Electrical and curvature responses of the avena coleoptile to unilateral ultraviolet irradiation

The Base Curvature Response of Avena Seedlings to the Ultraviolet

“…Popp and McIIvaine. 1937;von Denffer andSchlitt, 1951: Mills andSchrank, 1954). To compare the process of photo-oxidation with the pbototropic response, the action spectrinn for the photo-oxidation of pure IAA in aqueons solution was determined.…”

“…During the course of an extended study of the spectral sensitivity of pholotropism in Avena it was noted that the base response was given particularly weli in tbe ultraviolet, and that in the shorter wavelengths of this region the plants were completely free from simultaneous tip curvatures. Mills and Schrank (1954) have also reported on curvatures of Avena caused by ultraviolet, and have noled that they appear iirst near the base. It was tberefore decided to make a detailed study of the base response.…”

A novel phototropic response to supplementary ultraviolet (UV-B and UV-A) radiation in the siliquas of oilseed rape (Brassica napus L.) grown under natural conditions

“…This is because such a defined response at this wavelength is rare, if not unique, under non-damaging conditions. Phototropic responses to UV radiation in juvenile tissues have been reported previously; following an earlier report, 62 Curry et al 63 described a UV action maximum near 280 nm for the phototropic curvature of Avena coleoptiles. Baskin and Iino 64 measured an action spectrum in the UV and B wavebands for the phototropic curvature of the hypocotyl of alfalfa grown under red light.…”