Enhancing root physiology for increased yield in water-saving and drought-resistance rice with optimal irrigation and nitrogen.

Objectives: Water-saving and drought-resistance rice (WDR) plays a vital role in the sustainable development of agriculture. Nevertheless, the impacts and processes of water and nitrogen on grain yield in WDR remain unclear. Methods: In this study, Hanyou 73 (WDR) and Hyou 518 (rice) were used as materials. Three kinds of nitrogen fertilizer application rate (NFAR) were set in the pot experiment, including no NFAR (nitrogen as urea applied at 0 g/pot), medium NFAR (nitrogen as urea applied at 15.6 g/pot), and high NFAR (nitrogen as urea applied at 31.2 g/pot). Two irrigation regimes, continuous flooding cultivation and water stress, were set under each NFAR. The relationships between root and shoot morphophysiology and grain yield in WDR were explored. Results: The results demonstrated the following: 1) under the same irrigation regime, the grain yield of two varieties increased with the increase of NFAR. Under the same NFAR, the reduction of irrigation amount significantly reduced the grain yield in Hyou 518 (7.1%-15.1%) but had no substantial influence on the grain yield in Hanyou 73. 2) Under the same irrigation regime, increasing the NFAR could improve the root morphophysiology (root dry weight, root oxidation activity, root bleeding rate, root total absorbing surface area, root active absorbing surface area, and zeatin + zeatin riboside contents in roots) and aboveground physiological indexes (leaf photosynthetic rate, non-structural carbohydrate accumulation in stems, and nitrate reductase activity in leaves) in two varieties. Under the same NFAR, increasing the irrigation amount could significantly increase the above indexes in Hyou 518 (except root dry weight) but has little effect on Hanyou 73. 3) Analysis of correlations revealed that the grain yield of Hyou 518 and Hanyou 73 was basically positively correlated with aboveground physiology and root morphophysiology, respectively. Conclusion: The grain yield could be maintained by water stress under medium NFAR in WDR. The improvement of root morphophysiology is a major factor for high yield under the irrigation regime and NFAR treatments in WDR.

Trends in bronchopulmonary dysplasia and respiratory support among extremely preterm infants in China over a decade.

OBJECTIVE: Bronchopulmonary dysplasia (BPD) is one of the most serious complications affecting extremely preterm infants. We aimed to evaluate temporal trends in BPD and administration of respiratory support among extremely preterm infants in China over a decade. METHODS: This was a retrospective study using data from a multicenter database, which included infants born less than 28 weeks' gestation discharged from 68 tertiary neonatal care centers in China between 2010 and 2019. Changes in rates and severity of BPD, as well as modalities and duration of respiratory support, were evaluated. RESULTS: Among 4808 eligible infants with gestational age (GA) of 21+6/7  to 27+6/7 weeks and a mean (SD) birth weight of 980 (177) g, no significant change of median GA was found over time. Overall, 780 (16.2%) infants died before 36 weeks' postmenstrual age, 2415 (50.2%) were classified as having no BPD, 917 (19.1%) developed Grade 1 BPD, 578 (12.0%) developed Grade 2 BPD, and 118 (2.5%) developed Grade 3 BPD. The rate of BPD increased from 20.8% in 2010 to 40.7% in 2019 (aRR for trend, 1.081; 95% confidence interval, 1.062-1.099), especially for Grade 1 and Grade 2. Although survival to discharge improved over the decade, the overall survival without BPD did not change during the study period. The use of invasive mechanical ventilation (IMV) remained unchanged. However, the use of noninvasive ventilation (NIV) increased from 71.5% in 2010 to 89.8% in 2019. Moreover, the median duration of NIV increased over time, from 17.0 (4.8, 34.0) days in 2010 to 33.0 (21.0, 44.0) days in 2019, without significant change in the duration of IMV. CONCLUSIONS: Although survival increased over the decade and respiratory support practices changed significantly between 2010 and 2019 in China, with increased use and duration of NIV, there was an increased rate of BPD and survival without BPD has not improved.

Mesophyll conductance and N allocation co-explained the variation in photosynthesis in two canola genotypes under contrasting nitrogen supply.

The application of nitrogen fertilizer within a normal range has been found to increase the leaf nitrogen content and photosynthetic rate of canola plants (Brassica napus L.). Despite numerous studies on the separate effects of CO2 diffusion limitation and nitrogen allocation trade-off on photosynthetic rate, few have examined both these factors in relation to the photosynthetic rate of canola. In this study, two genotypes of canola with varying leaf nitrogen content were analyzed to determine the impact of nitrogen supply on leaf photosynthesis, mesophyll conductance, and nitrogen partitioning. The results showed that the CO2 assimilation rate (A), mesophyll conductance (g m), and photosynthetic nitrogen content (N psn) increased with an increase in nitrogen supply in both genotypes. The relationship between nitrogen content and A followed a linear-plateau regression, while A had linear relationships with both photosynthetic nitrogen content and g m, indicating that the key to enhancing A is increasing the distribution of leaf nitrogen into the photosynthetic apparatus and g m, rather than just increasing nitrogen content. Under high nitrogen treatment, the genotype (QZ) with high nitrogen content had 50.7% more nitrogen than the other genotype (ZY21), but had similar A, which was primarily due to ZY21's higher photosynthetic nitrogen distribution ratio and stomatal conductance (g sw). On the other hand, QZ showed a higher A than ZY21 under low nitrogen treatment as QZ had higher N psn and g m compared to ZY21. Our results indicate that, in selecting high PNUE rapeseed varieties, it is important to consider the higher photosynthetic nitrogen distribution ratio and CO2 diffusion conductance.

Feasibility analysis of TCB, hs-CRP, and UCB/ALB as outcome measures for dynamic assessment during phototherapy of neonates with Hyperbilirubinemia.

Hyperbilirubinemia (HY) is a common condition in neonates that requires phototherapy treatment. This study aimed to evaluate the effectiveness of transcutaneous bilirubin measurements (TCB), hypersensitive C-reactive protein (hs-CRP), and unconjugated bilirubin (UCB)/albumin (ALB) as indicators of HY during neonatal phototherapy. A research group of 67 neonates with pathological HY and a control group of 55 healthy neonates were selected from a hospital between June 2020 and May 2021. TCB, hs-CRP, and UCB/ALB tests were performed before, during (at 3 days of treatment), and after (at 6 days of treatment) phototherapy in the research group and at admission in the control group. The study also included a 1-year prognostic follow-up on the research group. The study observed the difference in TCB, hs-CRP, and UCB/ALB test results between both groups and their assessment effect on adverse reactions, treatment effects, and poor prognosis in phototherapy. TCB, hs-CRP, and UCB/ALB levels were higher in the research group than in the control group and gradually decreased during phototherapy (P < 0.05). The combined TCB, hs-CRP, and UCB/ALB assay had 100.0% sensitivity and 64.58% specificity (P < 0.001) for predicting adverse reactions, 88.24% sensitivity and 80.00% specificity (P < 0.001) for predicting the effect of phototherapy, and 90.91% sensitivity and 88.89% specificity (P < 0.001) for predicting poor prognosis. The combined TCB, hs-CRP, and UCB/ALB assay showed superior assessment of adverse effects, clinical outcomes, and poor prognosis in HY neonates treated with phototherapy. TCB, hs-CRP, and UCB/ALB could be used as dynamic disease assessment indicators for HY to better prevent and treat the occurrence of HY.

Improvement of Salinity Tolerance in Water-Saving and Drought-Resistance Rice (WDR).

Rice is one of the most economically important staple food crops in the world. Soil salinization and drought seriously restrict sustainable rice production. Drought aggravates the degree of soil salinization, and, at the same time, increased soil salinity also inhibits water absorption, resulting in physiological drought stress. Salt tolerance in rice is a complex quantitative trait controlled by multiple genes. This review presents and discusses the recent research developments on salt stress impact on rice growth, rice salt tolerance mechanisms, the identification and selection of salt-tolerant rice resources, and strategies to improve rice salt tolerance. In recent years, the increased cultivation of water-saving and drought-resistance rice (WDR) has shown great application potential in alleviating the water resource crisis and ensuring food and ecological security. Here, we present an innovative germplasm selection strategy of salt-tolerant WDR, using a population that is developed by recurrent selection based on dominant genic male sterility. We aim to provide a reference for efficient genetic improvement and germplasm innovation of complex traits (drought and salt tolerance) that can be translated into breeding all economically important cereal crops.

Molecular Breeding of Water-Saving and Drought-Resistant Rice for Blast and Bacterial Blight Resistance.

Rice production is often affected by biotic and abiotic stressors. The breeding of resistant cultivars is a cost-cutting and environmentally friendly strategy to maintain a sustainable high production level. An elite water-saving and drought-resistant rice (WDR), Hanhui3, is susceptible to blast and bacterial blight (BB). This study was conducted to introgress three resistance genes (Pi2, xa5, and Xa23) for blast and BB into Hanhui3, using marker-assisted selection (MAS) for the foreground selection and a whole-genome single-nucleotide polymorphism (SNP) array for the background selection. As revealed by the whole-genome SNP array, the recurrent parent genome (RPG) recovery of the improved NIL was 94.2%. The resistance levels to blast and BB of the improved NIL and its derived hybrids were higher than that of the controls. In addition, the improved NIL and its derived hybrids retained the desired agronomic traits from Hanhui3, such as yield. The improved NIL could be useful to enhance resistance against biotic stressors and produce stable grain yields in Oryza sativa subspecies indica rice breeding programs.

Linkage mapping and association analysis to identify a reliable QTL for stigma exsertion rate in rice.

The commercialization of hybrid rice has greatly contributed to the increase in rice yield, with the improvement of its seed production capacity having played an important role. The stigma exsertion rate (SER) is a key factor for improving the outcrossing of the sterile line and the hybrid rice seed production. We used the Zhenshan 97B × IRAT109 recombinant inbred population comprising 163 lines and a natural population of 138 accessions to decipher the genetic foundation of SER over 2 years in three environments. Additionally, we detected eight QTLs for SER on chromosomes 1, 2, and 8 via linkage mapping. We also identified seven and 19 significant associations for SER using genome-wide association study in 2016 and 2017, respectively. Interestingly, we located two lead SNPs (sf0803343504 and sf083344610) on chromosome 8 in the qTSE8 QTL region that were significantly associated with total SER. After transcriptomic analysis, quantitative real-time PCR, and haplotype analysis, we found 13 genes within this reliable region as important candidate genes. Our study results will be beneficial to molecular marker-assisted selection of rice lines with high outcrossing rate, thereby improving the efficiency of hybrid seed production.

From Green Super Rice to green agriculture: Reaping the promise of functional genomics research.

Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge. Here, we review the concept and practices of Green Super Rice (GSR) that have led to a paradigm shift in goals for crop genetic improvement and models of food production for promoting sustainable agriculture. The momentous achievements and global deliveries of GSR have been fueled by the integration of abundant genetic resources, functional gene discoveries, and innovative breeding techniques with precise gene and whole-genome selection and efficient agronomic management to promote resource-saving, environmentally friendly crop production systems. We also provide perspectives on new horizons in genomic breeding technologies geared toward delivering green and nutritious crop varieties to further enhance the development of green agriculture and better nourish the world population.

Breeding an early maturing, blast resistance water-saving and drought-resistance rice (WDR) cultivar using marker-assisted selection coupled with rapid generation advance.

The japonica water-saving and drought-resistance rice (Oryza sativa L.) (WDR) cultivar Huhan 9 harbors genes for resistance to rice blast (Magnaporthe oryzae), including Pi-ta and Pi-b. The early maturing japonica rice cultivar Suhuxiangjing and the high-yield WDR cultivars Huhan 3 and Huhan 11 were used as the parents to conduct single cross breeding and composite hybridization breeding. Strict drought resistance screening was conducted in the segregating generations, the genotypes of which were determined using functional markers of Pi-ta and Pi-b genes. By combining the rapid generation advance of the industrialized breeding system and multi-site shuttle identification, the new WDR cultivar Huhan 106 with early maturity, blast resistance, high yield, and high quality was bred, and it was certified by the Agricultural Crop Variety Certification Commission of Shanghai in 2020. Molecular marker-assisted selection coupled with rapid generation advance and multi-site shuttle identification is a rapid and efficient breeding method for the value-added improvement of crop varieties. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01319-3.

Molecular Breeding of a Novel PTGMS Line of WDR for Broad-Spectrum Resistance to Blast Using Pi9, Pi5, and Pi54 Genes.

BACKGROUND: The two-line method based on the photoperiod and thermo-sensitive genic male sterile (PTGMS) lines is more cost-effective, simple, and efficient than the three-line system based on cytoplasmic male-sterility. Blast and drought are the most prevalent biotic and abiotic stress factors hampering rice production. Molecular techniques demonstrate higher efficacy in the pyramiding of disease resistance genes, providing green performance under the background of water-saving and drought-resistance rice. RESULTS: This study employed molecular marker-assisted selection, conventional hybridization, and high-intensity stress screening to integrate three broad-spectrum blast resistance genes Pi9, Pi5, and Pi54 into Huhan 1S. Subsequently, a novel water-saving and drought-resistance rice (WDR) PTGMS line Huhan 74S was developed. The drought resistance of the new PTGMS line Huhan 74S was comparable to that of Huhan 1S. Pathogenicity assays involving the inoculation of 14 blast prevalent isolates in the glasshouse showed that the blast resistance frequency of Huhan 74S was 85.7%. Further evaluation under natural blast epidemic field conditions showed that Huhan 74S and its hybrids were resistant to leaf and neck blast. The critical temperature point of fertility-sterility alteration of Huhan 74S was 23 °C daily mean temperature. The complete male sterility under natural growth conditions in 2017 at Shanghai lasted for 67 days. Also, both the agronomic and grain quality traits met the requirement for two-line hybrid rice production. CONCLUSION: These results indicate that the newly bred PTGMS line Huhan 74S can be used to breed high-yielding, good-quality, disease-resistant two-line hybrid water-saving and drought-resistance rice (WDR), hence promoting sustainable rice production in China.

Significance of amplitude integrated electroencephalography in early stage of neonatal hypoxic-ischemic encephalopathy and cerebral function monitoring in Neonatal Intensive Care Units.

OBJECTIVE: To investigate the role of amplitude integrated electroencephalography (aEEG) diagnosis in early stage of neonatal hypoxic-ischemic encephalopathy (HIE), and to evaluate the feasibility of aEEG in cerebral function monitoring in Neonatal Intensive Care Units (NICU). METHODS: 60 cases of term infants with neonatal HIE were included in the observation group, and 50 healthy term infants were enrolled as the control group. Both groups received aEEG monitoring within 6 hours after birth, and the results were analyzed. RESULTS: The correlation coefficient between the degree of asphyxia, SWC, SA and aEEG background activity was r = 0.571 (P<0.001); r = 0.512 (P<0.001) and r = 0.293 (P<0.001), respectively. The correlation coefficient between HIE degree and aEEG background activity, SWC was r = 0.742 (P<0.001) and r = 0.763 (P<0.001), respectively. The Gessell scores of the control group at 1, 3, 6, 9, and 12 months after birth were higher than those of the mild asphyxia group and the severe asphyxia group, and the mild asphyxia group showed higher Gessell scores than the severe asphyxia group (P<0.001). The predicted ROC curve of aEEG monitoring on the occurrence of neonatal HIE showed the area under the curve (AUC) = 0.6354, Std. Error = 0.05668 (95% CI: 0.5243-0.7465, P = 0.0209). CONCLUSION: aEEG had obvious diagnostic value in brain injury in the early stage of full-term neonates with asphyxia, and could be used to monitor the cerebral function of NICU, which is helpful for early clinical detection of brain injury of full-term neonates with asphyxia, so as to improve early diagnosis and treatment.

Exosomal circ_0004136 enhances the progression of pediatric acute myeloid leukemia depending on the regulation of miR-570-3p/TSPAN3 axis.

Circular RNAs (circRNAs) have been implicated in the progression of pediatric acute myeloid leukemia (AML). Although circ_0004136 has been found to play a crucial role in AML, our understanding of its molecular mechanism remains very limited. The levels of circ_0004136, miR-570-3p and tetraspanin 3 (TSPAN3) were determined by quantitative real-time PCR or western blot. Cell viability, migration, invasion, cell cycle and apoptosis were detected using the Cell Counting Kit-8, transwell and flow cytometry assays. Targeted relationships among circ_0004136, miR-570-3p and TSPAN3 were validated by dual-luciferase reporter and RNA immunoprecipitation assays. Our data showed that circ_0004136 could be transmitted by exosomes, and exosomal circ_0004136 was highly expressed in AML serum and cells. Circ_0004136 was unusually stable and mainly localized in the cytoplasm. Circ_0004136 knockdown mediated by exosomes hampered AML cell viability, cell cycle progression, migration and invasion, and promoted cell apoptosis. Moreover, circ_0004136 worked as a sponge of miR-570-3p and TSPAN3 was a functional target of miR-370-3p in AML cells. The suppression of circ_0004136 knockdown mediated by exosomes on AML cell malignant progression was reversed by miR-570-3p downregulation, and the increased miR-570-3p expression hindered the progression of aggressive AML by downregulating TSPAN3. Furthermore, circ_0004136 worked as a miR-570-3p sponge to modulate TSPAN3 expression. Our findings identified a novel regulatory mechanism in which exosome-mediated circ_0004136 knockdown restrained AML cell malignant progression at least partly through targeting the miR-570-3p/TSPAN3 axis, highlighting a novel therapeutic strategy for AML management.

Transcriptomic divergence between upland and lowland ecotypes contributes to rice adaptation to a drought-prone agroecosystem.

INTRODUCTION: Transcriptomic divergence drives plant ecological adaptation. Upland rice is differentiated in drought tolerance from lowland rice during its adaptation to the drought-prone environment. They provide a good system to learn the evolution of drought tolerance in rice. METHODS AND RESULTS: We estimate morphological differences between the two rice ecotypes under well-watered and drought conditions, as well as their genetic and transcriptomic divergences by the high-throughput sequencing. Upland rice possesses higher expression diversity than lowland rice does. Thousands of genes exhibit expression divergences between the two rice ecotypes, which contributes to their morphological differences in drought tolerance. These transcriptomic divergences contribute to drought adaptation of upland rice during its domestication. Mutations in transcriptional regulatory regions, which cause presence and absence of cis-elements, are the cause of expression divergence. About 15.3% transcriptionally selected genes also receive sequence-based selection in upland or lowland ecotype. Some highly differentiated genes promote the transcriptomic divergence between rice ecotypes via gene co-expression network. In addition, we also detected transcriptomic trade-offs between drought tolerance and productivity. DISCUSSION: Many key genes, which promote transcriptomic adaptation to drought in upland rice, have great prospective in breeding water-saving and drought-resistant rice. Meanwhile, appropriate strategies are required in breeding to overcome the potential transcriptomic trade-off.

[A clinical epidemiological investigation of neonatal acute respiratory distress syndrome in southwest Hubei, China].

OBJECTIVE: To investigate the clinical features and outcome of neonatal acute respiratory distress syndrome (ARDS) in southwest Hubei, China. METHODS: According to the Montreux definition of neonatal ARDS, a retrospective clinical epidemiological investigation was performed on the medical data of neonates with ARDS who were admitted to Department of Neonatology/Pediatrics in 17 level 2 or level 3 hospitals in southwest Hubei from January to December, 2017. RESULTS: A total of 7 150 neonates were admitted to the 17 hospitals in southwest Hubei during 2017 and 66 (0.92%) were diagnosed with ARDS. Among the 66 neonates with ARDS, 23 (35%) had mild ARDS, 28 (42%) had moderate ARDS, and 15 (23%) had severe ARDS. The main primary diseases for neonatal ARDS were perinatal asphyxia in 23 neonates (35%), pneumonia in 18 neonates (27%), sepsis in 12 neonates (18%), and meconium aspiration syndrome in 10 neonates (15%). Among the 66 neonates with ARDS, 10 neonates (15%) were born to the mothers with an age of ≥35 years, 30 neonates (45%) suffered from intrauterine distress, 32 neonates (49%) had a 1-minute Apgar score of 0 to 7 points, 24 neonates (36%) had abnormal fetal heart monitoring results, and 21 neonates (32%) experienced meconium staining of amniotic fluid. Intraventricular hemorrhage was the most common comorbidity (12 neonates), followed by neonatal shock (9 neonates) and patent ductus arteriosus (8 neonates). All 66 neonates with ARDS were treated with mechanical ventilation in addition to the treatment for primary diseases. Among the 66 neonates with ARDS, 10 died, with a mortality rate of 15% (10/66), and 56 neonates were improved or cured, with a survival rate of 85% (56/66). CONCLUSIONS: Neonatal ARDS in southwest Hubei is mostly mild or moderate. Perinatal asphyxia and infection may be the main causes of neonatal ARDS in this area. Intraventricular hemorrhage is the most common comorbidity. Neonates with ARDS tend to have a high survival rate after multimodality treatment.

Fine mapping a quantitative trait locus, qSER-7, that controls stigma exsertion rate in rice (Oryza sativa L.).

BACKGROUND: Stigma exsertion rate (SER) is a key determinant of outcrossing in hybrid rice seed production. A quantitative trait locus (QTL) for stigma exsertion rate in rice, qSER-7, has previously been detected on chromosome 7 by using a F2 population derived from two indica cytoplasmic male sterility (CMS) maintainers, Huhan 1B and II-32B. RESULTS: The chromosomal location of qSER-7 was precisely delimited by fine-scale mapping. Near-isogenic lines (NILs) were established, one of which isolated the locus in the qSER-7II-32B line, which contains an introgressed segment of II-32B in the Huhan 1B genetic background, and exhibits a significantly higher stigma exsertion rate than that of the recurrent parent. Using 3192 individuals from the BC4F2 segregation population, the QTL qSER-7 was narrowed down to a 28.4-kb region between the markers RM3859 and Indel4373 on chromosome 7. According to the rice genome annotation database, three genes were predicted within the target region. Real-time PCR analysis showed significantly higher expression levels of LOC_Os07g15370 and LOC_Os07g15390 in II-32B than in Huhan 1B. LOC_Os07g15370(OsNRAMP5) was a previously reported gene for Mn and Cd transporter. The stigma exertion rates of OsNRAMP5-overexpressing plants were significantly higher than that of wild type plants, in contrast, a T-DNA insertion mutant osnramp5 showed a lower stigma exertion rate. CONCLUSIONS: In the present study, the QTL qSER-7 was isolated to a region between the markers RM3859 and Indel4373. Two candidate genes were selected based on the expression difference between the two parents, which can facilitate the further cloning of the gene underlying the quantitative trait associated with qSER-7 as well as the marker-assisted transfer of desirable genes for stigma exsertion rate improvement in rice.

The association between body lead levels and childhood rickets: A meta-analysis based on Chinese cohort.

China has serious lead pollution and a high incidence of childhood rickets. High lead levels have been reported in childhood rickets, but the results were inconsistent.To evaluate the association between body lead levels and childhood rickets.After a systematic literature search, we identified 15 studies determining body lead levels between rickets children and healthy controls, and 4 studies focusing on the cases of different disease severity. Standard mean differences (SMD) and the corresponding 95% confidence intervals (CI) were pooled to compare the lead levels between different groups.Sixteen case-control studies were included with a total of 5082 cases and 6054 controls. Compared with healthy controls, the body lead levels in rickets children were significantly higher (SMD (95%CI): 0.67 (0.41-0.93)), and subgroup analyses showed consistent results. The cases with moderate-to-severe disease activity also had a significantly higher lead level than mild-to-moderate cases (SMD (95%CI): 0.64 (0.31-0.97)).This meta-analysis suggested an association between body lead levels and childhood rickets, and lead exposure might be a risk factor for rickets.