No description available.

No description available.

Using a micro-potometric method, it was ,found that X-irradiation (400 R - 18 Kr) of the shoots of the onion plant Allium cepa will produce an immediate, pronounced (200%) and reversible enhancement of the water uptake by the shielded roots. Unfiltered X-irradiation.(1200 R/min., 120 KVP, 5 ma) was delivered at right angles to the shoot. Readings were taken at 10-minute intervals before, and immediately following X-irradiation. The greatest enhancement occurred at dosages between 4.8 Kr (150%) and 6.0 Kr (190%). The data indicate that the irradiation effect on water uptake was a physical rather than a metabolic one.

No description available.

No description available.

Bystander effects are traditionally known as a phenomenon whereby unexposed cells exhibit the molecular symptoms of stress exposure when adjacent or nearby cells are traversed by ionizing radiation. However, the realm of bystander effects can be expanded to include any systemic changes to cellular homeostasis in response to a number of biotic or abiotic stresses, in any molecular system. This thesis encompasses three independent experiments looking at bystander and bystander-like responses in both plant and animal models. In plants, an investigation into the regulation of small RNAs has given us some insights into the regulation of the plant hormone auxin in both stress-treated and systemic (bystander) leaves. Another plant model shows that a bystander-like plant-plant signal can be induced upon ionizing radiation to increase the genome instability of neighbouring unexposed (bystander) plants. In animals, it is shown that the microRNAome is largely affected in the bystander cells in a three-dimensional human tissue model. In silico and bioinfomatic analysis of this data provide us with clues as to the nature of bystander signalling in this human ‘in vivo’ model. / xiv, 141 p. : ill. ; 29 cm.