Project description:We have investigated the genomic response of Arabidopsis cell suspension culture under high light. Our main goal has been twofold: first, to establish whether chloroplasts in Arabidopsis cell suspension culture are functional and, as such, can act as sensors of adverse external stimuli leading to the activation of genomic defence responses in a manner similar to that described in whole plants exposed to a wide range of environmental stresses and; second, to distinguish which of the ROS that would be probably generated in the chloroplasts is predominant. Our functional genomic analysis has led us to conclude that singlet oxygen is the major ROS in Arabidopsis cell suspension culture under high light stress and that singlet oxygen production is responsible for a genomic activation associated with the biosynthesis and signalling pathway of several phytohormones that ultimately triggers accelerated cell death.
Project description:We have investigated the genomic response of Arabidopsis cell suspension culture under high light. Our main goal has been twofold: first, to establish whether chloroplasts in Arabidopsis cell suspension culture are functional and, as such, can act as sensors of adverse external stimuli leading to the activation of genomic defence responses in a manner similar to that described in whole plants exposed to a wide range of environmental stresses and; second, to distinguish which of the ROS that would be probably generated in the chloroplasts is predominant. Our functional genomic analysis has led us to conclude that singlet oxygen is the major ROS in Arabidopsis cell suspension culture under high light stress and that singlet oxygen production is responsible for a genomic activation associated with the biosynthesis and signalling pathway of several phytohormones that ultimately triggers accelerated cell death. After the ninth day of growth, a volume of 200 mL of Arabidopsis cell suspension culture with a cell density of approximately 150-200 mg/mL was placed in a glass vessel surrounded by a water bath to maintain constant temperature during the light treatment. Nine microarray experiments were designed and classified as follows: control 1âÂÂ3 (50 microE/m2/s), 1-h dark 1âÂÂ3 and high light 1âÂÂ3 (1800 microE/m2/s); where 1âÂÂ3 stands for the number of biological replicates. After each treatment, sample RNA was extracted and its quality evaluated. The transcriptomic analysis was performed using Affymetrix GeneChip Arabidopsis genome ATH1 arrays.
Project description:RNA-seq provided a general overview of the gene expression profiles of the body walls of A. japonicus exposed to strong light (“light”), normal light (“control”) and fully dark (“dark”) environment.
Project description:We used RNA sequencing to measure genome-wide gene expression in the cyanobacterium Synechococcus elongatus PCC 7942 grown under dynamic light regimes that mimic the variation in light intensity seen on a Clear Day in nature, or the rapid changes in light intensity that accompany changes in shading We compare these gene expression dynamics to those of a culture grown under a Low Light condition that mimics the standard laboratory conditions used for study of cyanobacteria. Our analysis reveals that naturally relevant light conditions drastically modify gene expression dynamics in cyanobacteria Notably, the expression of circadian clock-controlled genes is responsive to changes in light intensity, showing modulated dynamics that can allow cyanobacteria to adapt their metabolism to changing environmental conditions
Project description:Tigecycline, as a new type of tetracycline antibiotic, has unstable physicochemical properties. When exposed to light, it easily loses its antibacterial activity. This study found that after adding copper ions, the antibacterial activity of tigecycline under light conditions was significantly enhanced.
Project description:The ocular circadian clock has been thought to be regulated primarily by environmental light. In many peripheral tissues, however, circadian clocks are influenced by temporal information conveyed by adrenal glucocorticoids, while glucocorticoid-dependent regulation of the eye clock, a light-receptive organ, has remained unclear. To investigate this mechanism, we generated retina-specific Nr3c1 (glucocorticoid receptor; GR) knockout mice by crossing Chx10-Cre mice, in which Cre-recombinase is driven by the Chx10 promoter expressed in the developing optic cup, with Nr3c1 flox/flox mice. Using these mice, we performed time-course tissue collection under light-dark conditions followed by time-series RNA-seq analysis. The analysis showed that many rhythmic genes detected in control retina were lost in retina-specific Nr3c1-deficient mice, suggesting that glucocorticoid signaling contributes to rhythmic retinal gene expression.
Project description:The size of tomato fruits are largely dependent on growth conditions. To obtain insights on how light intensity contributes to translocation from a leaf and a fruit, we developed a plant irradiation system based on light-emitting diodes (LEDs) to a leaf. By using this system, we investigated the changes of transcript profiles of tomato leaves and fruits grown under different light conditions.