Effect of circularly polarized light on germination, hypocotyl elongation and biomass production of arabidopsis and lettuce: Involvement of phytochrome B

Abstract

Circular dichroism (CD), defined as the differential absorption of left-and right-handed circularly polarized light (CPL), is a useful spectroscopic technique for structural studies of biological systems composed of chiral molecules. The present study evaluated the effects of CPL on germination, hypocotyl elongation and biomass production of Arabidopsis and lettuce. Higher germination rates were observed when Arabidopsis and lettuce seedlings were irradiated with red right-handed CPL (R-CPL) than with red left-handed CPL (L-CPL). Hypocotyl elongation was effectively inhibited when Arabidopsis and lettuce seedlings were irradiated with red R-CPL than with red L-CPL. This difference was not observed when a phytochrome B (phyB) deficient mutant of Arabidopsis was irradiated, suggesting that inhibition of elongation by red R-CPL was mediated by phyB. White R-CPL induced greater biomass production by adult Arabidopsis plants, as determined by their fresh shoot weight, than white L-CPL. To determine the molecular basis of these CPL effects, CD spectra and the effect of CPL on the photoreaction of a sensory module of Arabidopsis phyB were measured. The red lightabsorbing form of phyB showed a negative CD in the red light-absorbing region, consistent with the results of germination, inhibition of hypocotyl elongation and biomass production. L-CPL and R-CPL, however, did not differ in their ability to induce the interconversion of the red light-absorbing and far-red light-absorbing forms of phyB. These findings suggest that these CPL effects involve phyB, along with other photoreceptors and the photosynthetic process.

Phytochrome B enhances seed germination tolerance to high temperature by reducing S‐nitrosylation of HFR1

“…It is possible that there was still residual phyB in this line present as the activate form (Pfr form). These results are consistent with previous studies on lettuce (Borthwick et al, 1952;Frankland & Smith, 1967;Takaki & Zaia, 1984;Huo et al, 2013;Lkhamkhuu et al, 2020), and suggest active phyB enhances seed germination tolerance to HT stress.…”

Luminescence-based circular polarization convertors: polarization conversion of linearly polarized photoluminescence from one-dimensionally aligned quantum rods using retardation films

“…Circularly polarized (CP) visible light is gathering worldwide attention as a next-generation light source because it exhibits extensive optical information, a wide viewing angle, and asymmetric effects, such as chiral induction, 1 enantioselective chemical reactions, 2,3 and enhancement of the energy conversion efficiency of photovoltaics (inverse Faraday effect). 4 In recent years, the improvement of various optical properties, such as the polarization degree, light intensity, and color tunability, has been considered an important issue in the generation of CP light.…”

Protein–chromophore interactions controlling photoisomerization in red/green cyanobacteriochromes

“…The absorption spectrum of the holoprotein (protein-chromophore complex) determines the action spectrum for a given photobiological effect, providing a biological response to colors of light that are resonant with that absorption spectrum. However, such systems can also detect light intensity, day/night cycles, and even polarization of the incident light [4,[43][44][45][46][47]. As with light-harvesting proteins in photosynthesis, light absorption also poses a challenge for photoreceptors themselves.…”