Human Papilloma Virus DNA Detection in Clinical Samples Using Fluorogenic Probes Based on Oligonucleotide Gated Nanoporous Anodic Alumina Films.

In this work, fluorogenic probes based on oligonucleotide capped nanoporous anodic alumina films are developed for specific and sensitive detection of human papilloma virus (HPV) DNA. The probe consists of anodic alumina nanoporous films loaded with the fluorophore rhodamine B (RhB) and capped with oligonucleotides bearing specific base sequences complementary to genetic material of different high-risk (hr) HPV types. Synthesis protocol is optimized for scale up production of sensors with high reproducibility. The sensors' surfaces are characterized by scanning electron microscopy (HR-FESEM) and atomic force microscopy (AFM) and their atomic composition is determined by energy dispersive X-ray spectroscopy (EDXS). Oligonucleotide molecules onto nanoporous films block the pores and avoid diffusion of RhB to the liquid phase. Pore opening is produced when specific DNA of HPV is present in the medium, resulting in RhB delivery, that is detected by fluorescence measurements. The sensing assay is optimized for reliable fluorescence signal reading. Nine different sensors are synthesized for specific detection of 14 different hr-HPV types in clinical samples with very high sensitivity (100%) and high selectivity (93-100%), allowing rapid screening of virus infections with very high negative predictive values (100%).

Overexpression of LeNHX2 and SlSOS2 increases salt tolerance and fruit production in double transgenic tomato plants.

Transgenic tomato plants (Solanum lycopersicum L. cv. MicroTom) overexpressing both the K+,Na+/H+ antiporter LeNHX2 and the regulatory kinase SlSOS2 were produced by crossing transgenic homozygous lines overexpressing LeNHX2 and SlSOS2. LeNHX2 expression was enhanced in plants overexpressing LeNHX2 but surprisingly even more in plants overexpressing SlSOS2 with and without LeNHX2. All transgenic plants showed better NaCl tolerance than wild type controls and plants overexpressing both LeNHX2 and SlSOS2 grew better under saline conditions than plants overexpressing only one of these genes. Yield related parameters indicated that single and above all double transgenic plants performed significantly better than wild type controls. All transgenic plants produced fruits with a higher K+ content than wild-type plants and plants overexpressing SlSOS2 accumulated more Na+ in fruits than the rest of the plants when grown with NaCl. Roots, stems and leaves of transgenic plants overexpressing LeNHX2 showed a higher K+ content than wild type and single transgenic plants overexpressing SlSOS2. Na+ content in stems and leaves of NaCl treated plants was higher in SlSOS2 overexpressing plants than in wild type and LeNHX2 single transgenic plants. All transgenic lines showed a higher leaf relative water content and a higher plant water content and water use efficiency than wild type controls when both were grown in the presence of NaCl. Results in this work indicate that the joint overexpression of LeNHX2 and SlSOS2 improves growth and water status under NaCl stress, affects K+ and Na+ homeostasis and enhances fruit yield of tomato plants.

Plant NHX cation/proton antiporters.

Although physiological and biochemical data since long suggested that Na(+)/H(+) and K(+)/H(+) antiporters are involved in intracellular ion and pH regulation in plants, it has taken a long time to identify genes encoding antiporters that could fulfil these roles. Genome sequencing projects have now shown that plants contain a very large number of putative Cation/Proton antiporters, the function of which is only beginning to be studied. The intracellular NHX transporters constitute the first Cation/Proton exchanger family studied in plants. The founding member, AtNHX1, was identified as an important salt tolerance determinant and suggested to catalyze Na(+) accumulation in vacuoles. It is, however, becoming increasingly clear, that this gene and other members of the family also play crucial roles in pH regulation and K(+) homeostasis, regulating processes from vesicle trafficking and cell expansion to plant development.