OsPDCD5 negatively regulates plant architecture and grain yield in rice.

Plant architecture is an important agronomic trait that affects crop yield. Here, we report that a gene involved in programmed cell death, OsPDCD5, negatively regulates plant architecture and grain yield in rice. We used the CRISPR/Cas9 system to introduce loss-of-function mutations into OsPDCD5 in 11 rice cultivars. Targeted mutagenesis of OsPDCD5 enhanced grain yield and improved plant architecture by increasing plant height and optimizing panicle type and grain shape. Transcriptome analysis showed that OsPDCD5 knockout affected auxin biosynthesis, as well as the gibberellin and cytokinin biosynthesis and signaling pathways. OsPDCD5 interacted directly with OsAGAP, and OsAGAP positively regulated plant architecture and grain yield in rice. Collectively, these findings demonstrate that OsPDCD5 is a promising candidate gene for breeding super rice cultivars with increased yield potential and superior quality.

Novel Salinity-Tolerant Third-Generation Hybrid Rice Developed via CRISPR/Cas9-Mediated Gene Editing.

Climate change has caused high salinity in many fields, particularly in the mud flats in coastal regions. The resulting salinity has become one of the most significant abiotic stresses affecting the world's rice crop productivity. Developing elite cultivars with novel salinity-tolerance traits is regarded as the most cost-effective and environmentally friendly approach for utilizing saline-alkali land. To develop a highly efficient green strategy and create novel rice germplasms for salt-tolerant rice breeding, this study aimed to improve rice salinity tolerance by combining targeted CRISPR/Cas9-mediated editing of the OsRR22 gene with heterosis utilization. The novel alleles of the genic male-sterility (GMS) and elite restorer line (733Srr22-T1447-1 and HZrr22-T1349-3) produced 110 and 1 bp deletions at the third exon of OsRR22 and conferred a high level of salinity tolerance. Homozygous transgene-free progeny were identified via segregation in the T2 generation, with osrr22 showing similar agronomic performance to wild-type (733S and HZ). Furthermore, these two osrr22 lines were used to develop a new promising third-generation hybrid rice line with novel salinity tolerance. Overall, the results demonstrate that combining CRISPR/Cas9 targeted gene editing with the "third-generation hybrid rice system" approach allows for the efficient development of novel hybrid rice varieties that exhibit a high level of salinity tolerance, thereby ensuring improved cultivar stability and enhanced rice productivity.

Heterosis in root microbiota inhibits growth of soil-borne fungal pathogens in hybrid rice.

In nature, plants are colonized by various microbes that play essential roles in their growth and health. Heterosis is a natural genetic phenomenon whereby first-generation hybrids exhibit superior phenotypic performance relative to their parents. It remains unclear whether this concept can be extended to the "hybridization" of microbiota from two parents in their descendants and what benefits the hybrid microbiota might convey. Here, we investigated the structure and function of the root microbiota from three hybrid rice varieties and their parents through amplicon sequencing analysis of bacterial 16S ribosomal DNA (rDNA) and fungal internal transcribed spacer (ITS) regions. We show that the bacterial and fungal root microbiota of the varieties are distinct from those of their parental lines and exhibit potential heterosis features in diversity and composition. Moreover, the root bacterial microbiota of hybrid variety LYP9 protects rice against soil-borne fungal pathogens. Systematic analysis of the protective capabilities of individual strains from a 30-member bacterial synthetic community derived from LYP9 roots indicated that community members have additive protective roles. Global transcription profiling analyses suggested that LYP9 root bacterial microbiota activate rice reactive oxygen species production and cell wall biogenesis, contributing to heterosis for protection. In addition, we demonstrate that the protection conferred by the LYP9 root microbiota is transferable to neighboring plants, potentially explaining the observed hybrid-mediated superior effects of mixed planting. Our findings suggest that some hybrids exhibit heterosis in their microbiota composition that promotes plant health, highlighting the potential for microbiota heterosis in breeding hybrid crops.

Mutation of Leaf Senescence 1 Encoding a C2H2 Zinc Finger Protein Induces ROS Accumulation and Accelerates Leaf Senescence in Rice.

Premature senescence of leaves causes a reduced yield and quality of rice by affecting plant growth and development. The regulatory mechanisms underlying early leaf senescence are still unclear. The Leaf senescence 1 (LS1) gene encodes a C2H2-type zinc finger protein that is localized to both the nucleus and cytoplasm. In this study, we constructed a rice mutant named leaf senescence 1 (ls1) with a premature leaf senescence phenotype using CRISPR/Cas9-mediated editing of the LS1 gene. The ls1 mutants exhibited premature leaf senescence and reduced chlorophyll content. The expression levels of LS1 were higher in mature or senescent leaves than that in young leaves. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were significantly increased and catalase (CAT) activity was remarkably reduced in the ls1 plants. Furthermore, a faster decrease in pigment content was detected in mutants than that in WT upon induction of complete darkness. TUNEL and staining experiments indicated severe DNA degradation and programmed cell death in the ls1 mutants, which suggested that excessive ROS may lead to leaf senescence and cell death in ls1 plants. Additionally, an RT-qPCR analysis revealed that most senescence-associated and ROS-scavenging genes were upregulated in the ls1 mutants compared with the WT. Collectively, our findings revealed that LS1 might regulate leaf development and function, and that disruption of LS1 function promotes ROS accumulation and accelerates leaf senescence and cell death in rice.

Rice MutLγ, the MLH1-MLH3 heterodimer, participates in the formation of type I crossovers and regulation of embryo sac fertility.

The development of embryo sacs is crucial for seed production in plants, but the genetic basis regulating the meiotic crossover formation in the macrospore and microspore mother cells remains largely unclear. Here, we report the characterization of a spontaneous rice female sterile variation 1 mutant (fsv1) that showed severe embryo sacs abortion with low seed-setting rate. Through map-based cloning and functional analyses, we isolated the causal gene of fsv1, OsMLH3 encoding a MutL-homolog 3 protein, an ortholog of HvMLH3 in barley and AtMLH3 in Arabidopsis. OsMLH3 and OsMLH1 (MutL-homolog 1) interact to form a heterodimer (MutLγ) to promote crossover formation in the macrospore and microspore mother cells and development of functional megaspore during meiosis, defective OsMLH3 or OsMLH1 in fsv1 and CRISPR/Cas9-based knockout lines results in reduced type I crossover and bivalent frequency. The fsv1 and OsMLH3-knockout lines are valuable germplasms for development of female sterile restorer lines for mechanized seed production of hybrid rice.

Genetic analysis for rice grain quality traits in the YVB stable variant line using RAD-seq.

The future of rice breeding will likely be built on the basis of the further utilization of heterosis between elite cultivars and genetic resources from distant subspecies of rice. Previous studies have proved that exogenous genomic DNA transformation methods can be used to transfer genetic information from distant relatives (donor) into cultivated rice (recipient). However, the mechanism underlying this form of genetic transfer is poorly characterized, and the genes that cause the phenotypic changes in these variants are typically difficult to identify. This study examined YVB, a stable variant line with greatly improved grain quality traits that was derived from an indica variety (V20B) by transferring genomic DNA of O.minuta through the "spike-stalk injection method (SIM)". We used restriction-site associated DNA sequencing technology (RAD-seq) to evaluate a population of BC1F5 backcross lines (YVB × V20B); the RAD-seq data were used to construct a genetic linkage map with high-density SNPs for use in association analysis exploring genotype-phenotype relationships at the whole-genome level. A total of 17 quantitative trait loci (QTLs) for rice quality traits were mapped to chromosomes 3, 5, 6, 8, and 9. 8 major QTLs controlling different phenotypic variations were mapped to the same region of chromosome 5. This region contained the GS5 gene for grain weight and the qSW5/GW5 gene for grain width. This study provides new resources and insights into the molecular mechanisms of grain trait phenotypic variation and the transmission of genetic information via the introduction of genomic DNA to a distantly related crop relative species.

Characteristic and inheritance analysis of targeted mutagenesis mediated by genome editing in rice.

The transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) systems are two current genome editing technologies. Here, we compare and analyze the characteristics of the targeted mutations mediated by these two systems, such as efficiency, type, position, time, and genetic patterns. Both the TALEN and CRISPR/Cas9 systems can induce site-specific mutations in T0 rice plants effectively, but CRISPR/Cas9 is more effective. The major mutation type in both systems is the short insertion/deletion(InDel) mutation within 10 base pairs: deletions ranging from 1 to 10 bps are more often in TALEN, and 1bp insertions are more often in CRISPR/Cas9. Moreover, double-strand breaks (DSBs) generated by CRISPR/Cas9 are more precise than TALEN. In addition, DSBs could be repaired by the homologous recombination at a low frequency, causing DNA fragment duplication mutations. In some cases, the DNA fragments between the two close targets are deleted or inverted, and the mutation efficiency does not positively correlatewith the mutation efficiency of each target. Mutagenesis mediated by the TALEN or CRISPR/Cas9 system can occur as early as in transformed callus cells, and less frequently in somatic cells. Consequently, four different mutation types are formed, including homozygous, heterozygous, bi-allelic and chimeric mutations, with bi-allelic mutations having the highest rate and chimeric mutations having the lowest rate. All, except chimeric mutations, can descend stably into the next generation.

Deep re-sequencing of a widely used maintainer line of hybrid rice for discovery of DNA polymorphisms and evaluation of genetic diversity.

Genetic diversity within parental lines of hybrid rice is the foundation of heterosis utilization and yield improvement. Previous studies have suggested that genetic diversity was narrow in cytoplasmic male sterile (CMS/A line) and restorer lines (R line) for Three-line hybrid rice. However, the genetic diversity within maintainer lines (B line), especially at a genome-wide scale, remains largely unknown. In the present study, we performed deep re-sequencing of the elite maintainer line V20B (Oryza sativa L. ssp. indica). We then compared the V20B sequence with the 93-11 (Oryza sativa L. ssp. indica) genome sequence. 112.1 × 106 paired-end reads (PE reads) were generated with approximately 30-fold sequencing depth. The V20B PE reads uniquely covered 87.6 % of the 93-11 genome sequence. Overall, a total of 660,778 single-nucleotide polymorphism (SNPs) and 266,301 insertions and deletions (InDels) were identified, yielding an average of 2.1 SNPs/kb and 0.8 InDels/kb. Genome-wide distribution of the SNPs and InDels was non-random, and variation-rich and variation-poor regions were identified in all chromosomes. A total of 20,562 non-synonymous SNPs spanning 8,854 genes were annotated. Our results identified DNA polymorphisms at the genome-wide scale and uncovered the high level of genetic diversity between V20B and 93-11. Our results proved that next-generation sequencing technologies can be powerful tools to study genome-wide DNA polymorphisms, to query genetic diversity, and to enable molecular improvement efforts with Three-line hybrid rice. Further, our results also indicated that 93-11 could be used as core germplasm for the improvement of wild-abortive CMS lines and the maintainer lines.

Iron Plaque: A Shield against Soil Contamination and Key to Sustainable Agriculture.

Soils play a dominant role in supporting the survival and growth of crops and they are also extremely important for human health and food safety. At present, the contamination of soil by heavy metals remains a globally concerning environmental issue that needs to be resolved. In the environment, iron plaque, naturally occurring on the root surface of wetland plants, is found to be equipped with an excellent ability at blocking the migration of heavy metals from soils to plants, which can be further developed as an environmentally friendly strategy for soil remediation to ensure food security. Because of its large surface-to-volume porous structure, iron plaque exhibits high binding affinity to heavy metals. Moreover, iron plaque can be seen as a reservoir to store nutrients to support the growth of plants. In this review, the formation process of iron plaque, the ecological role that iron plaque plays in the environment and the interaction between iron plaque, plants and microbes, are summarized.

Research on Physiological Characteristics and Differential Gene Expression of Rice Hybrids and Their Parents under Salt Stress at Seedling Stage.

Soil salinization is one of the most important abiotic stresses which can seriously affect the growth and development of rice, leading to the decrease in or even loss of a rice harvest. Increasing the rice yield of saline soil is a key issue for agricultural production. The utilization of heterosis could significantly increase crop biomass and yield, which might be an effective way to meet the demand for rice cultivation in saline soil. In this study, to elucidate the regulatory mechanisms of rice hybrids and their parents that respond to salt stress, we investigated the phenotypic characteristics, physiological and biochemical indexes, and expression level of salt-related genes at the seedling stage. In this study, two sets of materials, encapsulating the most significant differences between the rice hybrids and their parents, were screened using the salt damage index and a hybrid superiority analysis. Compared with their parents, the rice hybrids Guang-Ba-You-Hua-Zhan (BB1) and Y-Liang-You-900 (GD1) exhibited much better salt tolerance, including an increased fresh weight and higher survival rate, a better scavenging ability towards reactive oxygen species (ROS), better ionic homeostasis with lower content of Na+ in their Na+/K+ ratio, and a higher expression of salt-stress-responsive genes. These results indicated that rice hybrids developed complex regulatory mechanisms involving multiple pathways and genes to adapt to salt stress and provided a physiological basis for the utilization of heterosis for improving the yield of rice under salt stress.

OsPMS1 Mutation Enhances Salt Tolerance by Suppressing ROS Accumulation, Maintaining Na+/K+ Homeostasis, and Promoting ABA Biosynthesis.

World-wide, rice (Oryza sativa L.) is an important food source, and its production is often adversely affected by salinity. Therefore, to ensure stable rice yields for global food security, it is necessary to understand the salt tolerance mechanism of rice. The present study focused on the expression pattern of the rice mismatch repair gene post-meiotic segregation 1 (OsPMS1), studied the physiological properties and performed transcriptome analysis of ospms1 mutant seedlings in response to salt stress. Under normal conditions, the wild-type and ospms1 mutant seedlings showed no significant differences in growth and physiological indexes. However, after exposure to salt stress, compared with wild-type seedlings, the ospms1 mutant seedlings exhibited increased relative water content, relative chlorophyll content, superoxide dismutase (SOD) activity, K+ and abscisic acid (ABA) content, and decreased malondialdehyde (MDA) content, Na+ content, and Na+/K+ ratio, as well as decreased superoxide anion (O2-) and hydrogen peroxide (H2O2) accumulation. Gene ontology (GO) analysis of the differentially expressed genes (DEGs) of ospms1 mutant seedlings treated with 0 mM and 150 mM NaCl showed significant enrichment in biological and cytological processes, such as peroxidase activity and ribosomes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis showed that the DEGs specifically enriched ascorbate and aldarate metabolism, flavone and flavonol biosynthesis, and glutathione metabolism pathways. Further quantitative real-time reverse transcription-PCR (qRT-PCR) analysis revealed significant changes in the transcription levels of genes related to abscisic acid signaling (OsbZIP23, OsSAPK6, OsNCED4, OsbZIP66), reactive oxygen scavenging (OsTZF1, OsDHAR1, SIT1), ion transport (OsHAK5), and osmoregulation (OsLEA3-2). Thus, the study's findings suggest that the ospms1 mutant tolerates salt stress at the seedling stage by inhibiting the accumulation of reactive oxygen species, maintaining Na+ and K+ homeostasis, and promoting ABA biosynthesis.

[Clinical study of intercondylar fossa formation to prevent intercondylar fossa impingement after high tibia osteotomy].

OBJECTIVE: To observe the clinical efficacy of intercondylar fossa plasty in preventing intercondylar fossa impingement syndrome after high tibial osteotomy. METHODS: From August 2018 to August 2020, 84 patients with inverted knee osteoarthritis were treated by arthroscopy combined with high tibial osteotomy, and were divided into two groups with 42 cases in each group according to different surgical methods. In the intercondylar fossa plasty group, there were 13 males and 29 females, age ranged from 52 to 67 years old with an average of(58.27±4.32) years old, and arthroscopic intercondylar fossa plasty was performed first, and then high tibial osteotomy. In the arthroscopic cleansing group, 16 males and 26 females, age ranged from 50 to 71 years old with an average of (59.02±5.14) years old, underwent arthroscopic cleansing and then high tibial osteotomy. Postoperative treatment was evaluated using visual analogue scale(VAS), hospital for special surgery (HSS) score for the knee, and the occurrence of intercondylar percussa impingement. RESULTS: All 84 patients were followed up, the duration ranged from 12 to 18 months with an average of (14.1±1.6) months. The VAS and HSS score of knee joint at 6, 12 and 18 months after surgery were significantly improved compared with preoperative period, and there was no significant difference between the two groups (P>0.05), but the incidence of intercondylar fossa index and intercondylar fossa impact between the two groups was significantly compared 18 months after surgery (P<0.05). CONCLUSION: Intercondylar fossa plasty can effectively prevent the incidence of intercondylar fossa impact after high tibial osteotomy, and has a more significant effect on postoperative knee pain and function improvement.

Patellar Height after High Tibial Osteotomy of the Distal Tibial Tuberosity: A Retrospective Study of Age Stratification.

OBJECTIVE: To explore the effect of age stratification on patellar height after single-plane high tibial osteotomy of the distal tibial tuberosity (DTT-HTO). METHODS: A retrospective analysis was performed on 110 knee joints undergoing DTT-HTO. Patients were divided into three groups according to age: under 60 years old, 28 cases; 60 to 70 years old, 61 cases; and over 70 years old, 21 cases. All patients were followed up for no less than 12 months, and at each follow-up, short-leg radiographs and whole-leg radiographs were taken. The values of the Caton-Deschamps index (CDI) and Blackburne-Peel index (BPI) of single-short-leg radiographs and the femoral-tibial angle (FTA) and weight-bearing line ratio (WBLR) of whole-leg radiographs were measured before and at the last follow-up. The Lysholm score before and at the last follow-up and the visual analogue scale (VAS) score before and 3 days after surgery and at the last follow-up were calculated. The frequency of classification of the normal-height patella, patella alta, and patella baja before and after surgery was recorded. RESULTS: There were no significant differences in CDI and BPI preoperatively or postoperatively among the three groups (P > 0.05), and there were no statistically significant differences in FTA and WBLR. There were no significant differences in CDI, BPI, FTA, or WBLR between the three groups before and after the operation (P > 0.05). The Lysholm score increased from 48.84 ± 10.10 before surgery to 91.96 ± 3.082 after surgery (P < 0.05); the VAS score decreased from 8.23 ± 0.99 before surgery to 1.93 ± 0.953 at 3 days after surgery and 1.07 ± 0.53 at the last follow-up (P < 0.01). No significant difference was observed in the incidence of each patellar height classification between the three groups preoperatively and postoperatively. CONCLUSION: Patellar height is not influenced by DTT-HTO. The age of patients is not a limiting factor for the selection of this surgical procedure. Without affecting the height of the patella, DTT-HTO can effectively reduce pain in the knee joint, restore the function of the knee joint, and delay the progression of patellar arthritis.

Double-seedlings and embryo-free seeds generated by genetic engineering.

Apomixis can fix the heterosis of Hybrid F1, by maintaining its heterozygous genotype, and is an ideal way for the development of hybrid rice. In this paper, we designed an engineering strategy for realizing apomictic reproduction of hybrid rice in the way of induce adventitious embryos. An embryogenesis gene, AtWUS, controlled by the ovule-specific promoter, a ribonuclease gene Barnase driven by the egg cell-specific promoter pDD45, and an inactivation gene ZmAA1 driven by the pollen-specific promoter pG47 were simultaneously integrated into one T-DNA, and co-transformed with the second T-DNA carrying a Barstar gene. Double-seedlings were observed in transgenic line. Whole-genome sequencing and ploidy levels confirmed by flow cytometry showed that one of the double-seedlings was heterozygous diploid and the other seedling was homozygous haploid, which confirmed that embryogenesis in one of the double-seedlings arises from the zygote after fertilization and the other derived from an unfertilized gamete. Meanwhile we obtained embryo-free seeds at frequencies of 2.6% to 3.8% in T1 generation, and 0.75% to 3% in T2 generation. Though we did not obtained adventitious embryos in hybrid rice in this study, the phenomenon of double-seedlings and embryo-free seeds in transgenic line was informative and strongly suggested that endosperm development is an autonomously organized process in rice, independent of egg cell fertilization and embryo-endosperm communication. This provides novel insights into the induction of haploid embryos and lends theoretical support to successful clonal propagation using synthetic apomixis.

Three-dimensional surgical planning and clinical evaluation of the efficacy of distal tibial tuberosity high tibial osteotomy in obese patients with varus knee osteoarthritis.

PURPOSE: High tibial osteotomy (HTO) is an effective surgical treatment for varus knee osteoarthritis. However, obese patients require reinforced internal fixation materials to prevent internal fixation fractures and hardware failure after osteotomy. Therefore, the purpose of our study is to evaluate the clinical efficacy of distal tibial tuberosity high tibial osteotomy (DTT-HTO) using the new patented π-shaped plate in obese patients with varus knee osteoarthritis. METHOD: Thirty-four obese patients (39 knees) with varus knee osteoarthritis who underwent DTT-HTO with the π-shaped plate and second-look arthroscopy when implant removal occurred from September 2017 to June 2020 were retrospectively reviewed. Three-dimensional surgical planning using DTT-HTO on the knees is performed. There were 9 males and 25 females, with body mass index (BMI) values ranging from 30.3 to 38.5 kg/m2 and ages ranging from 50 to 75 years old. The radiological assessment was performed with the femora tibial angle (FTA) and the weight-bearing line ratio (WBLR). The clinical outcomes were evaluated by the Hospital for Special Surgery (HSS) knee score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The status of the cartilage was evaluated by the International Cartilage Repair Society (ICRS) grading system. RESULTS: All patients were followed up for 18-30 months. The FTA significantly changed from 181.68±1.68.preoperatively to171.29±1.51.at the last follow-up (P<0.001). The WBLR significantly increased from 16.85±2.20 to 55.41±2.46% from before surgery to the last follow-up after surgery (P<0.001). The HSS score significantly improved from 56.65±5.27 preoperatively to 68.79±2.61, 77.82±2.15, and 86.12±2.78 at the 6-month, 12-month, and last follow-up after surgery (P<0.001). The WOMAC score significantly decreased from 105.47±3.89 preoperatively to 80.50±4.20, 71.44±4.65, and 52.44±3.14 at the 6-month, 12-month, and last follow-up after surgery (P<0.001). During implant removal, no internal fixation fractures occurred in any patient. The articular cartilage grade in the medial compartment of the knee were significantly higher in the second arthroscopy than in the first arthroscopy, according to the ICRS grading system (P<0.001). The articular cartilage grade in the lateral compartment of the knee showed no statistical differences from the first- to the second-look arthroscopy (P>0.05). CONCLUSION: There are no correlation between BMI and postoperative outcomes. DTT-HTO shows yield excellent clinical results in obese patients with varus knee osteoarthritis. It can be recommended to be used for the heavy patients.

Medial compartment cartilage repair and lower extremity biomechanical changes after single-plane high tibial osteotomy of distal tibial tuberosity.

OBJECTIVE: To observe the cartilage repair of the medial compartment and the biomechanical changes of the lower extremities after single-plane high tibial osteotomy of distal tibial tuberosity (DTT-HTO). METHODS: A total of 30 patients, including 11 males and 19 females, who underwent DTT-HTO with arthroscopic operation in our hospital from January 2020 to January 2021 and underwent arthroscopic exploration again during the second operation for internal fixation were enrolled. There were 32 knees, including 13 left knees and 19 right knees. Age ranged from 50 to 78, with an average of 63.20 ± 6.61 years old. All patients completed two surgeries and were followed up, and no adverse events occurred during the period. International Cartilage Repair Society (ICRS) was used to assess the cartilage condition of the medial compartment of the knee during the two surgeries. In this paper, the weight-bearing line ratio (WBLR), the medial proximal tibia angle (MPTA), the femoral tibial angle (FTA) and the posterior tibial slope (PTS) were used to evaluate the changes of the mechanical state of the lower limbs. The visual analogue scale (VAS) score and the Western Ontario and McMaster University Osteoarthritis (WOMAC) Index score were used to evaluate the improvement in knee pain and function. RESULTS: All patients completed two operations without adverse events and serious complications. The medial compartment cartilage of all patients had different degrees of repair during the second operation, and the difference was statistically significant compared with the first operation (P < 0.05). During the second operation, the WBLR was corrected from (17.69 ± 2.16)% to (60.90 ± 1.97)%, the MPTA was corrected from (80.72 ± 1.61)° to (89.91 ± 2.58)°, the FTA was corrected from (182.31 ± 3.03)° to (171.81 ± 2.24)°, the difference was statistically significant (P < 0.05). There was no statistical difference in PTS between the two surgeries (P > 0.05). At the second operation, the VAS score decreased from 7.50 ± 1.34 to 0.34 ± 0.85, the WOMAC score decreased from 119.50 ± 10.43 to 46.25 ± 4.13, and the difference was statistically significant (P < 0.05). CONCLUSION: DTT-HTO can significantly correct the weight-bearing line, restore the biomechanical parameters of the lower limb to the normal range, significantly relieve pain and improve knee function, and the medial compartment cartilage repair and regeneration phenomenon will occur after the correction of the weight-bearing line.

Knockout of OsNRAMP5 enhances rice tolerance to cadmium toxicity in response to varying external cadmium concentrations via distinct mechanisms.

OsNRAMP5 is a transporter responsible for cadmium (Cd) and manganese (Mn) uptake and root-to-shoot translocation of Mn in rice plants. Knockout of OsNRAMP5 is regarded as an effective approach to minimize Cd uptake and accumulation in rice. It is vital to evaluate the effects of knocking out OsNRAMP5 on Cd and Mn accumulation, as well as Cd tolerance of rice plants in response to varying environmental Cd concentrations, and to uncover the underlying mechanism, which until now, has remained largely unexplored. This study showed that knockout of OsNRAMP5 decreased Cd uptake, but simultaneously facilitated Cd translocation from roots to shoots. The effect of OsNRAMP5 knockout on reducing root Cd uptake weakened, however its effect on improving root-to-shoot Cd translocation was constant with increasing environmental Cd concentrations. As a result, its mutation dramatically reduced Cd accumulation in shoots under low and moderate Cd stress, but inversely increased that under high Cd conditions. Interestingly, Cd tolerance of its knockout mutants was persistently enhanced, irrespective of lower or higher Cd concentrations in shoots, compared with that of wild-type plants. Knockout of OsNRAMP5 mitigated Cd toxicity by dramatically diminishing Cd uptake at low or moderate external Cd concentrations. Remarkably, its knockout effectively complemented deficient mineral nutrients in shoots, thereby indirectly enhancing rice tolerance to severe Cd stress. Additionally, its mutation conferred preferential delivery of Mn to young leaves and grains. These results have important implications for the application of the OsNRAMP5 mutation in mitigating Cd toxicity and lowering the risk of excessive Cd accumulation in rice grains.

Overexpression of OsLCT2, a Low-Affinity Cation Transporter Gene, Reduces Cadmium Accumulation in Shoots and Grains of Rice.

Cadmium (Cd)-contaminated rice is a serious issue affecting food safety. Understanding the molecular regulatory mechanisms of Cd accumulation in rice grains is crucial to minimizing Cd concentrations in grains. We identified a member of the low-affinity cation transporter family, OsLCT2 in rice. It was a membrane protein. OsLCT2 was expressed in all tissues of the elongation and maturation zones in roots, with the strongest expression in pericycle and stele cells adjacent to the xylem. When grown in Cd-contaminated paddy soils, rice plants overexpressing OsLCT2 significantly reduced Cd concentrations in the straw and grains. Hydroponic experiment demonstrated its overexpression decreased the rate of Cd translocation from roots to shoots, and reduced Cd concentrations in xylem sap and in shoots of rice. Moreover, its overexpression increased Zn concentrations in roots by up-regulating the expression of OsZIP9, a gene responsible for Zn uptake. Overexpression of OsLCT2 reduces Cd accumulation in rice shoots and grains by limiting the amounts of Cd loaded into the xylem and restricting Cd translocation from roots to shoots of rice. Thus, OsLCT2 is a promising genetic resource to be engineered to reduce Cd accumulation in rice grains.

Corrigendum: Correlations Between Parental Lines and Indica Hybrid Rice in Terms of Eating Quality Traits.

[This corrects the article DOI: 10.3389/fnut.2020.583997.].

[High tibial osteotomy combined with lateral retinacular release for the treatment of knee varus osteoarthritis with lateral patellar compression syndrome].

OBJECTIVE: To investigate the clinical effect of high tibial osteotomy combined with arthroscopic lateral retinacular release in the treatment of knee varus osteoarthritis. METHODS: From October 2017 to April 2019, a retrospective analysis was performed on 43 patients with knee varus osteoarthritis and lateral patellar compression syndrome treated by high tibial osteotomy combined with arthroscopic lateral retinacular release. There were 15 males and 28 females, aged 53 to 72(62.05±5.17) years. The visual analogue scale(VAS), Lysholm, and the knee range of motion were used to evaluate knee pain and functional recovery before operation, 2 weeks, 3 months and 12 months after operation. And the congruence angle (CA), patellar tilt angle (PTA), and femala-tibial angle (FTA) were measured respectively before and 12 months after operation to evaluate the congruence of patellar joint, and the improvement of line of gravity of lower limb. RESULTS: All 43 patients were followed up for more than 12 months, with a follow-up time of 14 to 28 (19.60±4.50) months. The VAS scores decreased from 6.65±0.65 before operation to 2.16±0.95, 0.51±0.77 and 0.33±0.64 at 2 weeks, 3 months and 12 months after operation, and the difference was statistically significant (P<0.001). Lysholm score increased from 43.02±8.54 before operation to 46.84±2.81, 72.42±5.30, and 93.40±5.44 at 2 weeks, 3 months and 12 months after operation, and the difference was statistically significant (P<0.001). The knee range of motion increased from (86.97±5.02)° before operation to (99.38±3.27)°, (110.13±4.13)°, and (113.03±4.85)° at 2 weeks, 3 months and 12 months after operation, the difference was statistically significant (P<0.001). The CA decreased from (7.81±1.21)° before operation to (5.82±4.10)° at 12 months after operation, the PTA decreased from (15.87±2.89)° before operation to (13.79±4.26)° at 12 months after operation, and the FTA decreased from(182.61±2.07)° before operation to(170.89±0.89)° at 12 months after operation, and the differences were statistically significant (P<0.05). One case received proper braking and anticoagulation after operation, and was improved after 1 week. The swelling was observed in 14 patients after operation, and subsided about 2 weeks later. CONCLUSION: High tibial osteotomy combined with arthroscopic lateral retinacular release can relieve weight-bearing pain in frontal axis and improve the function of knee in sagittal axis.