Articles
Far-red signaling affects the regulation of photosynthesis in tomatoes
Article number
1391_26
Pages
191 – 196
Language
English
Abstract
The cut edge of photosynthesis active radiation is set at 700 nm, as wavelengths above this are not efficient for photosynthesis.
However, shorter wavelengths can improve the efficiency of higher wavelengths through wavelength synergy, known as the Emerson enhancement effect. This study hypothesizes that while far-red is not efficient in deriving photosynthesis, its signaling properties can impact photosynthesis efficiency.
Additionally, the intensity of background light can modify these effects.
In this study, plants were exposed to low (250 µmol m‑2 s‑1) and high (650 µmol m‑2 s‑1) intensity white light with or without additional far-red (60 µmol m‑2 s‑1). Results show that the light compensation point was increased by high light only in mutants of phytochrome B1 and phytochrome B2. Additionally, low light + far-red increased the light compensation point of phytochrome A mutants but had a drastic decline in other genotypes.
Light compensation point was decreased by high light + far-red irrespective of genotype, suggesting that it depends on both light intensity and signaling.
Dark respiration was affected by high light in mutants compared to low light, but not in the wild type.
Non-photochemical quenching was increased by high light and far-red only reduced that of phytochrome A mutants.
The study concludes that both the energy and signaling aspects of far-red affect photosynthesis and that background light intensity can modify the impact of far-red signaling and energy on photosynthesis.
However, shorter wavelengths can improve the efficiency of higher wavelengths through wavelength synergy, known as the Emerson enhancement effect. This study hypothesizes that while far-red is not efficient in deriving photosynthesis, its signaling properties can impact photosynthesis efficiency.
Additionally, the intensity of background light can modify these effects.
In this study, plants were exposed to low (250 µmol m‑2 s‑1) and high (650 µmol m‑2 s‑1) intensity white light with or without additional far-red (60 µmol m‑2 s‑1). Results show that the light compensation point was increased by high light only in mutants of phytochrome B1 and phytochrome B2. Additionally, low light + far-red increased the light compensation point of phytochrome A mutants but had a drastic decline in other genotypes.
Light compensation point was decreased by high light + far-red irrespective of genotype, suggesting that it depends on both light intensity and signaling.
Dark respiration was affected by high light in mutants compared to low light, but not in the wild type.
Non-photochemical quenching was increased by high light and far-red only reduced that of phytochrome A mutants.
The study concludes that both the energy and signaling aspects of far-red affect photosynthesis and that background light intensity can modify the impact of far-red signaling and energy on photosynthesis.
Authors
A. Shomali, C.O. Ottosen, R. Zhou, S. Aliniaeifard, L. Abdelhakim
Keywords
energy balance, light compensation point, spectral composition, wavelength synergy
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