Biomolecular condensation programs floral transition to orchestrate flowering time and inflorescence architecture.

Biomolecular condensation involves the concentration of biomolecules (DNA, RNA, proteins) into compartments to form membraneless organelles or condensates with unique properties and functions. This ubiquitous phenomenon has garnered considerable attention in recent years owing to its multifaceted roles in developmental processes and responses to environmental cues in living systems. Recent studies have revealed that biomolecular condensation plays essential roles in regulating the transition of plants from vegetative to reproductive growth, a programmed process known as floral transition that determines flowering time and inflorescence architecture in flowering plants. In this Tansley insight, we review advances in how biomolecular condensation integrates developmental and environmental signals to program and reprogram the floral transition thus diversifies flowering time and inflorescence architecture.

Control of inflorescence architecture in tomato by BTB/POZ transcriptional regulators.

Plant productivity depends on inflorescences, flower-bearing shoots that originate from the stem cell populations of shoot meristems. Inflorescence architecture determines flower production, which can vary dramatically both between and within species. In tomato plants, formation of multiflowered inflorescences depends on a precisely timed process of meristem maturation mediated by the transcription factor gene TERMINATING FLOWER (TMF), but the underlying mechanism is unknown. We show that TMF protein acts together with homologs of the Arabidopsis BLADE-ON-PETIOLE (BOP) transcriptional cofactors, defined by the conserved BTB (Broad complex, Tramtrack, and Bric-a-brac)/POZ (POX virus and zinc finger) domain. TMF and three tomato BOPs (SlBOPs) interact with themselves and each other, and TMF recruits SlBOPs to the nucleus, suggesting formation of a transcriptional complex. Like TMF, SlBOP gene expression is highest during vegetative and transitional stages of meristem maturation, and CRISPR/Cas9 elimination of SlBOP function causes pleiotropic defects, most notably simplification of inflorescences into single flowers, resembling tmf mutants. Flowering defects are enhanced in higher-order slbop tmf mutants, suggesting that SlBOPs function with additional factors. In support of this, SlBOPs interact with TMF homologs, mutations in which cause phenotypes like slbop mutants. Our findings reveal a new flowering module defined by SlBOP-TMF family interactions that ensures a progressive meristem maturation to promote inflorescence complexity.

ROS regulated reversible protein phase separation synchronizes plant flowering.

How aerobic organisms exploit inevitably generated but potentially dangerous reactive oxygen species (ROS) to benefit normal life is a fundamental biological question. Locally accumulated ROS have been reported to prime stem cell differentiation. However, the underlying molecular mechanism is unclear. Here, we reveal that developmentally produced H2O2 in plant shoot apical meristem (SAM) triggers reversible protein phase separation of TERMINATING FLOWER (TMF), a transcription factor that times flowering transition in the tomato by repressing pre-maturation of SAM. Cysteine residues within TMF sense cellular redox to form disulfide bonds that concatenate multiple TMF molecules and elevate the amount of intrinsically disordered regions to drive phase separation. Oxidation triggered phase separation enables TMF to bind and sequester the promoter of a floral identity gene ANANTHA to repress its expression. The reversible transcriptional condensation via redox-regulated phase separation endows aerobic organisms with the flexibility of gene control in dealing with developmental cues.

Loss of Function of an RNA Polymerase III Subunit Leads to Impaired Maize Kernel Development.

Kernel size is an important factor determining grain yield. Although a number of genes affecting kernel development in maize (Zea mays) have been identified by analyzing kernel mutants, most of the corresponding mutants cannot be used in maize breeding programs due to low germination or incomplete seed development. Here, we characterized small kernel7, a recessive small-kernel mutant with a mutation in the gene encoding the second-largest subunit of RNA polymerase III (RNAPΙΙΙ; NRPC2). A frame shift in ZmNRPC2 leads to a premature stop codon, resulting in significantly reduced levels of transfer RNAs and 5S ribosomal RNA, which are transcribed by RNAPΙΙΙ. Loss-of-function nrpc2 mutants created by CRISPR/CAS9 showed significantly reduced kernel size due to altered endosperm cell size and number. ZmNRPC2 affects RNAPIII activity and the expression of genes involved in cell proliferation and endoreduplication to control kernel development via physically interacting with RNAPIII subunits RPC53 and AC40, transcription factor class C1 and Floury3. Notably, unlike the semidominant negative mutant floury3, which has defects in starchy endosperm, small kernel7 only affects kernel size but not the composition of kernel storage proteins. Our findings provide novel insights into the molecular network underlying maize kernel size, which could facilitate the genetic improvement of maize in the future.

A Core Regulatory Pathway Controlling Rice Tiller Angle Mediated by the LAZY1-Dependent Asymmetric Distribution of Auxin.

Tiller angle in cereals is a key shoot architecture trait that strongly influences grain yield. Studies in rice (Oryza sativa) have implicated shoot gravitropism in the regulation of tiller angle. However, the functional link between shoot gravitropism and tiller angle is unknown. Here, we conducted a large-scale transcriptome analysis of rice shoots in response to gravistimulation and identified two new nodes of a shoot gravitropism regulatory gene network that also controls rice tiller angle. We demonstrate that HEAT STRESS TRANSCRIPTION FACTOR 2D (HSFA2D) is an upstream positive regulator of the LAZY1-mediated asymmetric auxin distribution pathway. We also show that two functionally redundant transcription factor genes, WUSCHEL RELATED HOMEOBOX6 (WOX6) and WOX11, are expressed asymmetrically in response to auxin to connect gravitropism responses with the control of rice tiller angle. These findings define upstream and downstream genetic components that link shoot gravitropism, asymmetric auxin distribution, and rice tiller angle. The results highlight the power of the high-temporal-resolution RNA-seq data set and its use to explore further genetic components controlling tiller angle. Collectively, these approaches will identify genes to improve grain yields by facilitating the optimization of plant architecture.

[De novo domestication to create new crops].

Crop improvement by domestication and traditional breeding often results in fitness penalties and loss of genetic diversity, which greatly threatens crop production and food security under the challenging global climate. De novo domestication has been proposed as a novel strategy for crop breeding. By combining multi-omics, genome editing and synthetic biology approaches, domestication of wild or semi-wild plant species can be accelerated by rapidly introducing desirable traits without causing an associated drag on their inherent traits. In this review, we summarize the history of crop domestication, emphasize the urgency for breeding strategy innovation, and discuss recent progress of de novo crop domestication.

Transient High-Glucose Stimulation Induces Persistent Inflammatory Factor Secretion from Rat Glomerular Mesangial Cells via an Epigenetic Mechanism.

BACKGROUND/AIMS: Diabetic nephropathy is the one of the most serious microvascular complications of diabetes mellitus, and "metabolic memory" plays a vital role in the development of diabetic complications. To investigate the effect of epigenetics on metabolic memory, we analyzed the impact of transient high-glucose stimulation on the secretion of inflammatory factors from rat glomerular mesangial cells. METHODS: Rat glomerular mesangial cells (HBZY-1) were divided into three groups: high-glucose group (25 mM glucose), hypertonic group (5.5 mM glucose+19.5 mM mannitol), and normal-glucose control group (5.5 mM glucose). Mesangial cells were cultured in high-glucose, hypertonic, and normal-glucose media for 24 h and transitioned to normal-glucose culture for 24, 48, and 72 h. Then, protein, mRNA, and supernatants were harvested. The expression of monomethylated H3K4 was determined by western blot analysis, and the expression of the NF-κB subunit p65 and histone methyltransferase set7/9 was determined by quantitative real-time PCR. The expression of monocyte chemoattractant protein 1 (MCP-1) and vascular cell adhesion molecule 1 (VCAM-1) was detected by an enzyme-linked immunosorbent assay. RESULTS: Compared with the control group, H3K4me1 expression was upregulated after transient high-glucose stimulation, gradually downregulated in the following 48 h (P < 0.05), and reached the level of the control group at 72 h (P > 0.05). The expression of set7/9 was increased after 24 h of high-glucose stimulation and the following 24 h and 48 h (P < 0.05); it then returned to the level of the control group at 72 h. Compared with the control group, the increased expression of p65, VCAM-1, and MCP-1 was sustained for at least 72 h in the high-glucose group. CONCLUSION: Transient high-glucose stimulation can induce the persistent secretion of inflammatory factors from rat glomerular mesangial cells via histone modification.

SENP1 regulates cell migration and invasion in neuroblastoma.

Neuroblastoma (NB) is an embryonic solid tumor derived from precursor cells of the sympathetic nervous system, and accounts for 11% of childhood cancers and around 15% of cancer deaths in children. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in diverse cancers. However, nothing is known about the role of SENPs in NBL. In the present study, we found that SENP1 expression was significantly high in metastatic NB tissues compared with primary NB tissues. Overexpression of SENP1 promoted NB cells migration and invasion. Inhibition of SENP1 could significantly suppress NB cell migration and invasion. Moreover, we found that SENP1 could regulate the expression of CDH1, MMP9, and MMP2. In summary, the data presented here indicate a significant role of SENP1 in the regulation of cell migration and invasion in NB and suppress SENP1 expression as promising candidates for novel treatment strategies of NB.

Long none coding RNA HOTTIP/HOXA13 act as synergistic role by decreasing cell migration and proliferation in Hirschsprung disease.

Long noncoding RNAs (lncRNAs) have been confirmed to be associated with various human diseases. However, whether they are associated with Hirschsprung disease (HSCR) progression remains unclear. In this study, we designed the experiment to explore the relationship between lncRNA HOTTIP and HOXA13, and their pathogenicity to HSCR. Quantitative real-time PCR and Western blot were performed to detect the levels of lncRNA, mRNAs, and proteins in colon tissues from 79 patients with HSCR and 79 controls. Small RNA interference transfection was used to study the function experiments in human 293T and SK-N-BE cell lines. The cell viability and activities were detected by the transwell assays, CCK8 assay, and flow cytometry, respectively. LncRNA HOTTIP and HOXA13 were significantly down-regulated in HSCR compared to the controls. Meanwhile, the declined extent of their expression levels makes sense between two main phenotype of HSCR. SiRNA-mediated knock-down of HOTTIP or HOXA13 correlated with decreased levels of each other and both reduced the cell migration and proliferation without affecting cell apoptosis or cell cycle. Our study demonstrates that aberrant reduction of HOTTIP and HOXA13, which have a bidirectional regulatory loop, may play an important role in the pathogenesis of HSCR.

Miniature spectrometer based on diffraction in a dispersive hole array.

We present an ultra-compact spectrometer that uses a 10×10 hole array as the dispersive component. Our analysis shows that the two-dimensional intensity distribution can be modeled by a system of simultaneous linear equations when the size of each hole in the dispersive component has been pre-designed appropriately. One can readily recover the spectral contents of the input radiation by solving the linear equation system with regularized procedure. Experimental results show that the reconstruction range is at least within the entire visible band, which can be further extended if a near-infrared CCD is used. One therefore envisions strong potential for many wavelength analysis applications.

The estrogenic activity of isoflavones extracted from chickpea Cicer arietinum L sprouts in vitro.

Isoflavones have drawn attention due to their potential therapeutic use. Isoflavones are the important chemical components of the seeds and sprouts of chickpea and higher isoflavones in sprouts than in seeds. However, there have been no previous reports of the estrogenic activity of isoflavones extracted from chickpea Cicer arietinum L sprouts (ICS) in vitro. In this study, which incorporated several in vitro bioassays methods, we systematically evaluated the estrogenic properties of ICS. MTT assay showed that ICS at the low concentration ranges (10(-3)-1 mg/L) promoted MCF-7 cell growth, while at high concentrations, (>1 mg/L) inhibited cell proliferation, indicating ICS worked at a diphasic mechanism. Flow cytometric analysis further calculated the proliferation rate of ICS at low concentration (1 mg/L). ERα/Luc trans-activation assay and then semi-quantitative RT-PCR analysis indicated that ICS at low concentrations induced ERα-mediated luciferase activity in MCF-7 cells and promoted the ER downstream target gene pS2 and PR trans-activation. These effects were inhibited by ICI 182,780, a special antagonist of ER, indicating that an ER-mediating pathway was involved. Alkaline phosphatase (AP) expression in Ishikawa cells showed that ICS at low concentrations stimulated AP expression. Our current study is the first to demonstrate that ICS has significant estrogenic activity in vitro. ICS may be useful as a supplement to hormone replacement therapy and in dietary supplements.

Molecular regulation of tomato male reproductive development.

The reproductive success of flowering plants, which directly affects crop yield, is sensitive to environmental changes. A thorough understanding of how crop reproductive development adapts to climate changes is vital for ensuring global food security. In addition to being a high-value vegetable crop, tomato is also a model plant used for research on plant reproductive development. Tomato crops are cultivated under highly diverse climatic conditions worldwide. Targeted crosses of hybrid varieties have resulted in increased yields and abiotic stress resistance; however, tomato reproduction, especially male reproductive development, is sensitive to temperature fluctuations, which can lead to aborted male gametophytes, with detrimental effects on fruit set. We herein review the cytological features as well as genetic and molecular pathways influencing tomato male reproductive organ development and responses to abiotic stress. We also compare the shared features among the associated regulatory mechanisms of tomato and other plants. Collectively, this review highlights the opportunities and challenges related to characterizing and exploiting genic male sterility in tomato hybrid breeding programs.

Progress on the Mechanism of Visceral Hypersensitivity in Nonerosive Reflux Disease.

Nonerosive reflux disease (NERD) is the most common type of gastroesophageal reflux disease (GERD). Its clinical symptoms can recur, and clinical treatment is often ineffective, causing patients severe economic and psychological burden. In recent years, studies that have explored in-depth the pathogenesis of NERD have found that visceral hypersensitivity (VH) plays an important role. VH refers to the phenomenon that viscera react strongly to nociceptive stimuli or produce a negative reaction to physiological stimuli due to the decrease of one's visceral pain threshold. Studies have found that the VH mechanism in NERD primarily includes abnormal neurotransmitters, the activation of acid-sensitive receptors, and abnormal psychological factors-all of which we review in this article.

Drugs used in regional block analgesia for thyroidectomy: A network meta-analysis of randomized controlled trials.

BACKGROUND: Postoperative pain has become one of the major obstacles to postoperative recovery and can lead to increasing demand for opioids. So far, a wide variety of drugs is used for regional block anesthesia, but which one is the best remains unclear. Thus, this study aims to obtain the best drug for thyroid surgery regional block based on their efficacy and side effects through Bayesian network meta-analysis. METHODS: Systemically searched MEDLINE, CENTRAL, Embase, and web of science on July 3, 2021 to obtain randomized controlled trials (RCTs) focusing on adults who underwent open thyroidectomy and regional blocks, and took opioids requirement, and the postoperative pain level as outcomes. The "Gemtc" package of R-4.1.1 was used for Bayesian network meta-analysis based on extracted data. RESULTS: We retrieved 398 articles, and finally included 31 RCTs, which included a total of 2221 patients. Patients received levobupivacaine had the lowest requirement rate for opioids and lowest pain score at T6 and T12. Non-steroidal anti-inflammatory drugs show significant superiority neither in the opioids requirement nor the pain score. Clonidine has a better potential to act as a qualified anesthetic adjuvant compared to adrenaline. The ranking results of the subgroup analysis were consistent with the integrated analysis. CONCLUSION: Levobupivacaine has a relatively greater advantage in reducing opioids requirement and decreasing the pain score of patients, and bilateral superficial cervical plexus blockade and pre thyroidectomy intervention have more advantages than local wound infiltration and post thyroidectomy intervention in alleviating patients' pain.

Dynamic evolution of small signalling peptide compensation in plant stem cell control.

Gene duplications are a hallmark of plant genome evolution and a foundation for genetic interactions that shape phenotypic diversity1-5. Compensation is a major form of paralogue interaction6-8 but how compensation relationships change as allelic variation accumulates is unknown. Here we leveraged genomics and genome editing across the Solanaceae family to capture the evolution of compensating paralogues. Mutations in the stem cell regulator CLV3 cause floral organs to overproliferate in many plants9-11. In tomato, this phenotype is partially suppressed by transcriptional upregulation of a closely related paralogue12. Tobacco lost this paralogue, resulting in no compensation and extreme clv3 phenotypes. Strikingly, the paralogues of petunia and groundcherry nearly completely suppress clv3, indicating a potent ancestral state of compensation. Cross-species transgenic complementation analyses show that this potent compensation partially degenerated in tomato due to a single amino acid change in the paralogue and cis-regulatory variation that limits its transcriptional upregulation. Our findings show how genetic interactions are remodelled following duplications and suggest that dynamic paralogue evolution is widespread over short time scales and impacts phenotypic variation from natural and engineered mutations.

Heterotypic transcriptional condensates formed by prion-like paralogous proteins canalize flowering transition in tomato.

BACKGROUND: Paralogs that arise from gene duplications during genome evolution enable genetic redundancy and phenotypic robustness. Variation in the coding or regulatory sequence of paralogous transcriptional regulators diversifies their functions and relationships, which provides developmental robustness against genetic or environmental perturbation. The fate transition of plant shoot stem cells for flowering and reproductive success requires a robust transcriptional control. However, how paralogs function and interact to achieve such robustness is unknown. RESULTS: Here, we explore the genetic relationship and protein behavior of ALOG family transcriptional factors with diverse transcriptional abundance in shoot meristems. A mutant spectrum covers single and higher-order mutant combinations of five ALOG paralogs and creates a continuum of flowering transition defects, showing gradually enhanced precocious flowering, along with inflorescence simplification from wild-type-like to progressively fewer flowers until solitary flower with sterile floral organs. Therefore, these paralogs play unequal roles and act together to achieve a robust genetic canalization. All five proteins contain prion-like intrinsically disordered regions (IDRs) and undergo phase separation. Accumulated mutations following gene duplications lead to IDR variations among ALOG paralogs, resulting in divergent phase separation and transcriptional regulation capabilities. Remarkably, they retain the ancestral abilities to assemble into a heterotypic condensate that prevents precocious activation of the floral identity gene ANANTHA. CONCLUSIONS: Our study reveals a novel genetic canalization mechanism enabled by heterotypic transcriptional condensates formed by paralogous protein interactions and phase separation, uncovering the molecular link between gene duplication caused IDR variation and robust transcriptional control of stem cell fate transition.

Intraoperative assessment of bone viability through improved analysis and visualization of dynamic contrast-enhanced fluorescence imaging: technique report.

Bone devitalization is believed to be a critical determinant of complications such as infection or nonunion. However, intraoperative assessment of bone devitalization, particularly in open fractures and infections, remains highly subjective resulting in variation in treatment. Optical imaging tools, particularly dynamic contrast-enhanced fluorescence imaging, can provide real-time, intraoperative assessment of bone and soft tissue perfusion, which informs the tissues' ability to heal and fight infection. We describe a novel technique to apply indocyanine green-based fluorescence imaging, using a device that is frequently used in the operating room to assess skin or flap perfusion in plastic surgery, to assess bone and deep tissue perfusion in three pertinent cases: (1) a chronic infection/nonunion after a Gustilo type 3A tibia fracture (patient 1), (2) an acute Gustilo type 3C tibia open fracture with extensive degloving/soft tissue stripping (patient 2), and (3) an atrophic nonunion of the humerus (patient 3). In all three cases, fluorescence imaging (both time-specific fluorescence and maximum fluorescence) and derived kinetic maps of time-to-peak, ingress slope, and egress slope demonstrated clear spatial variation in perfusion that corresponded to the patient pathogenesis. The impact of this information on patient outcome will need to be evaluated in future clinical trials; however, these cases demonstrate in principle that optical imaging information has the potential to inform surgical practice, reduce the variation in treatment, and improve outcomes observed in these challenging patients.

[Involvement of quorum-sensing in biosynthesis of polyhydroxyalkanoates in Pseudomonas aeruginosa].

UNLABELLED: Quorum-sensing (QS) is a regulatory mechanism with which bacteria regulate the gene expression according to their population density. Pseudomonas aeruginosa regulates the expression of multiple genes via a hierarchical quorum-sensing cascade through LasR and RhlR and their cognate signal molecules N-(3-oxododecanoyl)-L-homoserine lactone (30-C12-HSL) and N-(butanoyl)-L-homoserine lactone (C4-HSL). OBJECTIVE: It aims to explore the regulation of QS on biosynthesis of polyhydroxyalkanoates (PHA) in P. aeruginosa. METHODS: Wild-type P. aeruginosa PA01 and its QS mutants were used to investigate the effects of quorum-sensing on biosynthesis of PHA by GC and real-time PCR at physiological and molecular level. RESULTS: After treated with QS signal molecule synthesis inhibitor azithromycin, the accumulation of PHA significantly decreased in P. aeruginosa PA01 and its QS mutant strains. The content of PHA in C4-HSL synthase gene rhlI mutant strain PA0210 had no significant difference compared with that of the wild type. However, the PHA contents were significantly affected in 30C12-HSL synthase gene lasl mutant strain PA055, 30C12-HSL transcriptional regulator gene lasR mutant strain PA056 and lasI/lasR double mutant strain PA057. PHA synthase gene phaC1 expression exhibited a significant reduction in lasI mutant and lasR mutant strains. 30C12-HSL signal molecules complementary experiment shows that the expression of phaC1 can be recovered to the level of the wild type, but the synthesis of PHA is only partially restored in lasI mutant strain. CONCLUSION: The results implicates that lasI/lasR system might be involved in the regulation of intracellular PHA biosynthesis in P. aeruginosa PA01.

Controlling the thermally activated delayed fluorescence of axially chiral organic emitters and their racemate for information encryption.

A pair of axially chiral organic enantiomers were facilely prepared through a one-pot sequential synthesis. They exhibit circularly polarized luminescence activities and have thermally activated delayed fluorescence (TADF) and aggregation-induced emission enhancement properties. Meanwhile, these two enantiomers present remarkable and reversible thermochromism in the crystalline state, enabling dual-colour TADF switching between orange and red. However, when they form cocrystals, the resulting racemate shows opposite thermochromic behaviors. These intriguing results probably emanate from their different optical activities, leading to distinct molecular packing modes and molecular conformation variations. Moreover, information encryption based on thermochromism of organic enantiomers and their racemate has been presented for the first time. This work may expand the application scope of chiral organic luminogens and pave a new way to construct intelligent luminescent systems.