under drought

Key message

The homologous genes to OsSUT1-5 in wheat were identified and detailed analysed. TaSUT1 was the predominant sucrose transporter group and it illustrated the genotypic variations towards drought during grain filling.

Abstract

Sucrose transporters (SUT) play crucial roles in wheat stem water soluble carbohydrate (WSC) remobilization to grain. To determine the major functional SUT gene groups in shoot parts of wheat during grain development, drought tolerant varieties, Westonia and Kauz, were investigated in field drought experiments. Fourteen homologous genes to OsSUT1-5 were identified on five homeologous groups, namely TaSUT1_4A, TaSUT1_4B, TaSUT1_4D; TaSUT2_5A, TaSUT2_5B, TaSUT2_5D; TaSUT3_1A, TaSUT3_1D; TaSUT4_6A, TaSUT4_6B, TaSUT4_6D; TaSUT5_2A, TaSUT5_2B, and TaSUT5_2D, and their gene structures were analysed. Wheat plants above the ground were harvested from pre-anthesis to grain maturity and the stem, leaf sheath, rachis, lemma and developing grain were used for analysing TaSUT gene expression. Grain weight, thousand grain weight, kernel number per spike, biomass and stem WSC were characterized. The study showed that among the five TaSUT groups, TaSUT1 was the predominant sucrose transporting group in all organs sampled, and the expression was particularly high in the developing grain. In contrast to TaSUT1, the gene expression levels of TaSUT2, TaSUT3 and TaSUT4 were lower, except for TaSUT3 which showed preferential expression in the lemma before anthesis. The TaSUT5 gene group was very weakly expressed in all tissues. The upregulated gene expression of TaSUT1 Westonia type in stem and grain reveal a crucial role in stem WSC remobilization to grain under drought. The high TaSUT1 gene expression and the significant correlations with thousand grain weight (TGW) and kernel number per spike demonstrated the contribution in Kauz’s high grain yield in an irrigated environment and high TGW in Westonia under drought stress. Further molecular level identification is required for gene marker development.

     

Heterotrophic bacteria associated with the green alga <Emphasis Type="Italic">Ulva rigida</Emphasis>: identification and antimicrobial potential

Heterotrophic bacteria associated with the green alga Ulva rigida, collected from the coast of Tunisia, were isolated and subsequently identified by their 16S rRNA gene sequences and by phylogenetic analysis. The 71 isolates belong to four phyla: Proteobacteria (Alpha-and Gamma- subclasses), Bacteroidetes, Firmicutes, and Actinobacteria. Most of the isolates belong to Proteobacteria. The Gram-positive Firmicutes and especially the genus Bacillus were well-represented at the surface of U. rigida, collected from the coast as well as from the lagoon, while Actinobacteria were represented only at the surface of algae collected from the coast of Cap Zebib. Bacteroidetes were more represented at the surface of algae collected from the Ghar El Melh lagoon. The bacterial community of the water surrounding the algae was different from that associated with the surface of the algae. Moreover, the abundance of bacteria in the surrounding water was much lower compared to the density of bacteria associated with the surface of the algae. Bacteria isolated from the algal surface were tested for their antimicrobial potential. The results show that ~?36% of the algae-associated bacterial isolates possess antibacterial activity whereas free-living bacteria, isolated from the surrounding water, did not show such activity. The surface of U. rigida was colonized by a high diversity of culturable and possibly novel epiphytic bacteria that may be an important source of antimicrobial compounds and are therefore of biotechnological interest.     

Probing the interaction of anticancer drug temsirolimus with human serum albumin: molecular docking and spectroscopic insight

The binding interaction between temsirolimus, an important antirenal cancer drug, and HSA, an important carrier protein was scrutinized making use of UV and fluorescence spectroscopy. Hyper chromaticity observed in UV spectroscopy in the presence of temsirolimus as compared to free HSA suggests the formation of complex between HSA and temsirolimus. Fluorescence quenching experiments clearly showed quenching in the fluorescence of HSA in the presence of temsirolimus confirming the complex formation and also confirmed that static mode of interaction is operative for this binding process. Binding constant values obtained through UV and fluorescence spectroscopy reveal strong interaction; temsirolimus binds to HSA at 298 K with a binding constant of 2.9 × 10⁴ M^?1implying the strength of interaction. The negative Gibbs free energy obtained through Isothermal titration calorimetry as well as quenching experiments suggests that binding process is spontaneous. Molecular docking further provides an insight of various residues that are involved in this binding process; showing the binding energy to be -12.9 kcal/mol. CD spectroscopy was retorted to analyze changes in secondary structure of HSA; increased intensity in presence of temsirolimus showing changes in secondary structure of HSA induced by temsirolimus. This study is of importance as it provides an insight into the binding mechanism of an important antirenal cancer drug with an important carrier protein. Once temsirolimus binds to HSA, it changes conformation of HSA which in turn can alter the functionality of this important carrier protein and this altered functionality of HSA can be highlighted in variety of diseases.     

First record of non-marine ostracods from the Paleogene “hamadian deposits” of Méridja area,west of Bechar (southwestern Algeria)

A new non-marine ostracod fauna from the Paleogene “hamadian deposits” outcropping west of Bechar (southwestern Algeria) has been recovered from lacustrine to fluvial deposits of the Oued Méridja section and fluvial deposits on the southern edge of the Hamada de Méridja section. Recently, these sections have been dated as late Thanetian – early Ypresian (latest Paleocene to earliest Eocene) and Ypresian – earliest Lutetian (early to earliest middle Eocene), respectively, based on charophytes. The associated ostracod fauna recovered consists of relatively mostly moderately to badly preserved specimens and comprises 14 taxa, none of which could be identified to species level in view of its poor state of preservation; we have nevertheless been able to identify and describe the following taxa: Herpetocypris sp., Cyprinotus? sp., Heterocypris? sp. 1 and sp. 2, Cypris? sp., Ilyocypris sp., Cytheroidea indet. sp. 1 and sp. 2, Limnocytheridae indet. sp. 1, Cypridoidea indet. sp. 1, Cyprididae indet. sp. 1, and Ostracoda indet. sp. 1, 2 and 3. Only Heterocypris sp. 1 occurs in both sections. Although the fauna can as yet not be related to the few other contemporaneous faunas reported from the wider palaeogeographic area, it adds important new information to our poor knowledge on Eocene non-marine ostracods in North Africa and southern Europe. The Méridja sections and area are promising regarding the discovery of more, better preserved material and further studies, and one main limitation to the correlation of the fauna is the hitherto insufficient taxonomic knowledge on many faunal elements of Eocene non-marine ostracods to which our section contributes considerably.     

Palaeobiogeographic implications of the first report of the eocrinoid genus Ascocystites Barrande (Echinodermata,Blastozoa) in the Upper Ordovician of the Ougarta Range (Western Algeria)

Several specimens of the genus Ascocystites (Blastozoa, Eocrinoidea) are described for the first time in Late Ordovician deposits (Bou M’Haoud Formation) from the Ougarta Range, Algeria. This genus was previously known in Darriwilian–Sandbian deposits of four other areas of the Mediterranean Province (Czech Republic, France, Morocco and Portugal). The Algerian material completes its palaeobiogeographic distribution in the peri-Gondwanan area, restricted in shallow water settings.     

Foliar application of the triterpene derivative 24-methylen-elemo-lanosta-8,24-dien-3-one alleviates salt toxicity in grapevine

This work focused on the effect triterpene derivative 24-methylen-elemo-lanosta-8,24-dien-3-one (F3) on the induction of salt stress tolerance of the Moroccan grapevine cv. “Doukkali”. Hardwood cuttings of the grapevine from a homogeneous plant material collected in the field were grown in hydroponic medium under different salt concentrations and treated with 50 or 100 µg ml^?1 of F3. Salt stress affected several physiological and biochemical parameters including relative water content, chlorophyll a and b content, peroxidase, and polyphenol oxidase activities, which decreased along with time. Meanwhile, proline, proteins, soluble sugars, H₂O₂, and carotenoid content, as well as phenolic compound content increased, suggesting an evidence of tolerance of this local variety to salinity. An exogenous supply of the triterpenic product increased all these parameters under normal conditions. In addition, F3 at low dose was found to be successful in lowering Na⁺ content and alleviating the inhibitory effects of salt stress on relative water content as well as on chlorophyll a and b.     

Recombinational and Physical Mapping of the Locus for Primary Open-Angle Glaucoma (GLC1A) on Chromosome 1q23–q25

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness in industrialized countries. A locus for juvenile-onset POAG,GLC1A,has been mapped to 1q21–q31 in a 9-cM interval. With recombinant haplotypes, we have now reduced theGLC1Ainterval to a maximum of 3 cM, between theD1S452/NGA1/D1S210andNGA5loci. These loci are 2.8 Mb apart on a 4.7-Mb contig that we have completed between theD1S2851andD1S218loci and that includes 96 YAC clones and 48 STSs. The newGLC1Ainterval itself is now covered by 25 YACs, 30 STSs, and 16 restriction enzyme site landmarks. The lack of aNotI site suggests that the region has few CpG islands and a low gene content. This is compatible with its predominant cytogenetic location on the 1q24 G-band. Finally, we have excluded important candidate genes, including genes coding for three ATPases (ATP1B1, ATP2B4, ATP1A2), an ion channel (VDAC4), antithrombine III (AT3), and prostaglandin synthase (PTGS2). Our results provide a basis to identify theGLC1Agene.     

Moraxella (Branhamella) catarrhalis Adherence to Human Bronchial and Oropharyngeal Cells: The Role of Adherence in Lower Respiratory Tract Infections

To study the role of Moraxella (subgenus Branhamella) catarrhalis (B. catarrhalis) adherence to airway cells in lower respiratory tract infections, the in vitro attachments of B. catarrhalis to upper airway (oropharyngeal) and lower airway (bronchial) epithelial cells were compared. The adherence of 4 strains (1 nonfimbriated and 3 fimbriated) of B. catarrhalis to respiratory tract epithelial cells collected from 11 patients with chronic pulmonary disease (CPD) and 11 healthy individuals was evaluated. Both the fimbriated and nonfimbriated strains showed increased attachment to oropharyngeal cells in the CPD patients (mean ± SEM; 25.0 ± 3.2/cell; P < 0.01) when compared to the control subjects (12.1 ± 1.1/cell). On the average, the attachment to bronchial cells was 6.1 to 13.6 times greater per surface area (bacteria/μ²) than the attachment to oropharyngeal cells. The fimbriated strains tended to adhere in higher numbers to bronchial cells (19.0 ± 1.8/cell) than the nonfimbriated strain (8.7 ± 1.2/cell), although there was no difference between the CPD and control groups. In conclusion, the attachment of B. catarrhalis to oropharyngeal cells may be an enhancing factor for colonization in the upper respiratory tract in patients with CPD, and elevated adherence of the bacteria to bronchial cells may suggest pathogenic importance when mucociliary function is impaired.