Project description:To investigate the effect of the interaction between the MRG1/2 and PIF4, here we analysed differentially expressed genes compared to the mutant and wild-type by RNA-seq under different temperature. We performed gene expression profiling analysis using data obtained from RNA-seq of WT, mrg1 mrg2, pif4, and mrg1 mrg2 pif4 plants at 22degC and 28degC.
Project description:Purpose: RNA-seq analysis of the pbl19/pPBL19:PBL19C3A-GFP-HA, sid2pbl19/pPBL19:PBL19C3A-GFP-HA and eds1pbl19/pPBL19:PBL19C3A-GFP-HA plants and identified a large number of differentially expressed genes in these plants relative to wild-type plants. Methods: For RNA-seq analyses, a total amount of 1 mg RNA per sample was used for RNA-seq library construction. Results: RNA-seq analysis of wild type(WT), pbl19/pPBL19:PBL19C3A-GFP-HA, sid2pbl19/pPBL19:PBL19C3A-GFP-HA and eds1pbl19/pPBL19:PBL19C3A-GFP-HA at 28 DAG.Numbers of differentially expressed genes in pbl19/pPBL19::PBL19C3A-GFP-HA plants compared to WT.1981 differentially expressed genes were constantly up-regulated in pbl19/pPBL19::PBL19C3A-GFP-HA plants compared to WT Conclusions: Receptor-like cytoplasmic kinase PBL19 exhibited the highest transcriptional upregulation among the forty-six genes of the RLCK VII subfamily in pbl19/pPBL19C3A-GFP-HA and sid2 pbl19/pPBL19C3A-GFP-HA transgenic plants.eds1 pbl19/pPBL19:PBL19C3A-GFP-HA plants were fully restored to a wild-type(WT) appearance
Project description:In plants, an elevation in ambient temperature induces morphological changes including elongation hypocotyls, considered to be adaptive responses to alleviate the heat-induced damages. The high temperature-induced morphological changes are called thermomorphogenesis, which is predominantly regulated by a bHLH transcription factor PIF4. Although PIF4 is expressed in all aerial tissues including the epidermis, mesophyll, and vascular bundle, its tissue-specific functions in thermomorphogenesis are not known. Here, we found that epidermis-specific expression of PIF4 induced constitutive long hypocotyls, while vasculature-specific expression of PIF4 had no effect on hypocotyl growth. Consistently, RNA-Seq and qRT-PCR analyses revealed that auxin responsive genes and growth-related genes were highly activated by epidermal, but not by vascular, PIF4. The epidermal, but not vascular, inactivation of PIF4 by a PIF4 artificial microRNA or a dominant negative form of PIF4 suppressed thermoresponsive gene expression and hypocotyl growth. Additionally, both the block of epidermal auxin signaling and the epidermal overexpression of a thermosensor phytochrome B (phyB) inhibited thermoresponsive growth, indicating that epidermal PIF4-auxin pathway are essential for the temperature responses. We further show that epidermal PIF4 is increased by high temperatures mainly through the transcriptional activation of PIF4. Taken together, our study demonstrates that the epidermis regulates thermoresponsive growth through the phyB-PIF4-auxin pathway.
Project description:Warm ambient temperatures do not trigger stress responses in plants but stimulate the growth of specific organs. The basic helix-loop-helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) plays a central role in regulating thermomorphogenetic hypocotyl elongation in various plant species, including the model dicotyledonous plant Arabidopsis thaliana. Although it is well known that PIF4 promotes plant thermosensory growth by activating key genes involved in the biosynthesis and signaling of the phytohormone auxin, the detailed molecular mechanism of such transcriptional activation is still not clear. Our previous studies demonstrated that HEMERA (HMR), a transcription co-activator of PIF4, promotes the thermo-induced expression of PIF4 target genes through the nine-amino-acid transactivation domain (9aaTAD) in its carboxy-terminus. In this report, we investigate the role of the Mediator complex in the PIF4/HMR-mediated thermoresponsive gene expression. Through the characterization of various mutants of the Mediator complex, a tail subunit named MED14 is identified as an essential factor for thermomorphogenetic hypocotyl growth. MED14 is required for the thermal induction of key PIF4 target genes but has a marginal effect on the levels of PIF4 and HMR. Further transcriptomic analyses confirm that the expression of numerous PIF4/HMR-dependent, auxin-related genes requires MED14 at a warm temperature. Moreover, PIF4 and HMR physically interact with MED14 and both are indispensable for the association of MED14 with the promoters of these thermoresponsive genes. Together, these results unveil an important thermomorphogenetic mechanism, in which PIF4 and its coactivator HMR recruit the Mediator complex to activate auxin-related growth-promoting genes when plants sense moderate increases in ambient temperature.
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:High ambient temperature regulated the plant systemic response to the beneficial endophytic fungus Serendipita indica. Most plants in nature establish symbiotic associations with endophytic fungi in soil. Beneficial endophytic fungi induce a systemic response in the aboveground parts of the host plant, thus promoting the growth and fitness of host plants. Meanwhile, temperature elevation from climate change widely affects global plant biodiversity as well as crop quality and yield. Over the past decades, great progresses have been made in the response of plants to high ambient temperature and to symbiosis with endophytic fungi. However, little is known about their synergistic effect on host plants. The endophytic fungus Serendipita indica colonizes the roots of a wide range of plants, including Arabidopsis. Based on the Arabidopsis-S. indica symbiosis experimental system, we analyzed the synergistic effect of high ambient temperature and endophytic fungal symbiosis on host plants. By transcriptome analysis, we found that DNA replication-related genes were significantly upregulated during the systemic response of Arabidopsis aboveground parts to S. indica colonization. Plant hormones, such as jasmonic acid (JA) and ethylene (ET), play important roles in plant growth and systemic responses. We found that high ambient temperature repressed the JA and ET signaling pathways of Arabidopsis aboveground parts during the systemic response to S. indica colonization in roots. Meanwhile, PIF4 is the central hub transcription factor controlling plant thermosensory growth under high ambient temperature in Arabidopsis. PIF4 is also involving JA and/or ET signaling pathway. We found that PIF4 target genes overlapped with many differentially expressed genes (DEGs) during the systemic response, and further showed that the growth promotion efficiency of S. indica on the pif4 mutant was higher than that on the wild type plants.
Project description:To improve both drought stress tolerance and growth of plants, we generated transgenic Arabidopsis plants that overexpress two transcription factors: DREB1A and PIF4. It was reported that DREB1A improves drought stress tolerance in various crops but causes dwarfism, and PIF4 enhances cell elongation through activation of cell wall synthesis. We performed microarray experiments using a single overexpressor of PIF4 and the double overexpressor of DREB1A and PIF4 to study the potential interactions of the gene networks regulated by the two transcription factors in the double overexpressor.