Photocontrollable DNA Walker-Based Molecular Circuit for the Tunable Detection of MicroRNA-21 Using Metal-Organic Frameworks as Label-Free Fluorescence Tags.

Tunable detection of microRNA is crucial to meet the desired demand for sample species with varying concentrations in clinical settings. Herein, we present a DNA walker-based molecular circuit for the detection of miRNA-21 (miR-21) with tunable dynamic ranges and sensitivity levels ranging from fM to pM. The phosphate-activated fluorescence of UiO-66-NH2 metal-organic framework nanoparticles was used as label-free fluorescence tags due to their competitive coordination effect with the Zr atom, which significantly inhibited the ligand-to-metal charge transfer. To achieve a tunable detection performance for miR-21, the ultraviolet sensitive o-nitrobenzyl was induced as a photocleavable linker, which was inserted at various sites between the loop and the stem of the hairpin probe to regulate the DNA strand displacement reaction. The dynamic range can be precisely regulated from 700- to 67,000-fold with tunable limits of detection ranging from 2.5 fM to 36.7 pM. Impressively, a Boolean logic tree and complex molecular circuit were constructed for logic computation and cancer diagnosis in clinical blood samples. This intelligent biosensing method presents a powerful solution for converting complex biosensing systems into actionable healthcare decisions and will facilitate early disease diagnosis.

d-Penicillamine@Ag/Cu Nanocluster-Based Fluorescent Nanoneuron for Logic Screening Phosphonate-Type Organophosphate Pesticides and Steganographically Encrypting Information.

Organophosphate pesticides are used in agriculture due to their high effectiveness and low persistence in eradicating insects and pests. However, conventional detection methods encounter the limitation of undesired detection specificity. Thus, screening phosphonate-type organophosphate pesticides (OOPs) from their analogues, phosphorothioate organophosphate pesticides (SOPs), remains a challenge. Here, we reported a d-penicillamine@Ag/Cu nanocluster (DPA@Ag/Cu NCs)-based fluorescence assay to screen OOPs from 21 kinds of organophosphate pesticides, which can be used for logic sensing and information encryption. Acetylthiocholine chloride was enzymatically split by acetylcholinesterase (AChE) to produce thiocholine, which reduced the fluorescence of DPA@Ag/Cu NCs due to the transmission of electrons from DPA@Ag/Cu NCs donor to the thiol group acceptor. Impressively, OOPs acted as an AChE inhibitor and retained the high fluorescence of DPA@Ag/Cu NCs due to the stronger positive electricity of the phosphorus atom. Conversely, SOPs possessed weak toxicity to AChE, which led to low fluorescence intensity. By setting 21 kinds of organophosphate pesticides as the inputs and the fluorescence of the resulting products as the outputs, DPA@Ag/Cu NCs could serve as a fluorescent nanoneuron to construct Boolean logic tree and complex logic circuit for molecular computing. As a proof of concept, by converting the selective response patterns of DPA@Ag/Cu NCs into binary strings, molecular crypto-steganography for encoding, storing, and concealing information was successfully achieved. This study is expected to advance the progress and practical application of nanoclusters in the area of logic detection and information security while also enhancing the relationship between molecular sensors and the world of information.

A dual-signal fluorescent colorimetric tetracyclines sensor based on multicolor carbon dots as probes and smartphone-assisted visual assay.

The widespread presence of tetracyclines in the environment has raised concerns about the potential risks to ecosystems and human health. The ratiometric fluorescence sensor for detecting tetracyclines was developed using europium-doped carbon dots (Eu-CDs) as probes under alkaline conditions. The sensing mechanism of sensor for tetracyclines was considered as inner filter effect (IFE), antenna effect (AE), and self-quenching effect (SQE). The sensor had a wide linear detection range than the reported europium ions-based tetracyclines sensors. The linear detection ranges of oxytetracycline (OTC), tetracycline (TC), doxycycline (DC) and chlorotetracycline (CTC) were respectively 0.00-603.75 µM, 0.00-623.82 µM, 0.00-594.61 µM and 0.00-601.54 µM, and the corresponding detection limits were respectively 9.50 nM, 15.80 nM, 10.40 nM and 90.30 nM. The smartphone with RGB Color Picker was further employed to analyze the concentration of tetracyclines, which provided a new method for visual tetracyclines detection. The application of Eu-CDs test paper was also explored, and the results showed that the Eu-CDs test paper has great potential application in the visual detection of tetracyclines. In addition, the accuracy of the established tetracyclines sensor was compared with that of the China national standard method by high-performance liquid chromatography (HPLC), and the results showed that the established method in this work has similar accuracy to the China national standard method. The sensor has been employed to detect tetracyclines in the actual samples with satisfactory results, which indicated that this method has promising applications in the real-time monitoring tetracyclines of food and environment.

A novel thiolysis-high-performance liquid chromatography method for the determination of proanthocyanidins in grape seeds.

A novel thiolysis-high-performance liquid chromatography method for the quantitative determination of total proanthocyanidins and the mean degree of polymerization in grape seeds has been developed. Following thiolysis with formic acid and benzyl mercaptan, reaction products were separated and purified. Three proanthocyanidin monomers and three derivatives were obtained and their structures were identified by liquid chromatography-mass spectrometry, FTIR spectroscopy, and NMR spectroscopy. A decomposition model of the thiolysis products and a correction formula for proanthocyanidins concentration were established. This thiolysis-high-performance liquid chromatography method displayed good calibration linearity (R2  > 0.999 over the concentration range 0.01 to 10 mg/mL), excellent accuracy (recoveries of 97.9-99.6%), and precision (repeatability relative standard deviations of 0.45-0.75%). This method is suitable for the quantitative analysis of proanthocyanidins in grape seed products.

A ratiometric fluorescent sensor for tetracyclines detection in meat based on pH-dependence of targets with lanthanum-doped carbon dots as probes.

Although some ratiometric fluorescent sensors have been reported to detect tetracyclines, most of ratiometric fluorescent sensors were established based on europium ion with a narrow linear range. In this work, a ratiometric fluorescent sensor for tetracyclines detection was established based on the dual-emission lanthanum-doped carbon dots (La-CDs) as probes combining with the characteristic pH-response of tetracyclines. The fluorescence intensity of tetracyclines will be enhanced in high pH, and the emission peak of tetracyclines overlapped with the peak of probes. The superposition effect of tetracyclines and probes at 515 nm greatly improved the sensitivity of the ratiometric fluorescent sensor and widened the detection range, and linear ranges for oxytetracycline (OTC) and tetracycline (TC) were respectively 0.00-805.20 µM and 0.00-1039.50 µM. Moreover, the preparation procedure of the La-CDs was simple and time saving and the coupling agent was not required. A comparison of La-CDs with undoped carbon dots (un-CDs) showed that the optical performance and sensing performance of La-CDs were improved. In addition, a portable paper sensor with La-CDs as probes was preliminarily explored in this work, and the sensor has been applied to detect OTC and TC in pork and fish with satisfactory results.

Nostoc flagelliforme capsular polysaccharides from different culture conditions improve hyperlipidemia and regulate intestinal flora in C57BL/6J mice to varying degrees.

Two capsular polysaccharides (WL-CPS-1 and GLU-CPS-1) purified from Nostoc flagelliforme under normal and mixotrophic culture conditions were used to investigate the hypolipidemic activity and effect on intestinal flora in C57BL/6J mice respectively. Their molecular weight and monosaccharide composition have been determined in previous studies. They both improved the lipid level by affecting the expression of lipid metabolism genes. They down-regulated the TNF-α and IL-1ß levels in serum and up-regulated the activity of antioxidant enzymes in liver thus decreased the atherosclerosis index and MDA content. They up-regulated the short chain fatty acids (SCFAs) synthesis. They decreased the abundance of pathogenic bacteria and increased the abundance of probiotics positively correlated with SCFAs. Compared with WL-CPS-1, GLU-CPS-1 exhibited higher in vivo activity and enriched Odoribacter and Alloprevotella correlating with the gene expression of lipid metabolism, suggesting that the bioactivity of polysaccharides could be regulated by culture conditions. These findings contributed to application of N. flagelliforme polysaccharides with higher activity in hypolipidemia by adjusting culture conditions.

Cu2+ enhanced fluorescent Ag nanoclusters with tunable emission from red to yellow and the application for Ag+ sensing.

In this work, the water-soluble fluorescent Ag nanoclusters (DPA@Ag NCs) were first prepared based on D-Penicillamine (DPA) as a stabilizer, however, the fluorescence quantum yield (QY) of DPA@Ag NCs was very low, then Cu2+ was employed to improve the fluorescence QY and the doped Ag nanoclusters with Cu2+ (DPA@Ag/Cu NCs) were obtained. The study showed that the QY increased fourfold and the emission of nanoclusters changed from red to yellow after addition of Cu2+. The reasonfor change of fluorescent properties wasattributed to the change of self-assembly structures caused by adding Cu2+ into reaction system, leading to the aggregation-induced emission enhancement (AIEE) effect and enhancing the band gap (Eg) between the HOMO and LUMO in nanoclusters. Subsequently, a fluorescent Ag+ sensor with high sensitivity and selectivity was established based on the DPA@Ag/Cu NCs as probes in aqueous solution. Experiments showed that the Ag+ could significantly quench the fluorescence of DPA@Ag/Cu NCs under experimental conditions, and there was a good linear relationship between the fluorescent intensity quenching value and Ag+ concentration in the range of 0.05-800 µM, and the limit of detection (LOD) was 0.03 µM (3σ/k). Meanwhile, most of common ions had no effect on the experimental results under the same conditions. In addition, the sensor was successfully applied on the detection of Ag+ in real water samples, and the recovery rate was 80.3-99.0%.

Comparisons of Functional Properties of Polysaccharides from Nostoc flagelliforme under Three Culture Conditions.

Nostoc flagelliforme is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of Nostoc flagelliforme polysaccharides although these have ignored the functional properties. In this study, we extracted and purified three polysaccharides (WL-CPS, NaCl-CPS and Glu-CPS) from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions, respectively, in order to change the physicochemical properties of polysaccharides with the aim of obtaining better functional properties. Both salt stress and mixotrophic culture conditions increased the specific yield of polysaccharides. Their functional properties were comparatively investigated and the results showed that NaCl-CPS exhibited the highest emulsification activity and flocculation capability, which was also higher than that of some commercial products. In contrast, Glu-CPS exhibited the highest water and oil holding capacities, foaming property, intrinsic viscosity and bile acids binding capacity. Our results indicated that both NaCl-CPS and Glu-CPS could be considered to be functional polysaccharides according to their respective characteristics, which have great potential in numerous applications, such as food, pharmaceutical, cosmetic, chemical and mineral industries. These findings also demonstrated the potential application of the proper regulation of culture conditions in the development of polysaccharides with desired functional properties.

ROS Is a Factor Regulating the Increased Polysaccharide Production by Light Quality in the Edible Cyanobacterium Nostoc flagelliforme.

To explore the regulatory factor of light quality affecting exopolysaccharide (EPS) production, transcriptome analysis of Nostoc flagelliforme cells exposed to red light (R), blue light (B), and mixed light (B/R = 15:7) (BR) with white fluorescent light as control was performed. The differentially expressed genes mainly enriched in carbohydrate metabolism and energy metabolism. Significant enrichment in the oxidation-reduction process and energy metabolism indicated that intracellular redox homeostasis was disrupted. An assay of reactive oxygen species (ROS) and malondialdehyde contents demonstrated light quality induced oxidative stress. To illustrate the relationship between ROS level and EPS accumulation, the effects of the exogenous addition of ROS scavenger N-acetyl cysteine and inducer H2O2 on the oxidation-reduction level and EPS production were compared. The results revealed that light quality regulated EPS biosynthesis via the intracellular ROS level directly other than oxidative stress. Understanding such relationships might provide guidance for efficient EPS production to regulate the intracellular redox level.

Comparative proteomic analysis of Nostoc flagelliforme reveals the difference in adaptive mechanism in response to different ultraviolet-B radiation treatments.

Nostoc flagelliforme is a pioneer organism in the desert and highly resistant to ultraviolet B (UV-B) radiation, while the involved adaptive mechanism has not been fully explored yet. To elucidate the responsive mechanism, two doses of UV-B radiation (low: 1 W/m2 and high: 5 W/m2) were irradiated for 6 h and 48 h, respectively, and their effects on global metabolism in N. flagelliforme were comprehensively investigated. In this study, we used iTRAQ-based proteomic approach to explore the proteomes of N. flagelliforme, and 151, 172, 124 and 148 differentially expressed proteins were identified under low and high UV-B doses for 6 h and 48 h, respectively. Functional classification analysis showed these proteins were mainly involved in photosynthesis, amino acid metabolism, antioxidant activity and carbohydrate metabolism. Further analysis revealed that UV-B imposed restrictions on primary metabolism including photosynthesis, Calvin cycle, and amino acid metabolism, and cells started defense mechanism through repair of DNA and protein damage, increasing antioxidant activity, and accumulating extracellular polysaccharides to minimize the damage. Moreover, high UV-B dose imposed more severe restrictions and activated stronger defense mechanism compared with low dose. The results would improve the understanding of molecular mechanisms of UV-B-stress adaption in N. flagelliforme.

Effect of culture conditions on the physicochemical properties and antioxidant activities of polysaccharides from Nostoc flagelliforme.

Three polysaccharides (WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1) were extracted and purified from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions respectively. Their physicochemical properties and antioxidant activities were investigated. WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1 chemical composition differed in sugar and uronic acid contents, and they were composed of nine constituent monosaccharides and one uronic acid with different ratios, with the average molecular weights of 1.02 × 103, 1.12 × 103 and 1.33 × 103 kDa, respectively. They presented similar fourier transform infrared spectra, but different surface morphology, chain length and branching. Antioxidant assay showed that they all exhibited strong scavenging activity on ABTS+ and hydroxyl radicals and moderate activity on DPPH radical. Glu-CPS-1 exhibited the highest antioxidant activity suggested culture conditions could regulate the bioactivity through influencing the structure and properties. These findings demonstrated the potential application of proper regulation of culture conditions in the development of polysaccharides with high antioxidant activity.

The physiological responses of terrestrial cyanobacterium Nostoc flagelliforme to different intensities of ultraviolet-B radiation.

Nostoc flagelliforme is a pioneer organism in the desert and exerts important ecological functions. The habitats of N. flagelliforme are characterized by intense solar radiation, while the ultraviolet B (UV-B) tolerance has not been fully explored yet. To evaluate the physiological responses of N. flagelliforme to UV-B radiation, three intensities (1 W m-2, 3 W m-2 and 5 W m-2) were used, and the changes in photosynthetic pigments, cell morphology, mycosporine-like amino acids (MAAs) synthesis and cell metabolism were comparatively investigated. Under high UV-B intensity or long term radiation, chlorophyll a, allophycocyanin and phycocyanin were greatly decreased; scanning electron microscope observations showed that cell morphology significantly changed. To reduce the damage, cells synthesized a large amount of carotenoid. Moreover, three kinds of MAAs were identified, and their concentrations varied with the changes of UV-B intensity. Under 1 W m-2 radiation, cells synthesized shinorine and porphyra-334 against UV-B, while with the increase of intensity, more shinorine turned into asterine-330. Metabolite profiling revealed the contents of some cytoprotective metabolites were greatly increased under 5 W m-2 radiation. The principal component analysis showed cells exposed to UV-B were metabolically distinct from the control sample, and the influence on metabolism was particularly dependent on intensity. The results would improve the understanding of physiological responses of N. flagelliforme to UV-B radiation and provide an important theoretical basis for applying this organism to control desertification.

The relationship between monosaccharide composition of extracellular polysaccharide and activities of related enzymes in Nostoc flagelliforme under different culture conditions.

The relationship between monosaccharide composition of Nostoc flagelliforme extracellular polysaccharide (EPS) and activities of EPS synthesis enzymes under various carbon sources, nitrogen sources and light culture condition was investigated. Culture conditions showed significant influences on both monosaccharide composition and related enzyme activities. Under both carbon and nitrogen sources conditions, mannose mole percentage was increased with the increase of initial mole ratio of C/N and positively related to fructose-1, 6-bisphosphatase activity, and glucuronic acid and galactose mole percentages were positively correlated with UDP-glucose dehydrogenase, while arabinose and rhamnose mole percentages were negatively associated with UDP-glucose pyrophosphorylase. Different correlation between monosaccharide composition and enzymes activity from carbon and nitrogen sources conditions was found under light condition. These findings will be helpful to establish a novel fermentation process aimed to produce the N. flagelliforme EPS with desired monosaccharide composition.

Rapid Detection of Small Molecule Metabolites in Serum of Hepatocellular Carcinoma Patients Using Ultrafast Liquid Chromatography-Ion Trap-Time of Flight Tandem Mass Spectrometry.

A method was developed for analyzing broad spectrum small molecule metabolites in the serum of hepatocellular carcinoma (HCC) patients based on ultrafast liquid chromatography-ion trap-time of flight tandem mass spectrometry (UFLC-IT-TOF MS). Serum samples were collected from 80 HCC patients and healthy persons. After pretreatment process for protein precipitation, the supernatant was analyzed with the UFLC-IT-TOF MS to obtain information on the metabonomics of small molecules. The eight compounds of glycocholic acid, choline glycerophosphate, acetyl-L-phenylalanine, oleamide, tetradecanamide, acetylcarnitine, lysolecithin and glycochenodeoxycholic acid in the HCC group were identified with significant differences from those in the health group (P <0.01). By using multidimensional analysis of variation coefficient and principal component analysis for the repeatability and 48 h stability, the method was demonstrated to have good repeatability, excellent precision, and high stability, which can satisfy the metabonomics research requirement. The high throughput and practical usability of the method further shows perspective for metabonomic analysis of large-batch serum samples.

Complete Genome Sequence of Actinomyces hongkongensis HKU8T Isolated from Human Blood.

Members of the genus Actinomyces are strongly associated with human diseases. We present here the complete genome sequence of Actinomyces hongkongensis HKU8T, which consists of one circular chromosome. The strain characteristically contains various genes encoding for enzymes involved in arylamidase utilization.

Feasibility of Pb phytoextraction using nano-materials assisted ryegrass: Results of a one-year field-scale experiment.

The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed. Ryegrass shoot concentrations of Pb were lower with nano-materials application than without nano-materials for the first month. However, the shoot concentrations of Pb were significantly increased with nano-materials application, in particular NHAP groups. The ryegrass root concentrations of Pb were lower with nano-materials application for the first month. These results indicated that nano-materials had significant effects on stabilization of lead, especially at the beginning of the experiment. Along with the experimental proceeding, phytotoxicity was alleviated after the incorporation of nano-materials. The ryegrass biomass was significantly higher with nano-materials application. Consequently, the Pb phytoextraction potential of ryegrass significantly increased with nano-materials application compared to the gounps without nano-materials application. The total removal rates of soil Pb were higher after combined application of NHAP than NCB. NHAP is more suitable than NCB for in-situ remediation of Pb-contaminated soils. The ryegrass translocation factor exhibited a marked increase with time. It was thought that the major role of NHP and NBA might be to alleviate the Pb phytotoxicity and increase biomass of plants.

[Synthesis and characterization of non fluorescent ZnS nano clusters].

Zinc sulfide nano clusters were synthesized and characterized. A kind of method using zinc sulfide nanoparticles cluster cation exchange reaction(CX) to detect trace biological molecules was established. Non fluorescent ZnS nanoparticles (NCCs) were synthesized and characterized. The property of nano clusters directly influences the detection results. Through transmission electron microscopy images and X-ray diffraction, nano clusters which could quickly release a mass of Zn2+ from rapid cation exchange reaction were known to be porous and generate fluorescence signal under the action of zinc reagent. The external crystal arranges loosely compared to the internal, which is conducive to rapid cation exchange, and the crystal size is related to heating time. It was demonstrated that the smallest nanocluster had a relative large surface area and higher cationic exchange efficiency through the determination of the specific surface area of nano clusters for detecting surface area and pore size. Three methods (acid dissolution method, cation exchange and micro wave aided by cation exchange) which effected Zn2+ release performance were experimented. It turned out that microwave auxiliary cation exchange method had high SNR, simple operation, and could be used in zinc sulfide nanoparticle immunoassay. Having compared the relations between the release efficiency, target binding force of ZnZ2+ and its average diameter, the results show that the nano cluster size of 44 nm exhibits the highest cation exchange efficiency. All these features make the ZnS nanocluster cation exchange amplifier to be a highly sensitive, fairly biocompatible, low-cost and environment friendly detection tool in the detection of biomolecules.

Comparison of bacterial community structures of terrestrial cyanobacterium Nostoc flagelliforme in three different regions of China using PCR-DGGE analysis.

Filamentous Nostoc flagelliforme form colloidal complex, with beaded cells interacting with other bacteria embedded in the complex multilayer sheath. However, the species of bacteria in the sheath and the interaction between N. flagelliforme and associated bacteria remain unclear. In this study, PCR-denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial communities of N. flagelliforme from three regions of China. DGGE patterns showed variations in all samples, exhibiting 25 discrete bands with various intensities. The diversity index analysis of bands profiles suggested the high similarity of bacterial communities to each other but also the dependence of microbial composition on each location. Phylogenetic affiliation indicated that the majority of the sequences obtained were affiliated with Actinobacteria, Cyanobacteria, Proteobacteria, Acidobacteria, Bacteroidetes, of which Cyanobacteria was dominant, followed the Proteobacteria. Members of the genus Nostoc were the most abundant in all samples. Rhizobiales and Actinobacteria were identified, whereas, Craurococcus, Caulobacter, Pseudomonas, Terriglobus and Mucilaginibacter were also identified at low levels. Through comparing the bacterial composition of N. flagelliforme from different regions, it was revealed that N. flagelliforme could facilitate the growth of other microorganisms including both autotrophic bacteria and heterotrophic ones and positively contributed to their harsh ecosystems. The results indicated N. flagelliforme played an important role in diversifying the microbial community composition and had potential application in soil desertification.

Metabolomic approach to optimizing and evaluating antibiotic treatment in the axenic culture of cyanobacterium Nostoc flagelliforme.

The application of antibiotic treatment with assistance of metabolomic approach in axenic isolation of cyanobacterium Nostoc flagelliforme was investigated. Seven antibiotics were tested at 1-100 mg L(-1), and order of tolerance of N. flagelliforme cells was obtained as kanamycin > ampicillin, tetracycline > chloromycetin, gentamicin > spectinomycin > streptomycin. Four antibiotics were selected based on differences in antibiotic sensitivity of N. flagelliforme and associated bacteria, and their effects on N. flagelliforme cells including the changes of metabolic activity with antibiotics and the metabolic recovery after removal were assessed by a metabolomic approach based on gas chromatography-mass spectrometry combined with multivariate analysis. The results showed that antibiotic treatment had affected cell metabolism as antibiotics treated cells were metabolically distinct from control cells, but the metabolic activity would be recovered via eliminating antibiotics and the sequence of metabolic recovery time needed was spectinomycin, gentamicin > ampicillin > kanamycin. The procedures of antibiotic treatment have been accordingly optimized as a consecutive treatment starting with spectinomycin, then gentamicin, ampicillin and lastly kanamycin, and proved to be highly effective in eliminating the bacteria as examined by agar plating method and light microscope examination. Our work presented a strategy to obtain axenic culture of N. flagelliforme and provided a method for evaluating and optimizing cyanobacteria purification process through diagnosing target species cellular state.

[Identification of geographical origins of rice with pattern recognition technique by near infrared spectroscopy].

A rapid method was developed for discrimination of the geographical origins of rice with pattern recognition technique by near infrared spectrocopy (NIRS). A total of 119 geography signs product Xiangshui rice samples and 90 rice (Non-Xiangshui rice) samples produced from other places were analyzed by NIRS. After first derivative and smooth processing, principal component analysis (PCA) was used to reduce the dimensionality of the spectral data. Through the loading graph of the first three principal components, characteristic wave band (7 700-6 700, 5 700-4 300 cm(-1)) with max-relativity was determined. In whole wave, using agglomerative hierarchical cluster analysis and Fisher's linear discriminant, the discrimination of Xiangshui rice and Non-Xiangshui rice was all 100%. The correct rate of specific geographical origins of Non-Xiangshui rice was 91.9% by cluster analysis and 96.7% by discriminant analysis. For analysis in the characteristic wave bands, the correct rate of discriminant by cluster analysis was higher than the analysis result through the range of the whole band. Therefore, characteristic wave band has strong representativeness. The results indicate that it is feasible to discriminate the geographical origins of rice with pattern recognition technique by NIRS, and selecting characteristic wave band is one of the validated methods to improve the precision of the discrimination mode.