Piezo1 Promotes Osteogenesis Through CaMKII Signalling in a Rat Maxillary Expansion Model.

OBJECTIVES: Rapid maxillary expansion (RME) is a widely used technique to treat maxillary transverse deficiency. Piezo1 is a cation channel that is activated by mechanical force and regulates bone formation. This study aims to elucidate the role of Piezo1 in bone remodelling during the RME process. MATERIALS AND METHODS: In this study, the periosteal-derived stem cells (PDSCs) were cultured and stretched by the Flexcell system. The effects of Piezo1 on osteogenesis were assessed via RNA sequencing, real-time quantitative PCR, and western blot analyses. Moreover, for in vivo analyses, the rat RME model was established. The function of Piezo1 in mid-palatal suture bone remodelling was evaluated using micro-CT, haematoxylin-eosin (HE) staining, and immunohistochemistry analyses. RESULTS: It was revealed that under tension force, the osteogenic factors (Runt-related transcription factor 2, Osterix, and Alkaline Phosphatase) and Ca2+/calmodulin -dependent protein kinase (CaMKII) were significantly enhanced in PDSCs over time. Furthermore, these were also upregulated in the RME model with the expansion of the mid-palatal suture. However, Piezo1 inhibition by Grammostola spatulata mechanotoxin 4 downregulated the levels of these factors in the RME model. CONCLUSIONS: This study indicated that Piezo1 is associated with the osteogenesis of PDSCs and bone remodelling in the RME process. CaMKII might also participate in this process.

Targeting non-muscle myosin II inhibits proliferative vitreoretinopathy through regulating epithelial-mesenchymal transition.

Proliferative vitreoretinopathy (PVR) is a common complication of rhegmatogenous retinal detachment, eventually leading to vision loss. To date, there are no effective drugs for the treatment of this disease. In this study, we investigated the effect of blebbistatin, a non-muscle myosin II inhibitor, on the ARPE-19 cell line and in a rabbit model of proliferative vitreoretinopathy. In vitro, we found that blebbistatin inhibited the epithelial-mesenchymal transition of retinal pigment epithelial (RPE) cells and inhibited the ability of RPE cells to migrate, proliferate, generate extracellular matrix, and affect contractility. In vivo the PVR model showed that blebbistatin significantly delayed PVR progression. It also partially prevents the loss of retinal function caused by PVR. Our results suggest that blebbistatin is a potential drug with clinical applications for the treatment of PVR.

The role of cyanoalanine synthase and alternative oxidase in promoting salt stress tolerance in Arabidopsis thaliana.

BACKGROUND: Cyanide is a toxic chemical that inhibits cellular respiration. In plants, cyanide can be produced by themselves, especially under stressful conditions. Cyanoalanine synthase (CAS) is a key enzyme involved in plant cyanide detoxification. There are three genes encoding CAS in Arabidopsis thaliana, but the roles of these genes in the plant's response to stress are less studied. In addition, it is known that alternative oxidase (AOX) mediates cyanide-resistant respiration, but the relationship between CAS and AOX in regulating the plant stress response remains largely unknown. RESULTS: Here, the effects of the overexpression or mutation of these three CAS genes on salt stress tolerance were investigated. The results showed that under normal conditions, the overexpression or mutation of the CAS genes had no significant effect on the seed germination and growth of Arabidopsis thaliana compared with wild type (WT). However, under 50, 100, and 200 mM NaCl conditions, the seeds overexpressing CAS genes showed stronger salt stress resistance, i.e., higher germination speed than WT seeds, especially those that overexpressed the CYS-C1 and CYS-D1 genes. In contrast, the seeds with CAS gene mutations exhibited salt sensitivity, and their germination ability and growth were significantly damaged by 100 and 200 mM NaCl. Importantly, this difference in salt stress resistance became more pronounced in CAS-OE, WT, and mutant seeds with increasing salt concentration. The CAS-OE seeds maintained higher respiration rates than the WT and CAS mutant seeds under salt stress conditions. The cyanide contents in CAS mutant seeds were approximately 3 times higher than those in WT seeds and more than 5 times higher than those in CAS-OE seeds. In comparison, plants overexpressing CYS-C1 had the fastest detoxification of cyanide and the best salt tolerance, followed by those overexpressing CYS-D1 and CYS-D2. Furthermore, less hydrogen sulfide (H2S) was observed in CAS-OE seedlings than in WT seedlings under long-term salt stress conditions. Nonetheless, the lack of AOX impaired CAS-OE-mediated plant salt stress resistance, suggesting that CAS and AOX interact to improve salt tolerance is essential. The results also showed that CAS and AOX contributed to the reduction in oxidative damage by helping maintain relatively high levels of antioxidant enzyme activity. CONCLUSION: In summary, the findings of the present study suggest that overexpression of Arabidopsis CAS family genes plays a positive role in salt stress tolerance and highlights the contribution of AOX to CAS-mediated plant salt resistance, mainly by reducing cyanide and H2S toxicity.

Transcriptional profiling of long noncoding RNAs associated with flower color formation in Ipomoea nil.

MAIN CONCLUSION: LncRNAs regulate flower color formation in Ipomoea nil via vacuolar pH, TCA cycle, and oxidative phosphorylation pathways. The significance of long noncoding RNA (lncRNA) in diverse biological processes is crucial in plant kingdoms. Although study on lncRNAs has been extensive in mammals and model plants, lncRNAs have not been identified in Ipomoea nil (I. nil). In this study, we employed whole transcriptome strand-specific RNA sequencing to identify 11,203 expressed lncRNA candidates, including 961 known lncRNA and 10,242 novel lncRNA in the I. nil genome. These lncRNAs in I. nil had fewer exons and were generally shorter in length compared to mRNA genes. Totally, 1141 different expression lncRNAs (DELs) were significantly identified between white and red flowers. The functional analysis indicated that lncRNA-targeted genes were enriched in the TCA cycle, photosynthesis, and oxidative phosphorylation-related pathway, which was also found in differentially expressed genes (DEGs) functional enrichments. LncRNAs can regulate transcriptional levels through cis- or trans-acting mechanisms. LncRNA cis-targeted genes were significantly enriched in potassium and lysosome. For trans-lncRNA, two energy metabolism pathways, TCA cycles and oxidative phosphorylation, were identified from positive association pairs of trans-lncRNA and mRNA. This research advances our understanding of lncRNAs and their role in flower color development, providing valuable insights for future selective breeding of I. nil.

New insights into the role of cyanide in the promotion of seed germination in tomato.

BACKGROUND: Cyanide is a natural metabolite that exists widely in plants, and it is speculated to be involved in the regulation of various growth and development processes of plants in addition to being regarded as toxic waste. Previous studies have shown that exogenous cyanide treatment helps to improve seed germination, but the mechanism is still unclear. In this study, tomato (Solanum lycopersicum cv. Alisa Craig) was used as the material, and the effects of cyanide pretreatment at different concentrations on tomato seed germination were investigated. RESULTS: The results showed that exogenous application of a lower concentration of cyanide (10 µmol/L KCN) for 12 h strongly increased the tomato seed germination rate. RNA-Seq showed that compared with the control, a total of 15,418 differentially expressed genes (P<0.05) were obtained after pretreatment with KCN for 12 h, and in the next 12 h, a total of 13,425 differentially expressed genes (P<0.05) were regulated. GO and KEGG analyses demonstrated that exogenous KCN pretreatment was involved in regulating the expression (mainly downregulation) of seed storage proteins, thereby accelerating the degradation of stored proteins for seed germination. In addition, KCN pretreatment was also involved in stimulating glycolysis, the TCA cycle and oxidative phosphorylation. Notably, it is shown that KCN acted on the regulation of plant hormone biosynthesis and perception, i.e., down-regulated the gene expression of ABA biosynthesis and signal transduction, but up-regulated the expression of genes related to GA biosynthesis and response. Consistent with this, plant hormone measurements confirmed that the levels of ABA were reduced, but GA levels were induced after pretreatment with KCN. CONCLUSION: These findings provide new insights into the regulation of seed germination by cyanide, that is cyanide-mediated seed germination occurs in a time- and dose-dependent manner, and is related to the mobilization of energy metabolism and the regulation of some plant hormone signals.

Highly sensitive metal ion sensing by graphene oxide functionalized micro-tapered long-period fiber grating.

An accurate as well as highly sensitive label-free chemical sensing platform for the detection of various metal ions was demonstrated. The chemical sensor was derived from the micro-tapered long-period fiber grating (MLPG) by depositing graphene oxide (GO) by chemical-bonding and optical-tweezer effects. The enhancement in refractive index (RI) sensitivity as well as reusability was obtained by evaluating the deposition thickness in the range of approximately 97.7 to 158.9 nm. Based on the analysis of adsorption principles, the enhanced RI sensitivity leads to a limit of detection as low as 3.2 ppb. The highest sensitivities for the cases studied using sodium and manganese ions in a wide concentration range of 1 ppb to 1 × 106 ppb are respectively 2.2 × 10-3 dB per ppb and 3.2 × 10-3 dB per ppb. Mixture samples were also studied to evaluate the properties of sensing the doped ions. This demonstration of GO modified MLPG is bound to find potential applications that require sensing of mixed samples and illustrates significant importance in developing cost-effective, label-free, reusable, and real-time chemical sensors.

Integrative analysis of transcriptome and proteome provides insights into adaptation to cadmium stress in Sedum plumbizincicola.

Sedum plumbizincicola, a cadmium (Cd) hyperaccumulating herbaceous plant, can accumulate large amounts of Cd in the above-ground tissues without being poisoned. However, the molecular mechanisms regulating the processes are not fully understood. In this study, Transcriptional and proteomic analyses were integrated to investigate the response of S. plumbizincicola plants to Cd stress and to identify key pathways that are potentially responsible for Cd tolerance and accumulation. A total of 630 DAPs (differentially abundant proteins, using fold change >1.5 and adjusted p-value <0.05) were identified from Tandem Mass Tag (TMT)- based quantitative proteomic profiling, which were enriched in processes including phenylpropanoid biosynthesis, protein processing in endoplasmic reticulum, and biosynthesis of secondary metabolites. Combined with the previous transcriptomic study, 209 genes and their corresponding proteins showed the identical expression pattern. The identified genes/proteins revealed the potential roles of several metabolism pathways, including phenylpropanoid biosynthesis, oxidative phosphorylation, phagosome, and glutathione metabolism, in mediating Cd tolerance and accumulation. Lignin staining and Cd accumulation assay of the transgenic lines over-expressing a selected Cd up-regulated gene SpFAOMT (Flavonoid 3',5'-methyltransferase) showed its functions in adapting to Cd stress, and provided insight into its role in lignin biosynthesis and Cd accumulation in S. plumbizincicola during Cd stress.

MAPK Cascades and Transcriptional Factors: Regulation of Heavy Metal Tolerance in Plants.

In nature, heavy metal (HM) stress is one of the most destructive abiotic stresses for plants. Heavy metals produce toxicity by targeting key molecules and important processes in plant cells. The mitogen-activated protein kinase (MAPK) cascade transfers the signals perceived by cell membrane surface receptors to cells through phosphorylation and dephosphorylation and targets various effector proteins or transcriptional factors so as to result in the stress response. Signal molecules such as plant hormones, reactive oxygen species (ROS), and nitric oxide (NO) can activate the MAPK cascade through differentially expressed genes, the activation of the antioxidant system and synergistic crosstalk between different signal molecules in order to regulate plant responses to HMs. Transcriptional factors, located downstream of MAPK, are key factors in regulating plant responses to heavy metals and improving plant heavy metal tolerance and accumulation. Thus, understanding how HMs activate the expression of the genes related to the MAPK cascade pathway and then phosphorylate those transcriptional factors may allow us to develop a regulation network to increase our knowledge of HMs tolerance and accumulation. This review highlighted MAPK pathway activation and responses under HMs and mainly focused on the specificity of MAPK activation mediated by ROS, NO and plant hormones. Here, we also described the signaling pathways and their interactions under heavy metal stresses. Moreover, the process of MAPK phosphorylation and the response of downstream transcriptional factors exhibited the importance of regulating targets. It was conducive to analyzing the molecular mechanisms underlying heavy metal accumulation and tolerance.

Association between periodontal status and degree of maxillary sinus mucosal thickening: a retrospective CBCT study.

BACKGROUND: It is well known that periodontitis can stimulate thickening of the maxillary sinus mucosa, but the association between periodontitis status and the degree of maxillary sinus mucosal thickening (maxMT) has not been reported. The objectives of this study were to investigate the effect of periodontal status of maxillary molars on the degree of maxMT. METHODS: Retrospective analysis of cone-beam computed tomographic (CBCT) images of 203 periodontitis cases with maxMT. Parameters related to periodontitis in maxillary molars were measured and recorded on CBCT images. The dimension and length of the maxMT were also recorded. Multiple linear regression analysis was used to identify periodontal factors influencing the severity of maxMT, and multivariate logistic regression analysis was used to identify the odds ratio of these factors. RESULTS: The factors affecting the degree of maxMT were mainly the amount of alveolar bone loss (ABL) and the minimum residual alveolar bone height (miniRABH). Compared to mild ABL, severe and moderate ABL were more likely to display severe maxMT. And the lower the miniRABH, the more severe the maxMT. CONCLUSIONS: The severity of periodontal status of maxillary molars can influence the degree of maxMT.

Binary amplitude-only image reconstruction through a MMF based on an AE-SNN combined deep learning model.

The obstacle of imaging through multimode fibers (MMFs) is encountered due to the fact that the inherent mode dispersion and mode coupling lead the output of the MMF to be scattered and bring about image distortions. As a result, only noise-like speckle patterns can be formed on the distal end of the MMF. We propose a deep learning model exploited for computational imaging through an MMF, which contains an autoencoder (AE) for feature extraction and image reconstruction and self-normalizing neural networks (SNNs) sandwiched and employed for high-order feature representation. It was demonstrated both in simulations and in experiments that the proposed AE-SNN combined deep learning model could reconstruct image information from various binary amplitude-only targets going through a 5-meter-long MMF. Simulations indicate that our model works effectively even in the presence of system noise, and the experimental results prove that the method is valid for image reconstruction through the MMF. Enabled by the spatial variability and the self-normalizing properties, our model can be generalized to solve varieties of other computational imaging problems.

Novel rice mutants overexpressing the brassinosteroid catabolic gene CYP734A4.

KEY MESSAGE: Moderate overexpression of CYP734A4 improves grain number per main panicle and seed setting rate. Brassinosteroid (BR) homeostasis and signaling are crucial for plant growth and development. CYP734A genes encode cytochrome P450 monooxygenases that control the level of bioactive BRs by degrading BRs. However, fertile plants overexpressing CYP734As have not been reported in rice. Here, we isolated a novel semi-dominant mutant brd3-D, in which T-DNA was inserted approximately 4 kb upstream of the CYP734A4 gene (GenBank Accession AB488667), causing its overexpression. The mutant is characterized by dwarfism, small grains, and erect leaves and is less sensitive to brassinolide-induced lamina joint inclination and primary root elongation. However, increased grain number per main panicle and improved seed setting rate were also found in heterozygous brd3-D. To our knowledge, these traits have not been reported in other BR deficient mutants. Quantitative real-time PCR analysis indicated that phenotypic severity of the brd3-D mutant is positively correlated with the CYP734A4 transcription level. In accordance with the increased expression of CYP734A4, a lower castasterone (a rice BR) content was detected in the brd3-D mutants. Knockout of brd3-D by using the CRISPR/Cas9 system rescued the mutation. In addition, transgenic plants overexpressing CYP734A4 with the 35S enhancer mimicked the brd3-D phenotypes, confirming that moderate overexpression of the CYP734A4 gene can improve grain number per main panicle and the seed setting rate in rice. Further studies showed that overexpression of CYP734A4 influences the expressions of multiple genes involved in the BR pathway, and the expression of CYP734A4 is induced by exogenous brassinolide, confirming the negative regulatory role of CYP734A4 in the BR pathway. CYP734A4 might provide a useful gene resource for developing new high-yielding rice varieties.

[Protective effects of Purα on rat hippocampus DNA damage induced by epilepsy].

OBJECTIVE: To investigate the protective effects of Purα protein on rat hippocampus DNA damage induced by epilepsy and the effects of Purα protein on the repair of DNA damage. METHODS: The Purα overexpressing and siRNA lentiviruses were packaged in vitro and the high tittered virion was injected into rat hippocampus guided by stereotaxic apparatus. 14 days later after the lentivirus injection, epileptic onset is induced by intraperitoneal injection of pilocarpine. The experimental animals were executed 1 hour after the epileptic onset and the hippocampus samples were collected for immunohistochemical staining and Western blotting assay was used to examine the pertinent protein expression to investigate the protective effects of Purα on DNA damage and repair. RESULTS: Immunohistochemical analysis demonstrated that γH2AX, a signal protein of DNA damage, expressed in rat hippocampal CA1 region. 20 slides of rat hippocampal CA1 region with the same background and position were chosen for γH2AX positive staining cell analysis with image analysis software iPP6.0 and the cells with positive staining were selected to evaluate the average optical density. Compared with empty vector group (0.40 ± 0.11) and control group (0.42 ± 0.05), the number of positive staining cells in Purα overexpression group (0.15 ± 0.05) was significantly decreased (P < 0.01), while the number increased in Purα silence group (0.68 ± 0.06) (P < 0.01). Western blotting analysis showed, compared with empty vector group (0.93 ± 0.11) and control group (1.00 ± 0.00), that the expression levels of proteins related to the DNA repair such as parp-1, was much lower in Purα overexpression group (0.17 ± 0.09), while it increased in Purα silence group (P < 0.01). CONCLUSION: The DNA damage can occur in the early stage of epilepsy onset, and Purα protein can protect the DNA damage caused by epilepsy and also participate in the repair process of DNA damage.

A Case of Rapidly Diagnosed Mycobacterium intracellulare in a Frail Geriatric Patient With Multimorbidity.

The prevalence of non-tuberculous mycobacteria (NTM) infections has been on the rise in recent years, especially among the elderly population and other immunocompromised groups. Risk factors for NTM infections include advanced age, preexisting pulmonary diseases, and low body mass index. This study presents a case of NTM pulmonary disease attributed to Mycobacterium intracellulare, which was rapidly identified using metagenomic next-generation sequencing (mNGS). An 82-year-old male presented with persistent fever, cough, and shortness of breath. Initial assessments revealed an elevated white blood cell count and high-sensitivity C-reactive protein, with chest CT showing newly formed nodular shadows and cavity formation. Sputum tests confirmed NTM infection through positive acid-fast staining and mNGS, which rapidly identified M. intracellulare within 48 hours. Subsequent sputum samples confirmed the diagnosis using traditional methods. The patient had a complex medical history, including pulmonary tuberculosis, chronic pancreatitis, chronic hepatitis B, diabetes, and malnutrition. The patient was treated with a combination of cefotaxime, moxifloxacin, clarithromycin, and acetylcysteine, in addition to receiving nutritional support. After the treatment, there was an improvement in symptoms, normalization of body temperature, and a decrease in cough and sputum production. This case highlights the significance of mNGS in promptly diagnosing and treating NTM pulmonary disease, especially in elderly patients with various underlying health conditions. The collaborative effort among different medical specialties enabled more thorough patient care, ultimately leading to better outcomes. Incorporating cutting-edge diagnostic techniques such as mNGS alongside a holistic treatment approach is crucial for the successful management of NTM infections in at-risk populations.

SpSIZ1 from hyperaccumulator Sedum plumbizincicola orchestrates SpABI5 to fine-tune cadmium tolerance.

Sedum plumbizincicola is a renowned hyperaccumulator of cadmium (Cd), possesses significant potential for eco-friendly phytoremediation of soil contaminated with Cd. Nevertheless, comprehension of the mechanisms underpinning its Cd stress response remains constrained, primarily due to the absence of a comprehensive genome sequence and an established genetic transformation system. In this study, we successfully identified a novel protein that specifically responds to Cd stress through early comparative iTRAQ proteome and transcriptome analyses under Cd stress conditions. To further investigate its structure, we employed AlphaFold, a powerful tool for protein structure prediction, and found that this newly identified protein shares a similar structure with Arabidopsis AtSIZ1. Therefore, we named it Sedum plumbizincicola SIZ1 (SpSIZ1). Our study revealed that SpSIZ1 plays a crucial role in positively regulating Cd tolerance through its coordination with SpABI5. Overexpression of SpSIZ1 significantly enhanced plant resistance to Cd stress and reduced Cd accumulation. Expression pattern analysis revealed higher levels of SpSIZ1 expression in roots compared to stems and leaves, with up-regulation under Cd stress induction. Importantly, overexpressing SpSIZ1 resulted in lower Cd translocation factors (Tfs) but maintained relatively constant Cd levels in roots under Cd stress, leading to enhanced Cd stress resistance in plants. Protein interaction analysis revealed that SpSIZ1 interacts with SpABI5, and the expression of genes responsive to abscisic acid (ABA) through SpABI5-dependent signaling was significantly up-regulated in SpSIZ1-overexpressing plants with Cd stress treatment. Collectively, our results illustrate that SpSIZ1 interacts with SpABI5, enhancing the expression of ABA downstream stress-related genes through SpABI5, thereby increasing Cd tolerance in plants.

Genome-wide identification of bHLH gene family and its response to cadmium stress in Populus × canescens.

The basic helix-loop-helix (bHLH) gene family is integral to various aspects of plant development and the orchestration of stress response. This study focuses on the bHLH genes within Populus × canescens, a poplar species noted for its significant tolerance to cadmium (Cd) stress. Through our comprehensive genomic analysis, we have identified and characterized 170 bHLH genes within the P. canescens genome. These genes have been systematically classified into 22 distant subfamilies based on their evolutionary relationships. A notable conservation in gene structure and motif compositions were conserved across these subfamilies. Further analysis of the promoter regions of these genes revealed an abundance of essential cis-acting element, which are associated with plant hormonal regulation, development processes, and stress response pathway. Utilizing quantitative PCR (qPCR), we have documented the differential regulation of PcbHLHs in response to elevated Cd concentrations, with distinct expression patterns observed across various tissues. This study is poised to unravel the molecular mechanism underpinning Cd tolerance in P. canescens, offering valuable insights for the development of new cultivars with enhanced Cd accumulation capacity and tolerance. Such advancements are crucial for implementing effective phytoremediation strategies to mitigate soil pollution caused by Cd.

SpCTP3 from the hyperaccumulator Sedum plumbizincicola positively regulates cadmium tolerance by interacting with SpMDH1.

Cadmium (Cd) is a heavy metal pollutant mainly originating from the discharge of industrial sewage, irrigation with contaminated water, and the use of fertilizers. The phytoremediation of Cd polluted soil depends on the identification of the associated genes in hyperaccumulators. Here, a novel Cd tolerance gene (SpCTP3) was identified in hyperaccumulator Sedum plumbizincicola. The results of Cd2+ binding and thermodynamic analyses, revealed the CXXC motif in SpCTP3 functions is a Cd2+ binding site. A mutated CXXC motif decreased binding to Cd by 59.93%. The subcellular localization analysis suggested that SpCTP3 is primarily a cytoplasmic protein. Additionally, the SpCTP3-overexpressing (OE) plants were more tolerant to Cd and accumulated more Cd than wild-type Sedum alfredii (NHE-WT). The Cd concentrations in the cytoplasm of root and leaf cells were significantly higher (53.75% and 71.87%, respectively) in SpCTP3-OE plants than in NHE-WT. Furthermore, malic acid levels increased and decreased in SpCTP3-OE and SpCTP3-RNAi plants, respectively. Moreover, SpCTP3 interacted with malate dehydrogenase 1 (MDH1). Thus, SpCTP3 helps regulate the subcellular distribution of Cd and increases Cd accumulation when it is overexpressed in plants, ultimately Cd tolerance through its interaction with SpMDH1. This study provides new insights relevant to improving the Cd uptake by Sedum plumbizincicola.

Label-free and selective cholesterol detection based on multilayer functional structure coated fiber fabry-perot interferometer probe.

A reflective fiber-optic Fabry-Perot cavity probe sensor is proposed to selectively measure cholesterol concentration by insert single mode fiber into ceramic tube and immobilize epoxy resin (ER)/graphene oxide (GO)/beta-cyclodextrin (ß-CD) multi-layer film onto end face of ceramic tube. EDC/NHS activated GO is selected to form chemical binding with ß-CD, and ß-CD is the sensitive materials to bind with cholesterol molecules. With multi-layer film assisted, the sensitivity of sensor to cholesterol concentration can reach 3.92 nm/mM and the limit of detection reaches 3.48 µ M. In addition, 4 mM hemoglobin, glucose and ascorbic acid are doped into a set cholesterol sample and verified the highly selectivity of sensing cholesterol. Furthermore, the reproducibility was proved by measure the spectrum of four sensors with same fabrication process, and the reusability was also proved by repeated measurements. Overall, the sensor features with high mechanical strength, ease of fabrication, real-time monitoring, low cost and ease for measurement that given by probe structure. Therefore, the sensor provides a remarkable analytical platform for biosensing applications.

Contribution of the Tyrosinase (MoTyr) to Melanin Synthesis, Conidiogenesis, Appressorium Development, and Pathogenicity in Magnaporthe oryzae.

Dihydroxynapthalene-(DHN) and L-dihydroxyphenylalanine (L-DOPA) are two types of dominant melanin in fungi. Fungal melanins with versatile functions are frequently associated with pathogenicity and stress tolerance. In rice blast fungus, Magnaporthe oryzae, DHN melanin is essential to maintain the integrity of the infectious structure, appressoria; but the role of the tyrosinase-derived L-DOPA melanin is still unknown. Here, we have genetically and biologically characterized a tyrosinase gene (MoTyr) in M. oryzae. MoTyr encodes a protein of 719 amino acids that contains the typical CuA and CuB domains of tyrosinase. The deletion mutant of MoTyr (ΔMoTyr) was obtained by using a homologous recombination approach. Phenotypic analysis showed that conidiophore stalks and conidia formation was significantly reduced in ΔMoTyr. Under different concentrations of glycerol and PEG, more appressoria collapsed in the mutant strains than in the wild type, suggesting MoTyr is associated with the integrity of the appressorium wall. Melanin measurement confirmed that MoTyr loss resulted in a significant decrease in melanin synthesis. Accordingly, the loss of MoTyr stunted the conidia germination under stress conditions. Importantly, the MoTyr deletion affected both infection and pathogenesis stages. These results suggest that MoTyr, like DHN pigment synthase, plays a key role in conidiophore stalks formation, appressorium integrity, and pathogenesis of M. oryzae, revealing a potential drug target for blast disease control.

Genome-wide identification of chromatin regulators in Sorghum bicolor.

Chromatin regulators play important roles in plant development and stress response. In this study, we identified totally 231 chromatin regulators including 63 histones, 29 histone chaperones, 101 histone modification enzymes, and 38 chromatin remodeling factors from Sorghum bicolor (L.) Moench. Most of these chromatin regulators are homologous to their counterparts in Arabidopsis or rice. However, sorghum genome evolves a few novel histone variants specific to some grass species and a sorghum-unique chromatin remodeling factor that contain the domains belonging to the elongation factor EF-Tu and the histone chaperone SPT16. Finally, we performed co-expression analysis for the chromatin regulator-encoding genes by clustering the expression patterns of these genes. Our results provide useful information for the future studies on the mechanism of epigenetic regulation in sorghum and its roles in development and stress response. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03181-8.

Genome-Wide Characterization, Evolutionary Analysis of ARF Gene Family, and the Role of SaARF4 in Cd Accumulation of Sedum alfredii Hance.

Auxin response factors (ARFs) play important roles in plant development and environmental adaption. However, the function of ARFs in cadmium (Cd) accumulation are still unknown. Here, 23 SaARFs were detected in the genome of hyperaccumulating ecotype of Sedum alfredii Hance (HE), and they were not evenly distributed on the chromosomes. Their protein domains remained highly conservative. SaARFs in the phylogenetic tree can be divided into three groups. Genes in the group Ⅰ contained three introns at most. However, over ten introns were found in other two groups. Collinearity relationships were exhibited among ten SaARFs. The reasons for generating SaARFs may be segmental duplication and rearrangements. Collinearity analysis among different species revealed that more collinear genes of SaARFs can be found in the species with close relationships of HE. A total of eight elements in SaARFs promoters were related with abiotic stress. The qRT-PCR results indicated that four SaARFs can respond to Cd stress. Moreover, that there may be functional redundancy among six SaARFs. The adaptive selection and functional divergence analysis indicated that SaARF4 may undergo positive selection pressure and an adaptive-evolution process. Overexpressing SaARF4 effectively declined Cd accumulation. Eleven single nucleotide polymorphism (SNP) sites relevant to Cd accumulation can be detected in SaARF4. Among them, only one SNP site can alter the sequence of the SaARF4 protein, but the SaARF4 mutant of this site did not cause a significant difference in cadmium content, compared with wild-type plants. SaARFs may be involved in Cd-stress responses, and SaARF4 may be applied for decreasing Cd accumulation of plants.