Genome-edited powdery mildew resistance in wheat without growth penalties.

Disruption of susceptibility (S) genes in crops is an attractive breeding strategy for conferring disease resistance1,2. However, S genes are implicated in many essential biological functions and deletion of these genes typically results in undesired pleiotropic effects1. Loss-of-function mutations in one such S gene, Mildew resistance locus O (MLO), confers durable and broad-spectrum resistance to powdery mildew in various plant species2,3. However, mlo-associated resistance is also accompanied by growth penalties and yield losses3,4, thereby limiting its widespread use in agriculture. Here we describe Tamlo-R32, a mutant with a 304-kilobase pair targeted deletion in the MLO-B1 locus of wheat that retains crop growth and yields while conferring robust powdery mildew resistance. We show that this deletion results in an altered local chromatin landscape, leading to the ectopic activation of Tonoplast monosaccharide transporter 3 (TaTMT3B), and that this activation alleviates growth and yield penalties associated with MLO disruption. Notably, the function of TMT3 is conserved in other plant species such as Arabidopsis thaliana. Moreover, precision genome editing facilitates the rapid introduction of this mlo resistance allele (Tamlo-R32) into elite wheat varieties. This work demonstrates the ability to stack genetic changes to rescue growth defects caused by recessive alleles, which is critical for developing high-yielding crop varieties with robust and durable disease resistance.

GSK3 phosphorylates and regulates the Green Revolution protein Rht-B1b to reduce plant height in wheat.

The utilization of stabilized DELLA proteins Rht-B1b and Rht-D1b was crucial for increasing wheat (Triticum aestivum) productivity during the Green Revolution. However, the underlying mechanisms remain to be clarified. Here, we cloned a gain-of-function allele of the GSK3/SHAGGY-like kinase-encoding gene GSK3 by characterizing a dwarf wheat mutant. Furthermore, we determined that GSK3 interacts with and phosphorylates the Green Revolution protein Rht-B1b to promote it to reduce plant height in wheat. Specifically, phosphorylation by GSK3 may enhance the activity and stability of Rht-B1b, allowing it to inhibit the activities of its target transcription factors. Taken together, we reveal a positive regulatory mechanism for the Green Revolution protein Rht-B1b by GSK3, which might have contributed to the Green Revolution in wheat.

Q negatively regulates wheat salt tolerance through directly repressing the expression of TaSOS1 and reactive oxygen species scavenging genes.

The Q transcription factor plays important roles in improving multiple wheat domestication traits such as spike architecture, threshability and rachis fragility. However, whether and how it regulates abiotic stress adaptation remain unclear. We found that the transcriptional expression of Q can be induced by NaCl and abscisic acid treatments. Using the q mutants generated by CRISPR/Cas9 and Q overexpression transgenic lines, we showed that the domesticated Q gene causes a penalty in wheat salt tolerance. Then, we demonstrated that Q directly represses the transcription of TaSOS1-3B and reactive oxygen species (ROS) scavenging genes to regulate Na+ and ROS homeostasis in wheat. Furthermore, we showed that wheat salt tolerance protein TaWD40 interacts with Q to competitively interfere with the interaction between Q and the transcriptional co-repressor TaTPL. Taken together, our findings reveal that Q directly represses the expression of TaSOS1 and some ROS scavenging genes, thus causing a harmful effect on wheat salt tolerance.

Physical exercise in liver diseases.

Liver diseases contribute to ~2 million deaths each year and account for 4% of all deaths globally. Despite various treatment options, the management of liver diseases remains challenging. Physical exercise is a promising nonpharmacological approach to maintain and restore homeostasis and effectively prevent and mitigate liver diseases. In this review, we delve into the mechanisms of physical exercise in preventing and treating liver diseases, highlighting its effects on improving insulin sensitivity, regulating lipid homeostasis, and modulating immune function. In addition, we evaluate the impact of physical exercise on various liver diseases, including liver ischemia/reperfusion injury, cardiogenic liver disease, metabolic dysfunction-associated steatotic liver disease, portal hypertension, cirrhosis, and liver cancer. In conclusion, the review underscores the effectiveness of physical exercise as a beneficial intervention in combating liver diseases.

WOX family transcriptional regulators modulate cytokinin homeostasis during leaf blade development in Medicago truncatula and Nicotiana sylvestris.

The plant-specific family of WUSCHEL (WUS)-related homeobox (WOX) transcription factors is key regulators of embryogenesis, meristem maintenance, and lateral organ development in flowering plants. The modern/WUS clade transcriptional repressor STENOFOLIA/LAMINA1(LAM1), and the intermediate/WOX9 clade transcriptional activator MtWOX9/NsWOX9 antagonistically regulate leaf blade expansion, but the molecular mechanism is unknown. Using transcriptome profiling and biochemical methods, we determined that NsCKX3 is the common target of LAM1 and NsWOX9 in Nicotiana sylvestris. LAM1 and NsWOX9 directly recognize and bind to the same cis-elements in the NsCKX3 promoter to repress and activate its expression, respectively, thus controlling the levels of active cytokinins in vivo. Disruption of NsCKX3 in the lam1 background yielded a phenotype similar to the knockdown of NsWOX9 in lam1, while overexpressing NsCKX3 resulted in narrower and shorter lam1 leaf blades reminiscent of NsWOX9 overexpression in the lam1 mutant. Moreover, we established that LAM1 physically interacts with NsWOX9, and this interaction is required to regulate NsCKX3 transcription. Taken together, our results indicate that repressor and activator WOX members oppositely regulate a common downstream target to function in leaf blade outgrowth, offering a novel insight into the role of local cytokinins in balancing cell proliferation and differentiation during lateral organ development.

The Intermode Polariton Parametric Scattering Laser in a Strong Coupled Microcavity Via Two-Photon Absorption.

Exciton-polaritons, hybrid quasiparticles from the strong coupling of excitons and cavity photons in semiconductor microcavities, offer a platform for exploring quantum coherence and nonlinear optical properties. The unique polariton parametric scattering (PPS) laser is of interest for its potential in quantum technologies and nonlinear devices. However, direct resonant excitation of polaritons in strong-coupling microcavities is challenging. This study proposes an innovative two-photon absorption (TPA) pump mechanism to address this. We observe TPA-driven PPS lasing in a strongly coupled microcavity at room temperature. High K-value exciton injections promote coherent stimulated emission of polariton scattering through intermode channels. Angle-resolved spectra confirm a TPA process, showing evolution from pump-state to signal-state. Hanbury Brown-Twiss measurement of second-order correlation g2(τ) of signal state indicates a phase transition from a classical thermal state to a quantum coherent state. Theoretical modeling provides insights into the physical mechanisms of PPS. Our work advances nonlinear phenomena exploration in strongly coupled light-matter systems, contributing to quantum polaritonics and nonlinear optics.

Sequential activation of strigolactone and salicylate biosynthesis promotes leaf senescence.

Leaf senescence is a complex process strictly regulated by various external and endogenous factors. However, the key signaling pathway mediating leaf senescence remains unknown. Here, we show that Arabidopsis SPX1/2 negatively regulate leaf senescence genetically downstream of the strigolactone (SL) pathway. We demonstrate that the SL receptor AtD14 and MAX2 mediate the age-dependent degradation of SPX1/2. Intriguingly, we uncover an age-dependent accumulation of SLs in leaves via transcriptional activation of SL biosynthetic genes by the transcription factors (TFs) SPL9/15. Furthermore, we reveal that SPX1/2 interact with the WRKY75 subclade TFs to inhibit their DNA-binding ability and thus repress transcriptional activation of salicylic acid (SA) biosynthetic gene SA Induction-Deficient 2, gating the age-dependent SA accumulation in leaves at the leaf senescence onset stage. Collectively, our new findings reveal a signaling pathway mediating sequential activation of SL and salicylate biosynthesis for the onset of leaf senescence in Arabidopsis.

Plant-specific BLISTER interacts with kinase BIN2 and BRASSINAZOLE RESISTANT1 during skotomorphogenesis.

Brassinosteroids play an essential role in promoting skotomorphogenesis, yet the underlying mechanisms remain unknown. Here we report that a plant-specific BLISTER (BLI) protein functions as a positive regulator of both BR signaling and skotomorphogenesis in Arabidopsis (Arabidopsis thaliana). We found that the glycogen synthase kinase 3 (GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2 interacts with and phosphorylates BLI at 4 phosphorylation sites (Ser70, Ser146, Thr256, and Ser267) for degradation; in turn, BR inhibits degradation of BLI. Specifically, BLI cooperates with the BRASSINAZOLE RESISTANT1 (BZR1) transcription factor to facilitate the transcriptional activation of BR-responsive genes. Genetic analyses indicated that BLI is essentially required for BZR1-mediated hypocotyl elongation in the dark. Intriguingly, we reveal that BLI and BZR1 orchestrate the transcriptional expression of gibberellin (GA) biosynthetic genes to promote the production of bioactive GAs. Our results demonstrate that BLI acts as an essential regulator of Arabidopsis skotomorphogenesis by promoting BR signaling and GA biosynthesis.

Hypoxia-induced miR-181a-5p up-regulation reduces epirubicin sensitivity in breast cancer cells through inhibiting EPDR1/TRPC1 to activate PI3K/AKT signaling pathway.

Breast carcinoma (BC) ranks as a predominant malignancy and constitutes the second principal cause of mortality among women globally. Epirubicin stands as the drug of choice for BC therapeutics. Nevertheless, the emergence of chemoresistance has significantly curtailed its therapeutic efficacy. The resistance mechanisms to Epirubicin remain not entirely elucidated, yet they are conjectured to stem from diminished tumor vascular perfusion and resultant hypoxia consequent to Epirubicin administration. In our investigation, we meticulously scrutinized the Gene Expression Omnibus database for EPDR1, a gene implicated in hypoxia and Epirubicin resistance in BC. Subsequently, we delineated the impact of EPDR1 on cellular proliferation, motility, invasive capabilities, and interstitial-related proteins in BC cells, employing methodologies such as the CCK-8 assay, Transwell assay, and western blot analysis. Our research further unveiled that hypoxia-induced miR-181a-5p orchestrates the regulation of BC cell duplication, migration, invasion, and interstitial-related protein expression via modulation of EPDR1. In addition, we identified TRPC1, a gene associated with EPDR1 expression in BC, and substantiated that EPDR1 influences BC cellular dynamics through TRPC1-mediated modulation of the PI3K/AKT signaling cascade. Our findings underscore the pivotal role of EPDR1 in the development of BC. EPDR1 was found to be expressed at subdued levels in BC tissues, Epirubicin-resistant BC cells, and hypoxic BC cells. The overexpression of EPDR1 curtailed BC cell proliferation, motility, invasiveness, and the expression of interstitial-related proteins. At a mechanistic level, the overexpression of hypoxia-induced miR-181a-5p was observed to inhibit the EPDR1/TRPC1 axis, thereby activating the PI3K/AKT signaling pathway and diminishing the sensitivity to Epirubicin in BC cells. In summation, our study demonstrates that the augmentation of hypoxia-induced miR-181a-5p diminishes Epirubicin sensitivity in BC cells by attenuating EPDR1/TRPC1 expression, thereby invigorating the PI3K/AKT signaling pathway. This exposition offers a theoretical foundation for the application of Epirubicin in BC therapy, marking a significant contribution to the existing body of oncological literature.

The STF/WOX1 MD is required for physical interaction with MtWOX9 and leaf blade outgrowth in Medicago truncatula.

Plant-specific WUSCHEL-related homeobox (WOX) family transcription factors play critical roles in maintaining meristems and lateral organ development. The WUS clade member STF/LAM1 physically interacts with the intermediate clade member WOX9. This interaction contributes to their antagonistical functions on leaf blade outgrowth by competing for the same cis-elements in the promoter of their common target in M. truncatula and N. sylvestris. Here, we identified the main interaction domains of STF and MtWOX9 in Medicago, shedding light on the mechanism of WOX gene function. The middle domain of STF and MtWOX9 are both critical for the interaction, while the conserved motif of STF in the C-terminal domain is also required. Deletion of the middle domain of STF partially rescued the leaf blade phenotypes of the stf null mutant, indicating that the middle domain plays an essential role during leaf blade expansion. This finding provides a new insight that the versatility of WOX function is not only caused by the conserved DNA binding and repression domains but also by the middle domain that recruits different partners.

ELF4 contributes to esophageal squamous cell carcinoma growth and metastasis by augmenting cancer stemness via FUT9.

Esophageal squamous cell carcinoma (ESCC) commonly has aggressive properties and a poor prognosis. Investigating the molecular mechanisms underlying the progression of ESCC is crucial for developing effective therapeutic strategies. Here, by performing transcriptome sequencing in ESCC and adjacent normal tissues, we find that E74-like transcription factor 4 (ELF4) is the main upregulated transcription factor in ESCC. The results of the immunohistochemistry show that ELF4 is overexpressed in ESCC tissues and is significantly correlated with cancer staging and prognosis. Furthermore, we demonstrate that ELF4 could promote cancer cell proliferation, migration, invasion, and stemness by in vivo assays. Through RNA-seq and ChIP assays, we find that the stemness-related gene fucosyltransferase 9 ( FUT9) is transcriptionally activated by ELF4. Meanwhile, ELF4 is verified to affect ESCC cancer stemness by regulating FUT9 expression. Overall, we first discover that the transcription factor ELF4 is overexpressed in ESCC and can promote ESCC progression by transcriptionally upregulating the stemness-related gene FUT9.

A novel configuration for the fixation of intra-articular C2.3 distal humerus fractures with the potential for minimally invasive surgery: a biomechanical evaluation and finite element analysis.

BACKGROUND: Distal humerus fractures are a challenge to treat, and the current standard of care, open reduction internal fixation with a double-plate, has a high rate of complications. We proposed a novel internal fixation configuration, lateral intramedullary nail and medial plate (LINMP) and verified its rigidity through biomechanical tests and finite element analysis. METHODS: The study involved biomechanical testing of 30 synthetic humerus models to compare 2 different fixation systems for an AO 13C-2.3 type fracture. The orthogonal double-plate (ODP) group and the LINMP group were compared through biomechanical testing to measure stiffness and failure load fewer than 3 working conditions. Based on the results, we optimized the intramedullary nail by eliminating the holes at the distal end of the nail and incorporating a 2-hole external locking plate. The Finite element analysis was also conducted to further compare the modified LINMP configuration with the previous 2 fixation configurations. RESULTS: In biomechanical tests, the ODP group exhibited lower stiffness under bending and compression forces compared to the LINMP group, but higher stiffness and failure loads under torsion force. In finite element analysis, the modified LINMP reduces the maximum stress of the fixation structure without significantly reducing the stiffness under bending stress and axial compression conditions. In torsion stress conditions, the modified LINMP enhances both the maximum stress and the stiffness, although it remains marginally inferior to the ODP structure. CONCLUSION: Our study demonstrates that the innovative LINMP presents comparable or slightly superior concerning bending and axial loading compared to orthogonal double-plate osteosynthesis for distal humeral intra-articular fractures, which might become a minimally invasive option for these fractures.

Characterization and expression profiles of WUSCHEL-related homeobox (WOX) gene family in cultivated alfalfa (Medicago sativa L.).

The WUSCHEL-related homeobox (WOX) family members are plant-specific transcriptional factors, which function in meristem maintenance, embryogenesis, lateral organ development, as well as abiotic stress tolerance. In this study, 14 MsWOX transcription factors were identified and comprehensively analyzed in the cultivated alfalfa cv. Zhongmu No.1. Overall, 14 putative MsWOX members containing conserved structural regions were clustered into three clades according to phylogenetic analysis. Specific expression patterns of MsWOXs in different tissues at different levels indicated that the MsWOX genes play various roles in alfalfa. MsWUS, MsWOX3, MsWOX9, and MsWOX13-1 from the three subclades were localized in the nucleus, among which, MsWUS and MsWOX13-1 exhibited strong self-activations in yeast. In addition, various cis-acting elements related to hormone responses, plant growth, and stress responses were identified in the 3.0 kb promoter regions of MsWOXs. Expression detection of separated shoots and roots under hormones including auxin, cytokinin, GA, and ABA, as well as drought and cold stresses, showed that MsWOX genes respond to different hormones and abiotic stress treatments. Furthermore, transcript abundance of MsWOX3, and MsWOX13-2 were significantly increased after rhizobia inoculation. This study presented comprehensive data on MsWOX transcription factors and provided valuable insights into further studies of their roles in developmental processes and abiotic stress responses in alfalfa.

PKL is stabilized by MMS21 to negatively regulate Arabidopsis drought tolerance through directly repressing AFL1 transcription.

Drought stress causes substantial losses in crop production per year worldwide, threatening global food security. Identification of the genetic components underlying drought tolerance in plants is of great importance. In this study, we report that loss-of-function of the chromatin-remodeling factor PICKLE (PKL), which is involved in repression of transcription, enhances drought tolerance of Arabidopsis. At first, we find that PKL interacts with ABI5 to regulate seed germination, but PKL regulates drought tolerance independently of ABI5. Then, we find that PKL is necessary for repressing the drought-tolerant gene AFL1, which is responsible for the drought-tolerant phenotype of pkl mutant. Genetic complementation tests demonstrate that the Chromo domain and ATPase domain but not the PHD domain are required for the function of PKL in regulating drought tolerance. Interestingly, we find that the DNA-binding domain (DBD) is essential for the protein stability of PKL. Furthermore, we demonstrate that the SUMO E3 ligase MMS21 interacts with and enhances the protein stability of PKL. Genetic interaction analysis shows that MMS21 and PKL additively regulate plant drought tolerance. Collectively, our findings uncover a MMS21-PKL-AFL1 module in regulating plant drought tolerance and offer insights into a novel strategy to improve crop drought tolerance.

Measurable residual disease detected by flow cytometry independently predicts prognoses of NPM1-mutated acute myeloid leukemia.

Acute myeloid leukemia (AML) with NPM1 mutation is a distinct genetic entity with favorable outcomes. Nevertheless, emerging evidence suggests that NPM1-mutated AML is still a highly heterogeneous disorder. In this study, 266 patients with AML with NPM1 mutations were retrospectively analyzed to evaluate the associations between variant allele frequency (VAF) of NPM1 mutations, co-mutated genes, measurable residual disease (MRD), and patient outcomes. Multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (RT-PCR) were used for monitoring MRD. Ultimately, 106 patients were included in the long-term follow-up period. Patients with high NPM1 VAF (≥ 42.43%) had poorer 2-year relapse-free survival (RFS) (55.7% vs. 70.2%, P = 0.017) and overall survival (OS) (63.7% vs. 82.0%, P = 0.027) than those with low VAF. DNMT3A mutations negatively influenced the outcomes of patients with NPM1 mutations. Patients with high DNMT3A VAF or NPM1/DNMT3A/FLT3-ITD triple mutations had shorter RFS and significantly lower OS than that in controls. After two cycles of chemotherapy, patients with positive MFC MRD results had lower RFS (MRD+ vs. MRD-:44.9% vs. 67.6%, P = 0.007) and OS (61.5% vs. 76.6%, P = 0.011) than those without positive MFC MRD results. In multivariate analysis, high NPM1 VAF (hazard ratio [HR] = 2.045; P = 0.034) and positive MRD after two cycles of chemotherapy (HR = 3.289; P = 0.003) were independent risk factors for RFS; MRD positivity after two cycles of chemotherapy (HR = 3.293; P = 0.008) independently predicted the OS of the patients. These results indicate that VAF of both NPM1 gene itself or certain co-occurring gene pre-treatment and MRD post-treatment are potential markers for restratifying the prognoses of patients AML having NPM1 mutations.

No-touch endoscopic full-thickness resection technique for gastric gastrointestinal stromal tumors.

BACKGROUND : There remain concerns regarding the technical feasibility of endoscopic resection for large gastrointestinal stromal tumors (GISTs), mainly relating to the risk of tumor rupture and the adequacy of the resection margins. This study aimed to evaluate the feasibility and therapeutic outcomes of the newly developed no-touch endoscopic full-thickness resection (NT-EFTR) technique for GISTs. METHODS : In this retrospective study, 92 patients with gastric GISTs undergoing NT-EFTR were included. Clinicopathological, endoscopic, and follow-up data were collected and analyzed. RESULTS : The median tumor size was 2.5 cm and en bloc resection was achieved in all patients with negative surgical margins. The median time of the NT-EFTR procedure was 59.5 minutes. Large tumors (> 3.0 cm), extraluminal tumor growth pattern, and large gastric defects were significant contributors to long operative times. Patients were discharged within 4 days postoperatively. During follow-up, all patients were free from local recurrence and distant metastasis. CONCLUSIONS : NT-EFTR was a feasible method for the resection of gastric GISTs and can be expected to achieve complete radical resection. Large tumors with extraluminal growth and large gastric defects impact procedural difficulty.

A Multi-Step Precision Pathway for Predicting Allograft Survival in Heterogeneous Cohorts of Kidney Transplant Recipients.

Accurate prediction of allograft survival after kidney transplantation allows early identification of at-risk recipients for adverse outcomes and initiation of preventive interventions to optimize post-transplant care. Many prediction algorithms do not model cohort heterogeneity and may lead to inaccurate assessment of longer-term graft outcomes among minority groups. Using data from a national Australian kidney transplant cohort (2008-2017) as the derivation set, we developed P-Cube, a multi-step precision prediction pathway model for predicting overall graft survival in three ethnic subgroups: European Australians, Asian Australians and Aboriginal and Torres Strait Islander Peoples. The concordance index for the European Australians, Asian Australians, and Aboriginal and Torres Strait Islander Peoples subpopulations were 0.99 (0.98-0.99), 0.93 (0.92-0.94) and 0.92 (0.91-0.93), respectively. Similar findings were observed when validating P-cube using an external dataset [Scientific Registry of Transplant Recipient Registry (2006-2020)]. Six sub-categories of recipients with distinct risk factor profiles were identified. Some factors such as blood group compatibility were considered important across the entire transplant population. Other factors such as human leukocyte antigen (HLA)-DR mismatches were unique to older recipients. The P-cube model identifies allograft survival specific risk factors within a heterogenous population and offers personalized survival predictions in a diverse cohort.

Shikonin exerts an anti-leukemia effect against FLT3-ITD mutated acute myeloid leukemia cells via targeting FLT3 tyrosine kinase and its downstream pathways.

INTRODUCTION: Acute myeloid leukemia (AML) with internal tandem duplication (ITD) mutations in Fms-like tyrosine kinase 3 (FLT3) has an unfavorable prognosis. Recently, using newly emerging inhibitors of FLT3 has led to improved outcomes of patients with FLT3-ITD mutations. However, drug resistance and relapse continue to be significant challenges in the treatment of patients with FLT3-ITD mutations. This study aimed to evaluate the anti-leukemic effects of shikonin (SHK) and its mechanisms of action against AML cells with FLT3-ITD mutations in vitro and in vivo. METHODS: The CCK-8 assay was used to analyze cell viability, and flow cytometry was used to detect cell apoptosis and differentiation. Western blotting and real-time polymerase chain reaction (RT-PCR) were used to examine the expression of certain proteins and genes. Leukemia mouse model was created to evaluate the anti-leukemia effect of SHK against FLT3-ITD mutated leukemia in vivo. RESULTS: After screening a series of leukemia cell lines, those with FLT3-ITD mutations were found to be more sensitive to SHK in terms of proliferation inhibition and apoptosis induction than those without FLT3-ITD mutations. SHK suppresses the expression and phosphorylation of FLT3 receptors and their downstream molecules. Inhibition of the NF-κB/miR-155 pathway is an important mechanism through which SHK kills FLT3-AML cells. Moreover, a low concentration of SHK promotes the differentiation of AML cells with FLT3-ITD mutations. Finally, SHK could significantly inhibit the growth of MV4-11 cells in leukemia bearing mice. CONCLUSION: The findings of this study indicate that SHK is a promising drug for the treatment of FLT3-ITD mutated AML.

Study on Microwave-Assisted Ignition Using a Novel Aero-Engine Combustor.

Microwave plasma can improve the performance of ignition and combustion, as well as reduce pollutant emissions. By designing a novel microwave feeding device, the combustor can be used as a cavity resonator to generate microwave plasma and improve the performance of ignition and combustion. In order to feed the energy of microwave into the combustor as much as possible, and effectively adapt to the change in resonance frequency of combustor during ignition and combustion, the combustor was designed and manufactured by optimizing the size of slot antenna and setting the tuning screws, according to the simulation results of HFSS software (version: 2019 R 3). The relationship between the size, position of metal tip in the combustor and the discharge voltage was studied using HFSS software, as well as the interaction between ignition kernel, flame and microwave. The resonant characteristics of combustor and the discharge of microwave-assisted igniter were subsequently studied via experiments. The results show that the combustor as microwave cavity resonator has a wider resonance curve and can adapt to the change in resonance frequency during ignition and combustion. It is also indicated that microwave can enhance the discharge development of igniter and increase the discharge size. Based on this, the electric and magnetic field effects of microwave are decoupled.

Ectopic Expression of PvHMA2.1 Enhances Cadmium Tolerance in Arabidopsis thaliana.

Cadmium (Cd) in soil inhibits plant growth and development and even harms human health through food chain transmission. Switchgrass (Panicum virgatum L.), a perennial C4 biofuel crop, is considered an ideal plant for phytoremediation due to its high efficiency in removing Cd and other heavy metals from contaminated soil. The key to understanding the mechanisms of switchgrass Cd tolerance is to identify the genes involved in Cd transport. Heavy-metal ATPases (HMAs) play pivotal roles in heavy metal transport, including Cd, in Arabidopsis thaliana and Oryza sativa, but little is known about the functions of their orthologs in switchgrass. Therefore, we identified 22 HMAs in switchgrass, which were distributed on 12 chromosomes and divided into 4 groups using a phylogenetic analysis. Then, we focused on PvHMA2.1, which is one of the orthologs of the rice Cd transporter OsHMA2. We found that PvHMA2.1 was widely expressed in roots, internodes, leaves, spikelets, and inflorescences, and was significantly induced in the shoots of switchgrass under Cd treatment. Moreover, PvHMA2.1 was found to have seven transmembrane domains and localized at the cell plasma membrane, indicating that it is a potential transporter. The ectopic expression of PvHMA2.1 alleviated the reduction in primary root length and the loss of fresh weight of Arabidopsis seedlings under Cd treatment, suggesting that PvHMA2.1 enhanced Cd tolerance in Arabidopsis. The higher levels of relative water content and chlorophyll content of the transgenic lines under Cd treatment reflected that PvHMA2.1 maintained water retention capacity and alleviated photosynthesis inhibition under Cd stress in Arabidopsis. The roots of the PvHMA2.1 ectopically expressed lines accumulated less Cd compared to the WT, while no significant differences were found in the Cd contents of the shoots between the transgenic lines and the WT under Cd treatment, suggesting that PvHMA2.1 reduced Cd absorption from the environment through the roots in Arabidopsis. Taken together, our results showed that PvHMA2.1 enhanced Cd tolerance in Arabidopsis, providing a promising target that could be engineered in switchgrass to repair Cd-contaminated soil.