The wall-associated kinase GWN1 controls grain weight and grain number in rice.

Grain size is a crucial agronomic trait that determines grain weight and final yield. Although several genes have been reported to regulate grain size in rice (Oryza sativa), the function of Wall-Associated Kinase family genes affecting grain size is still largely unknown. In this study, we identified GRAIN WEIGHT AND NUMBER 1 (GWN1) using map-based cloning. GWN1 encodes the OsWAK74 protein kinase, which is conserved in plants. GWN1 negatively regulates grain length and weight by regulating cell proliferation in spikelet hulls. We also found that GWN1 negatively influenced grain number by influencing secondary branch numbers and finally increased plant grain yield. The GWN1 gene was highly expressed in inflorescences and its encoded protein is located at the cell membrane and cell wall. Moreover, we identified three haplotypes of GWN1 in the germplasm. GWN1hap1 showing longer grain, has not been widely utilized in modern rice varieties. In summary, GWN1 played a very important role in regulating grain length, weight and number, thereby exhibiting application potential in molecular breeding for longer grain and higher yield.

Natural Variation in OsLG3 Increases Drought Tolerance in Rice by Inducing ROS Scavenging.

Improving the performance of rice (Oryza sativa) under drought stress has the potential to significantly affect rice productivity. Here, we report that the ERF family transcription factor OsLG3 positively regulates drought tolerance in rice. In our previous work, we found that OsLG3 has a positive effect on rice grain length without affecting grain quality. In this study, we found that OsLG3 was more strongly expressed in upland rice than in lowland rice under drought stress conditions. By performing candidate gene association analysis, we found that natural variation in the promoter of OsLG3 is associated with tolerance to osmotic stress in germinating rice seeds. Overexpression of OsLG3 significantly improved the tolerance of rice plants to simulated drought, whereas suppression of OsLG3 resulted in greater susceptibility. Phylogenetic analysis indicated that the tolerant allele of OsLG3 may improve drought tolerance in cultivated japonica rice. Introgression lines and complementation transgenic lines containing the elite allele of OsLG3IRAT109 showed increased drought tolerance, demonstrating that natural variation in OsLG3 contributes to drought tolerance in rice. Further investigation suggested that OsLG3 plays a positive role in drought stress tolerance in rice by inducing reactive oxygen species scavenging. Collectively, our findings reveal that natural variation in OsLG3 contributes to rice drought tolerance and that the elite allele of OsLG3 is a promising genetic resource for the development of drought-tolerant rice varieties.

Alternative splicing of OsLG3b controls grain length and yield in japonica rice.

Grain size, one of the important components determining grain yield in rice, is controlled by the multiple quantitative trait loci (QTLs). Intensive artificial selection for grain size during domestication is evidenced in modern cultivars compared to their wild relatives. Here, we report the molecular cloning and characterization of OsLG3b, a QTL for grain length in tropical japonica rice that encodes MADS-box transcription factor 1 (OsMADS1). Six SNPs in the OsLG3b region led to alternative splicing, which were associated with grain length in an association analysis of candidate region. Quantitative PCR analysis indicated that OsLG3b expression was higher during the panicle and seed development stages. Analysis of haplotypes and introgression regions revealed that the long-grain allele of OsLG3b might have arisen after domestication of tropical japonica and spread to subspecies indica or temperate japonica by natural crossing and artificial selection. OsLG3b is therefore a target of human selection for adaptation to tropical regions during domestication and/or improvement of rice. Phylogenetic analysis and pedigree records showed that OsLG3b had been employed by breeders, but the gene still has much breeding potential for increasing grain length in indica. These findings will not only aid efforts to elucidate the molecular basis of grain development and domestication, but also facilitate the genetic improvement of rice yield.

OsLG3 contributing to rice grain length and yield was mined by Ho-LAMap.

BACKGROUND: Most agronomic traits in rice are complex and polygenic. The identification of quantitative trait loci (QTL) for grain length is an important objective of rice genetic research and breeding programs. RESULTS: Herein, we identified 99 QTL for grain length by GWAS based on approximately 10 million single nucleotide polymorphisms from 504 cultivated rice accessions (Oryza sativa L.), 13 of which were validated by four linkage populations and 92 were new loci for grain length. We scanned the Ho (observed heterozygosity per locus) index of coupled-parents of crosses mapping the same QTL, based on linkage and association mapping, and identified two new genes for grain length. We named this approach as Ho-LAMap. A simulation study of six known genes showed that Ho-LAMap could mine genes rapidly across a wide range of experimental variables using deep-sequencing data. We used Ho-LAMap to clone a new gene, OsLG3, as a positive regulator of grain length, which could improve rice yield without influencing grain quality. Sequencing of the promoter region in 283 rice accessions from a wide geographic range identified four haplotypes that seem to be associated with grain length. Further analysis showed that OsLG3 alleles in the indica and japonica evolved independently from distinct ancestors and low nucleotide diversity of OsLG3 in indica indicated artificial selection. Phylogenetic analysis showed that OsLG3 might have much potential value for improvement of grain length in japonica breeding. CONCLUSIONS: The results demonstrated that Ho-LAMap is a potential approach for gene discovery and OsLG3 is a promising gene to be utilized in genomic assisted breeding for rice cultivar improvement.

Body fluids biomarkers associated with prognosis of acute ischemic stroke: progress and prospects.

Acute ischemic stroke (AIS) is one of the most common strokes posing a grave threat to human life and health. Predicting the prognosis of AIS allows for an understanding of disease progress, and a better quality of life by making individualized treatment scheme. In this paper, we conducted a systematic search on PubMed, focusing on the relevant literature in the last 5 years. Summarizing the candidate prognostic biomarkers of AIS in body fluids such as blood, urine, saliva and cerebrospinal fluid is often of great significance for the management of acute ischemic stroke, which has the potential to facilitate early diagnosis, treatment, prevention and long-term outcome improvement.

Acute ischemic stroke stands as a prominent contributor to global mortality and disability rates. This comprehensive review delves into the present state and advancements in the study of prognostic biomarkers for AIS in body fluids, enabling the monitoring of disease progression and prediction of prognosis. Furthermore, we elucidate the utilization of multiple biomarkers to predict outcomes more precisely. This paper emphasizes the importance of predicting disease progression as early as possible so that clinicians can change treatment regimens in time to better treat their patients.

Impact of early high protein intake in critically ill patients: a randomized controlled trial.

BACKGROUND: Conflicting findings regarding the impact of High protein intake during the early phase in critically ill patients have been reported. Therefore, we aimed to assess the influence of higher early protein intake on the prognosis of critically ill patients. METHODS: This randomized controlled trial involved 173 critically ill patients who stayed in the Intensive Care Unit/Emergency ICU (ICU/EICU) for at least 7 days. The Low group (n = 87) and High group (n = 86) received protein supplementation of 0.8 g/kg.d and 1.5 g/kg.d, respectively, within 1-3 days of enteral nutrition (EN) initiation, with both groups transitioning to 1.5 g/kg.d on the 4th day. The serum prealbumin (PA), blood urea nitrogen/creatinine, and rectus femoris muscle thickness and cross-sectional area of all patients was measured on the 1th, 3rd, 5th, 7th day, and the day of ICU/EICU discharge. RESULTS: Patients in both Low and High groups showed no significant differences in age, APACHE II scores, or other demographic and baseline characteristics. There were also no significant differences in the primary outcome (28-day mortality rate) and secondary outcomes (incidence rate of refeeding syndrome and EN tolerance score) between the two groups. However, the Low group exhibited a significantly higher 28-day mortality rate (HR = 2.462, 95% CI: 1.021-5.936, P = 0.045) compared to High group, as determined by Cox proportional hazards models incorporating the time factor. The High group exhibited significantly shorter durations of mechanical ventilation and ICU stay compared to the Low group. Serum PA levels were higher, and rectus femoris muscle atrophy rates were lower in the High group. Furthermore, for septic patients, high protein intake significantly reduced the 28-day mortality rate despite a small sample size (n = 34). CONCLUSIONS: Our study indicates that increasing early protein intake to 1.5 g/kg.d may be safe and help improve the nutritional status and prognosis of critically ill patients. TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry (ChiCTR2000039997, https://www.chictr.org.cn/ ).