Friend or Foe? Unraveling the effects of UV-A1 on Plant Growth and Photosynthesis

Samenvatting (Engelstalig)

Ultraviolet radiation (UV; 100–400 nm) is an important spectrum of solar radiation, with UV-A (315-400 nm) accounting for approximately 95% of all UV arriving at the Earth’s surface. Currently, there are only a few reviews on the effects of UV-A on plant growth and physiology, and these reviews indicate that the knowledge of UV-A photobiology is limited. This is partially because previous insights into UV-A effects on plants were obtained from measurements conducted in the field. In this thesis, UV-A wavelength, UV-A dose and species were studied in a well-controlled environment, and the main findings were that UV-A radiation triggers wavelength-dependent photosynthetic performance and photoprotective acclimation as well as photoinhibition, with the net result that plant growth was barely affected by UV-A exposure. This thesis filled some knowledge gaps around the effects of UV-A on plants, by using novel LEDs.