No abstract

The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is a highly conserved protein complex that regulates signaling pathways in plants under abiotic stress. We discuss the potential molecular mechanisms of CSN under abiotic stress, including oxidative stress with reactive oxygen species signaling, salt stress with jasmonic acid, gibberellic acid, and abscisic acid signaling, high-temperature stress with auxin signaling, and optical radiation with DNA damage and repair response. We conclude that CSN likely participates in affecting antioxidant biosynthesis and hormone signaling by targeting receptors, kinases, and transcription factors in response to abiotic stress, which potentially provides valuable information for engineering stress-tolerant crops.

The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is involved in various regulations during plant development. The CSN is a highly conserved protein complex with nine subunits, and CSN1 acts in a network of signaling pathways critical for plant development. Although CSN1 has been widely studied in Arabidopsis thaliana, there have been few investigations on CSN1 in rice. In this paper, using the CRISPR/Cas9 system, CSN1 was edited from Oryza sativa subsp. japonica (rice). After screening out the OsCSN1 knockout mutant and OsCSN1 reduce mutant, the phenotype and protein expression were identified under different light conditions. Experiments showed that in OsCSN1 knockout mutant and OsCSN1 reduce mutant, the SLR1 protein was rapidly degraded at the rice seedling. In this study, the OsCSN1 acted as a negative regulator to affect seedling growth and development through CUL4-based E3 ligase, which is involved in the degradation of SLR1 in the GA signaling pathway. However, its direct target and mechanism of action are not clear.