Early Detection of Rice Blast Using a Semi-Supervised Contrastive Unpaired Translation Iterative Network Based on UAV Images.

Rice blast has caused major production losses in rice, and thus the early detection of rice blast plays a crucial role in global food security. In this study, a semi-supervised contrastive unpaired translation iterative network is specifically designed based on unmanned aerial vehicle (UAV) images for rice blast detection. It incorporates multiple critic contrastive unpaired translation networks to generate fake images with different disease levels through an iterative process of data augmentation. These generated fake images, along with real images, are then used to establish a detection network called RiceBlastYolo. Notably, the RiceBlastYolo model integrates an improved fpn and a general soft labeling approach. The results show that the detection precision of RiceBlastYolo is 99.51% under intersection over union (IOU0.5) conditions and the average precision is 98.75% under IOU0.5-0.9 conditions. The precision and recall rates are respectively 98.23% and 99.99%, which are higher than those of common detection models (YOLO, YOLACT, YOLACT++, Mask R-CNN, and Faster R-CNN). Additionally, external data also verified the ability of the model. The findings demonstrate that our proposed model can accurately identify rice blast under field-scale conditions.

Preparation and properties of phosphinic acid-functionalized polyacrylonitrile hollow fiber membrane for heavy metal adsorption.

In this study, phosphorylated polyacrylonitrile hollow fiber membrane was synthesized by reacting aminated polyacrylonitrile hollow fiber membrane with phosphinic acid in a Mannich reaction. The batch single-factor measurements revealed that the phosphorylated polyacrylonitrile (PPAN) membrane had an outstanding ability for Hg2+ adsorption. Thermodynamic investigations indicated that the adsorption process was homogenous, and the theoretical maximum adsorption capacity predicted by the Langmuir model was 371.75 mg·g-1. The PPAN membrane was able to successfully chelate Hg2+ ions and attain saturation in 4 h, demonstrating that the reaction was chemically controlled by the adsorption kinetics. Based on the FT-IR and XPS spectral characterization data, successful phosphinic acid group grafting was proven, and a plausible mechanism for Hg2+ adsorption by PPAN membranes was presented. Furthermore, the five adsorption-desorption cycle experiments revealed that PPAN hollow fiber membranes had outstanding reusability, indicating a possible use for removing heavy metal ions from wastewater.

Effects of Nitrogen Deficiency on the Metabolism of Organic Acids and Amino Acids in Oryza sativa.

Organic acids metabolism and nitrogen (N) metabolism in rice seedlings and the relationship between them are not fully understood. In this study, rice (Oryza sativa L. ssp. Indica) variety "Huanghuazhan" was used as the experimental material, and three N levels (5 mM, 1 mM, and 0 mM NH4NO3) were set by the hydroponic method for different levels of N treatment. Our results showed that the increased content of malate in rice leaves caused by reducing N level was related to the increased synthesis of malate (the activity of leaf PEPC increased)and the decreased degradation of malate (the activity of leaf NADP-ME decreased), while the increased contents of citrate and isocitrate in rice leaves caused by reducing N level might not be caused by the increased biosynthesis, but due to the decrease in degradation of citrate and isocitrate (the activities of leaf CS, ACO, and NADP-IDH decreased). The increased content of malate in rice roots caused by reducing N level might be related to the increased biosynthesis and the decreased degradation of root malate (the activities of root NAD-MDH and PEPC increased, while the activity of NADP-ME decreased). Compared to the control (5 mM NH4NO3), the increased content of citrate in rice roots caused by reducing N level might be related to the increased biosynthesis rather than the decreased degradation of citrate, due to the higher activities of CS and ACO in rice roots under 0 mM N and 1mM N treatment when compared to that of the control ones. At the same time, the increased content of isocitrate in roots was related to the increased isomerization of isocitrate (the activity of root ACO increased) and the decreased degradation of isocitrate (the activity of root NADP-IDH decreased). With the reducing N level, the activities of N metabolism-related enzymes, such as nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT), decreased in rice leaves and roots, resulting in the decreased contents of total free amino acids (TFAAs) and soluble proteins in rice seedlings, and finally led to the growth inhibition. Our results showed that the dynamics of organic acids metabolism caused by reducing N level were different in rice leaves and roots. In conclusion, there was a close correlation between organic acids metabolism and N metabolism in rice leaves and roots under N-limited conditions; furthermore, such a correlation was more obvious in rice leaves than that of roots.

Evaluation on antiosteoporosis of collagen peptides prepared by immobilized protease with eggshell membrane.

Collagen peptides are a potential treatment for osteoporosis due to their antiosteoporosis activity. In this study, we prepared immobilized protease with eggshell membrane as carrier, and then hydrolyzed collagen to obtain collagen peptide. The antiosteoporosis of collagen peptides was confirmed by hBMSC osteogenic differentiation and bone mineralization improvement results. Surprisingly, antiosteoporosis of collagen peptides was related to the molecular weight of collagen peptides. This was derived from the osteoblast marker gene expressions, and mineral elements in P1 treatment were higher than those in P3 treatment. Consequently, these results confirmed that antiosteoporosis of low molecular weight collagen peptides is higher than that of higher molecular weight collagen peptides. Furthermore, the antiosteoporosis activity of P1 was due to its peptide sequences with known antiosteoporosis activity in P1. PRACTICAL APPLICATION: Using eggshell membrane as carrier to prepare immobilized protease was meaningful for solving the problem of resource waste. In addition, the results showed that collagen peptides possessed antiosteoporosis, and the effect of low molecular weight collagen peptides was better. This study provides a theoretical basis for developing high antiosteoporosis collagen peptides able to treat osteoporosis.

An overview of the bioactivity of monacolin K / lovastatin.

Monacolin K (MK) is the principal active substance in Monascus-fermentation products (e.g. red yeast rice). MK is effective in reducing cholesterol levels in humans and has been widely used as a lipid-lowering drug. The mechanism for this is through a high degree of competitive inhibition of the rate-limiting enzyme HMG-CoA reductase (HMGR) in the cholesterol synthesis pathway. In addition to lowering blood lipid levels, MK also prevents colon cancer, acute myeloid leukemia and neurological disorders such as Parkinson's disease and type I neurofibromatosis. The aim of this manuscript is to comprehensively review the progress in the study of the biological activity of MK and its imechanism of action in reducing blood lipid concentration, prevention of cancer and its neuroprotective, anti-inflammatory and antibacterial properties. This review provides a reference for future applications of MK in functional foods and medicine.

Preventive effects of combinative natural foods produced by elite crop varieties rich in anticancer effects on N-nitrosodiethylamine-induced hepatocellular carcinoma in rats.

The World Cancer Research Fund International has released 32 anticancer effects (ACEs) that targeted every stage of cancer processes. Thus, we designed two formulas of natural food combination Diet I and Diet II, mainly produced by elite crop varieties rich in ACEs with different mixture ratios, and evaluated their cancer preventive effects on N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis. After 20 weeks of dietary intervention, Diet I and Diet II reduced incidence, size, and number of hepatic nodules (p < 0.01) and prevented hepatic tumor formation in NDEA-induced hepatocarcinogenesis rats. Low-grade hepatic dysplasia incidence was 20% for Diet II and 40% for Diet I, and apparent hepatocellular carcinomas (HCC) rates were both 0, while 90% HCC in control diet treatment group (p < 0.01). Diet I and Diet II ameliorated abnormal liver function enzymes, reduced serum alpha fetal protein, tumor-specific growth factor, dickkopf-related protein 1, tumor necrosis factor-alpha and interleukin-6 levels, regulated hepatic phase I and II xenobiotic-metabolizing enzymes, enhanced antioxidant capacity, suppressed NDEA-initiated oxidative DNA damage, and induced apoptosis coupled to down-regulation of proinflammatory, invasion, and angiogenesis markers. Daily intake of combination diet produced from ACEs-rich elite crop varieties can effectively prevent or delay occurrence and development of NDEA-induced hepatocarcinogenesis in rats.

Proteomic Analysis Reveals Coordinated Regulation of Anthocyanin Biosynthesis through Signal Transduction and Sugar Metabolism in Black Rice Leaf.

Black rice (Oryza sativa L.) is considered to be a healthy food due to its high content of anthocyanins in the pericarp. The synthetic pathway of anthocyanins in black rice grains has been identified, however, the proteomic profile of leaves during grain development is still unclear. Here, isobaric Tags Relative and Absolute Quantification (iTRAQ) MS/MS was carried out to identify statistically significant changes of leaf proteome in the black rice during grain development. Throughout three sequential developmental stages, a total of 3562 proteins were detected and 24 functional proteins were differentially expressed 3-10 days after flowering (DAF). The detected proteins are known to be involved in various biological processes and most of these proteins were related to gene expression regulatory (33.3%), signal transduction (16.7%) and developmental regulation and hormone-like proteins (12.5%). The coordinated changes were consistent with changes in regulatory proteins playing a leading role in leaves during black rice grain development. This indicated that signal transduction between leaves and grains may have an important role in anthocyanin biosynthesis and accumulation during grain development of black rice. In addition, four identified up-regulated proteins associated with starch metabolism suggested that the remobilization of nutrients for starch synthesis plays a potential role in anthocyanin biosynthesis of grain. The mRNA transcription for eight selected proteins was validated with quantitative real-time PCR. Our results explored the proteomics of the coordination between leaf and grain in anthocyanins biosynthesis of grain, which might be regulated by signal transduction and sugar metabolism in black rice leaf.

Production of Marker-free Transgenic Rice (Oryza sativa L.) with Improved Nutritive Quality Expressing AmA1.

Background: Rice seed proteins are lacking essential amino acids (EAAs). Genetic engineering offers a fast and sustainable method to solve this problem as it allows the specific expression of heterologous EAA-rich proteins. The use of selectable marker gene is essential for generation of transgenic crops, but might also lead to potential environmental and food safety problems. Therefore, the production of marker-free transgenic crops is becoming an extremely attractive alternative and could contribute to the public acceptance of transgenic crops. Objectives: The present study was conducted to examine whether AmA1 can be expressed specifically in rice seeds, and generate marker-free transgenic rice with improved nutritive value. Materials and Methods:AmA1 was transferred into rice using Agrobacterium-mediated co-transformation system with a twin T-DNA binary vector and its integration in rice genome was confirmed by southern blot. Transcription of AmA1 was analyzed by Real-Time PCR and its expression was verified by western analysis. Protein and amino acid content were measured by the Kjeldahl method and the high-speed amino acid analyzer, respectively. Results: Five selectable marker-free homozygous transgenic lines were obtained from the progeny. The expression of recombinant AmA1 was confirmed by the observation of a 35 kDa band in SDS-PAGE and western blot. Compared to the wild-type control, the total protein contents in the seeds of five homozygous lines were increased by 1.06~12.87%. In addition, the content of several EAAs, including lysine, threonine, and valine was increased significantly in the best expressing line. Conclusions: The results indicated that the amino acid composition of rice grain could be improved by seed-specific expression of AmA1.

iTRAQ-Based Quantitative Proteomics Analysis of Black Rice Grain Development Reveals Metabolic Pathways Associated with Anthocyanin Biosynthesis.

BACKGROUND: Black rice (Oryza sativa L.), whose pericarp is rich in anthocyanins (ACNs), is considered as a healthier alternative to white rice. Molecular species of ACNs in black rice have been well documented in previous studies; however, information about the metabolic mechanisms underlying ACN biosynthesis during black rice grain development is unclear. RESULTS: The aim of the present study was to determine changes in the metabolic pathways that are involved in the dynamic grain proteome during the development of black rice indica cultivar, (Oryza sativa L. indica var. SSP). Isobaric tags for relative and absolute quantification (iTRAQ) MS/MS were employed to identify statistically significant alterations in the grain proteome. Approximately 928 proteins were detected, of which 230 were differentially expressed throughout 5 successive developmental stages, starting from 3 to 20 days after flowering (DAF). The greatest number of differentially expressed proteins was observed on 7 and 10 DAF, including 76 proteins that were upregulated and 39 that were downregulated. The biological process analysis of gene ontology revealed that the 230 differentially expressed proteins could be sorted into 14 functional groups. Proteins in the largest group were related to metabolic process, which could be integrated into multiple biochemical pathways. Specifically, proteins with a role in ACN biosynthesis, sugar synthesis, and the regulation of gene expression were upregulated, particularly from the onset of black rice grain development and during development. In contrast, the expression of proteins related to signal transduction, redox homeostasis, photosynthesis and N-metabolism decreased during grain maturation. Finally, 8 representative genes encoding different metabolic proteins were verified via quantitative real-time polymerase chain reaction (qRT-PCR) analysis, these genes had differed in transcriptional and translational expression during grain development. CONCLUSIONS: Expression analyses of metabolism-related protein groups belonging to different functional categories and subcategories indicated that significantly upregulated proteins were related to flavonoid and starch synthesis. On the other hand, the downregulated proteins were determined to be related to nitrogen metabolism, as well as other functional categories and subcategories, including photosynthesis, redox homeostasis, tocopherol biosynthetic, and signal transduction. The results provide valuable new insights into the characterization and understanding of ACN pigment production in black rice.

Production of dammarane-type sapogenins in rice by expressing the dammarenediol-II synthase gene from Panax ginseng C.A. Mey.

Ginsenosides are the main active ingredients in Chinese medicinal ginseng; 2,3-oxidosqualene is a precursor metabolite to ginsenosides that is present in rice. Because rice lacks a key rate-limiting enzyme (dammarenediol-II synthase, DS), rice cannot synthesize dammarane-type ginsenosides. In this study, the ginseng (Panax ginseng CA Mey.) DS gene (GenBank: AB265170.1) was transformed into rice using agrobacterium, and 64 rice transgenic plants were produced. The Transfer-DNA (T-DNA) insertion sites in homozygous lines of the T2 generation were determined by using high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR) and differed in all tested lines. One to two copies of the T-DNA were present in each transformant, and real-time PCR and Western blotting showed that the transformed DS gene could be transcribed and highly expressed. High performance liquid chromatography (HPLC) analysis showed that the dammarane-type sapogenin 20(S)-protopanaxadiol (PPD) content was 0.35-0.59 mg/g dw and the dammarane-type sapogenin 20(S)-protopanaxatriol (PPT) content was 0.23-0.43 mg/g dw in the transgenic rice. LC/MS analysis confirmed production of PPD and PPT. These results indicate that a new "ginseng rice" germplasm containing dammarane-type sapogenins has been successfully developed by transforming the ginseng DS gene into rice.

Production of oleanane-type sapogenin in transgenic rice via expression of ß-amyrin synthase gene from Panax japonicus C. A. Mey.

BACKGROUND: Panax japonicus C. A. Mey. is a rare traditional Chinese herbal medicine that uses ginsenosides as its main active ingredient. Rice does not produce ginsenosides because it lacks a key rate-limiting enzyme (ß-amyrin synthase, ßAS); however, it produces a secondary metabolite, 2,3-oxidosqualene, which is a precursor for ginsenoside biosynthesis. RESULTS: In the present study, the P. japonicus ßAS gene was transformed into the rice cultivar 'Taijing 9' using an Agrobacterium-mediated approach, resulting in 68 rice transgenic plants of the T0 generation. Transfer-DNA (T-DNA) insertion sites in homozygous lines of the T2 generation were determined by using high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR) and were found to vary among the tested lines. Approximately 1-2 copies of the ßAS gene were detected in transgenic rice plants. Real-time PCR and Western blotting analyses showed that the transformed ßAS gene could be overexpressed and ß-amyrin synthase could be expressed in rice. HPLC analysis showed that the concentration of oleanane-type sapogenin oleanolic acid in transgenic rice was 8.3-11.5 mg/100 g dw. CONCLUSIONS: The current study is the first report on the transformation of P. japonicus ßAS gene into rice. We have successfully produced a new rice germplasm, "ginseng rice", which produces oleanane-type sapogenin.

Genome re-sequencing and bioinformatics analysis of a nutraceutical rice.

The genomes of two rice cultivars, Nipponbare and 93-11, have been well studied. However, there is little available genetic information about nutraceutical rice cultivars. To remedy this situation, the present study aimed to provide a basic genetic landscape of nutraceutical rice. The genome of Black-1, a black pericarp rice containing higher levels of anthocyanins, flavonoids, and a more potent antioxidant capacity, was sequenced at ≥30 × coverage using Solexa sequencing technology. The complete sequences of Black-1 genome shared more consensus sequences with indica cultivar 93-11 than with Nipponbare. With reference to the 93-11 genome, Black-1 contained 675,207 single-nucleotide polymorphisms, 43,130 insertions and deletions (1-5 bp), 1,770 copy number variations, and 10,911 presence/absence variations. These variations were observed to reside preferentially in Myb domains, NB-ARC domains and kinase domains, providing clues to the diversity of biological functions or secondary metabolisms in this cultivar. Intriguingly, 496 unique genes were identified by comparing it with the genomes of these two rice varieties; among the genes, 119 genes participate in the biosynthesis of secondary metabolites. Furthermore, several unique genes were predicted to be involved in the anthocyanins synthesis pathway. The genome-wide landscape of Black-1 uncovered by this study represents a valuable resource for further studies and for breeding nutraceutical rice varieties.

Genome-wide analysis of radiation-induced mutations in rice (Oryza sativa L. ssp. indica).

Radiation has been efficiently used for rice germplasm innovation. However, the molecular mechanisms by which radiation induces mutations are still unclear. In this study, we performed whole genome sequencing to reveal the comprehensive mutations in rice treated with radiation. Red-1 (a rice rich in beneficial ingredients for human health) was derived from rice 9311 after γ-radiation. Solexa sequencing technology was applied to uncover the mutations. Compared with the 9311 genome, 9.19% of genome sequences were altered in the Red-1 genome. Among these alterations, there were 381,403 SNPs, 50,116 1-5 bp Indels, 1279 copy number variations, and 10,026 presence/absence variations. These alterations were located in 14,493 genes, the majority of which contained a kinase domain, leucine rich repeats, or Cyt_P450. Point mutations were the main type of variation in the Red-1 genome. Gene ontology clustering revealed that genes that are associated with cell components, binding function, catalytic activity and metabolic processes were susceptible to γ-radiation. It was also predicted that 8 mutated genes were involved in the biosynthetic pathways of beneficial products or pigment accumulation. We conclude that genome-wide analysis of mutations provides novel insights into the mechanisms by which radiation improves the beneficial ingredients in rice Red-1.

DNp73 improves generation efficiency of human induced pluripotent stem cells.

BACKGROUND: Recent studies have found that p53 and its' associated cell cycle pathways are major inhibitors of human induced pluripotent stem (iPS) cell generation. In the same family as p53 is p73, which shares sequence similarities with p53. However, p73 also has distinct properties of its own, such as two alternative promoters to express transactivation of p73 (TAp73) and N terminal deleted p73 (DNp73). Functionally, TAp73 acts similarly to p53 in tumor suppression. However, DNp73, on the other hand acts as an oncogene to suppress p53 and p73 induced apoptosis. Therefore, how can p73 have opposing roles in human iPS cell generation? RESULTS: Transcription factors, Oct4, Sox2, Klf4 and cMyc (4TF, Yamanaka factors) are used as basal conditions to generate iPS cells. In addition, the factor of DNp73(actually alpha splicing DNp73, DNp73α) is used to generate iPS cells. The experiment found that the addition of DNp73 gene increases human iPS cell generation efficiency by 12.6 folds in comparison to human fibroblast cells transduced with only the basal conditions. Also, iPS cells generated with DNp73 expression are more resistant to in vitro and in vivo differentiation. CONCLUSIONS: This study found DNp73, a family member of p53, is also involved in the human iPS cell generation. Specifically, that the involvement of DNp73 generates iPS cells that are more resistant to in vitro and in vivo differentiation. Therefore, this data may prove to be useful in future developmental studies and cancer researches.