The resistance of Solanum lycopersicum photosynthetic apparatus to high-intensity blue light is determined mainly by the cryptochrome 1 content

Abstract

The effects of deficiency of cryptochrome 1 (CRY1), phytochrome B2 (phyB2) and the photoreceptor signalling DET-1 protein (hp-2 mutant) on photosynthesis and pro-/antioxidant balance in Solanum lycopersicum exposed to high-intensity blue light [HIBL, 72 h, 500/1,000 μmol(photon) m–2 s–1] were studied. Noticeable photoinhibition of photosynthesis and PSII was found in all these variants. However, the greatest decrease in photosynthesis and PSII activity was observed in the cry1 mutant. The difference among the other options was less pronounced. This low resistance of the cry1 mutant to HIBL is associated with reduced photosynthetic pigments, phenols, and anthocyanins. It appears that under HIBL, CRY1 and, to a lesser extent, phyB2 are required to maintain photosynthesis and antioxidant defence, mitigating blue light-induced oxidative stress. This study expands our understanding of the defence functions of CRY1 and highlights its importance in adapting the photosynthetic apparatus to HIBL. © 2025 Elsevier B.V., All rights reserved.