BVOC emission responses to acute short-wave monochromatic radiations
Author(s)
Pallozzi, Emanuele
Date Issued
April 13, 2012
Type
Doctoral Thesis
Abstract
We studied the high energy portion of solar light which reaches Earths’ surface, focusing on the interaction of UVB, UVA and blue light with plants, and investigating on plant response as BVOCs emission.
We assessed the direct effects of high UVB radiation on both wild-type non-emitting and transgenic isoprene-emitting tobacco plants. We found that mechanisms regulating BVOC emissions were not very sensitive to high UVB intensities even if isoprene was able to mitigate UVB effect. The isoprene-induced protection was combined with an independent higher activation of antioxidant cycle as mechanism for ROS scavenging.
We studied the effects of short-term, acute exposure to UVA, treating poplar plants in the middle of summer and then repeating it towards the end of the summer. In the middle of summer photosynthesis was inhibited by high doses of UVA radiation while isoprene bursted increasingly as the UVA dose increased. At the end of the summer, there were no longer significant differences in the time course of A and isoprene emission in response to high UVA radiation. The adaxial flavonoid level increased significantly over the period monitored, probably played a protective role against UVA radiation by shielding leaves.
The relationship between isoprenoid emissions and diffusional limitation to photosynthesis were studied in response to blue light. We used three different plant species, a strong isoprene emitter (poplar), a strong monoterpene emitter with a small storage pool (holm oak) and a monoterpene emitter with a big storage pool (mandarin). Our results confirmed the strong effect of blue light on A and gm. Isoprene emission was also highly affected by blue light whereas monoterpenes emissions were in general not affected.
Additional information
Dottorato di ricerca in Ecologia forestale
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