Project description:Exposure to high irradiance results in dramatic changes in nuclear gene expression in plants. However, little is known about the mechanisms by which changes in irradiance are sensed and how the information is transduced to the nucleus to initiate the genetic response. To investigate whether the photoreceptors are involved in the response to high irradiance, we analyzed expression of ELIP1, ELIP2, APX2 and LHCB2.4 in the phyA, phyB, cry1 and cry2 photoreceptor mutants and hy5 and hyh transcription factor mutants. Following exposure to high intensity white light for 3 h (HL, 1000 micro mol quanta m-2 s-1) expression of ELIP1/2 and APX2 was strongly induced and LHCB2.4 expression repressed in wild type. The cry1 and hy5 mutants showed specific mis-regulation of ELIP1/2 and we show that the induction of ELIP1/2 expression is mediated via CRY1 in a blue light intensity-dependent manner. Furthermore, using the Affymetrix Arabidopsis 24K Gene-Chip we showed that 77 of the HL responsive genes are regulated via CRY1, and 26 of those genes were also HY5 dependent. As a consequence of the mis-regulation of these genes the cry1 mutant displayed a high irradiance-sensitive phenotype with significant photoinactivation of PSII, indicated by reduced Fv/Fm. Thus, we describe a novel function of CRY1 in mediating plant responses to high irradiances that is essential to the induction of photoprotective mechanisms. This indicates that high irradiance can be sensed in a chloroplast-independent manner by a cytosolic/nucleic component. Keywords: photoreceptor, transcription factor, cytosolic/nuclear component, chloroplast, stress response, photoprotection
Project description:Exposure to high irradiance results in dramatic changes in nuclear gene expression in plants. However, little is known about the mechanisms by which changes in irradiance are sensed and how the information is transduced to the nucleus to initiate the genetic response. To investigate whether the photoreceptors are involved in the response to high irradiance, we analyzed expression of ELIP1, ELIP2, APX2 and LHCB2.4 in the phyA, phyB, cry1 and cry2 photoreceptor mutants and hy5 and hyh transcription factor mutants. Following exposure to high intensity white light for 3 h (HL, 1000 micro mol quanta m-2 s-1) expression of ELIP1/2 and APX2 was strongly induced and LHCB2.4 expression repressed in wild type. The cry1 and hy5 mutants showed specific mis-regulation of ELIP1/2 and we show that the induction of ELIP1/2 expression is mediated via CRY1 in a blue light intensity-dependent manner. Furthermore, using the Affymetrix Arabidopsis 24K Gene-Chip we showed that 77 of the HL responsive genes are regulated via CRY1, and 26 of those genes were also HY5 dependent. As a consequence of the mis-regulation of these genes the cry1 mutant displayed a high irradiance-sensitive phenotype with significant photoinactivation of PSII, indicated by reduced Fv/Fm. Thus, we describe a novel function of CRY1 in mediating plant responses to high irradiances that is essential to the induction of photoprotective mechanisms. This indicates that high irradiance can be sensed in a chloroplast-independent manner by a cytosolic/nucleic component. Experiment Overall Design: All samples were done in biological triplicates (named A, B, C): Arabidopsis Col-O: growth conditions (7 d continuous white light; 100 micro mol quanta m-2 s-1, 22 °C), growth conditions followed by high light (3 hours 1000 micro mol quanta m-2 s-1, 22 °C) and growth conditions followed by blue light (3 hours; HQI-T 400 W lamps were filtered through color filter #74, 400-540 nm, absorption maximum: 470 nm (Night Blue; Rosco International)) Experiment Overall Design: cryptochrome 1 (cry1) mutant: growth conditions and growth conditions followed by 3 hours high light Experiment Overall Design: long hypocotyl 5 (hy5) mutant: growth conditions and growth conditions followed by 3 hours high light
Project description:Using m6A-seq, we present transcriptome-wide distribution of m6A in wild type, cry1 and cry1 cry2 seedlings with or without blue light treatment. Analysis of m6A distribution reveals CRY1 and CRY1 are involved blue light induced changes of m6A distribution in Arabidopsis
Project description:Plants have evolved several mechanisms for sensing increased irradiance, involving signal perception by photoreceptors, and subsequent biochemical and metabolic clues to transmit the signals. This retrograde signaling controls nuclear gene expression. We used microarrays to detail the gene expression response to increased irradiance in three photosynthetically diverse accesssions of Arabidopsis thaliana.
Project description:Transcriptome-wide high-throughput deep m6A-seq reveals unique m6A methylation differential patterns among three organs in Arabidopsis
Project description:Examine global gene expression patterns in control and 35S:PAP1 Arabidopsis plants upon environmental perturbation (light and temperature) over the course of the experiments. Experiment Overall Design: Red coloured 35S:PAP1, and empty vector control, plants of Arabidopsis thaliana Columbia were grown under room temperature, high light (RTHL, 22°C, 440 µmol m-2 s-1 irradiance) conditions to promote red leaf colouration. The growth conditions were then changed to a high day temperature, low light (HTLL: 30°C day, 150 µmol m-2 s-1 irradiance) stress treatment for six days, during which time the 35S:PAP1 leaves lost much of their red colouration, turning green. The growth conditions were then returned to a low temperature high light (LTHL, 15°C, 62% RH, 440 µmol m-2 s-1 irradiance) regime to restore the red colouration.