TY - JOUR
T1 - Do UV-A radiation and blue light during growth prime leaves to cope with acute high-light in photoreceptor mutants of Arabidopsis thaliana?
AU - Brelsford, Craig
AU - Morales Suarez, Luis Orlando
AU - Nezval, Jakub
AU - Kotilainen, Titta Katariina
AU - Hartikainen, Saara Maria
AU - Aphalo, Pedro J.
AU - Robson, Thomas Matthew
PY - 2019/3
Y1 - 2019/3
N2 - We studied how plants acclimated to growing conditions that included combinations of blue light (BL) and ultraviolet (UV)-A radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under-canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild-type were compared with mutants lacking functional blue light and UV photoreceptors: phototropin 1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using light-emitting-diode (LED) lamps in a controlled environment to create treatments with or without BL, in a split-plot design with or without UV-A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 min of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (phi PSII, a proxy for photosynthetic performance) and dark-adapted maximum quantum yield (F-v/F-m to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic compound accumulation in response to BL and UV-A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV-A dose. Interestingly, phototropin 1 partially mediated constitutive accumulation of phenolic compounds in the absence of BL. Low-irradiance BL and UV-A did not improve phi PSII and F-v/F-m upon our acute high-light treatment; however, CRYs played an important role in ameliorating high-light stress.
AB - We studied how plants acclimated to growing conditions that included combinations of blue light (BL) and ultraviolet (UV)-A radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under-canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild-type were compared with mutants lacking functional blue light and UV photoreceptors: phototropin 1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using light-emitting-diode (LED) lamps in a controlled environment to create treatments with or without BL, in a split-plot design with or without UV-A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 min of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (phi PSII, a proxy for photosynthetic performance) and dark-adapted maximum quantum yield (F-v/F-m to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic compound accumulation in response to BL and UV-A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV-A dose. Interestingly, phototropin 1 partially mediated constitutive accumulation of phenolic compounds in the absence of BL. Low-irradiance BL and UV-A did not improve phi PSII and F-v/F-m upon our acute high-light treatment; however, CRYs played an important role in ameliorating high-light stress.
KW - 1183 Plant biology, microbiology, virology
KW - SYNTHASE GENE-EXPRESSION
KW - PHOTOSYNTHETICALLY ACTIVE RADIATION
KW - ULTRAVIOLET-B RADIATION
KW - SIGNAL-TRANSDUCTION
KW - PHOTOSYSTEM-II
KW - HIGHER-PLANTS
KW - CHLOROPHYLL FLUORESCENCE
KW - ELECTRON-TRANSPORT
KW - LEAF CHLOROPHYLL
KW - RED-LIGHT
U2 - 10.1111/ppl.12749
DO - 10.1111/ppl.12749
M3 - Article
VL - 165
SP - 537
EP - 554
JO - Physiologia Plantarum
JF - Physiologia Plantarum
SN - 0031-9317
IS - 3
ER -