The photoreceptor UVR8 mediates the perception of both UV‐B and UV‐A wavelengths up to 350 nm of sunlight with responsivity moderated by cryptochromes

Abstract

The following Supporting Information is available for this article: Figure S1. Solar spectrum at different times of the day when plants were moved outdoors. Figure S2. Photon irradiance for different wavebands in solar radiation.Figure S3. Multidimensional scaling of RNA-seq data.Figure S4. Comparison between RNA-seq and qRT-PCR data.Figure S5. Venn diagrams showing the number differentially expressed genes in RNA-seq data.Figure S6. Enrichment of KEGG pathways in RNA-seq data.Figure S7. In vitro absorption spectra of Arabidopsis UVR8 protein.Figure S8. Position weight matrices of the enriched DNA-binding motifs.Figure S9. Transcript abundance of seven genes measured using qRT-PCR.Table S1. Information of primers used and genes assessed in qRT-PCR. Table S2. Summary of the ANOVA of the qRT-PCR data.Methods S1. Description of the filters and the waveband contrasts.Dataset S1. Outcome of differential gene expression analysis for the three genotypes and multiple waveband contrasts combination. The dataset is included as a separate file in .Rda format and can be read using R.

Anything New under the Sun? An Update on Modulation of Bioactive Compounds by Different Wavelengths in Agricultural Plants

“…Cryptochromes also perceive green wavelengths. The UVR8 receptor is specifically involved in UV-B sensing, while UV-A is perceived by the blue light receptors, though very recently the involvement of UVR8 in mediating UV-A perception was demonstrated in Arabidopsis [ 6 ]. Despite plant responsiveness to green light being observed, presently, there is less known about the mechanism at the basis of green or yellow light perception.…”

“…The UV RESISTANCE LOCUS 8 (UVR8) is the specific receptor of UV-B radiation [ 29 ], though very recently, a role in the perception of short wavelength UV-A (315–350 nm) was demonstrated in Arabidopsis [ 6 ]. UVR8, in its inactive form, is a dimeric protein located in the cytosol.…”

A leap in quantum efficiency through light harvesting in photoreceptor UVR8

“…For the WT and the mutant 6W d + 4W c , the absorption spectra extend to above 330 nm and such red-tail lowest energy absorption comes from the closely packed 4W c , a signature of possible exciton formation 16 . The red-side absorption of 4W c explains the recently reported UVR8 monomerization in response to UV-A light up to 350-nm wavelength 27 . For the mutant 6W d + 3W p , the absorption is blue-shifted due to the removal of 4W c , still extending to 315 nm.…”

Ultraviolet Radiation From a Plant Perspective: The Plant-Microorganism Context

“…UV-B mediated flavonoid accumulation is UVR8 dependent (Demkura and Ballare, 2012;Morales et al, 2013), leading to an induction of CHS, chalcone flavanone isomerase (CHI), flavanone 3-hydroxylase (F3H) and flavonol synthase (FLS) (Hideg et al, 2013), all of which are HY5 inducible (Shin et al, 2013;Wu et al, 2019), Interestingly dihydroflavonol reductase (DFR) was only shown to be induced in UV-A conditions (Morales et al, 2013). However, the role of UVR8 in the induction of DFR transcript is not COP1 regulated under UV-B conditions (Oravecz et al, 2006) and therefore hints at an interaction between photoreceptors (Morales et al, 2013) below 350 nm (Morales et al, 2013;Rai et al, 2020). Not surprisingly, Arabidopsis plants missing CHS due to point mutations are much more sensitive to the effects of UV-B (Li et al, 1993).…”