Effect of Fat Content on Rice Taste Quality through Transcriptome Analysis.

Rice is an important crop in the word, and fat is one of the main important nutrient components of rice. The lipid content and fatty acid composition of grains significantly influences the quality of rice. In this study, 94 homozygous recombination inbred lines (RILs) were developed and the crude fat content of them displayed a normal distribution ranging from 0.44% to 2.62%. Based on their taste quality, a positive association between fat content and eating quality was revealed. Then, two lines (FH and FL) were selected with similar agronomic characteristics and different lipid content and taste quality for RNA sequencing analysis, and a total of 619 differentiable expressed genes were detected, primarily enriched in metabolic pathways such as starch and sucrose metabolism, fatty acid metabolism, and amino acid metabolism. The expression of two genes related to fatty acid synthesis and elongation was significantly up-regulated, while the expression of three genes related to fatty acid degradation was significantly down-regulated in FH grains. By using liquid chromatography, the relative levels of palmitic acid and oleic acid were discovered significantly higher in FH grains. Additionally, the comparative genomic analysis was conducted to visualize genomic differences of five genes. Ultimately, two genes (Os07g0417200 and Os12g0102100) were selected to be the key gene to affect the lipid metabolism, especially for the synthesis of unsaturated fatty acids, significantly changing the eating quality of rice. These results provide a theoretical basis for improving the taste quality of rice.

Pyramiding Breeding of Low-Glutelin-Content Indica Rice with Good Quality and Resistance.

Low-glutelin-content rice, a type of functional rice with glutelin levels below 4%, is an essential dietary supplement for chronic kidney disease (CKD) patients. Developing low-glutelin-content rice varieties is crucial to catering to the growing CKD population. In this study, we aimed to create a new low-glutelin indica rice variety with excellent agronomic traits. To achieve this, we employed a combination of molecular-marker-assisted selection and traditional breeding techniques. The cultivars W3660, Wushansimiao (WSSM), and Nantaixiangzhan (NTXZ) were crossbred, incorporating the Lgc-1, Pi-2, Xa23, and fgr alleles into a single line. The result of this breeding effort was "Yishenxiangsimiao", a new indica rice variety that inherits the desirable characteristics of its parent lines. Yishenxiangsimiao (YSXSM) possesses not only a low glutelin content but also dual resistance to blast and bacterial blight (BB). It exhibits high-quality grains with a fragrant aroma. This new low-glutelin indica cultivar not only ensures a stable food supply for CKD patients but also serves as a healthy dietary option for the general public. We also performed RNA-seq of these rice varieties to investigate their internal gene expression differences. The YSXSM exhibited a higher biotic-resistance gene expression in comparison to NTXZ. In summary, we successfully developed a novel low-glutelin indica rice variety, "Yishenxiangsimiao", with superior agronomic traits. This rice variety addresses the dietary needs of CKD patients and offers a nutritious choice for all consumers.

The Dsup coordinates grain development and abiotic stress in rice.

DNA damage is a serious threat to all living organisms and may be induced by environmental stressors. Previous studies have revealed that the tardigrade (Ramazzotius varieornatus) DNA damage suppressor protein Dsup has protective effects in human cells and tobacco. However, whether Dsup provides radiation damage protection more widely in crops is unclear. To explore the effects of Dsup in other crops, stable Dsup overexpression lines through Agrobacterium-mediated transformation were generated and their agronomic traits were deeply investigated. In this study, the overexpression of Dsup not only enhanced the DNA damage resistance at the seeds and seedlings stages, they also exhibited grain size enlargement and starch granule structure and cell size alteration by the scanning electron microscopy observation. Notably, the RNA-seq revealed that the Dsup plants increased radiation-related and abiotic stress-related gene expression in comparison to wild types, suggesting that Dsup is capable to coordinate normal growth and abiotic stress resistance in rice. Immunoprecipitation enrichment with liquid chromatography-tandem mass spectrometry (IP-LC-MS) assays uncovered 21 proteins preferably interacting with Dsup in plants, suggesting that Dsup binds to transcription and translation related proteins to regulate the homeostasis between DNA protection and plant development. In conclusion, our data provide a detailed agronomic analysis of Dsup plants and potential mechanisms of Dsup function in crops. Our findings provide novel insights for the breeding of crop radiation resistance.

1H NMR-Based Metabolic Profiling to Follow Changes in Pomelo Cultivars during Postharvest Senescence.

This study investigated metabolite changes in three pomelo cultivars during postharvest senescence using 1H NMR-based metabolic profiling. Three pomelo cultivars, 'Hongroumiyou', 'Bairoumiyou' and 'Huangroumiyou', abbreviated as "R", "W" and "Y" according to the color of their juice sacs, were stored at 25 °C for 90 days, and NMR was applied to determine the metabolite changes in juice sacs during storage. Fifteen metabolites were identified, including organic acids, sugars, amino acids, fatty acids, phenols and naringin. Partial least squares discriminant analysis (PLS-DA) was used to screen the significant metabolites according to the variable importance for the projection (VIP) scores in three pomelo cultivars during 90 days of storage. Additionally, eight metabolites, naringin, alanine, asparagine, choline, citric acid, malic acid, phosphocholine and ß-D-glucose, were screened to be the crucial biomarkers with VIP > 1. The undesirable flavor of "bitter and sour" during the 60 days of storage was mainly attributed to the naringin, citric acid and sugars. According to the correlation analysis, the citric acid content determined by NMR showed a significantly positive relationship with that analyzed by HPLC. These findings suggested that NMR technology was accurate and efficient for metabolomic analysis of pomelo fruit, and the 1H NMR-based metabolic profiling can be efficient during quality evaluation and useful for improving the fruit flavor quality during postharvest storage.

Integration of high-throughput omics technologies in medicinal plant research: The new era of natural drug discovery.

Medicinal plants are natural sources to unravel novel bioactive compounds to satisfy human pharmacological potentials. The world's demand for herbal medicines is increasing year by year; however, large-scale production of medicinal plants and their derivatives is still limited. The rapid development of modern technology has stimulated multi-omics research in medicinal plants, leading to a series of breakthroughs on key genes, metabolites, enzymes involved in biosynthesis and regulation of active compounds. Here, we summarize the latest research progress on the molecular intricacy of medicinal plants, including the comparison of genomics to demonstrate variation and evolution among species, the application of transcriptomics, proteomics and metabolomics to explore dynamic changes of molecular compounds, and the utilization of potential resources for natural drug discovery. These multi-omics research provide the theoretical basis for environmental adaptation of medicinal plants and allow us to understand the chemical diversity and composition of bioactive compounds. Many medicinal herbs' phytochemical constituents and their potential health benefits are not fully explored. Given their large diversity and global distribution as well as the impacts of growth duration and environmental factors on bioactive phytochemicals in medicinal plants, it is crucial to emphasize the research needs of using multi-omics technologies to address basic and applied problems in medicinal plants to aid in developing new and improved medicinal plant resources and discovering novel medicinal ingredients.

A Nested Case-Control Study of the Relationship between Salivary Inflammatory Mediators, Periodontal Parameters, and Preterm Birth in a Chinese Population.

Background: To explore whether salivary inflammatory mediators and periodontal indices at different gestational stages can be taken as indicators of preterm birth (PTB). Methods: This nested case-control study enrolled systemically healthy pregnant women at 9 to 36 weeks of gestation. Periodontal indices were measured at the enrollment date, and interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor (TNF-α), prostaglandin E2 (PGE2), and 8-hydroxy-deoxyguanosine (8-OHdG) in the saliva were determined by enzyme-linked immunosorbent assay (ELISA). The birth outcome was recorded. Results: PTB occurred in 26 women. A total of 104 matched women with full-term birth (FTB) were used as controls. The PTB women enrolled at 24-28 gestational weeks displayed a significantly greater bleeding index (BI), probing pocket depth (PD), PD ≥ 4 mm sites (%), saliva-TNF-α, and saliva-PGE2 (P < 0.05). BI and PGE2 in the saliva were found to be positively associated with PTB (OR = 4.79, P = 0.048, 95%CI = 1.014 to 22.628; OR = 1.07, P = 0.04, 95%CI = 1.004 to 1.135, respectively). The areas under the receiver operating characteristic curve (ROC) of BI and saliva-PGE2 were 0.82 and 0.78, respectively, and that of the combined detection was 0.91, which was larger than either marker alone, although the differences were not significant (P > 0.05). Conclusions: The combination of BI and PGE2 in saliva at 24-28 gestational weeks could be a predictor of PTB in asymptomatic women. However, the results should be further explored with larger sample size.

Initiation and Execution of Programmed Cell Death and Regulation of Reactive Oxygen Species in Plants.

Programmed cell death (PCD) plays crucial roles in plant development and defence response. Reactive oxygen species (ROS) are produced during normal plant growth, and high ROS concentrations can change the antioxidant status of cells, leading to spontaneous cell death. In addition, ROS function as signalling molecules to improve plant stress tolerance, and they induce PCD under different conditions. This review describes the mechanisms underlying plant PCD, the key functions of mitochondria and chloroplasts in PCD, and the relationship between mitochondria and chloroplasts during PCD. Additionally, the review discusses the factors that regulate PCD. Most importantly, in this review, we summarise the sites of production of ROS and discuss the roles of ROS that not only trigger multiple signalling pathways leading to PCD but also participate in the execution of PCD, highlighting the importance of ROS in PCD.

Improving the Rice Photosynthetic Efficiency and Yield by Editing OsHXK1 via CRISPR/Cas9 System.

Rice (Oryza sativa L.) is an important food crop species in China. Cultivating high-yielding rice varieties that have a high photosynthetic efficiency is an important goal of rice breeding in China. In recent years, due to the continual innovation of molecular breeding methods, many excellent genes have been applied in rice breeding, which is highly important for increasing rice yields. In this paper, the hexokinase gene OsHXK1 was knocked out via the CRISPR/Cas9 gene-editing method in the indica rice varieties Huanghuazhan, Meixiangzhan, and Wushansimiao, and OsHXK1-CRISPR/Cas9 lines were obtained. According to the results of a phenotypic analysis and agronomic trait statistics, the OsHXK1-CRISPR/Cas9 plants presented increased light saturation points, stomatal conductance, light tolerance, photosynthetic products, and rice yields. Moreover, transcriptome analysis showed that the expression of photosynthesis-related genes significantly increased. Taken together, our results revealed that knocking out OsHXK1 via the CRISPR/Cas9 gene-editing method could effectively lead to the cultivation of high-photosynthetic efficiency and high-yielding rice varieties. They also revealed the important roles of OsHXK1 in the regulation of rice yield and photosynthesis.

Association between periodontal indexes and biomarkers in gingival crevicular fluid and preterm birth in pregnancy: a nested case-control study.

OBJECTIVES: This study aimed to investigate the association between periodontal indexes and biomarkers in gingival crevicular fluid (GCF) and preterm birth (PTB) in pregnancy, as well as to assess the clinical value of these indexes as predictors of PTB. METHODS: A nested case-control study was conducted. A total of 300 systematically healthy pregnant women were selected within 36 weeks of gestation and grouped according to the enrolled weeks. Periodontal indexes, including probing depth (PD), bleeding index (BI), gingival index (GI), and five biomarkers in GCF, including interleukin (IL)-1ß, IL-6, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were measured at the enrolled date. The detailed birth outcome was recorded. RESULTS: Only women at 24-28 weeks of gestation per PTB case (four full-term births) were selected as controls subjects, PTB displayed significantly greater GI, BI, and 8-OHdG (P<0.05). Logistic regression analysis revealed that BI and 8-OHdG were the dependent risk factors of PTB (OR=5.90, P=0.034; OR=1.18, P=0.045, respectively). The areas under the receiver operating characteristic curve (ROC) of BI and 8-OHdG were 0.80 and 0.69, and that of the combined detection was 0.82, which was larger than the individual detection, although the differences were not significant (P>0.05). CONCLUSIONS: Increased BI and 8-OHdG at 24-28 weeks of gestation are risk factors for PTB. Their combined detection may have some value in the prediction of PTB, but further studies with a larger sample size are needed to explore it and thus provide experiment evidence for establishing an early warning system for PTB in pregnant women with periodontal disease.

Revegetation of a barren rare earth mine using native plant species in reciprocal plantation: effect of phytoremediation on soil microbiological communities.

Over-exploration of rare earth elements causes soil desertification and environmental degradation. However, the restoration of rare earth mine tailings requires the recovery of both vegetation and soil microbiota. Accordingly, the present study aimed to compare the efficacy of restoring mine tailings using organic compost and native plants (Miscanthus sinensis, Pinus massoniana, Bambusa textilis, or a mixture of all three). After three years, the mixed plantation harbored tenfold greater plant richness than that in the barren land. Among these, M. sinensis played a dominant role across all restored areas. The microbial communities of the soils were assessed using high-throughput 16S rDNA gene sequencing. A total of 34,870 16S rDNA gene sequences were obtained and classified into 15 bacterial phyla and 36 genera. The dominant genus across all the restored soils was Burkholderia, and the bacterial diversity of restored soils was greater than that of soils from either unrestored or natural (unexploited) areas, with the M. sinensis plantation yielding the greatest diversity. The effects of phytoremediation were mainly driven by changes in nutrient and metal contents. These results indicate that M. sinensis significantly improves phytoremediation and that mixed planting is ideal for restoring the soils of abandoned rare earth mines.