Potential Role of Phytochromes A and B and Cryptochrome 1 in the Adaptation of <i>Solanum lycopersicum</i> to UV-B Radiation
UV-B causes both damage to the photosynthetic apparatus (PA) and the activation of specific mechanisms that protect the PA from excess energy and trigger a cascade of regulatory interactions with different photoreceptors, including phytochromes (PHYs) and cryptochromes (CRYs). However, the role of p...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-08-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/17/13142 |
| Summary: | UV-B causes both damage to the photosynthetic apparatus (PA) and the activation of specific mechanisms that protect the PA from excess energy and trigger a cascade of regulatory interactions with different photoreceptors, including phytochromes (PHYs) and cryptochromes (CRYs). However, the role of photoreceptors in plants’ responses to UV-B radiation remains undiscovered. This study explores some of these responses using tomato photoreceptor mutants (<i>phya</i>, <i>phyb1</i>, <i>phyab2</i>, <i>cry1</i>). The effects of UV-B exposure (12.3 µmol (photons) m<sup>−2</sup> s<sup>−1</sup>) on photosynthetic rates and PSII photochemical activity, the contents of photosynthetic and UV-absorbing pigments and anthocyanins, and the nonenzymatic antioxidant capacity (TEAC) were studied. The expression of key light-signaling genes, including UV-B signaling and genes associated with the biosynthesis of chlorophylls, carotenoids, anthocyanins, and flavonoids, was also determined. Under UV-B, <i>phyab2</i> and <i>cry1</i> mutants demonstrated a reduction in the PSII effective quantum yield and photosynthetic rate, as well as a reduced value of TEAC. At the same time, UV-B irradiation led to a noticeable decrease in the expression of the <i>ultraviolet-B receptor (UVR8), repressor of UV-B photomorphogenesis 2 (RUP2), cullin 4 (CUL4), anthocyanidin synthase (ANT), phenylalanine ammonia-lease (PAL)</i>, and <i>phytochrome B2</i> (<i>PHYB2)</i> genes in <i>phyab2</i> and <i>RUP2, CUL4, ANT, PAL</i>, and <i>elongated hypocotyl 5 (HY5)</i> genes in the <i>cry1</i> mutant. The results indicate the mutual regulation of UVR8, PHYB2, and CRY1 photoreceptors, but not PHYB1 and PHYA, in the process of forming a response to UV-B irradiation in tomato. |
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| ISSN: | 1661-6596 1422-0067 |