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:RNA-seq was performed to examine the overall gene expression in a S. mutans FR strain and to identify potential genes that can mainly contribute to the generation of a fluoride resistance in S. mutans. Using RNA-seq technique, the differentially expressed genes that are implicated in phenotypic changes of the FR strain were studied.
Project description:Low reduced red:far-red ratio [R:FR] signaling through phytochromes induces shade avoidance responses, including petiole elongation. Jasmonic acid-mediated defense against herbivores and pathogens is inhibited under these conditions. Using microarrays we studied the crosstalk between low R:FR and JA at the global gene expression level in Arabidopsis thaliana.
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. Plants were exposed for 2 h. to the following treatments: high R/FR with mock spray, low R/FR with mock spray, high R/FR with SA spray, low R/FR with SA spray. Gene expression was determined in petioles.
Project description:Low reduced red:far-red ratio [R:FR] signaling through phytochromes induces shade avoidance responses, including petiole elongation. Jasmonic acid-mediated defense against herbivores and pathogens is inhibited under these conditions. Using microarrays we studied the crosstalk between low R:FR and JA at the global gene expression level in Arabidopsis thaliana. Plants were exposed for 2 h. to the following treatments: high R/FR with mock spray, low R/FR with mock spray, high R/FR with JA spray, low R/FR with JA spray. Gene expression was determined in petioles.
Project description:In dense plant stands, the ratio between red and far-red (R:FR) light declines and shade intolerant species will respond to this cue for future shade by inducing the shade avoidance syndrome (SAS), enabling them to outgrow their neighbours. Shade tolerant species from the forest understory are unable to outgrow neighbouring trees and will suppress SAS. Although the molecular mechanisms underlying SAS are well studied in various species, mechanisms of SAS-suppression in shade tolerant species have rarely been studied. We applied RNA sequencing on Geranium pyrenaicum and G. robertianum, two wild species with contrasting growth responses to low R:FR light. G. pyrenaicum strongly induces petiole elongation when exposed to low R:FR light, at any time of the photoperiod. Contrastingly, G. robertianum only induces this response early in the day, and suppresses petiole growth in low R:FR light at the end of the photoperiod, which results after 24 hours in a net difference with control treatments of zero. We compared expression patterns in the most apical (most responsive) part of the second petioles, in two-week-old Geranium plants (two leaf stage) after 2 and 11.5 hours of far-red light enrichment. This way, we identified a number of novel candidate regulators of shade avoidance, and differential phytochrome control of plant immunity genes in the two species. For de-novo assembly of the reference transcriptomes, we pooled petiole- and leaf lamina tissue exposed to normal white light (180 mol m-2 s-1 PAR, R:FR 1.8, ± 60 mol m-2 s-1 blue light), low R:FR light (0.2), blue-depleted light (± 4 mol m-2 s-1 blue) and green shade (50 mol m-2 s-1 PAR, R:FR 0.45, ± 13 mol m-2 s-1 blue) for 2, 11.5 and 24 hours. Libraries of these samples were normalized, Illumina sequenced, and together with sequences of non-normalized petiole samples of the expression analysis constructed into a reference transcriptome for each species, using the Trinity protocol. Transcripts were clustered into orthologue clusters using the ortho-MCL clustering technique. Non-normalized libraries of samples (control vs. low R:FR light, 2 and 11.5 hours after start of the treatment) were sequenced and aligned to the newly assembled transcriptomes. Read counts were summed per orthologue cluster before statistical analysis was proceeded.
Project description:Sensing environmental changes is important for survival of plants, as sessile organisms, in habi-tat. Recently, latitudinal clines in leaf senescence have been reported to be influenced by tem-perature and photoperiod. However, the relationship of light quality with latitudinal response of leaf senescence is still unclear. Here, we found that Arabidopsis accessions in far-red (FR) showed a strong negative correlation of leaf senescence with the latitude of their origin. phyto-chrome A (phyA) and B (phyB) mutants showed early and delayed senescence in FR, respec-tively, suggesting that PHYA and PHYB are involved in FR-dependent leaf senescence. Tran-scriptomic analysis identified genes oppositely regulated by PHYA and PHYB, and they were mainly associated with phytohormone, temperature, and defense, suggesting their associations with FR-dependent antagonistic effects of PHYA and PHYB on leaf senescence. Among these genes, the expression of WRKY6 in Arabidopsis accessions showed the highest correlation with latitude of their origin. Consistently, wrky6 mutant exhibited delayed senescence phenotype in FR. In conclusion, we propose that PHYs-regulated genes, including WRKY6, are involved in latitudinal leaf senescence in FR and this regulatory mode may contribute to latitudinal adapta-tion by responding FR, as a piece of geographical information.