Lacquer cracks in pathological myopia: a clinical review.

Lacquer cracks, described as breaks in the Bruch's membrane, are unique lesions in the spectrum of fundus changes associated with pathological myopia. Lacquer cracks are generally believed to be relatively innocuous lesions by themselves; however, progression to other features of myopic macular degeneration, such as patchy chorioretinal atrophy and choroidal neovascularization, may result in irreversible visual impairment. With the rising prevalence of pathological myopia to epidemic proportions, particularly in the Asian countries, ophthalmologists expect to encounter lacquer cracks more frequently in clinical practice. Therefore, it is crucial for the ophthalmic community to be aware of lacquer cracks and to actively look for these lesions in myopic patients so that early detection and close monitoring can help prevent blinding complications. This article provides a comprehensive review on lacquer cracks in eyes with pathological myopia from a clinical perspective.

Microbial contributions to sustainable paddy straw utilization for economic gain and environmental conservation.

Paddy straw is a versatile and valuable resource with multifaceted benefits for nutrient cycling, soil health, and climate mitigation. Its role as a rich nutrient source and organic matter significantly enhances soil vitality while improving soil structure and moisture retention. The impact of paddy straw extends beyond traditional agricultural benefits, encompassing the promotion of microbial activity, erosion control, and carbon sequestration, highlighting its crucial role in maintaining ecological balance. Furthermore, the potential of paddy straw in bioenergy is explored, encompassing its conversion into biogas, biofuels, and thermal energy. The inherent characteristics of paddy straw, including its high cellulose, hemicellulose, and lignin content, position it as a viable candidate for bioenergy production through innovative processes like pyrolysis, gasification, anaerobic digestion, and combustion. Recent research has uncovered state-of-the-art techniques and innovative technologies capable of converting paddy straw into valuable products, including sugar, ethanol, paper, and fiber, broadening its potential applications. This paper aims to underscore the possibilities for value creation through paddy straw, emphasizing its potential use in bioenergy, bio-products, and other environmental applications. Therefore, by recognizing and harnessing the value of paddy straw, we can advocate for sustainable farming practices, reduce waste, and pave the way for a resource-efficient circular economy. Incorporating paddy straw utilization into agricultural systems can pave the way for enhanced resource efficiency and a more sustainable circular economy.

Longitudinal Changes in Choroidal Vascularity in Myopic and Non-Myopic Children.

Purpose: The purpose of this study was to evaluate longitudinal changes in choroidal vascular characteristics in childhood, and their relationship with eye growth and refractive error. Methods: Analysis of high-resolution optical coherence tomography (OCT) scans, collected over an 18-month period as part of the Role of Outdoor Activity in Myopia (ROAM) study, was conducted in 101 children (41 myopic, 60 non-myopic, age 10-15 years). OCT images were automatically analyzed and binarized using a deep learning software tool. The output was then used to compute changes in macular choroidal vascularity index (CVI), choroidal luminal, and stromal thickness over 18-months. Associations of these variables with refractive error and axial length were analyzed. Results: CVI decreased significantly, whereas luminal and stromal thickness increased significantly over 18 months (all P < 0.001). The magnitude of change was approximately double in stromal tissue compared to luminal tissue (luminal ß = 2.6 µm/year; 95% confidence interval [CI] = -1.0 to 4.1 µm/year; stromal ß = 5.2 µm/year; 95% CI = 4.0, 6.5 µm/year). A significant interaction between baseline axial length and change in CVI over time (P = 0.047) was observed, with a greater CVI reduction in those with shorter axial lengths. Significant associations were observed between the change in CVI, luminal thickness, stromal thickness, and change in axial length over time (all P < 0.05). Conclusions: Faster axial eye growth was associated with smaller reductions in CVI, and less increase in choroidal luminal and stromal thickness. The changes in choroidal vascularity, particularly in the stromal component, may thus be a marker for eye growth. Translational Relevance: This knowledge of the longitudinal changes in choroidal vascularity in childhood and their relationship with eye growth may assist clinicians in the future to better predict eye growth and myopia progression in childhood.

Peripartum outcomes and immune responses after SARS-CoV-2 infection in the third trimester of pregnancy.

BACKGROUND: SARS-CoV-2 infection in pregnant women during the third trimester resulted in overall adverse pregnancy outcomes compared to non-infected controls and a unique humoral and cellular response at delivery. In this study we aimed to assess the impact of SARS-CoV-2 infection on maternal/neonatal peripartum outcomes andimmunological profiles. METHOD: In this study, we recruited 304 SARS-CoV-2 infected pregnant women and 910 SARS-CoV-2 non-infected pregnant women who were admitted for delivery. Peripartum and neonates' outcomes response to SARS-CoV-2 infection were analyzed. Furthermore, we characterized the antibody and cytokines profile in SARS-CoV-2 infected maternal blood (MB) and cord blood (CB). We also assessed routine laboratory tests and liver function tests in MB before labor. Unpaired T test, Mann-Whitney test and Spearman test were used to analyze the data. RESULTS: SARS-CoV-2 infected pregnant women were significantly associated with increased risk of adverse pregnancy outcomes, including preterm labor (13.8% vs. 9.5%, p = 0.033) and meconium-stained amniotic fluid (8.9% vs. 5.5%, p = 0.039). The risk of low birth weight (< 2500 g) (10.5% vs. 6.5%, p = 0.021) and Apgar score < 8 at 1-minute (9.2% vs. 5.8%, p = 0.049) significantly increased in newborns from COVID-19 positive mothers than their counterparts. Our results showed that antibodies were increased in adverse-outcome SARS-CoV-2 infected mothers and their neonates, and abnormal proportion of immune cells were detected in SARS-CoV-2 infected mothers. While the immune response showed no difference between adverse-outcome infected pregnant women and normal-outcome infected pregnant women. Thus, SARS-CoV-2 infection during the third trimester of pregnancy induced a unique humoral and cellular response at delivery. CONCLUSION: SARS-CoV-2 infection closer to delivery could incline to adverse pregnancy outcomes. Therefore, the utmost care is required for SARS-CoV-2 infected pregnant women and their newborns. TRIAL REGISTRATION: The study protocol was approved by the Institutional Review Board of the First Hospital of Jilin University with the approval code number 23K170-001, and informed consent was obtained from all enrolled patients prior to sample collection.

Molecular Mapping and Transfer of Quantitative Trait Loci (QTL) for Sheath Blight Resistance from Wild Rice Oryza nivara to Cultivated Rice (Oryza sativa L.).

Sheath blight (ShB) is the most serious disease of rice (Oryza sativa L.), caused by the soil-borne fungus Rhizoctonia solani Kühn (R. solani). It poses a significant threat to global rice productivity, resulting in approximately 50% annual yield loss. Managing ShB is particularly challenging due to the broad host range of the pathogen, its necrotrophic nature, the emergence of new races, and the limited availability of highly resistant germplasm. In this study, we conducted QTL mapping using an F2 population derived from a cross between a partially resistant accession (IRGC81941A) of Oryza nivara and the susceptible rice cultivar Punjab rice 121 (PR121). Our analysis identified 29 QTLs for ShB resistance, collectively explaining a phenotypic variance ranging from 4.70 to 48.05%. Notably, a cluster of four QTLs (qRLH1.1, qRLH1.2, qRLH1.5, and qRLH1.8) on chromosome 1 consistently exhibit a resistant response against R. solani. These QTLs span from 0.096 to 420.1 Kb on the rice reference genome and contain several important genes, including Ser/Thr protein kinase, auxin-responsive protein, protease inhibitor/seed storage/LTP family protein, MLO domain-containing protein, disease-responsive protein, thaumatin-like protein, Avr9/Cf9-eliciting protein, and various transcription factors. Additionally, simple sequence repeats (SSR) markers RM212 and RM246 linked to these QTLs effectively distinguish resistant and susceptible rice cultivars, showing great promise for marker-assisted selection programs. Furthermore, our study identified pre-breeding lines in the advanced backcrossed population that exhibited superior agronomic traits and sheath blight resistance compared to the recurrent parent. These promising lines hold significant potential for enhancing the sheath blight resistance in elite cultivars through targeted improvement efforts.

Precision mapping and expression analysis of recessive bacterial blight resistance gene xa-45(t) from Oryza glaberrima.

BACKGROUND: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating diseases of rice leading to huge yield losses in Southeast Asia. The recessive resistance gene xa-45(t) from Oryza glaberrima IRGC102600B, mapped on rice chromosome 8, spans 80 Kb with 9 candidate genes on Nipponbare reference genome IRGSP-1.0. The xa-45(t) gene provides durable resistance against all the ten Xanthomonas pathotypes of Northern India, thus aiding in the expansion of recessive bacterial blight resistance gene pool. Punjab Rice PR127, carrying xa-45(t), was released for wider use in breeding programs. This study aims to precisely locate the target gene among the 9 candidates conferring resistance to bacterial blight disease. METHODS AND RESULTS: Sanger sequencing of all nine candidate genes revealed seven SNPs and an Indel between the susceptible parent Pusa 44 and the resistant introgression line IL274. The genotyping with polymorphic markers identified three recombinant breakpoints for LOC_Os08g42370, and LOC_Os08g42400, 15 recombinants for LOC_Os08g423420 and 26 for LOC_Os08g42440 out of 190 individuals. Relative expression analysis across six time intervals (0, 8, 24, 48, 72, and 96 h) after bacterial blight infection showed over expression of LOC_Os08g42410-specific transcripts in IL274 compared to Pusa 44, with a significant 4.46-fold increase observed at 72 h post-inoculation. CONCLUSIONS: The Indel marker at the locus LOC_Os08g42410 was found co-segregating with the phenotype, suggesting its candidacy towards xa-45(t). The transcript abundance assay provides strong evidence for the involvement of LOC_Os08g42410 in the resistance conferred by the bacterial blight gene xa-45(t).

Physical mapping of the wheat genes in low-recombination regions: radiation hybrid mapping of the C-locus.

KEY MESSAGE: This work reports the physical mapping of an important gene affecting spike compactness located in a low-recombination region of hexaploid wheat. This work paves the way for the eventual isolation and characterization of the factor involved but also opens up possibilities to use this approach to precisely map other wheat genes located on proximal parts of wheat chromosomes that show highly reduced recombination. Mapping wheat genes, in the centromeric and pericentromeric regions (~ 2/3rd of a given chromosome), poses a formidable challenge due to highly suppressed recombination. Using an example of compact spike locus (C-locus), this study provides an approach to precisely map wheat genes in the pericentromeric and centromeric regions that house ~ 30% of wheat genes. In club-wheat, spike compactness is controlled by the dominant C-locus, but previous efforts have failed to localize it, on a particular arm of chromosome 2D. We integrated radiation hybrid (RH) and high-resolution genetic mapping to locate C-locus on the short arm of chromosome 2D. Flanking markers of the C-locus span a physical distance of 11.0 Mb (231.0-242 Mb interval) and contain only 11 high-confidence annotated genes. This work demonstrates the value of this integrated strategy in mapping dominant genes in the low-recombination regions of the wheat genome. A comparison of the mapping resolutions of the RH and genetic maps using common anchored markers indicated that the RH map provides ~ 9 times better resolution that the genetic map even with much smaller population size. This study provides a broadly applicable approach to fine map wheat genes in regions of suppressed recombination.

Association of Triglyceride Glucose Index with Prevalence and Incidence of Diabetic Retinopathy in a Singaporean Population.

Objective: To examine the association of triglyceride glucose (TyG) index (product of fasting triglyceride and glucose) with prevalence and incidence of diabetic retinopathy (DR) in type 2 diabetes. Methods: 1339 patients from an ongoing Singapore Study of Macro-angiopathy and Micro-Vascular Reactivity in Type 2 Diabetes (SMART2D) were included in this study. Fasting triglyceride and glucose levels were quantified and color fundus photographs were assessed for DR presence and severity. Logistic regression models were used to evaluate associations of TyG index with DR prevalence and incidence (median follow-up period = 3.2 years). Results: Mean TyG index was higher in patients with DR than no DR (9.24±0.7 versus 9.04± 0.6, p<0.001). TyG index was significantly associated with DR prevalence (OR=1.4, CI 1.1-1.7, p=0.002) and incidence (OR=1.8, CI 1.04-2.9, p=0.03), after adjusting for confounders. In a stratified analysis, the association between TyG index and DR prevalence reached significance only in the subgroup with HbA1c levels < 7.0% (OR=2, CI 1.1-3.8, p=0.03). TyG index significantly predicted DR prevalence and incidence with area under receiver operating curve as 0.77 (CI 0.74-0.80, p <0.001) and 0.66 (CI 0.57-0.76, p value <0.01), respectively. Conclusion: TyG index is a good predictor for DR prevalence and incidence. It can also be a secondary treatment target for patients with optimally controlled levels of HbA1c.

Uncovering natural allelic and structural variants of OsCENH3 gene by targeted resequencing and in silico mining in genus Oryza.

Plant breeding efforts to boost rice productivity have focused on developing a haploid development pipeline. CENH3 gene has emerged as a leading player that can be manipulated to engineer haploid induction system. Currently, allele mining for the OsCENH3 gene was done by PCR-based resequencing of 33 wild species accessions of genus Oryza and in silico mining of alleles from pre-existing data. We have identified and characterized CENH3 variants in genus Oryza. Our results indicated that the majority CENH3 alleles present in the Oryza gene pool carry synonymous substitutions. A few non-synonymous substitutions occur in the N-terminal Tail domain (NTT). SNP A/G at position 69 was found in accessions of AA genome and non-AA genome species. Phylogenetic analysis revealed that non-synonymous substitutions carrying alleles follow pre-determined evolutionary patterns. O. longistaminata accessions carry SNPs in four codons along with indels in introns 3 and 6. Fifteen haplotypes were mined from our panel; representative mutant alleles exhibited structural variations upon modeling. Structural analysis indicated that more than one structural variant may be exhibited by different accessions of single species (Oryza barthii). NTT allelic mutants, though not directly implicated in HI, may show variable interactions. HI and interactive behavior could be ascertained in future investigations.

MDSCs in pregnancy and pregnancy-related complications: an update†.

Maternal-fetal immune tolerance is a process that involves complex interactions of the immune system, and myeloid-derived suppressor cells have emerged as one of the novel immunomodulator in the maintenance of maternal-fetal immune tolerance. Myeloid-derived suppressor cells are myeloid progenitor cells with immunosuppressive activities on both innate and adaptive cells through various mechanisms. Emerging evidence demonstrates the accumulation of myeloid-derived suppressor cells during healthy pregnancy to establish maternal-fetal immune tolerance, placentation, and fetal-growth process. By contrast, the absence or decreased myeloid-derived suppressor cells in pregnancy complications like preeclampsia, preterm birth, stillbirth, and recurrent spontaneous abortion have been reported. Here, we have summarized the origin, mechanisms, and functions of myeloid-derived suppressor cells during pregnancy along with the recent advancements in this dynamic field. We also shed light on the immunomodulatory activity of myeloid-derived suppressor cells, which can be a foundation for potential therapeutic manipulation in immunological pregnancy complications.

From Evolution to Revolution: Accelerating Crop Domestication through Genome Editing.

Crop domestication has a tremendous impact on socioeconomic conditions and human civilization. Modern cultivars were domesticated from their wild progenitors thousands of years ago by the selection of natural variation by humans. New cultivars are being developed by crossing two or more compatible individuals. But the limited genetic diversity in the cultivars severely affects the yield and renders the crop susceptible to many biotic and abiotic stresses. Crop wild relatives (CWRs) are the rich reservoir for many valuable agronomic traits. The incorporation of useful genes from CWR is one of the sustainable approaches for enriching the gene pool of cultivated crops. However, CWRs are not suited for urban and intensive cultivation because of several undesirable traits. Researchers have begun to study the domestication traits in the CWRs and modify them using genome-editing tools to make them suitable for extensive cultivation. Growing evidence has shown that modification in these genes is not sufficient to bring the desired change in the neodomesticated crop. However, the other dynamic genetic factors such as microRNAs (miRNAs), transposable elements, cis-regulatory elements and epigenetic changes have reshaped the domesticated crops. The creation of allelic series for many valuable domestication traits through genome editing holds great potential for the accelerated development of neodomesticated crops. The present review describes the current understanding of the genetics of domestication traits that are responsible for the agricultural revolution. The targeted mutagenesis in these domestication genes via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 could be used for the rapid domestication of CWRs.

Genotyping-by-Sequencing Based Investigation of Population Structure and Genome Wide Association Studies for Seven Agronomically Important Traits in a Set of 346 Oryza rufipogon Accessions.

Being one of the most important staple dietary constituents globally, genetic enhancement of cultivated rice for yield, agronomically important traits is of substantial importance. Even though the climatic factors and crop management practices impact complex traits like yield immensely, the contribution of variation by underlying genetic factors surpasses them all. Previous studies have highlighted the importance of utilizing exotic germplasm, landraces in enhancing the diversity of gene pool, leading to better selections and thus superior cultivars. Thus, to fully exploit the potential of progenitor of Asian cultivated rice for productivity related traits, genome wide association study (GWAS) for seven agronomically important traits was conducted on a panel of 346 O. rufipogon accessions using a set of 15,083 high-quality single nucleotide polymorphic markers. The phenotypic data analysis indicated large continuous variation for all the traits under study, with a significant negative correlation observed between grain parameters and agronomic parameters like plant height, culm thickness. The presence of 74.28% admixtures in the panel as revealed by investigating population structure indicated the panel to be very poorly genetically differentiated, with rapid LD decay. The genome-wide association analyses revealed a total of 47 strong MTAs with 19 SNPs located in/close to previously reported QTL/genic regions providing a positive analytic proof for our studies. The allelic differences of significant MTAs were found to be statistically significant at 34 genomic regions. A total of 51 O. rufipogon accessions harboured combination of superior alleles and thus serve as potential candidates for accelerating rice breeding programs. The present study identified 27 novel SNPs to be significantly associated with different traits. Allelic differences between cultivated and wild rice at significant MTAs determined superior alleles to be absent at 12 positions implying substantial scope of improvement by their targeted introgression into cultivars. Introgression of novel significant genomic regions into breeder's pool would broaden the genetic base of cultivated rice, thus making the crop more resilient.

BSA-seq Identifies a Major Locus on Chromosome 6 for Root-Knot Nematode (Meloidogyne graminicola) Resistance From Oryza glaberrima.

Root-knot nematode (Meloidogyne graminicola) is one of the emerging threats to rice production worldwide that causes substantial yield reductions. There is a progressive shift of the cropping system from traditional transplanting to direct-seeded water-saving rice production that favored the development of M. graminicola. Scouting and deploying new resistance genes is an economical approach to managing the root-knot nematodes. Here, we report that the inheritance of root-knot nematode resistance in Oryza glaberrima acc. IRGC102206 is governed by a single dominant gene. Traditional mapping coupled with BSA-seq is used to map nematode resistance gene(s) using the BC1F1 population derived from a cross of O. sativa cv. PR121 (S) and O. glaberrima acc. IRGC102206 (R). One major novel genomic region spanning a 3.0-Mb interval on chromosome 6 and two minor QTLs on chromosomes 2 and 4 are the potential genomic regions associated with rice root-knot nematode resistance. Within the QTL regions, 19 putative candidate genes contain 81 non-synonymous variants. The detected major candidate region could be fine mapped to accelerate marker-assisted breeding for root-knot nematode resistance in rice.

MicroRNA-mediated host defense mechanisms against pathogens and herbivores in rice: balancing gains from genetic resistance with trade-offs to productivity potential.

BACKGROUND: Rice (Oryza sativa L.) is the major source of daily caloric intake for more than 30% of the human population. However, the sustained productivity of this staple food crop is continuously threatened by various pathogens and herbivores. Breeding has been successful in utilizing various mechanisms of defense by gene pyramiding in elite cultivars, but the continuous resurgence of highly resistant races of pathogens and herbivores often overcomes the inherent capacity of host plant immunity. MicroRNAs (miRNAs) are endogenous, short, single-stranded, non-coding RNA molecules that regulate gene expression by sequence-specific cleavage of target mRNA or suppressing target mRNA translation. While miRNAs function as upstream regulators of plant growth, development, and host immunity, their direct effects on growth and development in the context of balancing defenses with agronomic potential have not been extensively discussed and explored as a more viable strategy in breeding for disease and pest resistant cultivars of rice with optimal agronomic potentials. RESULTS: Using the available knowledge in rice and other model plants, this review examines the important roles of miRNAs in regulating host responses to various fungal, bacterial, and viral pathogens, and insect pests, in the context of gains and trade-offs to crop yield. Gains from R-gene-mediated resistance deployed in modern rice cultivars are often undermined by the rapid breakdown of resistance, negative pleiotropic effects, and linkage drags with undesirable traits. In stark contrast, several classes of miRNAs are known to efficiently balance the positive gains from host immunity without significant costs in terms of losses in agronomic potentials (i.e., yield penalty) in rice. Defense-related miRNAs such as Osa-miR156, Osa-miR159, Osa-miR162, Osa-miR396, Osa-530, Osa-miR1432, Osa-miR1871, and Osa-miR1873 are critical in fine-tuning and integrating immune responses with physiological processes that are necessary to the maintenance of grain yield. Recent research has shown that many defense-related miRNAs regulate complex and agronomically important traits. CONCLUSIONS: Identification of novel immune-responsive miRNAs that orchestrate physiological processes critical to the full expression of agronomic potential will facilitate the stacking of optimal combinations of miRNA-encoding genes to develop high-yielding cultivars with durable resistance to disease and insect pests with minimal penalties to yield.

Molecular mapping and transfer of a novel brown planthopper resistance gene bph42 from Oryza rufipogon (Griff.) To cultivated rice (Oryza sativa L.).

BACKGROUND: Brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests of rice accounting for 52% of annual yield loss. The breakdown of resistance against known BPH biotypes necessitates the identification and deployment of new genes from diverse sources. The current study aimed at mapping and transfer of a novel BPH resistance gene from the wild species of rice O. rufipogon accession CR100441 to the elite rice cultivar against BPH biotype 4. METHODS AND RESULTS: The phenotypic screening against BPH biotype 4 was conducted using the standard seedbox screening technique (SSST). Inheritance study using damage score caused by BPH infestation at the seedling stage indicated the presence of a single major recessive gene with the segregation ratio of susceptible to resistant plants in 3:1 (210:66, χ2c = 0.17 ≤ χ20.05,1 = 3.84). The genotyping of the mapping population was done using polymorphic microsatellite markers between PR122 and O.rufipogon acc.CR100441 spanning all the 12 chromosomes of rice. A total of 537 SSR markers were used to map a BPH resistance gene (designated as bph42) on the short arm of chromosome 4 between RM16282 and RM6659. QTL analysis identified a peak marker RM16335 contributing 29% of the phenotypic variance at 40.76 LOD. CONCLUSIONS: The identified marker co-segregates with the bph42 and hence could be efficiently used for marker-assisted selection (MAS) for the transfer of resistance into elite rice cultivars. The introgression lines with higher yield and BPH resistance were identified and are under advanced yield trails for further varietal release.

A Prospective Review on Selectable Marker-Free Genome Engineered Rice: Past, Present and Future Scientific Realm.

As a staple food crop, rice has gained mainstream attention in genome engineering for its genetic improvement. Genome engineering technologies such as transgenic and genome editing have enabled the significant improvement of target traits in relation to various biotic and abiotic aspects as well as nutrition, for which genetic diversity is lacking. In comparison to conventional breeding, genome engineering techniques are more precise and less time-consuming. However, one of the major issues with biotech rice commercialization is the utilization of selectable marker genes (SMGs) in the vector construct, which when incorporated into the genome are considered to pose risks to human health, the environment, and biodiversity, and thus become a matter of regulation. Various conventional strategies (co-transformation, transposon, recombinase systems, and MAT-vector) have been used in rice to avoid or remove the SMG from the developed events. However, the major limitations of these methods are; time-consuming, leftover cryptic sequences in the genome, and there is variable frequency. In contrast to these methods, CRISPR/Cas9-based marker excision, marker-free targeted gene insertion, programmed self-elimination, and RNP-based delivery enable us to generate marker-free engineered rice plants precisely and in less time. Although the CRISPR/Cas9-based SMG-free approaches are in their early stages, further research and their utilization in rice could help to break the regulatory barrier in its commercialization. In the current review, we have discussed the limitations of traditional methods followed by advanced techniques. We have also proposed a hypothesis, "DNA-free marker-less transformation" to overcome the regulatory barriers posed by SMGs.

High-resolution mapping of the quantitative trait locus (QTLs) conferring resistance to false smut disease in rice.

Rice false smut (RFS), an emerging major fungal disease worldwide caused by Ustilaginoidea virens, affects rice grain quality and yield. RFS cause 2.8-49% global yield loss depending upon disease severity and cultivars. In India, the yield loss due to RFS ranged from 2 to 75%. Identification of the genes or quantitative trait loci (QTLs) governing disease resistance would be of utmost importance towards mitigating the economic losses incurred due to RFS. Here, we report mapping of RFS resistance QTLs from a resistant breeding line RYT2668. The mapping population was evaluated for RFS resistance under the field condition in three cropping seasons 2013, 2015, and 2016. A positive correlation among infected panicle/plant, total smut ball/panicle, and disease score was observed in the years 2013, 2015, and the mean data. A total of seven QTLs were mapped on rice chromosomes 2, 4, 5, 7, and 9 using 2326 single nucleotide polymorphism markers. Of these, two QTLs, qRFSr5.3 and qRFSr7.1a, were associated with the infected panicle per plant, one QTL qRFsr9.1 with total smut ball per panicle, and four QTLs qRFSr2.2, qRFSr4.3, qRFSr5.4, and qRFSr7.1b with disease score. Among them, a novel QTL qRFSr9.1 on chromosome 9 exhibits the largest phenotypic effect. The prediction of putative candidate genes within the qRFSr9.1 revealed four nucleotide-binding sites-leucine-rich repeat (NBS-LRR) domain-containing disease resistance proteins. In summary, our findings mark the hotspot region of rice chromosomes carrying genes/QTLs for resistance to the RFS disease.

The abnormal expression of Tim-3 is involved in the regulation of myeloid-derived suppressor cells and its correlation with preeclampsia.

INTRODUCTION: Maternal immune system tolerance to the semi-allogeneic fetus is critical to a successful pregnancy. We previously reported that myeloid-derived suppressor cells (MDSC) was associated with maternal immune imbalance. T cell immunoglobulin and mucin-containing protein 3 (Tim-3)/Galectin-9 (Gal-9) pathway modulates function of various immune cells in maternal-fetal interface. However, the regulatory effects of Tim-3/Gal-9 signaling on MDSCs and its role in preeclampsia (PE) remain unclear. METHODS: In the current study we investigated the expression of Tim-3 on MDSC in preeclampsia (PE) patients to further explore the pathogenesis of PE. RESULTS: The proportion of Tim-3+ M-MDSC (monocytic MDSC) cells was higher in PE patients than in healthy control. Meanwhile, the protein expression of Gal-9, as the ligand of Tim-3, was increased in placenta of PE patients. M-MDSC also expressed a higher level of interferon-γ (IFN-γ) and a lower level of transforming growth factor-ß (TGF-ß) in PE. Furthermore, our study suggested that blocking Tim-3 could attenuate the inhibitory function of MDSC. DISCUSSION: The abnormal expression of Tim-3 on MDSC might be involved in the pathogenesis of PE, and could be a marker to evaluate the immune function in PE.