Relationship between neonatal respiratory distress syndrome pulmonary ultrasonography and respiratory distress score, oxygenation index, and chest radiography grading.

BACKGROUND: Accurate condition assessment is critical for improving the prognosis of neonatal respiratory distress syndrome (RDS), but current assessment methods for RDS pose a cumulative risk of harm to neonates. Thus, a less harmful method for assessing the health of neonates with RDS is needed. AIM: To analyze the relationships between pulmonary ultrasonography and respiratory distress scores, oxygenation index, and chest X-ray grade of neonatal RDS to identify predictors of neonatal RDS severity. METHODS: This retrospective study analyzed the medical information of 73 neonates with RDS admitted to the neonatal intensive care unit of Liupanshui Maternal and Child Care Service Center between April and December 2022. The pulmonary ultrasonography score, respiratory distress score, oxygenation index, and chest X-ray grade of each newborn before and after treatment were collected. Spearman correlation analysis was performed to determine the relationships among these values and neonatal RDS severity. RESULTS: The pulmonary ultrasonography score, respiratory distress score, oxygenation index, and chest X-ray RDS grade of the neonates were significantly lower after treatment than before treatment (P < 0.05). Spearman correlation analysis showed that before and after treatment, the pulmonary ultrasonography score of neonates with RDS was positively correlated with the respiratory distress score, oxygenation index, and chest X-ray grade (ρ = 0.429-0.859, P < 0.05). Receiver operating characteristic curve analysis indicated that pulmonary ultrasonography screening effectively predicted the severity of neonatal RDS (area under the curve = 0.805-1.000, P < 0.05). CONCLUSION: The pulmonary ultrasonography score was significantly associated with the neonatal RDS score, oxygenation index, and chest X-ray grade. The pulmonary ultrasonography score was an effective predictor of neonatal RDS severity.

Experimental study on the detection of Gastrodia elata by enzymatic recombinase amplification and immunochromatography.

OBJECTIVE: The objective of this research is to develop two methodologies, Enzymatic recombinase amplification (ERA) and Polymerase Chain Reaction (PCR) coupled with Lateral Flow Dipstick (LFD), for the swift authentication of Gastrodia elata. METHODOLOGY: Primers and nfo probes for the ERA of Gastrodia elata were developed based on the ITS2 genome sequences of Gastrodia elata and its counterfeits. Specific primers for the PCR analysis of Gastrodia elata were generated using the NCBI (National Center for Biotechnology Information) online platform. Through experimental validation, the optimal reaction system and conditions for both methodologies were established, and their efficacy was assessed. RESULTS: The methodologies developed herein are applicable for the targeted analysis of the medicinal species, Gastrodia elata. The sensitivity of the ERA-LFD detection method matched that of the conventional PCR-LFD approach, recorded at 1 ng µL-1. Consistency was observed in the results across three replicates of visualization test strips for both techniques. Upon evaluation, both the PCR-LFD and ERA-LFD methods demonstrated a total compliance rate of 100 %. CONCLUSION: The ERA-LFD and PCR-LFD methods facilitate reduced detection times and offer visual results. These techniques are particularly effective for on-site detection and quality control in the authentication of Gastrodia elata within traditional Chinese medicine markets and at the primary level of healthcare provision.

Preparation and Properties of Multi-Responsive Liquid Crystalline Poly(urethane-acrylate)s and Its Composite Membranes.

In this work, a kind of side chain liquid crystalline poly(urethane-acrylate)s was synthesized by free polymerization based on self-made liquid crystalline monomers, and a series of liquid crystalline polyurethane/shape memory polyurethane composite membranes were prepared by electrospinning. The synthesized liquid crystalline poly(urethane-acrylate)s have excellent thermal stability. Due to the regular arrangement of azobenzene on the side chains, polymers can rapidly undergo a photoinduced transition from trans-isomerism to cis-isomerism in THF solution and restore reversible configurational changes under visible light. The composite membranes prepared by electrospinning can also undergo photoinduced deformation within 6 s, and the deformation slowly returns under visible light. Meanwhile, the composites have shape memory, and after deformation caused by stretching, the membranes can quickly recover their original shape under thermal stimulation. These results indicate that the composites have triple response performances of photoinduced deformation, photo-, and thermal recovery.

Genetic Effects of Grain Quality Enhancement in Indica Hybrid Rice: Insights for Molecular Design Breeding.

Improving rice quality remains a crucial breeding objective, second only to enhancing yield, yet progress in quality improvement lags behind yield. The high temperature and ripening conditions in Southern China often result in poor rice quality, impacting hybrid rice production and utilization. Therefore, to address this challenge, analyzing the molecular basis of high-quality traits is essential for molecular design breeding of high-quality hybrid rice varieties. In this study, we investigated the molecular basis of grain shape, amylose content, gel consistency, gelatinization temperature, and aroma, which influence rice quality. We discovered that quality related alleles gs3, GW7TFA, gw8, chalk5, Wxb, ALKTT, and fgr can enhance rice quality when applied in breeding programs. Polymerization of gs3, GW7TFA, gw8, and chalk5 genes improves rice appearance quality. The gs3 and GW7TFA allele polymerization increasing the grain's length-width ratio, adding the aggregation of gw8 allele can further reducing grain width. The chalk5 gene regulates low chalkiness, but low correlation to chalkiness was exhibited with grain widths below 2.0 mm, with minimal differences between Chalk5 and chalk5 alleles. Enhancing rice cooking and eating quality is achieved through Wxb and ALKTT gene polymerization, while introducing the fgr(E7) gene significantly improved rice aroma. Using molecular marker-assisted technology, we aggregated these genes to develop a batch of indica hybrid rice parents with improved rice quality are obtained. Cross-combining these enhanced parents can generate new, high-quality hybrid rice varieties suitable for cultivation in Southern China. Therefore, our findings contribute to a molecular breeding model for grain quality improvement in high-quality indica hybrid rice. This study, along with others, highlights the potential of molecular design breeding for enhancing complex traits, particularly rice grain quality.

Rapid improvement of grain appearance in three-line hybrid rice via CRISPR/Cas9 editing of grain size genes.

KEY MESSAGE: Genetic editing of grain size genes quickly improves three-line hybrid rice parents to increase the appearance quality and yield of hybrid rice. Grain size affects rice yield and quality. In this study, we used CRISPR/Cas9 to edit the grain size gene GW8 in the maintainer line WaitaiB (WTB) and restorer line Guanghui998 (GH998). The new slender sterile line WTEA (gw8) was obtained in the BC2F1 generation by transferring the grain mutation of the maintainer plant to the corresponding sterile line WantaiA (WTA, GW8) in the T1 generation. Two slender restorer lines, GH998E1 (gw8(II)) and GH998E2 (gw8(I)), were obtained in T1 generation. In the early stage, new sterile and restorer lines in grain mutations were created by targeted editing of GS3, TGW3, and GW8 genes. These parental lines were mated to detect the impact of grain-type mutations on hybrid rice yield and quality. Mutations in gs3, gw8, and tgw3 had a minimal impact on agronomic traits except the grain size and thousand-grain weight. The decrease in grain width in the combination mainly came from gw8/gw8, gs3/gs3 increased the grain length, gs3/gs3-gw8/gw8 had a more significant effect on the grain length, and gs3/gs3-gw8/gw8(I) contributed more to grain length than gs3/gs3-gw8/gw8(II). The heterozygous TGW3/tgw3 may not significantly increase grain length. Electron microscopy revealed that the low-chalky slender-grain variety had a cylindrical grain shape, a uniform distribution of endosperm cells, and tightly arranged starch grains. Quantitative fluorescence analysis of endospermdevelopment-related genes showed that the combination of slender grain hybrid rice caused by gs3 and gw8 mutations promoted endosperm development and improved appearance quality. An appropriate grain size mutation resulted in hybrid rice varieties with high yield and quality.

Teaching effects of the online and offline flipped classroom model (FCM) in the post-epidemic era: Development and feasibility study.

With the rapid development of multimedia technology, the student centered flipped classroom model (FCM) and massive open online courses (MOOCs) have been increasingly introduced and implemented in higher medical education. However, comparative analyses of the offline face-to-face FCM and completely online FCM have been rarely reported. In this study, we focused specifically on a set of flipped classrooms in which prerecorded videos were provided before class. Using the Zhihuishu platform as the major online course platform, our team built a MOOC and evaluated the teaching effectiveness of the FCM in both the offline face-to-face class and the online electronic live class for medical genetics education. Questionnaires, paper-based and oral exams were used to collect data on the teaching effects of the different teaching methods. We found that student satisfaction and overall student performance in the offline FCM group was significantly higher than that in the completely online teaching group. Although online FCM allowed students to play back and review anywhere and anytime after class, students taught in offline FCM had a significantly higher degree of knowledge mastery, had a deeper understanding of theoretical knowledge, and were better at knowledge comprehensive application. The effects of their training on genetic disease clinical diagnosis and treatment skills were significantly better, and their capacity for scientific research was also significantly improved. Our research discussed the advantages of the online courses and the problems brought about by using these technologies, and it provided insight into online teaching practices in the era of internet-based medical education.

Low nitrogen priming improves nitrogen uptake and assimilation adaptation to nitrogen deficit stress in wheat seedling.

MAIN CONCLUSION: Early-stage low nitrogen priming promotes root growth and delays leaf senescence through gene expression, enhancing nitrogen absorption and assimilation in wheat seedlings, thereby alleviating growth inhibition under nitrogen deficit stress and supporting normal seedling development. Verifying the strategies to reduce the amount of nitrogen (N) fertilizer while maintaining high crop yields is important for improving crop N use efficiency (NUE) and protecting the environment. To determine whether low N (LN) priming (LNP) can alleviate the impact of N-deficit stress on the growth of wheat seedlings and improve their tolerance to N-deficit stress, we conducted hydroponic experiments using two wheat cultivars, Yangmai 158 (YM158, LN tolerant) and Zaoyangmai (ZYM, LN sensitive) to study the effects of LNP on wheat seedlings under N-deficit stress. N-deficit stress decreased the plant dry weight, leaf area, and leaf N content (LNC), while LNP could significantly reduce this reduction. Distinct sensitivities to N-deficit stress were observed between the wheat cultivars, with ZYM showing an early decrease in leaf N content compared to YM158, which exhibited a late-stage reduction. LNP promoted root growth, expanded N uptake area, and upregulated the expression of TaNRT1.1, TaNRT2.1, and TaNRT2.2 in wheat seedlings, suggesting that LNP can enhance root N uptake capacity to increase N accumulation in plants. In addition, LNP improved the activity of glutamine synthase (GS) to enhance the capacity of N assimilation of plants. The relative expression of TaGS1 in the lower leaves of priming and stress (PS) was lower than that of no priming and stress (NS) after LNP, indicating that the rate of N transfer from the lower leaves to the upper leaves became slower after LNP, which alleviated the senescence of the lower leaves. The relative expression of TaGS2 was significantly increased, which might be related to the enhanced photorespiratory ammonia assimilation capacity after LNP, which reduced the N loss and maintained higher LNC. Therefore, LNP in the early stage can improve the N absorption and assimilation ability and maintain the normal N supply to alleviate the inhibition of N-deficit stress in wheat seedlings.

Prenatal maternal inactivated COVID-19 vaccination: the maternal and neonatal outcomes, a retrospective cohort study.

Background: Despite the widespread adoption of COVID-19 vaccination, a comprehensive understanding of potential vaccine-induced adverse effects, particularly in the context of pregnancy, remains a critical area of investigation. Elevated concerns surround the maternal and neonatal outcomes subsequent to prenatal maternal COVID-19 vaccination. While existing studies have provided insights into the safety profile of COVID-19 mRNA vaccines, the extrapolation of these conclusions to inactivated COVID-19 vaccines poses uncertainties. Notably, limited data are available regarding the maternal and neonatal effects associated with inactivated COVID-19 vaccines. Objective: To evaluate the prenatal maternal inactivated COVID-19 vaccination and the impact on maternal and neonatal outcomes. Methods: This was a retrospective cohort study of women who delivered between January and June 2022 at a single university-affiliated hospital. Those who have completed at least one dose of inactivated vaccine before or during pregnancy were included in "vaccinated group," and those who were not vaccinated were included in "unvaccinated group," the maternal, pregnancy and neonatal outcomes were evaluated. Propensity score matching (PSM) was performed to balance the baseline parameters of the two groups. Results: A total of 1926 women were enrolled in this study, 827 (42.94%) women were prenatally vaccinated, and 1099 (57.06%) unvaccinated. The gestational week of delivery were slightly lower in the vaccinated group, 38.61 ± 1.89 weeks in the vaccinated group and 38.93 ± 1.49 weeks in the unvaccinated group. There was a higher rate of overall preterm delivery in the vaccinated group (aOR 1.61, 95% CI 1.07-2.42; p = 0.02), however, the probability of delivery before 34 weeks and before 32 weeks (early preterm delivery) were similar (p > 0.05). A total of 2009 infants were born, 851 in the vaccinated group and 1158 in the unvaccinated group. There were similar neonatal outcomes in the two groups. Conclusion: Although we found a slightly lower gestational week of delivery and a possible increased rate of late preterm birth in the vaccination group, there was no difference in mean neonatal weight, incidence of low birth weight infants and other neonatal adverse complications. Meanwhile, there was no difference in pregnancy and maternal outcomes between the two groups.

Multiplex-PCR method application to identify duck blood and its adulterated varieties.

This study applied and validated the Multiplex-PCR method to identify the authenticity of duck blood and four common adulterated animal blood varieties. To this end, the genomic DNAs of duck blood and its counterfeit products were extracted using an efficient high-throughput extraction method. Specific primers were designed using the cytochrome b gene. The reaction system and conditions of a multiplex (namely, Five-plex) PCR were optimized, and the proposed methodology was verified, proving its good specificity, repeatability, and sensitivity. The Five-plex PCR system detected nine duck blood samples sold in the local market, revealing the adulteration of duck blood products. The Multiplex-PCR system can accurately and quickly detect adulterated animal blood in duck blood products, effectively finding counterfeits and identifying the authenticity of genuine duck blood products.

Study on the diffusion and deposition law of pore slurry in gangue filling zone based on CFD-DEM coupling.

In this study, the slurry diffusion in a cavity filled with coal gangue was studied by combining experimental and numerical simulation methods. By calibrating slurry and particle materials, the grouting process in coal gangue filling area is simulated successfully, and the change of slurry diffusion flow field and particle movement and settling process in different dimensions are deeply analyzed. Both experimental and numerical simulation results show that the particle settlement presents a bell-shaped curve, which is of great significance for understanding the particle movement and settlement behavior in the filling cavity. In addition, it is found that the grouting speed has a significant effect on the particle settlement during the slurry diffusion process. When the grouting speed increases from 0.1m /s to 0.2m /s, the particle settlement and diffusion range increases about twice. In the plane flow field, it is observed that the outward diffusion trend and speed of grouting are more obvious. It is worth noting that in the whole process of grouting, it is observed that with the increase of grouting distance and depth, both the velocity of slurry and particles show a trend of rapid initial decline and gradually slow down, and the flow velocity of slurry near the grouting outlet at a flow rate of 0.2m/s is 2-4 times that of 0.1m/s. This provides important enlightenment for the porous seepage effect at different grouting speeds.

What are people's attitudes toward medical insurance fraud whistleblowers? a study from China.

PURPOSE: Medical insurance fraud has caused huge losses to countries around the world, and public reporting has become an important means to combat medical insurance fraud. The attitude of medical insurance fraud whistleblowers affects people's reporting behavior, and understanding people's attitude toward medical insurance fraud whistleblowers provides a basis for further improving the system and policy of public participation in medical insurance fund supervision. METHODS: We adopted the questionnaire method to conduct a national cross-sectional survey of the Chinese public and analyzed the data using Chi-square tests, Fisher's exact tests, and binary logistic regression models. RESULTS: A total of 837 respondents were included, and 81.8% of the population had a supportive attitude toward medical insurance fraud whistleblowers, with gender, whether they had used medical insurance reimbursement, and present life satisfaction being statistically significant (P < 0.05). CONCLUSION: The public is generally supportive of medical insurance fraud whistleblowers, and women, those who have used medical insurance for reimbursement, and those who are satisfied with their lives are more likely to be supportive of medical insurance fraud whistleblowers.

An experimental study on the visual identification of Fritillaria ussuriensis based on LAMP and nucleic acid colloidal gold technique.

Fritillaria ussuriensis Maxim is one of the traditional Chinese valuable herbs, which is the dried bulb of Fritillaria, a plant of the lily family. The identification of authenticity about F. ussuriensis is still technically challenging. In this study, visual identification was performed by ring-mediated isothermal amplification and nucleic acid colloidal gold techniques. Firstly, multiple sequence comparative analysis was performed by DNAMAN to find the differential sites of F. ussuriensis and its mixed pseudo-products, and the specific identification primers of F. ussuriensis were designed. Genomic DNA was extracted by the modified CTAB method, and the reaction system and reaction conditions were optimized to construct LAMP for the visual detection of F. ussuriensis, meanwhile, the genuine product was cloned and the extracted plasmid was sequenced. The specificity and sensitivity were detected, and also verified by nucleic acid colloidal gold method, and 20 commercially available samples were tested. The extracted DNA met the requirements of the experiment, and the genuine F. ussuriensis PCR product titrated on a test strip showed two bands on the T and C lines, while the counterfeit and negative control showed only one band on the C line, which matched the LAMP results. The specificity was 100 %, and the sensitivity of LAMP assay was up to 0.01 ng µL-1, while that of colloidal gold assay was 0.1 ng µL-1, thus the LAMP assay had high sensitivity. 14 out of 20 commercially available samples of F. ussuriensis were qualified, and 6 were unqualified, and the results of the two methods of identification were consistent. In this study, the combined detection method of LAMP and colloidal gold for nucleic acid was established to be specific, rapid, precise and visualized, which can provide a new technical idea for the detection of F. ussuriensis.

Preparation and Performance of Silicone Rubber Composites Modified by Polyurethane.

Silicone rubber composites with good comprehensive properties modified with polyurethane were obtained through mixing and vulcanizing methods. Firstly, the polyurethane prepolymer with double bonds was prepared by polytetrahydrofuran glycol (PTMG, Mn = 1000), isophorone diisocyanate (IPDI), and 2-hydroxyethyl methacrylate (HEMA). The prepolymer was then added to the silicone rubber compounds to prepare silicone rubber composites, combining the excellent properties of polyurethane with the silicone rubber materials. The effects of polyurethane content on the mechanical properties, insulation, hydrophobicity, thermal stability, and flame retardancy of composites were studied in detail. The results showed that the silicone rubber composites not only have good hydrophobicity, thermal stability and flame retardant properties, but the addition of polyurethane significantly improves the tensile strength at room and low temperatures and the volume resistivity of the materials. The tensile strength increased by 32.5%, and the volume resistivity nearly doubled. The excellent electrical insulation, high hydrophobicity and good mechanical properties make the silicone rubber composites appropriate for use in the field of polymeric house arresters.

Influence of electron donor and acceptor substituents on tuning the nonlinear optical properties of zinc phthalocyanine derivatives.

Four phthalocyanine derivatives with different electron donor and acceptor substituents (B1, B2, B3, and B4) were synthesized by a solid-phase melting method. The influence of substituent type on the nonlinear optical properties of the materials was investigated in detail. In the case of similar conjugated structures, B3, which has amino electron-donor groups, presents high intramolecular charge transfer, a low energy gap (2.05 eV), and good nonlinear optical properties. Compared with B3, B4 has a larger π-conjugated structure and its energy gap is 0.04 eV smaller. Moreover, B4 has stronger reverse saturation absorption (7 × 10-12 m/W) and optical limiting performance. The four phthalocyanine derivatives exhibit third harmonic generation (THG) characteristics. Furthermore, the third harmonic strengths of B1, B2, B3, and B4 are 4 times, 9 times, 11 times, and 21 times that of SiO2, respectively. So, B4 has the best application potential in laser protection and frequency conversion.

A real-time detection model for smoke in grain bins with edge devices.

The global food crisis is becoming increasingly severe, and frequent grain bins fires can also lead to significant food losses at the same time. Accordingly, this paper proposes a model-compressed technique for promptly detecting small and thin smoke at the early stages of fire in grain bins. The proposed technique involves three key stages: (1) conducting smoke experiments in a back-up bin to acquire a dataset; (2) proposing a real-time detection model based on YOLO v5s with sparse training, channel pruning and model fine-tuning, and (3) the proposed model is subsequently deployed on different current edge devices. The experimental results indicate the proposed model can detect the smoke in grain bins effectively, with mAP and detection speed are 94.90% and 109.89 FPS respectively, and model size reduced by 5.11 MB. Furthermore, the proposed model is deployed on the edge device and achieved the detection speed of 49.26 FPS, thus allowing for real-time detection.

A Ni-doped Mo2C/NCF composite for efficient electrocatalytic hydrogen evolution.

Ni-Mo2C nano catalysts dispersed on N-doped carbon flowers: a composite with nitrogen-containing carbon flowers carrying nickel-modified molybdenum carbide exhibits enhanced HER catalytic activity in alkaline electrolyte.

Synthesis and nonlinear optical properties of polyurethane composites containing a pyrene derivative.

The pyrene derivative (PD) was synthesized with pyrene-1-carboxaldehyde and p-aminoazobenzene by a Schiff base reaction. Then the obtained PD was dispersed in polyurethane (PU) prepolymer to prepare polyurethane/pyrene derivative PU/PD materials with good transmittance. The nonlinear optical (NLO) performances of the PD and PU/PD materials were studied by the Z-scan technique under picosecond and femtosecond laser pulses. The PD has reverse saturable absorption (RSA) properties under the excitation of 532 nm 15 ps pulses, 650 and 800 nm 180 fs pulses, and a low optical limiting (OL) threshold (0.01J/c m 2). The PU/PD has a larger RSA coefficient than that of the PD under 532 nm 15 ps pulses. With the enhanced RSA, the PU/PD materials exhibit excellent OL (OL) performance. Good NLO properties, high transparency, and easy processing performances make the PU/PD an excellent choice for use in OL and laser protection fields.

Utilization of natural alleles for heat adaptability QTLs at the flowering stage in rice.

BACKGROUND: Heat stress threatens rice yield and quality at flowering stage. In this study, average relative seed setting rate under heat stress (RHSR) and genotypes of 284 varieties were used for a genome-wide association study. RESULTS: We identified eight and six QTLs distributed on chromosomes 1, 3, 4, 5, 7 and 12 in the full population and indica, respectively. qHTT4.2 was detected in both the full population and indica as an overlapping QTL. RHSR was positively correlated with the accumulation of heat-tolerant superior alleles (SA), and indica accession contained at least two heat-tolerant SA with average RHSR greater than 43%, meeting the needs of stable production and heat-tolerant QTLs were offer yield basic for chalkiness degree, amylose content, gel consistency and gelatinization temperature. Chalkiness degree, amylose content, and gelatinization temperature under heat stress increased with accumulation of heat-tolerant SA. Gel consistency under heat stress decreased with polymerization of heat-tolerant SA. The study revealed qHTT4.2 as a stable heat-tolerant QTL that can be used for breeding that was detected in the full population and indica. And the grain quality of qHTT4.2-haplotype1 (Hap1) with chalk5, wx, and alk was better than that of qHTT4.2-Hap1 with CHALK5, WX, and ALK. Twelve putative candidate genes were identified for qHTT4.2 that enhance RHSR based on gene expression data and these genes were validated in two groups. Candidate genes LOC_Os04g52830 and LOC_Os04g52870 were induced by high temperature. CONCLUSIONS: Our findings identify strong heat-tolerant cultivars and heat-tolerant QTLs with great potential value to improve rice tolerance to heat stress, and suggest a strategy for the breeding of yield-balance-quality heat-tolerant crop varieties.

Engineering Cu/NiCu LDH Heterostructure Nanosheet Arrays for Highly-Efficient Water Oxidation.

The development of stable and efficient electrocatalysts for oxygen evolution reaction is of great significance for electro-catalytic water splitting. Bimetallic layered double hydroxides (LDHs) are promising OER catalysts, in which NiCu LDH has excellent stability compared with the most robust NiFe LDH, but the OER activity is not satisfactory. Here, we designed a NiCu LDH heterostructure electrocatalyst (Cu/NiCu LDH) modified by Cu nanoparticles which has excellent activity and stability. The Cu/NiCu LDH electrocatalyst only needs a low over-potential of 206 mV and a low Tafel slope of 86.9 mV dec-1 at a current density of 10 mA cm-2 and maintains for 70 h at a high current density of 100 mA cm-2 in 1M KOH. X-ray photoelectron spectroscopy (XPS) showed that there was a strong electronic interaction between Cu nanoparticles and NiCu LDH. Density functional theory (DFT) calculations show that the electronic coupling between Cu nanoparticles and NiCu LDH can effectively improve the intrinsic OER activity by optimizing the conductivity and the adsorption energy of oxygen-containing intermediates.

Identification of two novel rice S genes through combination of association and transcription analyses with gene-editing technology.

Traditional rice blast resistance breeding largely depends on utilizing typical resistance (R) genes. However, the lack of durable R genes has prompted rice breeders to find new resistance resources. Susceptibility (S) genes are potential new targets for resistance genetic engineering using genome-editing technologies, but identifying them is still challenging. Here, through the integration of genome-wide association study (GWAS) and transcriptional analysis, we identified two genes, RNG1 and RNG3, whose polymorphisms in 3'-untranslated regions (3'-UTR) affected their expression variations. These polymorphisms could serve as molecular markers to identify rice blast-resistant accessions. Editing the 3'-UTRs using CRISPR/Cas9 technology affected the expression levels of two genes, which were positively associated with rice blast susceptibility. Knocking out either RNG1 or RNG3 in rice enhanced the rice blast and bacterial blight resistance, without impacting critical agronomic traits. RNG1 and RNG3 have two major genotypes in diverse rice germplasms. The frequency of the resistance genotype of these two genes significantly increased from landrace rice to modern cultivars. The obvious selective sweep flanking RNG3 suggested it has been artificially selected in modern rice breeding. These results provide new targets for S gene identification and open avenues for developing novel rice blast-resistant materials.