BACKGROUND: The increasing ambient temperature significantly impacts plant growth, development, and reproduction. Uncovering the temperature-regulating mechanisms in plants is of high importance, for increasing our fundamental understanding of plant thermomorphogenesis, for its potential in applied science, and for aiding plant breeders in improving plant thermoresilience. Thermomorphogenesis, the developmental response to warm temperatures, has been primarily studied in seedlings and in the regulation of flowering time. PHYTOCHROME B and PHYTOCHROME-INTERACTING FACTORs (PIFs), particularly PIF4, are key components of this response. However, the thermoresponse of other adult vegetative tissues and reproductive structures has not been systematically evaluated, especially concerning the involvement of phyB and PIFs. RESULTS: 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 growth in soil, shoot, inflorescence, and seed. Our findings demonstrate that phyB-PIF4 is generally involved in the relay of temperature signals throughout plant development, including the reproductive stage. Furthermore, we 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 insight into the molecular mechanisms behind temperature-induced reduced fertilization rate. These include a downregulation of auxin metabolism, upregulation of genes involved auxin signalling, miRNA156 and miRNA160 pathways, and pollen tube attractants. CONCLUSIONS: Our findings demonstrate that phyB-PIF4 involvement in the interpretation of temperature signals is pervasive throughout plant development, including processes directly linked to reproduction.

• Klíčová slova
• Arabidopsis, Automatic phenotyping, PIF4, Pistils, Pollen tube guidance, Seeds, Thermomorphogenesis, phyB,
• MeSH
• Arabidopsis * genetika   metabolismus   růst a vývoj   fyziologie   MeSH
• fenotyp * MeSH
• fytochrom B * metabolismus   genetika   MeSH
• kořeny rostlin genetika   metabolismus   růst a vývoj   MeSH
• květy genetika   růst a vývoj   MeSH
• proteiny huseníčku * genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• signální transdukce MeSH
• transkripční faktory bHLH * genetika   metabolismus   MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fytochrom B * MeSH
• PHYB protein, Arabidopsis MeSH Prohlížeč
• PIF4 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku * MeSH
• transkripční faktory bHLH * MeSH

The size of plant organs is highly responsive to environmental conditions. The plant's embryonic stem, or hypocotyl, displays phenotypic plasticity, in response to light and temperature. The hypocotyl of shade avoiding species elongates to outcompete neighboring plants and secure access to sunlight. Similar elongation occurs in high temperature. However, it is poorly understood how environmental light and temperature cues interact to effect plant growth. We found that shade combined with warm temperature produces a synergistic hypocotyl growth response that dependent on PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) and auxin. This unique but agriculturally relevant scenario was almost totally independent on PIF4 activity. We show that warm temperature is sufficient to promote PIF7 DNA binding but not transcriptional activation and we demonstrate that additional, unknown factor/s must be working downstream of the phyB-PIF-auxin module. Our findings will improve the predictions of how plants will respond to increased ambient temperatures when grown at high density.

• MeSH
• Arabidopsis * metabolismus   MeSH
• DNA vazebné proteiny metabolismus   MeSH
• faktor VII genetika   metabolismus   MeSH
• fytochrom * metabolismus   MeSH
• hypokotyl metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• proteiny huseníčku * genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• světlo MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• faktor VII MeSH
• fytochrom * MeSH
• kyseliny indoloctové MeSH
• PIF7 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku * MeSH
• transkripční faktory bHLH MeSH

Plant adjustment to environmental changes involves complex crosstalk between extrinsic and intrinsic cues. In the past two decades, extensive research has elucidated the key roles of PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and the phytohormone auxin in thermomorphogenesis. In this study, we identified a previously unexplored role of jasmonate (JA) signaling components, the Mediator complex, and their integration with auxin signaling during thermomorphogenesis in Arabidopsis (Arabidopsis thaliana). Warm temperature induces expression of JA signaling genes including MYC2, but, surprisingly, this transcriptional activation is not JA dependent. Warm temperature also promotes accumulation of the JA signaling receptor CORONATINE INSENSITIVE1 (COI1) and degradation of the JA signaling repressor JASMONATE-ZIM-DOMAIN PROTEIN9, which probably leads to de-repression of MYC2, enabling it to contribute to the expression of MEDIATOR SUBUNIT17 (MED17). In response to warm temperature, MED17 occupies the promoters of thermosensory genes including PIF4, YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE19 (IAA19), and IAA29. Moreover, MED17 facilitates enrichment of H3K4me3 on the promoters of PIF4, YUC8, IAA19, and IAA29 genes. Interestingly, both occupancy of MED17 and enrichment of H3K4me3 on these thermomorphogenesis-related promoters are dependent on PIF4 (or PIFs). Altered accumulation of COI1 under warm temperature in the med17 mutant suggests the possibility of a feedback mechanism. Overall, this study reveals the role of the Mediator complex as an integrator of JA and auxin signaling pathways during thermomorphogenesis.

• MeSH
• Arabidopsis * metabolismus   MeSH
• cyklopentany metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• mediátorový komplex metabolismus   MeSH
• oxylipiny metabolismus   MeSH
• proteiny huseníčku * metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyklopentany MeSH
• jasmonic acid MeSH Prohlížeč
• kyseliny indoloctové MeSH
• mediátorový komplex MeSH
• oxylipiny MeSH
• proteiny huseníčku * MeSH

In cereals, the root system is mainly composed of post-embryonic shoot-borne roots, named crown roots. The CROWN ROOTLESS1 (CRL1) transcription factor, belonging to the ASYMMETRIC LEAVES2-LIKE/LATERAL ORGAN BOUNDARIES DOMAIN (ASL/LBD) family, is a key regulator of crown root initiation in rice (Oryza sativa). Here, we show that CRL1 can bind, both in vitro and in vivo, not only the LBD-box, a DNA sequence recognized by several ASL/LBD transcription factors, but also another not previously identified DNA motif that was named CRL1-box. Using rice protoplast transient transactivation assays and a set of previously identified CRL1-regulated genes, we confirm that CRL1 transactivates these genes if they possess at least a CRL1-box or an LBD-box in their promoters. In planta, ChIP-qPCR experiments targeting two of these genes that include both a CRL1- and an LBD-box in their promoter show that CRL1 binds preferentially to the LBD-box in these promoter contexts. CRISPR/Cas9-targeted mutation of these two CRL1-regulated genes, which encode a plant Rho GTPase (OsROP) and a basic helix-loop-helix transcription factor (OsbHLH044), show that both promote crown root development. Finally, we show that OsbHLH044 represses a regulatory module, uncovering how CRL1 regulates specific processes during crown root formation.

• Klíčová slova
• Oryza sativa, ASL/LBD transcription factor, CRL1, DNA binding domain, crown root, development, gene regulatory network, rice,
• MeSH
• DNA metabolismus   MeSH
• kořeny rostlin metabolismus   MeSH
• regulace genové exprese u rostlin genetika   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• rýže (rod) * metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH
• rostlinné proteiny MeSH
• transkripční faktory MeSH

Brassinosteroids (BRs) are essential phytohormones regulating various developmental and physiological processes during normal growth and development. cog1-3D (cogwheel1-3D) was identified as an activation-tagged genetic modifier of bri1-5, an intermediate BR receptor mutant in Arabidopsis (Arabidopsis thaliana). COG1 encodes a Dof-type transcription factor found previously to act as a negative regulator of the phytochrome signaling pathway. cog1-3D single mutants show an elongated hypocotyl phenotype under light conditions. A loss-of-function mutant or inducible expression of a dominant negative form of COG1 in the wild type results in an opposite phenotype. A BR profile assay indicated that BR levels are elevated in cog1-3D seedlings. Quantitative reverse transcription-polymerase chain reaction analyses showed that several key BR biosynthetic genes are significantly up-regulated in cog1-3D compared with those of the wild type. Two basic helix-loop-helix transcription factors, PIF4 and PIF5, were found to be transcriptionally up-regulated in cog1-3D Genetic analysis indicated that PIF4 and PIF5 were required for COG1 to promote BR biosynthesis and hypocotyl elongation. Chromatin immunoprecipitation and electrophoretic mobility shift assays indicated that COG1 binds to the promoter regions of PIF4 and PIF5, and PIF4 and PIF5 bind to the promoter regions of key BR biosynthetic genes, such as DWF4 and BR6ox2, to directly promote their expression. These results demonstrated that COG1 regulates BR biosynthesis via up-regulating the transcription of PIF4 and PIF5.

• MeSH
• Arabidopsis genetika   metabolismus   MeSH
• biologické modely MeSH
• biosyntetické dráhy genetika   MeSH
• bodová mutace genetika   MeSH
• brassinosteroidy biosyntéza   MeSH
• ethylmethansulfonát MeSH
• fenotyp MeSH
• hypokotyl růst a vývoj   metabolismus   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné geny MeSH
• sekvence nukleotidů MeSH
• suprese genetická MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• upregulace genetika   MeSH
• vazba proteinů genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• brassinosteroidy MeSH
• COG1 protein, Arabidopsis MeSH Prohlížeč
• ethylmethansulfonát MeSH
• PIF4 protein, Arabidopsis MeSH Prohlížeč
• PIF5 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• transkripční faktory bHLH MeSH
• transkripční faktory MeSH