Single-plant-omics reveals the cascade of transcriptional changes during the vegetative-to-reproductive transition.

Plants undergo rapid developmental transitions, which occur contemporaneously with gradual changes in physiology. Moreover, individual plants within a population undergo developmental transitions asynchronously. Single-plant-omics has the potential to distinguish between transcriptional events that are associated with these binary and continuous processes. Furthermore, we can use single-plant-omics to order individual plants by their intrinsic biological age, providing a high-resolution transcriptional time series. We performed RNA-seq on leaves from a large population of wild-type Arabidopsis (Arabidopsis thaliana) during the vegetative-to-reproductive transition. Though most transcripts were differentially expressed between bolted and unbolted plants, some regulators were more closely associated with leaf size and biomass. Using a pseudotime inference algorithm, we determined that some senescence-associated processes, such as the reduction in ribosome biogenesis, were evident in the transcriptome before a bolt was visible. Even in this near-isogenic population, some variants are associated with developmental traits. These results support the use of single-plant-omics to uncover rapid transcriptional dynamics by exploiting developmental asynchrony.

Timely Questions Emerging in Chronobiology: The Circadian Clock Keeps on Ticking.

Chronobiology investigations have revealed much about cellular and physiological clockworks but we are far from having a complete mechanistic understanding of the physiological and ecological implications. Here we present some unresolved questions in circadian biology research as posed by the editorial staff and guest contributors to the Journal of Circadian Rhythms. This collection of ideas is not meant to be comprehensive but does reveal the breadth of our observations on emerging trends in chronobiology and circadian biology. It is amazing what could be achieved with various expected innovations in technologies, techniques, and mathematical tools that are being developed. We fully expect strengthening mechanistic work will be linked to health care and environmental understandings of circadian function. Now that most clock genes are known, linking these to physiological, metabolic, and developmental traits requires investigations from the single molecule to the terrestrial ecological scales. Real answers are expected for these questions over the next decade. Where are the circadian clocks at a cellular level? How are clocks coupled cellularly to generate organism level outcomes? How do communities of circadian organisms rhythmically interact with each other? In what way does the natural genetic variation in populations sculpt community behaviors? How will methods development for circadian research be used in disparate academic and commercial endeavors? These and other questions make it a very exciting time to be working as a chronobiologist.

Reflections on Several Landmark Advances in Circadian Biology.

Circadian Biology intersects with diverse scientific domains, intricately woven into the fabric of organismal physiology and behavior. The rhythmic orchestration of life by the circadian clock serves as a focal point for researchers across disciplines. This retrospective examination delves into several of the scientific milestones that have fundamentally shaped our contemporary understanding of circadian rhythms. From deciphering the complexities of clock genes at a cellular level to exploring the nuances of coupled oscillators in whole organism responses to stimuli. The field has undergone significant evolution lately guided by genetics approaches. Our exploration here considers key moments in the circadian-research landscape, elucidating the trajectory of this discipline with a keen eye on scientific advancements and paradigm shifts.

Buccal Fat Advancement-Transposition Flap for Reconstruction of Midface Volume Defects.

Background: The buccal fat pad (BFP) has previously been utilized for repair of various defects of the head and neck. Objectives: We explore the utility of a pedicled buccal fat advancement-transposition (BFAT) flap in various forms of midface reconstruction through a variety of surgical approaches and characterize its volume and axial reach in human anatomic specimens. Methods: Ten adult full-head human anatomic specimens were dissected, and a single surgical case demonstrating the use of a BFAT flap is described. Results: Nasolabial, subciliary, and deep plane facelift incisions all provided access to the BFP for use as a BFAT flap. The mean volume of mobilizable fat contained within a BFAT flap accessible through external incision was 7.1 cm3. Once fully mobilized, the externalized BFAT flap had a mean axial reach of 6.9 cm without tension. We also present a case illustrating the successful use of a BFAT flap for volumization of a large midface defect secondary to Mohs micrographic surgical resection of a cutaneous malignancy. Discussion: The BFAT flap, which exhibited substantial volume and reach in this study, can be harvested through multiple dissection windows or pre-existing defects and be used to reconstruct a variety of midface defects.

Clinical and surgical factors associated with opioid refill rates following septorhinoplasty.

BACKGROUND: Septorhinoplasty is one the most common class of procedures performed worldwide, and opioids are frequently prescribed for post-operative pain [1]. OBJECTIVE: The objective of this study was to examine the rate of post-operative opioid prescription refills following septorhinoplasty. METHODS: This study was a case-control study of patients who underwent septoplasty and other secondary concomitant procedures. RESULTS: Of the 249 patients included in this study, the majority of patients (94.8%) were prescribed 12 tablets of hydrocodone-acetaminophen 5 mg - 325 mg and only 31 patients (13.3%) received refills. The presence of osteotomies and history of prior opioid use were associated with refills. Nasal valve repair type, open versus closed approach, and presence of autologous auricular cartilage graft harvest were not. DISCUSSION: Our study highlights factors that surgeons should consider when prescribing opioids after septorhinoplasty. Twelve tablets of an opioid are likely sufficient for the majority of patients, but if osteotomies are performed or the patient has a history of prior opioid use, more may be indicated to avoid the need for refills. Additional narcotics are not necessary for an open approach or for patients in which auricular cartilage is needed.

AraLeTA: An Arabidopsis leaf expression atlas across diurnal and developmental scales.

Mature plant leaves are a composite of distinct cell types, including epidermal, mesophyll, and vascular cells. Notably, the proportion of these cells and the relative transcript concentrations within different cell types may change over time. While gene expression data at a single-cell level can provide cell-type-specific expression values, it is often too expensive to obtain these data for high-resolution time series. Although bulk RNA-seq can be performed in a high-resolution time series, RNA-seq using whole leaves measures average gene expression values across all cell types in each sample. In this study, we combined single-cell RNA-seq data with time-series data from whole leaves to assemble an atlas of cell-type-specific changes in gene expression over time for Arabidopsis (Arabidopsis thaliana). We inferred how the relative transcript concentrations of different cell types vary across diurnal and developmental timescales. Importantly, this analysis revealed 3 subgroups of mesophyll cells with distinct temporal profiles of expression. Finally, we developed tissue-specific gene networks that form a community resource: an Arabidopsis Leaf Time-dependent Atlas (AraLeTa). This allows users to extract gene networks that are confirmed by transcription factor-binding data and specific to certain cell types at certain times of day and at certain developmental stages. AraLeTa is available at https://regulatorynet.shinyapps.io/araleta/.

Assessing the feasibility of a multimodal liquid biopsy for the diagnosis of HPV-associated oropharyngeal squamous cell carcinoma.

OBJECTIVES: In this feasibility study, we explored the combined use of circulating tumor human papillomavirus (HPV) DNA (ctHPVDNA) and HPV serology as diagnostic tests for HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). METHODS: Among patients with research-banked serum or plasma at diagnosis, IgG antibodies to oncoproteins from HPV types 16, 18, 31, 33, 35, 45, 52, and 58 were detected with multiplex serology. Positivity for HPV 16 was defined based on detection of combinations of anti-E6, E1, E2, and E7 and for other high-risk types on detection of anti-E6 and anti-E7. Circulating tumor HPV DNA was detected by custom digital droplet polymerase chain reaction (ddPCR) assays for HPV types 16, 18, 33, 35, and 45. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization (ISH) using a cocktail of 18 high-risk HPV types were performed on tissue. RESULTS: Of 75 patients, 67 (89.3%) were HPV-associated (p16 and HPV RNA ISH positive) and 8 (10.7%) were HPV-independent. All 8 HPV-independent patients were seronegative and negative for ctHPVDNA (100% specificity). Serology was positive in 53 (79.1%) of 67 HPV-associated patients, while ddPCR was positive for ctHPVDNA in 59 (88.6%) of 67 HPV-associated patients. Requiring both tests to be positive resulted in a sensitivity of 50 (74.6%) of 67 while combining assays (either positive) improved sensitivity to 62 (92.6%) of 67. CONCLUSIONS: Compared to HPV RNA ISH, HPV serology and ctHPVDNA are sensitive and highly specific biomarkers for HPV-associated OPSCC at the time of presentation.

Diurnal regulation of alternative splicing associated with thermotolerance in rice by two glycine-rich RNA-binding proteins.

Rice (Oryza sativa L.) production is threatened by global warming associated with extreme high temperatures, and rice heat sensitivity is differed when stress occurs between daytime and nighttime. However, the underlying molecular mechanism are largely unknown. We show here that two glycine-rich RNA binding proteins, OsGRP3 and OsGRP162, are required for thermotolerance in rice, especially at nighttime. The rhythmic expression of OsGRP3/OsGRP162 peaks at midnight, and at these coincident times, is increased by heat stress. This is largely dependent on the evening complex component OsELF3-2. We next found that the double mutant of OsGRP3/OsGRP162 is strikingly more sensitive to heat stress in terms of survival rate and seed setting rate when comparing to the wild-type plants. Interestingly, the defect in thermotolerance is more evident when heat stress occurred in nighttime than that in daytime. Upon heat stress, the double mutant of OsGRP3/OsGRP162 displays globally reduced expression of heat-stress responsive genes, and increases of mRNA alternative splicing dominated by exon-skipping. This study thus reveals the important role of OsGRP3/OsGRP162 in thermotolerance in rice, and unravels the mechanism on how OsGRP3/OsGRP162 regulate thermotolerance in a diurnal manner.

Forehead Flap Practices: A Cross-Sectional Survey of Facial Plastic and Reconstructive Surgeons.

Background: The paramedian forehead flap (PMFF) is a well-established technique utilized for reconstruction of complex nasal defects. Objective: To identify the different techniques and management of patients undergoing PMFF reconstruction and compare these with current literature. Methods: Members of the American Academy of Facial Plastic and Reconstructive Surgery were sent a practice survey highlighting various nuances in PMFF reconstruction. The survey included questions about flap design, operative techniques, and perioperative care. Results: In total, 172 responses were received (14% response rate). Mean years of practice after fellowship was 15.8 years with most respondents performing either 1-5 (33.1%) or 6-10 (27.3%) PMFFs per year. Common practices included the use of general anesthesia, elevation of PMFF in the subgaleal plane (59.6%), and pedicle division at 3 weeks (80%) (p < 0.001). Complication rates ranged between 1% and 5%. The nose was the most common site for revision (p < 0.001) and the average number of secondary procedures after forehead flap division was 1.1 (standard deviation 0.81). The most variability in responses was seen for methods of internal lining reconstruction. Conclusion: Reconstructive surgeons frequently divide the PMFF pedicle at 3 weeks or later and have variable approaches to reconstruction of the internal lining with low complication rates overall.

Complex epistatic interactions between ELF3, PRR9, and PRR7 regulate the circadian clock and plant physiology.

Circadian clocks are endogenous timekeeping mechanisms that coordinate internal physiological responses with the external environment. EARLY FLOWERING3 (ELF3), PSEUDO RESPONSE REGULATOR (PRR9), and PRR7 are essential components of the plant circadian clock and facilitate entrainment of the clock to internal and external stimuli. Previous studies have highlighted a critical role for ELF3 in repressing the expression of PRR9 and PRR7. However, the functional significance of activity in regulating circadian clock dynamics and plant development is unknown. To explore this regulatory dynamic further, we first employed mathematical modeling to simulate the effect of the prr9/prr7 mutation on the elf3 circadian phenotype. These simulations suggested that simultaneous mutations in prr9/prr7 could rescue the elf3 circadian arrhythmia. Following these simulations, we generated all Arabidopsis elf3/prr9/prr7 mutant combinations and investigated their circadian and developmental phenotypes. Although these assays could not replicate the results from the mathematical modeling, our results have revealed a complex epistatic relationship between ELF3 and PRR9/7 in regulating different aspects of plant development. ELF3 was essential for hypocotyl development under ambient and warm temperatures, while PRR9 was critical for root thermomorphogenesis. Finally, mutations in prr9 and prr7 rescued the photoperiod-insensitive flowering phenotype of the elf3 mutant. Together, our results highlight the importance of investigating the genetic relationship among plant circadian genes.

Single Institution Experience With Sinonasal Glomangiopericytoma: A Case Series.

Introduction: Sinonasal glomangiopericytoma (GPC) is an uncommon neoplasm, accounting for less than 0.5% of all sinonasal tumors. It is characterized as having low malignant potential, with complete surgical excision representing optimal treatment. Presenting symptoms are typically due to mass effect and vascularity of this tumor, often including unilateral nasal obstruction or epistaxis. Accounts of this tumor in the literature remain sparse. Methods: Single institution retrospective review. Results: Six cases of sinonasal GPC were identified from a review of the electronic medical records spanning from 2009 through 2021. Age at diagnosis ranged from 48 to 67 years, with a gender distribution of 5 males and 1 female. Most subjects presented with unilateral sinonasal obstruction of variable duration. Each underwent endoscopic resection of the mass with negative margins, and no adjuvant therapy was pursued. Pathologic specimens demonstrated a vascular patterned tumor with spindled cells surrounding vessels and were positive for smooth muscle actin and negative for cytokeratin. Active post-surgical follow-up ranged from 11 months to 10 years. All patients were without endoscopic evidence of recurrence, and 2 had post-operative imaging which showed no evidence of disease. Conclusions: This review of 6 cases of sinonasal GPC represents the largest known series of this rare pathology in the literature to date. Based on our experience, and in agreement with the available literature, this disease is reliably managed with complete surgical excision. Adjuvant therapy can be avoided in otherwise uncomplicated cases. Although rare, GPC should be considered in the differential diagnosis of all vascular sinonasal tumors.

A non-canonical function of Arabidopsis ERECTA proteins and a role of the SWI3B subunit of the SWI/SNF chromatin remodeling complex in gibberellin signaling.

The Arabidopsis ERECTA family (ERf) of leucine-rich repeat receptor-like kinases (LRR-RLKs) comprising ERECTA (ER), ERECTA-LIKE 1 (ERL1), and ERECTA-LIKE 2 (ERL2) controls epidermal patterning, inflorescence architecture, and stomata development and patterning. These proteins are reported to be plasma membrane associated. Here we show that the er/erl1/erl2 mutant exhibits impaired gibberellin (GA) biosynthesis and perception alongside broad transcriptional changes. The ERf kinase domains were found to localize to the nucleus where they interact with the SWI3B subunit of the SWI/SNF chromatin remodeling complex (CRCs). The er/erl1/erl2 mutant exhibits reduced SWI3B protein level and affected nucleosomal chromatin structure. Similar to swi3c and brm plants with inactivated subunits of SWI/SNF CRCs, it also does not accumulate DELLA RGA and GAI proteins. The ER kinase phosphorylates SWI3B in vitro, and the inactivation of all ERf proteins leads to the decreased phosphorylation of SWI3B protein in vivo. The identified correlation between DELLA overaccumulation and SWI3B proteasomal degradation, and the physical interaction of SWI3B with DELLA proteins indicate an important role of SWI3B-containing SWI/SNF CRCs in gibberellin signaling. Co-localization of ER and SWI3B on GID1 (GIBBERELLIN INSENSITIVE DWARF 1) DELLA target gene promoter regions and abolished SWI3B binding to GID1 promoters in er/erl1/erl2 plants supports the conclusion that ERf-SWI/SNF CRC interaction is important for transcriptional control of GA receptors. Thus, the involvement of ERf proteins in the transcriptional control of gene expression, and observed similar features for human HER2 (epidermal growth family receptor member), indicate an exciting target for further studies of evolutionarily conserved non-canonical functions of eukaryotic membrane receptors.

Balloon Sinuplasty and Stenting in the Management of Complex Frontal Sinus Outflow Tract Fractures.

OBJECTIVE: Classical management of complex fractures involving the frontal sinus outflow tract (FSOT) favors obliteration or cranialization to avoid delayed complications. We aim to exhibit success with a novel application of balloon sinuplasty and frontal stenting in the management of complex injuries disrupting the FSOT, which might have otherwise required more invasive interventions. STUDY DESIGN: Retrospective review. SETTING: Single institution, level 1 trauma center. METHODS: Retrospective review of patients presenting to a level 1 trauma center with fractures involving the FSOT. Outcomes include patency of the FSOT on imaging and endoscopy, rate of complications, degree of residual tabular displacement, and need for revision surgery. RESULTS: Twenty-five patients met inclusion criteria, with complete FSOT obstruction seen in all cases on computed tomography. All patients underwent balloon sinuplasty with frontal sinus stenting; 48% underwent concurrent anterior table repair, and 36% open repair of nasoorbitoethmoid complex fractures. The mean follow-up length was 13.9 months, at which time 91.3% of patients demonstrated radiographic and endoscopic FSOT patency. No residual sinus opacification or pneumocephalus was observed. CONCLUSION: Balloon sinuplasty with frontal sinus stenting is a straightforward and minimally invasive technique that can create a safe sinus in complex fractures disrupting the FSOT while avoiding the need for more invasive procedures.

Utility of PET-CT in Newly Diagnosed HPV-Associated Oropharyngeal Squamous Cell Carcinoma.

OBJECTIVE: To compare the utility of positron emission tomography-computed tomography (PET-CT) versus contrasted CT neck combined with routine chest imaging for disease staging and treatment planning in human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) with clinically evident sites of primary disease. METHODS: All adult patients with primary HPV-associated OPSCC at a single quaternary care cancer center from 2018 to 2019 were reviewed, and those with images available for re-review were included. Primary outcomes included concordance in clinical staging between the 2 imaging modalities of interest (PET-CT vs CT), as well as independent agreement of each with pathologic staging. Analysis was performed via ordinal logistic regression. A secondary outcome was treatment selection after diagnostic imaging, analyzed via chi-squared testing. RESULTS: In total, 100 patients were included for evaluation, of which 89% were male, 91% Caucasian, and mean age was 61.2 years (SD 9.6). Clinical disease staging agreed between imaging modalities in 95% of cases (54 of 57 patients). Pathologic staging agreed with clinical staging from CT neck in 93% of cases (25 of 27 patients; P = .004), and with PET-CT in 82% (14 of 17 patients; P =.003). No differences were observed between the 2 imaging modalities for subsequent treatment selection (P = .39). CONCLUSION: In uncomplicated HPV-associated OPSCC, CT offers equivalent diagnostic accuracy to that of combined whole-body PET-CT for clinical staging, and has no appreciable impact on treatment selection. A reduced reliance on routine PET-CT during initial workup of HPV-associated OPSCC may be favorable for otherwise healthy patients with clinically evident sites of primary disease.

Normative Values of the Nasal Obstruction Symptom Evaluation Scale.

Background: The Nasal Obstruction Symptom Evaluation (NOSE) scale is widely used by clinicians in evaluation of nasal airway obstruction (NAO). Objective: To determine normative values for the NOSE scale among both symptomatic and asymptomatic members of the general U.S. population. Methods: A survey of NAO symptoms in adults of age 18 years and older was performed. The distribution of NOSE scores among the general population was estimated. Influence of features including age, gender, race, location, and symptomatology on NOSE scores was evaluated. Results: Surveys were completed by 2333 participants. Mean NOSE score was 11 (standard deviation [SD] 11) in the asymptomatic, and 28 (SD 22) in the symptomatic population (p < 0.0001). Increasing age was associated with an increase in scores until 45 years, after which it was associated with decreasing scores. No significant differences were found related to other investigated demographics. Conclusions: Normative ranges for the NOSE scale are established, and are largely consistent with values in the existing literature. NOSE scores do not appear to be influenced by gender, race, or geography, although age should be considered in their interpretation.

Chemodenervation of the Posterior Belly of the Digastric Muscle in Facial Synkinesis.

Background: Patients with facial synkinesis may have jaw tightness and swallow discomfort despite chemodenervation of facial mimetic musculature, and the posterior belly of the digastric (PBD) muscle is a logical target to treat these symptoms. Learning/Study Objective: To compare patient-reported outcomes of botulinum toxin (BT) chemodenervation of the posterior belly of digastric muscle in patients with postparalytic facial synkinesis. Design Type: Retrospective review. Methods: Patients with facial synkinesis who underwent electromyography (EMG)-guided PBD BT chemodenervation in addition to their baseline therapeutic regimen were included. Pre- and post-treatment Synkinesis Assessment Questionnaires (SAQ) and a two-question survey regarding jaw tightness and swallow discomfort were administered. Results: Twenty-nine patients were included. An average of 5 U of BT-A was injected into the PBD, and 46.5 U across all facial muscles. From pre- to post-injection, patients demonstrated improvement in jaw tightness at rest (3.02 vs. 1.98/5.0, p < 0.001), with swallow (2.78 vs. 1.94/5.0, p < 0.001), and total SAQ (64.3 vs. 51.2/100, p < 0.001). Patients rated subjective benefit from PBD injection compared with prior treatments without PBD injection as 4.5/5.0. Conclusion: Synkinesis patients with jaw tightness or swallow discomfort may benefit from the addition of PBD injections to the therapeutic regimen.

Septal Perforation Repair Using a Temporoparietal Fascia and Polydioxanone Plate Construct: A Multi-Institutional Analysis.

Background: Nasal septal perforations (NSPs) are notoriously difficult to fix and closure can paradoxically lead to worsening of symptoms, prompting numerous techniques for repair including temporoparietal fascia (TPF)-polydioxanone (PDS) plate interposition grafting. Objectives: To compare rates of NSP closure with TPF-PDS interposition grafting among a variety of institutions with diverse environmental influences and patient-specific factors. Methods: Retrospective review of patients undergoing TPF-PDS interposition grafting at seven different U.S. institutions over 5 years. Outcomes include closure rate, self-reported symptom improvement, change in Nasal Obstruction Symptomatic Evaluation (NOSE) score, and postoperative complications. Results: Sixty-two patients (39 female) with a mean age of 41.5 years were included. Most common perforation location was anterior (53%), and average size was 1.70 cm2. NSP closure with symptomatic improvement was achieved in 95% of participants. Postoperative NOSE scores decreased on average by 42 points. Residual crusting occurred in 29% of patients, independent of external factors. Conclusions: TPF-PDS interposition grafting is highly effective for NSP repair in a wide variety of settings, and NOSE scores correspond well with patient-reported outcomes.

Professional Social Media in Facial Plastic and Reconstructive Surgery: Usage, Resources, and Barriers.

BACKGROUND: Social media is an important tool for networking, recruitment, and promoting clinical practice. No study has specifically assessed which FPRS practitioners have professional social media accounts, how they utilize them, and what barriers or resources exist to their use. OBJECTIVES: This study aims to examine differences in social media use based on provider demographics and practice setting, and identify resources and barriers to professional social media use. METHODS: This cross-sectional analysis was an anonymous survey sent to AAFPRS members. Data collected included demographics, practice setting, resources, and barriers encountered to use of professional social media. RESULTS: Most facial plastic surgeons (80%) use professional social media, notably Instagram and Facebook, and mostly post patient photos and stories (67.9%). Social media is more commonly utilized in private practice (56% vs 23%, P = .0016), where there are less institutional barriers (10% vs 40%, P = .02) and more resources available (82.5% vs 12.5%, P = .01). CONCLUSIONS: Social media is widely used in FPRS. Working in private practice is associated with increased availability of resources for support, and a reduction in institutional barriers to maintaining a social media presence. With this understanding, facial plastic surgeons can be better equipped for networking, marketing, and promoting the field of FPRS.

Varicella Zoster Virus Reactivation Involving the Vagus Nerve.

OBJECTIVES: To characterize the presentation, clinical course and functional outcomes of patients with varicella zoster virus (VZV) reactivation involving the vagus nerve. To highlight the role of otolaryngology in acute and long-term management of laryngopharyngeal VZV and its sequelae. METHODS: Retrospective review of 3 patients with laryngopharyngeal VZV, managed at a tertiary referral center. RESULTS: All cases presented with vesicular lesions involving mucosa of the laryngopharynx. Each experienced vocal fold hypomobility, among other otolaryngologic sequelae. All were treated with systemic antivirals and corticosteroids. Mucosal lesions resolved within 7 days of treatment initiation; functional deficits persisted for months to years. Dysphonia improved to a plateau at 3 months, while dysphagia took longer to resolve. One patient with disseminated disease experienced bilateral vocal fold paralysis requiring temporary tracheostomy. CONCLUSIONS: Vagal neuropathy secondary to VZV reactivation is a rare clinical entity with a variety of laryngeal manifestations. Early initiation of systemic therapy and serial endoscopic evaluations are critical components of acute management when laryngopharyngeal involvement is suspected. Otolaryngologists should plan for long-term phonatory and deglutitive therapy in these cases, as neurologic sequelae can persist for months to years following initial insult. LEVEL OF EVIDENCE: Level 4 (Case-series).

A competition-attenuation mechanism modulates thermoresponsive growth at warm temperatures in plants.

Global warming has profound impact on growth and development, and plants constantly adjust their internal circadian clock to cope with external environment. However, how clock-associated genes fine-tune thermoresponsive growth in plants is little understood. We found that loss-of-function mutation of REVEILLE5 (RVE5) reduces the expression of circadian gene EARLY FLOWERING 4 (ELF4) in Arabidopsis, and confers accelerated hypocotyl growth under warm-temperature conditions. Both RVE5 and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) accumulate at warm temperatures and bind to the same EE cis-element presented on ELF4 promoter, but the transcriptional repression activity of RVE5 is weaker than that of CCA1. The binding of CCA1 to ELF4 promoter is enhanced in the rve5-2 mutant at warm temperatures, and overexpression of ELF4 in the rve5-2 mutant background suppresses the rve5-2 mutant phenotype at warm temperatures. Therefore, the transcriptional repressor RVE5 finetunes ELF4 expression via competing at a cis-element with the stronger transcriptional repressor CCA1 at warm temperatures. Such a competition-attenuation mechanism provides a balancing system for modulating the level of ELF4 and thermoresponsive hypocotyl growth under warm-temperature conditions.