Natural variation of RGN1a regulates grain number per panicle in japonica rice

The grain number per panicle (GNP) is an important yield component. Identifying naturally favorable variations in GNP will benefit high-yield rice breeding. Here, we performed a genome-wide association study using a mini-core collection of 266 cultivated rice accessions with deep sequencing data and investigated the phenotype for three years. Three genes, i.e., TOTOU1 (TUT1), Grain height date 7 (Ghd7), and Days to heading 7/Grain height date 7.1/Pseudo-Response Regulator37 (DTH7/Ghd7.1/OsPRR37), which regulate GNP, were found in the quantitative trait loci (QTL) identified in this study. A stable QTL, qGNP1.3, which showed a strong correlation with variations in GNP, was repeatedly detected. After functional and transgenic phenotype analysis, we identified a novel gene, regulator of grain number 1a (RGN1a), which codes for protein kinase, controlling GNP in rice. The RGN1a mutation caused 37.2%, 27.8%, 51.2%, and 25.5% decreases in grain number, primary branch number per panicle, secondary branch number per panicle, and panicle length, respectively. Furthermore, breeding utilization analysis revealed that the additive effects of the dominant allelic variants of RGN1a and DTH7 played a significant role in increasing the grain number per panicle in japonica rice. Our findings enrich the gene pool and provide an effective strategy for the genetic improvement of grain numbers

A Multi‐Functional Separator for Li‐S Batteries: WS₂@C Nanoflowers Catalyze the Rapid Recycling of Lithium Polysulfides by Polar Attraction

Featuring high theoretical capacity, environmental friendliness and low cost, lithium‐sulfur (Li‐S) batteries become promising alternatives to satisfy the growing demand for energy storage. To boost their energy density for practical application, modified separators are needed to suppress shuttle effects resulting from the solubility of lithium polysulfides (LiPSs). Herein, we modified traditional polypropylene (PP) separators with functional WS₂@C nanoflower composites (WS₂@C‐PP). They can effectively adsorb LiPSs and catalyze their conversion on the edge sites of the WS₂. Also, the unique construction of a carbon layer coating on the WS₂ nanoflowers combines active sites and conducting properties. The material benefits the reversibility of redox reactions and reutilization of active materials. With the WS₂@C‐PP separator, the cell displays improved cycling stability and rate performance. When cycling at 0.1 C, the cell discharges a capacity of up to 1475 mAh g⁻¹, and it contributes 943 mAh g⁻¹ originally at 1 C, with a decay rate of only 0.07 % after 500 cycles. Our work highlights the potential of functional separators to advance the properties of Li‐S batteries

Low-dose PPI to prevent bleeding after ESD: A multicenter randomized controlled study

Background: Although proton pump inhibitors (PPIs) are widely used in the prevention of gastric bleeding caused by endoscopic submucosal dissection (ESD), there is no consensus on the optimal regimen for these patients. Therefore, we aim to investigate whether intermittent use of low-dose PPI is sufficient to prevent post-ESD bleeding. Methods: This multicenter, non-inferiority, randomized controlled trial was conducted at 9 hospitals in China. Consecutive eligible patients with a diagnosis of gastric mucosal lesions after ESD treatment were randomly assigned (1:1) to receive either intermittent low-dose or continuous high-dose PPIs treatment. After three days, all patients administered orally esomeprazole 40 mg once a day for 8 weeks. The primary endpoint was post-ESD bleeding within 7 days. Analysis was done according to the intention-to-treat principle with the non-inferiority margin (Δ) of 5%. Results: 526 consecutive patients were assessed for eligibility from 30 September 2017 to 30 July 2019, of whom 414 were randomly assigned to low-dose (n = 209) or high-dose (n = 205) esomeprazole treatment group without dropouts within7 days. The total post-ESD bleeding is occurred in 13 (6.2 %, 95 % CI 3.3–9.6) of 209 within 7 days in the intermittent low-dose group, and 12 (5.9 %, 95 % CI 2.9–9.3) of 205 in the continuous high-dose group. The absolute risk reduction (ARR) was 0.4 % (−4.2, 4.9). One month after ESD, There are 44 patients (21.1 %, 95 % CI 15.8, 26.8) and 39 patients (19.0 % 95 % CI 13.7, 24.4) in scar stage respectively in low-dose group and high-dose group (P = 0.875).The hospital costs in the low-dose PPI group was lower than high -dose group (P = 0.005). Conclusion: The intermittent use of low-dose PPIs is sufficient to prevent post-ESD bleeding. It might be applied in clinical practice to prevent post-ESD bleeding and reduce the costs related to PPIs

DataSheet_1_Natural variation of RGN1a regulates grain number per panicle in japonica rice.pdf

The grain number per panicle (GNP) is an important yield component. Identifying naturally favorable variations in GNP will benefit high-yield rice breeding. Here, we performed a genome-wide association study using a mini-core collection of 266 cultivated rice accessions with deep sequencing data and investigated the phenotype for three years. Three genes, i.e., TOTOU1 (TUT1), Grain height date 7 (Ghd7), and Days to heading 7/Grain height date 7.1/Pseudo-Response Regulator37 (DTH7/Ghd7.1/OsPRR37), which regulate GNP, were found in the quantitative trait loci (QTL) identified in this study. A stable QTL, qGNP1.3, which showed a strong correlation with variations in GNP, was repeatedly detected. After functional and transgenic phenotype analysis, we identified a novel gene, regulator of grain number 1a (RGN1a), which codes for protein kinase, controlling GNP in rice. The RGN1a mutation caused 37.2%, 27.8%, 51.2%, and 25.5% decreases in grain number, primary branch number per panicle, secondary branch number per panicle, and panicle length, respectively. Furthermore, breeding utilization analysis revealed that the additive effects of the dominant allelic variants of RGN1a and DTH7 played a significant role in increasing the grain number per panicle in japonica rice. Our findings enrich the gene pool and provide an effective strategy for the genetic improvement of grain numbers.</p

Genetic Architecture and Candidate Genes for Deep-Sowing Tolerance in Rice Revealed by Non-syn GWAS

Dry direct-seeding of rice is rapidly increasing in China, but variable planting depth associated with machine sowing can lead to low seedling emergence rates. Phenotype analysis of 621 rice accessions showed that mesocotyl length (ML) was induced by deep soil covering and was important in deep-sowing tolerance in the field. Here, we performed and compared GWAS using three types of SNPs (non-synonymous SNP, non-synonymous SNPs and SNPs within promoters and 3 million randomly selected SNPs from the entire set of SNPs) and found that Non-Syn GWAS (GWAS using non-synonyomous SNP) decreased computation time and eliminated confounding by other loci relative to GWAS using randomly selected SNPs. Thirteen QTLs were finally detected, and two new major-effect genes, named OsML1 and OsML2, were identified by an integrated analysis. There were 2 and 7 non-synonymous SNPs in OsML1 and OsML2, respectively, from which 3 and 4 haplotypes were detected in cultivated rice. Combinations of superior haplotypes of OsML1 and OsML2 increased ML by up to 4 cm, representing high emergence rate (85%) in the field with 10 cm of soil cover. The studies provide key loci and naturally occurring alleles of ML that can be used in improving tolerance to dry direct-seeding

Loci and natural alleles underlying robust roots and adaptive domestication of upland ecotype rice in aerobic conditions.

A robust (long and thick) root system is characteristic of upland japonica rice adapted to drought conditions. Using deep sequencing and large scale phenotyping data of 795 rice accessions and an integrated strategy combining results from high resolution mapping by GWAS and linkage mapping, comprehensive analyses of genomic, transcriptomic and haplotype data, we identified large numbers of QTLs affecting rice root length and thickness (RL and RT) and shortlisted relatively few candidate genes for many of the identified small-effect QTLs. Forty four and 97 QTL candidate genes for RL and RT were identified, and five of the RL QTL candidates were validated by T-DNA insertional mutation; all have diverse functions and are involved in root development. This work demonstrated a powerful strategy for highly efficient cloning of moderate- and small-effect QTLs that is difficult using the classical map-based cloning approach. Population analyses of the 795 accessions, 202 additional upland landraces, and 446 wild rice accessions based on random SNPs and SNPs within robust loci suggested that there could be much less diversity in robust-root candidate genes among upland japonica accessions than in other ecotypes. Further analysis of nucleotide diversity and allele frequency in the robust loci among different ecotypes and wild rice accessions showed that almost all alleles could be detected in wild rice, and pyramiding of robust-root alleles could be an important genetic characteristic of upland japonica. Given that geographical distribution of upland landraces, we suggest that during domestication of upland japonica, the strongest pyramiding of robust-root alleles makes it a unique ecotype adapted to aerobic conditions

Variation of a major facilitator superfamily gene contributes to differential cadmium accumulation between rice subspecies

Cadmium (Cd) accumulation in rice grain poses a serious threat to human health. While several transport systems have been reported, the complicity of rice Cd transport and accumulation indicates the necessity of identifying additional genes, especially those that are responsible for Cd accumulation divergence between indica and japonica rice subspecies. Here, we show that a gene, OsCd1, belonging to the major facilitator superfamily is involved in root Cd uptake and contributes to grain accumulation in rice. Natural variation in OsCd1 with a missense mutation Va1449Asp is responsible for the divergence of rice grain Cd accumulation between indica and japonica. Near-isogenic line tests confirm that the indica variety carrying the japonica allele OsCd1(V449) can reduce the grain Cd accumulation. Thus, the japonica allele OsCd1(V449) may be useful for reducing grain Cd accumulation of indica rice cultivars through breeding

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