Ornithine δ-aminotransferase OsOAT is critical for male fertility and cold tolerance during rice plant development.

Cold stress is a major factor limiting the production and geographical distribution of rice (Oryza sativa) varieties. However, the molecular mechanisms underlying cold tolerance remain to be elucidated. Here, we report that ornithine δ-aminotransferase (OsOAT) contributes to cold tolerance during the vegetative and reproductive development of rice. osoat mutant was identified as a temperature-sensitive male sterile mutant with deformed floral organs and seedlings sensitive to cold stress. Comparative transcriptome analysis showed that OsOAT mutation and cold treatment of the wild-type plant led to similar changes in the global gene expression profiles in anthers. OsOAT genes in indica rice Huanghuazhan (HHZ) and japonica rice Wuyungeng (WYG) are different in gene structure and response to cold. OsOAT is cold-inducible in WYG but cold-irresponsive in HHZ. Further studies showed that indica varieties carry both WYG-type and HHZ-type OsOAT, whereas japonica varieties mostly carry WYG-type OsOAT. Cultivars carrying HHZ-type OsOAT are mainly distributed in low-latitude regions, whereas varieties carrying WYG-type OsOAT are distributed in both low- and high-latitude regions. Moreover, indica varieties carrying WYG-type OsOAT generally have higher seed-setting rates than those carrying HHZ-type OsOAT under cold stress at reproductive stage, highlighting the favorable selection for WYG-type OsOAT during domestication and breeding to cope with low temperatures.

The ribosomal protein P0A is required for embryo development in rice.

BACKGROUND: The P-stalk is a conserved and vital structural element of ribosome. The eukaryotic P-stalk exists as a P0-(P1-P2)2 pentameric complex, in which P0 function as a base structure for incorporating the stalk onto 60S pre-ribosome. Prior studies have suggested that P0 genes are indispensable for survival in yeast and animals. However, the functions of P0 genes in plants remain elusive. RESULTS: In the present study, we show that rice has three P0 genes predicted to encode highly conserved proteins OsP0A, OsP0B and OsP0C. All of these P0 proteins were localized both in cytoplasm and nucleus, and all interacted with OsP1. Intriguingly, the transcripts of OsP0A presented more than 90% of the total P0 transcripts. Moreover, knockout of OsP0A led to embryo lethality, while single or double knockout of OsP0B and OsP0C did not show any visible defects in rice. The genomic DNA of OsP0A could well complement the lethal phenotypes of osp0a mutant. Finally, sequence and syntenic analyses revealed that OsP0C evolved from OsP0A, and that duplication of genomic fragment harboring OsP0C further gave birth to OsP0B, and both of these duplication events might happen prior to the differentiation of indica and japonica subspecies in rice ancestor. CONCLUSION: These data suggested that OsP0A functions as the predominant P0 gene, playing an essential role in embryo development in rice. Our findings highlighted the importance of P0 genes in plant development.

The nonlinear correlation between alanine aminotransferase to high-density lipoprotein cholesterol ratio and the risk of diabetes: a historical Japanese cohort study.

BACKGROUND: Low levels of high-density lipoprotein cholesterol (HDL-C) and high levels of alanine aminotransferase (ALT) are related to insulin resistance, metabolic syndrome, and diabetes mellitus (DM). However, evidence on the connection between the alanine aminotransferase to high-density lipoprotein cholesterol (ALT/HDL-C) ratio and diabetes mellitus (DM) risk was limited. The study aimed to investigate the relationship between baseline ALT/HDL-C ratio and DM among Japanese individuals. METHODS: This second analysis was based on a cohort study using open-source data. Data from 15,342 individuals who participated in the medical examination program were recorded at Murakami Memorial Hospital in Japan between 2004 and 2015. Smooth curve fitting, subgroup analysis, Cox proportional-hazards regression, and a series of sensitivity analyses were conducted to examine the relationship between ALT/HDL-C ratio and incident diabetes. The ability of the ALT/HDL-C ratio to predict diabetes was evaluated using a receiver operating characteristic curve analysis. RESULTS: After controlling for confounding covariates, the ALT/HDL-C ratio was found to be positively correlated to the DM risk in Japanese adults (HR: 1.01, 95%CI: 1.00-1.02, P = 0.049). This study also found a stable relationship between ALT/HDL-C ratio and diabetes after employing a series of sensitivity analyses. Additionally, there was a non-linear association between the ALT/HDL-C ratio and incident diabetes, and the ALT/HDL-C ratio inflection point was 30.12. When the ALT/HDL-C ratio was below 30.12, the present study discovered a significant positive association between the ALT/HDL-C ratio and incident diabetes (HR: 1.04, 95%CI: 1.02-1.06, P = 0.001). Furthermore, among liver enzymes, blood lipids, and anthropometric indicators, the ALT/HDL-C ratio best predicts DM (AUC = 0.75, 95%CI: 0.73-0.78). CONCLUSION: Increased ALT/HDL-C ratio levels at baseline correlated to incident DM. The relationship between ALT/HDL-C ratio and incident DM was also non-linear. When the ALT/HDL-C ratio is below 30.12, there is a statistically significant positive correlation between the ALT/HDL-C ratio and incident DM.

Diagnostic accuracy of the FRAIL scale for frailty screening in community-dwelling older adults with diabetes: A cross-sectional study.

There is limited evidence on the diagnostic accuracy of the FRAIL scale in community-dwelling older adults with diabetes. This study aimed to validate the diagnostic accuracy and determine the optimal cutoff point of the FRAIL scale in community-dwelling older adults with diabetes using the Fried Frailty Phenotype as the reference standard. A total of 489 community-dwelling older adults with diabetes aged 60 or above were recruited in this cross-sectional study. The FRAIL scale showed good diagnostic accuracy for frailty screening. The optimal cutoff point for frailty screening in older adults with diabetes was 2. The agreement between the FRAIL scale and the Fried Frailty Phenotype was substantial. The FRAIL scale classified more participants as frail (29.24%) than the Fried Frailty Phenotype (22.09%). These findings provide evidence that the FRAIL scale is a valid tool that can be applied to community-dwelling older adults with diabetes.

The plant-specific ABERRANT GAMETOGENESIS 1 gene is essential for meiosis in rice.

Meiotic recombination plays a central role in maintaining genome stability and increasing genetic diversity. Although meiotic progression and core components are widely conserved across kingdoms, significant differences remain among species. Here we identify a rice gene ABERRANT GAMETOGENESIS 1 (AGG1) that controls both male and female gametogenesis. Cytological and immunostaining analysis showed that in the osagg1 mutant the early recombination processes and synapsis occurred normally, but the chiasma number was dramatically reduced. Moreover, OsAGG1 was found to interact with ZMM proteins OsHEI10, OsZIP4, and OsMSH5. These results suggested that OsAGG1 plays an important role in crossover formation. Phylogenetic analysis showed that OsAGG1 is a plant-specific protein with a highly conserved N-terminal region. Further genetic and protein interaction analyses revealed that the conserved N-terminus was essential for the function of the OsAGG1 protein. Overall, our work demonstrates that OsAGG1 is a novel and critical component in rice meiotic crossover formation, expanding our understanding of meiotic progression. This study identified a plant-specific gene ABERRANT GAMETOGENESIS 1 that is required for meiotic crossover formation in rice. The conserved N-terminus of the AGG1 protein was found to be essential for its function.

Strategies to overcome the challenges of low or no expression of heterologous proteins in Escherichia coli.

Protein expression is a critical process in diverse biological systems. For Escherichia coli, a widely employed microbial host in industrial catalysis and healthcare, researchers often face significant challenges in constructing recombinant expression systems. To maximize the potential of E. coli expression systems, it is essential to address problems regarding the low or absent production of certain target proteins. This article presents viable solutions to the main factors posing challenges to heterologous protein expression in E. coli, which includes protein toxicity, the intrinsic influence of gene sequences, and mRNA structure. These strategies include specialized approaches for managing toxic protein expression, addressing issues related to mRNA structure and codon bias, advanced codon optimization methodologies that consider multiple factors, and emerging optimization techniques facilitated by big data and machine learning.

Construction of a Female Sterility Maintaining System Based on a Novel Mutation of the MEL2 Gene.

BACKGROUND: Hybrid rice has significant yield advantage and stress tolerance compared with inbred rice. However, production of hybrid rice seeds requires extensive manual labors. Currently, hybrid rice seeds are produced by crosspollination of male sterile lines by fertile paternal lines. Because seeds from paternal lines can contaminate the hybrid seeds, mechanized production by mixed-seeding and mixed-harvesting is difficult. This problem can be solved if the paternal line is female sterile. RESULTS: Here we identified a female infertile mutant named h569 carrying a novel mutation (A1106G) in the MEL2 gene that was previously reported to regulate meiosis entry both in male and female organs. h569 mutant is female infertile but male normal, suggesting that MEL2 regulates meiosis entry in male and female organs through distinct pathways. The MEL2 gene and h569 mutant gave us tools to construct female sterility maintaining systems that can be used for propagation of female sterile lines. We connected the wild-type MEL2 gene with pollen-killer gene ZmAA1 and seed-marker gene DsRed2 in one T-DNA cassette and transformed it into ZZH1607, a widely used restorer line. Transgenic line carrying a single transgene inserted in an intergenic region was selected to cross with h569 mutant. F2 progeny carrying homozygous A1106G mutation and hemizygous transgene displayed 1:1 segregation of fertile and infertile pollen grains and 1:1 segregation of fluorescent and non-fluorescent seeds upon self-fertilization. All of the non-fluorescent seeds generated female infertile plants, while the fluorescent seeds generated fertile plants that reproduced in the way as their previous generation. CONCLUSIONS: These results indicated that the female sterility maintaining system constructed in the study can be used to breed and propagate paternal lines that are female infertile. The application of this system will enable mechanized production of hybrid rice seed by using the mixed-seeding and mixed harvesting approach, which will significantly reduce the cost in hybrid rice seed production.

Global research states and trends of micro RNA in irritable bowel syndrome: a bibliometric analysis.

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder, but its diagnosis and treatment remain obscure. Non-coding RNAs (ncRNAs), as potential biomarkers, have attracted increasing attention in digestive diseases. Here, we present a comprehensive research status, development trends, and valuable insights in this subject area. The literature search was performed using Web of Science Core Collection. VOSviewer 1.6.20, Citespace 6.2.R4, and Microsoft Excel 2021 were used for bibliometric analysis. A total of 124 articles were included in the analysis. Overall, publication patterns fluctuated. Globally, People's Republic of China, the USA, and Germany were the top three contributors of publications. Guangzhou University of Chinese Medicine, University of California, Mayo Clinic, and University of California, Los Angeles contributed the highest number of publications. The pathways and specific mechanisms by which ncRNAs regulate transcription and translation and thus regulate the pathophysiological processes of IBS are the main research hotspots in this field. We found that microRNA (miRNAs) are intricately involved in the regulation of key pathologies such as viscera sensitivity, intestinal permeability, intestinal mucosal barrier, immunoinflammatory response, and brain-gut axis in the IBS, and these topics have garnered significant attention in research community. Notably, microecological disorders are also associated with IBS pathogenesis, and ncRNA may play an important role in the interactions between host and intestinal flora. This is the first bibliometric study to comprehensively summarize the research hotspots and trends related to IBS and ncRNAs (especially miRNAs). Our findings will help understand the role of ncRNAs in IBS and provide guidance to future studies.