Project description:Shade avoidance helps plants maximize their access to light for growth under crowding. It is unknown, however, whether a priming shade avoidance mechanism exists that allows plants to respond more effectively to successive shade conditions. Here, we show that the shade-intolerant plant Arabidopsis can remember a first experienced shade event and respond more efficiently to the next event on hypocotyl elongation. The transcriptional regulator PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) and the histone H3K27-demethylase RELATIVE OF EARLY FLOWERING 6 (REF6) were identified as being required for this shade avoidance memory. RNA-sequencing analysis revealed that shade induction of shade memory-related genes was impaired in the pif7 and ref6 mutants. Based on the enrichments of H3K27me3, REF6 and PIF7, we found that priming shade treatment induced PIF7 accumulation, which further recruited REF6 to demethylate H3K27me3 on the chromatin of certain memory-related genes, leading to a state poised for their transcription. Upon the second shade treatment, enhanced shade-mediated induction of these genes resulted in stronger hypocotyl growth responses. We conclude that the transcriptional memory mediated by epigenetic modification plays a key role in the ability of primed plants to remember previously experienced shade and acquire enhanced responses to recurring shade conditions.
Project description:Growth in dense stands induces shade avoidance responses. Early responses to neighbors seem to be assoctaed with touch, not light signalling. We studied gene expression in petioles during early canopy development when leaf hyponasty was visible but altered phytochrome signalling was not yet detectable.
Project description:Arabidopsis is a shade avioding plant. Under simulated shade light with reduced red-to-far red (R:FR) ratio around 0.7, hypocotyls of Arabidopsis seedlings elongate, which is one of the typical shade avoidance responses.We discovered that when the R:FR ratio further decreases to around 0.1 (strong shade), the shade-induced elongation of hypocotyl is abolished and phytochrome A (phyA) mediates this response.In this study, we aim to examine the difference between shade and strong shade treatment and uncover the role of phyA in regulating the shade avoidance responses.
Project description:Growth in dense stands induces shade avoidance responses. Early responses to neighbors seem to be assoctaed with touch, not light signalling. We studied gene expression in petioles during early canopy development when leaf hyponasty was visible but altered phytochrome signalling was not yet detectable. Plants were grown in small pots that were either kept single, or put in a high density of 2066 plants/m2. Gene expression measured in petioles when canopies had reached a leaf area index of 0.9.
Project description:For shade-intolerant species, shade light indicates the close proximity of neighboring plants and triggers the shade avoidance syndrome (SAS), which causes exaggerated growth and reduced crop yield. We report that nonsecreted ROT FOUR LIKE (RTFL)/DEVIL (DVL) peptides negatively regulate the SAS by repressing the activities of BRASSINOSTEROID SIGNALING KINASEs (BSKs) and PHYTOCHROME INTERACTING FACTOR 4 (PIF4) in Arabidopsis. To identify RTFL function during SAS, we performed RNA-seq to search for differentially expressed genes (DEGs) by comparing transcript levels between Col-0 and dvl1-1D, bsk36, or pif47 seedlings during white light and shade conditions.
Project description:Phytochrome Interacting Factor 5 plays an important role in adaptive responses of plants to shaded environment collectively called shade avoidance syndrome. PIF 5 belongs to the bHLH transcription factor family and regulated gene expression in a low R/FR dependent fashion. In this experiment we investigate PIF5-DNA-binding genome wide to generate a candidate list of genes, which are directly regulated by PIF5. ChIP-Seq sample of whole seedlings treated with low R/FR light
Project description:Phytochrome Interacting Factor 5 plays an important role in adaptive responses of plants to shaded environment collectively called shade avoidance syndrome. PIF 5 belongs to the bHLH transcription factor family and regulated gene expression in a low R/FR dependent fashion. In this experiment we investigate PIF5-DNA-binding genome wide to generate a candidate list of genes, which are directly regulated by PIF5.
Project description:Low R:FR signaling through phytochromes induces shade avoidance responses, including petiole elongation. Salicylic acid-mediated defense against pathogens is inhibited under these conditions. Using microarrays we studied the crosstalk between low R:FR and SA at the global gene expression level in Arabidopsis thaliana.
Project description:Plants grown under a canopy recognize changes in light quality and modify their growth patterns; this modification is known as shade avoidance syndrome. In leaves, leaf blade expansion is suppressed, whereas petiole elongation is promoted under the shade. However, the mechanisms that control these responses are largely unclear. Here, we demonstrated that both auxin and brassinosteroid (BR) are required for the normal leaf responses to shade. The microarray analysis of leaf blades and petioles treated with end-of-day far-red light (EODFR) revealed that almost half of the genes induced by the treatment in both parts were previously identified as auxin-responsive genes. Likewise, BR-responsive genes were overrepresented in the EODFR-induced genes. Hence, the auxin and BR responses were elevated by EODFR treatment in both leaf blades and petioles, although opposing growth responses were observed in these two parts. The analysis of the auxin-deficient doc1/big mutant and BR-deficient rot3/cyp90c1 mutant further indicates that auxin and BR were equally required for the normal petiole elongation response to the shade stimulus. In addition, the spotlight irradiation experiment revealed that phytochrome in leaf blades but not that in petioles regulated petiole elongation, which was probably mediated through regulation of the auxin/BR responses in petioles. On the basis of these findings, we conclude that auxin and BR cooperatively promote petiole elongation in response to the shade stimulus under the control of phytochrome in the leaf blade.
2009-11-01 | GSE17845 | GEO
Project description:Phytochrome-mediated shade avoidance responses impact the composition of the bacterial phyllosphere microbiome of Arabidopsis