Water relations of plants in the field: some comments on the measurement of selected parameters

Methods for the analysis of water status and transport in thesoil-plant-atmosphere continuum are briefly enumerated, withsome personal comments on their reliability when used on plantsgrowing in the field. These methods have provided us with acoherent system of data essentially free from major contradictionsto the cohesion theory of water transport. It is shown thatrecent attempts at replacing the xylem tensions postulated bythis theory with hypothetical osmotic transport mechanisms inorder to accommodate data from the xylem pressure probe arenot consistent with the bulk of results and furthermore areimplausible in view of the energetic expenditure required. Key words: Soil-plant-atmosphere continuum, water relations, xylem tension     

Temperatur- und osmotische Resistenz von Meeresalgen der bretonischen Küste

Ohne ZusammenfassungProfessor Dr. Karl Höfler zum 65. Geburtstag in dankbarer Verehrung gewidmet.     

Optogenetic delivery of trophic signals in a genetic model of Parkinson’s disease

Optogenetics has been harnessed to shed new mechanistic light on current and future therapeutic strategies. This has been to date achieved by the regulation of ion flow and electrical signals in neuronal cells and neural circuits that are known to be affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and are implicated in degenerative disorders, has never been demonstrated in an animal model of disease. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1^B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to inspire novel strategies towards a spatio-temporal regulation of tissue repair.     

Untersuchungen über Strahlenschutz an Pflanzenzellen

Ohne ZusammenfassungResearch carried out with the support of the International Atomic Energy Agency.     

Referate

Ohne Zusammenfassung     

Zellwandpermeabilität einiger Moose

Ohne Zusammenfassung     

Besprechungen

Ohne Zusammenfassung