Project description:The increasing ambient temperature significantly impacts plant growth, development, and reproduction. Uncovering the temperature-regulating mechanisms in plants is of high importance, not only for boosting our plant biology knowledge but also for assisting plant breeders in improving plant resilience to these stress conditions. Numerous studies on the molecular mechanisms by which plants regulate temperature responses revealed that plants employ distinct transcription factors to regulate thermomorphogenesis specific to each tissue type. A significant discovery in this field was the identification of PHYTOCHROME-INTERACTING FACTORs (PIFs) as key regulators of thermomorphogenesis during vegetative growth. PIF4, a regulator of auxin-mediated signaling pathways, is crucial in controlling high-temperature responses. In this study, we screened the temperature responses of the wild type and several PhyB-PIF4 pathway Arabidopsis mutant lines in combined and integrative phenotyping platforms for root in soil, shoot, inflorescence, and seed. We demonstrated that high ambient temperature differentially impacts vegetative and reproductive organs through this pathway. Suppression of the PhyB-PIF4 components mimics the response to a high ambient temperature in wild-type plants. We also identified correlative responses to high ambient temperature between shoot and root tissues. This integrative and automated phenotyping was complemented by monitoring the changes in transcript levels in reproductive organs. Transcriptomic profiling of the pistils from plants grown under high ambient temperature identified key elements that may provide clues to the molecular mechanisms behind temperature-induced reduced fertilization rate, such as a downregulation of auxin metabolism, upregulation of genes involved auxin signalling, miRNA156 and miRN160 pathways, pollen tube attractants.
Project description:Plants regulate their time to flowering by gathering information from the environment. Photoperiod and temperature are among the most important environmental variables. Suboptimal, but not near-freezing, temperatures regulate flowering through the thermosensory pathway, which overlaps with the autonomous pathway. Here we show that ambient temperature regulates flowering by two genetically distinguishable pathways, one that requires TFL1 and another that requires ELF3. The delay in flowering time observed at lower temperatures was partially suppressed in single elf3 and tfl1 mutants, whereas double elf3 tfl1 mutants were insensitive to temperature. tfl1 mutations abolished the temperature response in cryptochrome mutants that are deficient in photoperiod perception, but not in phyB mutants that have a constitutive photoperiodic response. Contrary to tfl1, elf3 mutations were able to suppress the temperature response in phyB mutants, but not in cryptochrome mutants. The gene expression profile revealed that the tfl1 and elf3 effects are due to the activation of different sets of genes and identified CCA1 and SOC1/AGL20 as being important cross talk points. Finally, genome-wide gene expression analysis strongly suggests a general and complementary role for ELF3 and TFL1 in temperature signalling. Three genotypes, WT (Columbia), elf3-7 and tfl1-1 mutants. Three biological replicates for each condition (genotype X temperature combination). RNA prepared independently for each sample.
Project description:It has been established that the frequently reported early flowering phenotype of the phyB mutant is very sensitive to small changes in ambient temperature (Halliday et al., 2003). A 6oC drop in temperature to 16oC is sufficient to abolish the pronounced early flowering phyB phenotype observed at 22oC. Using Affymetrix technology we will identify genes that are differentially regulated at 16oC and 22oC in a phyB-specific manner using phyB mutant and wild type seedlings.
Project description:It has been established that the frequently reported early flowering phenotype of the phyB mutant is very sensitive to small changes in ambient temperature (Halliday et al., 2003). A 6oC drop in temperature to 16oC is sufficient to abolish the pronounced early flowering phyB phenotype observed at 22oC. Using Affymetrix technology we will identify genes that are differentially regulated at 16oC and 22oC in a phyB-specific manner using phyB mutant and wild type seedlings. 16 samples were used in this experiment.
Project description:The mRNA expression profiles of the quadruple spa mutant spaQ and cop1-4 were analyzed in 1 hour red light treated condition. Under same condition, the gene expression changes in phyB-SPA1 interaction domain mutant was analyzed and compared with wild type.