Ultraviolet-induced fluorescence for plant monitoring: present state and prospects

Abstract

[EN] UV excitation of green leaves induces two distinct, fundamentally different, but still complementary types of fluorescence: a blue-green fluorescence in the 400-630 nm range and the chlorophyll a fluorescence in the red to far-red region (630-800 nm) of the spectrum. The relative intensities of these two types of fluorescence are highly sensitive to intrinsic leaf properties and environmental factors. Therefore, fluorescence emission spectra induced by UV radiation can be considered as a complex fluorescence signature that can reveal much about the physiological state of the plant. UV-induced fluorescence of leaves provides us with information on photosynthesis, primary photochemical reactions and chlorophyll content, and also on the presence and accumulation of the product of the secondary metabolism and the redox state of the cell. In this review we pay particular attention to the present and potential application of these signals to active remote sensing of vegetation, i.e. fluorosensing.